This was broken because of a malformed check line. Incidentally,
this exposed a case where we crash when we should just be returning
an error, so we should fix that. The demangler shouldn't crash due
to user input.
llvm-svn: 339466
Before we wouldn't properly demangle something like
Foo<const int>. Template args have a special escape sequence
'$$C' that is optional, but if it is present contains
qualifiers. So we need to check for this and only if it
present, demangle qualifiers before demangling the type.
With this fix, we re-enable some tests that were previously
marked FIXME.
llvm-svn: 339465
This includes a test that would have exposed the bug in rL339439
which was reverted at rL339446. The compare can be integer while
the binop is FP or vice-versa, so we need to use the binop type
when we ask for the identity constant.
llvm-svn: 339453
Summary: Similar to asan's flag, it can be used to disable the use of ifunc to access hwasan shadow address.
Reviewers: vitalybuka, kcc
Subscribers: srhines, hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D50544
llvm-svn: 339447
These were uncovered when porting the mangling tests in
ms-templates.cpp from clang/CodeGenCXX over to demangling
tests. The main issues fixed here are surrounding integer
literal signed and unsignedness, empty array dimensions,
and pointer and reference non-type template parameters.
Differential Revision: https://reviews.llvm.org/D50512
llvm-svn: 339434
Enabling ARMCodeGenPrepare by default caused a whole load of
failures. This is due to zexts and truncs not being handled properly.
ZExts are messy so it's just easier to disable for now and truncs
are allowed only as 'sinks'. I still need to figure out why allowing
them as 'sources' causes so many failures. The other main changes are
that we are explicit in the types that we converting to, it's now
always 'TypeSize'. Type support is also now performed while checking
for valid opcodes as it unnecessarily complicated having the checks
are different stages.
I've moved the tests around too, so we have the zext and truncs in
their own file as well as the overflowing opcode tests.
Differential Revision: https://reviews.llvm.org/D50518
llvm-svn: 339432
The previous name sounds like it inserts cfguard implementation, but it
really just emits the table of address-taken functions. Change the name
to better reflect that.
Clang will be updated in the next commit.
llvm-svn: 339419
If code is compiled for X86 without SSE support, the register save area
doesn't contain FPU registers, so `AMD64FpEndOffset` should be equal to
`AMD64GpEndOffset`.
llvm-svn: 339414
MemorySSA currently creates MemoryAccesses for lifetime intrinsics, and
sometimes treats them as clobbers. This may/may not be the best way
forward, but while we're doing it, we should consider
MayAlias/PartialAlias to be clobbers.
The ideal fix here is probably to remove all of this reasoning about
lifetimes from MemorySSA + put it into the passes that need to care. But
that's a wayyy broader fix that needs some consensus, and we have
miscompiles + a release branch today, and this should solve the
miscompiles just as well.
differential revision is D43269. Landing without an explicit LGTM (and
without using the special please-autoclose-this syntax) so we can still
use that revision as a place to decide what the right fix here is.
llvm-svn: 339411
Summary:
i64x2 and f64x2 operations are not implemented in V8, so we normally
do not want to emit them. However, they are in the SIMD spec proposal,
so we still want to be able to test them in the toolchain. This patch
adds a flag to enable their emission.
Reviewers: aheejin, dschuff
Subscribers: sunfish, jgravelle-google, sbc100, llvm-commits
Differential Revision: https://reviews.llvm.org/D50423
Patch by Thomas Lively (tlively)
llvm-svn: 339407
The motivating case is an otherwise dead loop with a fence in it. At the moment, this goes all the way through the optimizer and we end up emitting an entirely pointless loop on x86. This case may seem a bit contrived, but we've seen it in real code as the result of otherwise reasonable lowering strategies combined w/thread local memory optimizations (such as escape analysis).
To handle this simple case, we can teach LICM to hoist must execute fences when there is no other memory operation within the loop.
Differential Revision: https://reviews.llvm.org/D50489
llvm-svn: 339378
Summary:
LoopSimplifyCFG should update ScEv for all loops after a block is deleted.
If the deleted block "Succ" is part of L, then it is part of all parent loops, so forget topmost loop.
Reviewers: greened, mkazantsev, sanjoy
Subscribers: jlebar, javed.absar, uabelho, llvm-commits
Differential Revision: https://reviews.llvm.org/D50422
llvm-svn: 339363
The inalloca parameter has to be the only parameter passed in memory.
Changing the convention to fastcc can break that.
At some point we should teach global opt how to optimize ABI attributes
like inalloca and maybe byval. These attributes are mainly used to match
C ABIs. They are harder for LLVM to optimize and they don't always
generate the best code.
Fixes PR38487
llvm-svn: 339360
Similar to rL337966 - if the DAGCombiner's rotate matching was
working as expected, I don't think we'd see any test diffs here.
AArch only goes right, and PPC only goes left.
x86 has both, so no diffs there.
Differential Revision: https://reviews.llvm.org/D50091
llvm-svn: 339359
Summary: This change provides a common optimization path for both Unsafe and FMF driven optimization for this fsub fold adding reassociation, as it the flag that most closely represents the translation
Reviewers: spatel, wristow, arsenm
Reviewed By: spatel
Subscribers: wdng
Differential Revision: https://reviews.llvm.org/D50195
llvm-svn: 339357
As discussed on D41794, we have many cases where we fail to combine shuffles as the input operands have other uses.
This patch permits these shuffles to be combined as long as they don't introduce additional variable shuffle masks, which should reduce instruction dependencies and allow the total number of shuffles to still drop without increasing the constant pool.
However, this may mean that some memory folds may no longer occur, and on pre-AVX require the occasional extra register move.
This also exposes some poor PMULDQ/PMULUDQ codegen which was doing unnecessary upper/lower calculations which will in fact fold to zero/undef - the fix will be added in a followup commit.
Differential Revision: https://reviews.llvm.org/D50328
llvm-svn: 339335
According to PTX ISA .volatile has the same memory synchronization
semantics as .relaxed.sys, so it can be used to implement monotonic
atomic loads and stores. This is important for OpenMP's atomic
construct where
- 'read's and 'write's are lowered to atomic loads and stores, and
- an update of float or double types are lowered into a cmpxchg loop.
(Note that PTX could do better because it has atom.add.f{32,64} but
LLVM's atomicrmw instruction only allows integer types.)
Higher levels of atomicity (like acquire and release) need additional
synchronization properties which were added with PTX ISA 6.0 / sm_70.
So using these instructions still results in an error.
Differential Revision: https://reviews.llvm.org/D50391
llvm-svn: 339316
This pseudo-instruction is similar to la but uses PC-relative addressing
unconditionally. This is, la is only different to lla when using -fPIC. This
pseudo-instruction seems often forgotten in several specs but it is definitely
mentioned in binutils opcodes/riscv-opc.c. The semantics are defined both in
page 37 of the "RISC-V Reader" book but also in function macro found in
gas/config/tc-riscv.c.
This is a very first step towards adding PIC support for Linux in the RISC-V
backend.
The lla pseudo-instruction expands to a sequence of auipc + addi with a couple
of pc-rel relocations where the second points to the first one. This is
described in
https://github.com/riscv/riscv-elf-psabi-doc/blob/master/riscv-elf.md#pc-relative-symbol-addresses
For now, this patch only introduces support of that pseudo instruction at the
assembler parser.
Differential Revision: https://reviews.llvm.org/D49661
llvm-svn: 339314
The main interesting case is a fence in an otherwise dead loop or one containing only arithmetic. This can happen as a result of DSE or other transforms from seemingly reasonable initial IR.
llvm-svn: 339310
Changes the default Windows target triple returned by
GetHostTriple.cmake from the old environment names (which we wanted to
move away from) to newer, normalized ones. This also requires updating
all tests to use the new systems names in constraints.
Differential Revision: https://reviews.llvm.org/D47381
llvm-svn: 339307
isNegatibleForFree() should not matter here (as the test diffs show)
because it's always a win to replace an fsub+fadd with fneg. The
problem in D50195 persists because either (1) we are doing these
folds in the wrong order or (2) we're missing another fold for fadd.
llvm-svn: 339299
LLVM triple normalization is handling "unknown" and empty components
differently; for example given "x86_64-unknown-linux-gnu" and
"x86_64-linux-gnu" which should be equivalent, triple normalization
returns "x86_64-unknown-linux-gnu" and "x86_64--linux-gnu". autoconf's
config.sub returns "x86_64-unknown-linux-gnu" for both
"x86_64-linux-gnu" and "x86_64-unknown-linux-gnu". This changes the
triple normalization to behave the same way, replacing empty triple
components with "unknown".
This addresses PR37129.
Differential Revision: https://reviews.llvm.org/D50219
llvm-svn: 339294
On Darwin we pin the DWARF line tables to version 2. Stop doing so for
DWARF v5 and later.
Differential revision: https://reviews.llvm.org/D49381
llvm-svn: 339288
Normally, if any registers are spilled, we prefer to spill lr on Thumb1
so we can fold the "bx lr" into the "pop". However, if there are tail
calls involved, restoring lr is expensive, so skip the optimization in
that case.
The spill of r7 in the new test also isn't necessary, but that's
mostly orthogonal to this patch. (It's the same code in
ARMFrameLowering, but it's not related to tail calls.)
Differential Revision: https://reviews.llvm.org/D49459
llvm-svn: 339283
Template manglings use a fresh back-referencing context, so we
need to do the same. This fixes several existing tests which are
marked as FIXME, so those are now actually run.
llvm-svn: 339275
When reading a custom WASM section, it was possible that its name
extended beyond the size of the section. This resulted in a bogus value
for the section size due to the size overflowing.
Fixes heap buffer overflow detected by OSS-fuzz:
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=8190
Differential revision: https://reviews.llvm.org/D50387
llvm-svn: 339269
When using APPLE extensions, don't duplicate the compiler invocation's
flags both in AT_producer and AT_APPLE_flags.
Differential revision: https://reviews.llvm.org/D50453
llvm-svn: 339268
The scalar cases are handled in instcombine's internal
reassociation pass for FP ops, but it misses the vector types.
These patterns are similar to what was handled in InstSimplify in:
https://reviews.llvm.org/rL339171https://reviews.llvm.org/rL339174https://reviews.llvm.org/rL339176
...but we can't use instsimplify on these because we require negation
of the original operand.
llvm-svn: 339263
This patch aims to improve the codegen for vector loads involving the
scalar_to_vector (load X) sequence. Initially, ld->mv instructions were used
for scalar_to_vector (load X), so this patch allows scalar_to_vector (load X)
to utilize:
LXSD and LXSDX for i64 and f64
LXSIWAX for i32 (sign extension to i64)
LXSIWZX for i32 and f64
Committing on behalf of Amy Kwan.
Differential Revision: https://reviews.llvm.org/D48950
llvm-svn: 339260
Summary:
Currently, in line with GCC, when specifying reserved registers like sp or pc on an inline asm() clobber list, we don't always preserve the original value across the statement. And in general, overwriting reserved registers can have surprising results.
For example:
```
extern int bar(int[]);
int foo(int i) {
int a[i]; // VLA
asm volatile(
"mov r7, #1"
:
:
: "r7"
);
return 1 + bar(a);
}
```
Compiled for thumb, this gives:
```
$ clang --target=arm-arm-none-eabi -march=armv7a -c test.c -o - -S -O1 -mthumb
...
foo:
.fnstart
@ %bb.0: @ %entry
.save {r4, r5, r6, r7, lr}
push {r4, r5, r6, r7, lr}
.setfp r7, sp, #12
add r7, sp, #12
.pad #4
sub sp, #4
movs r1, #7
add.w r0, r1, r0, lsl #2
bic r0, r0, #7
sub.w r0, sp, r0
mov sp, r0
@APP
mov.w r7, #1
@NO_APP
bl bar
adds r0, #1
sub.w r4, r7, #12
mov sp, r4
pop {r4, r5, r6, r7, pc}
...
```
r7 is used as the frame pointer for thumb targets, and this function needs to restore the SP from the FP because of the variable-length stack allocation a. r7 is clobbered by the inline assembly (and r7 is included in the clobber list), but LLVM does not preserve the value of the frame pointer across the assembly block.
This type of behavior is similar to GCC's and has been discussed on the bugtracker: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=11807 . No consensus seemed to have been reached on the way forward. Clang behavior has briefly been discussed on the CFE mailing (starting here: http://lists.llvm.org/pipermail/cfe-dev/2018-July/058392.html). I've opted for following Eli Friedman's advice to print warnings when there are reserved registers on the clobber list so as not to diverge from GCC behavior for now.
The patch uses MachineRegisterInfo's target-specific knowledge of reserved registers, just before we convert the inline asm string in the AsmPrinter.
If we find a reserved register, we print a warning:
```
repro.c:6:7: warning: inline asm clobber list contains reserved registers: R7 [-Winline-asm]
"mov r7, #1"
^
```
Reviewers: eli.friedman, olista01, javed.absar, efriedma
Reviewed By: efriedma
Subscribers: efriedma, eraman, kristof.beyls, llvm-commits
Differential Revision: https://reviews.llvm.org/D49727
llvm-svn: 339257
Provide a pass-through of the numerator for divide by one cases - this is the same approach we take in DAGCombiner::visitSDIVLike.
I investigated whether we could achieve this by magic MULHU/SRL values but nothing appeared to work as we don't have a way for MULHU(x,c) -> x
llvm-svn: 339254
Match the GNU assembler in supporting immediate operands for these
instructions even when the reg-reg mnemonic is used.
Differential Revision: https://reviews.llvm.org/D50046
Patch by Kito Cheng.
llvm-svn: 339252
This accounts for the missing IR fold noted in D50195. We don't need any fast-math to enable the negation transform.
FP negation can always be folded into an fmul/fdiv constant to eliminate the fneg.
I've limited this to one-use to ensure that we are eliminating an instruction rather than replacing fneg by a
potentially expensive fdiv or fmul.
Differential Revision: https://reviews.llvm.org/D50417
llvm-svn: 339248
Making the test use urem relies on it calling udiv-like combines, but the real issue is with the udiv so we're better off using that directly.
llvm-svn: 339247
Summary:
https://rise4fun.com/Alive/IT3
Comes up in the [most ugliest] `signed int` -> `signed char` case of
`-fsanitize=implicit-conversion` (https://reviews.llvm.org/D50250)
Previously, we were stuck with `not`: {F6867736}
But now we are able to completely get rid of it: {F6867737}
(FIXME: why are we loosing the metadata? that seems wrong/strange.)
Here, we only want to do that it we will be able to completely
get rid of that 'not'.
Reviewers: spatel, craig.topper
Reviewed By: spatel
Subscribers: vsk, erichkeane, llvm-commits
Differential Revision: https://reviews.llvm.org/D50301
llvm-svn: 339243
Summary: Extend fix for PR34170 to support inline assembly with multiple output operands that do not naturally go in the register class it is constrained to (eg. double in a 32-bit GPR as in the PR).
Reviewers: bogner, t.p.northover, lattner, javed.absar, efriedma
Reviewed By: efriedma
Subscribers: efriedma, tra, eraman, javed.absar, llvm-commits
Differential Revision: https://reviews.llvm.org/D45437
llvm-svn: 339225
Function template names are not stored in the backref table,
but non-template function names are. The general pattern seems
to be that when you are demangling a symbol name, if the name
starts with '?' it does not go into the backreference table,
otherwise it does. Note that this even handles the general case
of operator names (template or otherwise) not going into the
back-reference table, anonymous namespaces not going into the
backreference table, etc.
It's important that we apply this check *only* for the
unqualified portion of a name, and only for symbol names.
For example, this does not apply to type names (such as class
templates) and we need to make sure that these still do go
into the backref table.
Differential Revision: https://reviews.llvm.org/D50394
llvm-svn: 339211
Fixup test to check for GCN prefix
These patterns always zero extend the result even though it might need sign extension.
This has been broken since the addition of i16 support.
It has popped up in mad_sat(char) test since min(max()) combination is turned into v_med3, resulting in the following (incorrect) sequence:
v_mad_i16 v2, v10, v9, v11
v_med3_i32 v2, v2, v8, v7
Fixes mad_sat(char) piglit on VI.
Differential Revision: https://reviews.llvm.org/D49836
llvm-svn: 339190
Add missing SIMD types (v2f64) and binary ops. Also adds
tablegen support for automatically prepending prefix byte to SIMD
opcodes.
Differential Revision: https://reviews.llvm.org/D50292
Patch by Thomas Lively
llvm-svn: 339186
Vgather requires must be in a packet with a store, which contradicts
the no-packets feature. As a consequence, gather/scatter could not be
used with no-packets. Relax this, and allow gather packets as exceptions
to the no-packets requirements.
llvm-svn: 339177
Summary:
This patch extends CFGSort pass to support exception handling. Once it
places a loop header, it does not place blocks that are not dominated by
the loop header until all the loop blocks are sorted. This patch extends
the same algorithm to exception 'catch' part, using the information
calculated by WebAssemblyExceptionInfo class.
Reviewers: dschuff, sunfish
Subscribers: sbc100, jgravelle-google, llvm-commits
Differential Revision: https://reviews.llvm.org/D46500
llvm-svn: 339172
Instcombine gets some, but not all, of these cases via
it's internal reassociation transforms. It fails in
all cases with vector types.
llvm-svn: 339168
Summary:
Reworked the previously committed patch to insert shuffles for reused
extract element instructions in the correct position. Previous logic was
incorrect, and might lead to the crash with PHIs and EH instructions.
Reviewers: efriedma, javed.absar
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D50143
llvm-svn: 339166
getOrCompHotCountThreshold/getOrCompColdCountThreshold introduced in
https://reviews.llvm.org/D45377 contain a bad mistake and will only return 1 or 0
instead of the true hot/cold cutoff value. The patch fixes the mistake. But the
mistake seems not causing big performance difference according to internal server
benchmarks testing.
Differential Revision: https://reviews.llvm.org/D50370
llvm-svn: 339162
Scatter could have multiple identical indices. We need to maintain sequential order. We get this right in LegalizeVectorTypes, but not in this code.
Differential Revision: https://reviews.llvm.org/D50374
llvm-svn: 339157
In combineMetadata, we should be able to preserve K's nonnull metadata,
if K does not move. This condition should hold for all replacements by
NewGVN/GVN, but I added a bunch of assertions to verify that.
Fixes PR35038.
There probably are additional kinds of metadata that could be preserved
using similar reasoning. This is follow-up work.
Reviewers: dberlin, davide, efriedma, nlopes
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D47339
llvm-svn: 339149
This fixes an inconsistency in code generation when compiling with or
without debug information (-g). When debug information is available in
an empty block, the original test would fail, resulting in possibly
different code.
Patch by: Jeroen Dobbelaere
Differential revision: https://reviews.llvm.org/D49467
llvm-svn: 339129
When potential jump instruction and target are in the same segment, use
jump instruction with immediate field.
In cases where offset does not fit immediate value of a bc/j instructions,
offset is stored into register, and then jump register instruction is used.
Differential Revision: https://reviews.llvm.org/D48019
llvm-svn: 339126
Summary:
The accelerator tables use the debug_str section to store their strings.
However, they do not support the indirect method of access that is
available for the debug_info section (DW_FORM_strx et al.).
Currently our code is assuming that all strings can/will be referenced
indirectly, and puts all of them into the debug_str_offsets section.
This is generally true for regular (unsplit) dwarf, but in the DWO case,
most of the strings in the debug_str section will only be used from the
accelerator tables. Therefore the contents of the debug_str_offsets
section will be largely unused and bloating the main executable.
This patch rectifies this by teaching the DwarfStringPool to
differentiate between strings accessed directly and indirectly. When a
user inserts a string into the pool it has to declare whether that
string will be referenced directly or not. If at least one user requsts
indirect access, that string will be assigned an index ID and put into
debug_str_offsets table. Otherwise, the offset table is skipped.
This approach reduces the overall binary size (when compiled with
-gdwarf-5 -gsplit-dwarf) in my tests by about 2% (debug_str_offsets is
shrunk by 99%).
Reviewers: probinson, dblaikie, JDevlieghere
Subscribers: aprantl, mgrang, llvm-commits
Differential Revision: https://reviews.llvm.org/D49493
llvm-svn: 339122
This patch refactors the existing TargetLowering::BuildUDIV base implementation to support non-uniform constant vector denominators.
It also includes a fold for MULHU by pow2 constants to SRL which can now more readily occur from BuildUDIV.
Differential Revision: https://reviews.llvm.org/D49248
llvm-svn: 339121
I was trying to add a test case for LLD and found that it
is impossible to set sh_entsize via yaml.
The patch implements the missing part.
Differential revision: https://reviews.llvm.org/D50235
llvm-svn: 339113
Summary:
Wasm does not have direct counterparts to some of LLVM IR's atomicrmw
instructions (min, max, umin, umax, and nand). This enables atomic
expansion using cmpxchg instruction within a loop for those atomicrmw
instructions.
Reviewers: dschuff
Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits
Differential Revision: https://reviews.llvm.org/D49440
llvm-svn: 339084
Summary:
The issue with the python path is that the path to python on Windows can contain spaces. To make the tests always work, the path to python needs to be surrounded by quotes.
This change updates several configuration files which specify the path to python as a substitution and also remove quotes from existing tests.
Reviewers: asmith, zturner, alexshap, jakehehrlich
Reviewed By: zturner, alexshap, jakehehrlich
Subscribers: mehdi_amini, nemanjai, eraman, kbarton, jakehehrlich, steven_wu, dexonsmith, stella.stamenova, delcypher, llvm-commits
Differential Revision: https://reviews.llvm.org/D50206
llvm-svn: 339073
This matches our behaviour for regular (i.e. relocated) references to
private symbols and therefore avoids needing to unnecessarily write
address-significant .L symbols to the object file's symbol table,
which can interfere with stack traces.
Fixes check-cfi after r339050.
llvm-svn: 339066
Everything should quiet, and I think everything should
flush.
I assume the min3/med3/max3 follow the same rules
as regular min/max for flushing, which should at
least be conservatively correct.
There are still more operations that need to
be handled.
llvm-svn: 339065
Not sure why this was checking for denormals for f16.
My interpretation of the IEEE standard is conversions
should produce a canonical result, and the ISA manual
says denormals are created when appropriate.
llvm-svn: 339064
If denormals are enabled, denormals are canonical.
Also fix a few other issues. minnum/maxnum are supposed
to canonicalize. Temporarily improve workaround for the
instruction behavior change in gfx9.
Handle selects and fcopysign.
The tests were also largely broken, since they were
checking for a flush used on some targets after the
store of the result.
llvm-svn: 339061
This assert fires when attempting to extract a subregister from the
global PIC base register. This virtual register SD node is not in the
VRBaseMap, so we shouldn't call getVR to look it up there. If this is a
RegisterSDNode, we should be able to use the virtual register directly.
Fixes PR38385
llvm-svn: 339056
Properly shrink `pow()` to `powf()` as a binary function and, when no other
simplification applies, do not discard it.
Differential revision: https://reviews.llvm.org/D50113
llvm-svn: 339046
Summary:
Expand isFNEG so that we generate the appropriate F(N)M(ADD|SUB)
instructions in more cases. For example, the following sequence
a = _mm256_broadcast_ss(f)
d = _mm256_fnmadd_ps(a, b, c)
generates an fsub and fma without this patch and an fnma with this
change.
Reviewers: craig.topper
Subscribers: llvm-commits, davidxl, wmi
Differential Revision: https://reviews.llvm.org/D48467
llvm-svn: 339043
If the store is volatile this might be a memory mapped IO access. In that case we shouldn't generate a load that didn't exist in the source
Differential Revision: https://reviews.llvm.org/D50270
llvm-svn: 339041
for all the uses from the same def is done.
We run into a compile time problem with flex generated code combined with
`-fno-jump-tables`. The cause is that machineLICM hoists a lot of invariants
outside of a big loop, and drastically increases the compile time in global
register splitting and copy coalescing. https://reviews.llvm.org/D49353
relieves the problem in global splitting. This patch is to handle the problem
in copy coalescing.
About the situation where the problem in copy coalescing happens. After
machineLICM, we have several defs outside of a big loop with hundreds or
thousands of uses inside the loop. Rematerialization in copy coalescing
happens for each use and everytime rematerialization is done, shrinkToUses
will be called to update the huge live interval. Because we have 'n' uses
for a def, and each live interval update will have at least 'n' complexity,
the total update work is n^2.
To fix the problem, we try to do the live interval update work in a collective
way. If a def has many copylike uses larger than a threshold, each time
rematerialization is done for one of those uses, we won't do the live interval
update in time but delay that work until rematerialization for all those uses
are completed, so we only have to do the live interval update work once.
Delaying the live interval update could potentially change the copy coalescing
result, so we hope to limit that change to those defs with many
(like above a hundred) copylike uses, and the cutoff can be adjusted by the
option -mllvm -late-remat-update-threshold=xxx.
Differential Revision: https://reviews.llvm.org/D49519
llvm-svn: 339035
Summary:
Ensure that NormalizedBuildVector returns a BUILD_VECTOR with operands of the
same type. This fixes an assertion failure in VerifySDNode.
Reviewers: SjoerdMeijer, t.p.northover, javed.absar
Reviewed By: SjoerdMeijer
Subscribers: kristof.beyls, llvm-commits
Differential Revision: https://reviews.llvm.org/D50202
llvm-svn: 339013
ld64 supplies its own Thumb bit for Thumb functions, and intentionally zeroes
out that part of any addend in an object file. But it only does that for
symbols marked N_EXT -- i.e. external symbols. So LLVM should avoid setting
that extra bit in other cases.
llvm-svn: 339007
The patch was reverted because of bug detected by sanitizer. The bug is fixed,
respective tests added.
Differential Revision: https://reviews.llvm.org/D50172
llvm-svn: 339005
Multiple failues reported by sanitizer-x86_64-linux, seem to be caused by this
patch. Reverting to see if they sustain without it.
Differential Revision: https://reviews.llvm.org/D50172
llvm-svn: 338994
`isKnownNonNullFromDominatingCondition` is able to prove non-null basing on `br` or `guard`
by `%p != null` condition, but is unable to do so basing on `(%p != null) && %other_cond`.
This patch allows it to do so.
Differential Revision: https://reviews.llvm.org/D50172
Reviewed By: reames
llvm-svn: 338990
If there is a frequently taken branch dominated by a guard, and its condition is available
at the point of the guard, we can widen guard with condition of this branch and convert
the branch into unconditional:
guard(cond1)
if (cond2) {
// taken in 99.9% cases
// do something
} else {
// do something else
}
Converts to
guard(cond1 && cond2)
// do something
Differential Revision: https://reviews.llvm.org/D49974
Reviewed By: reames
llvm-svn: 338988
Summary:
This patch improves Inliner to provide causes/reasons for negative inline decisions.
1. It adds one new message field to InlineCost to report causes for Always and Never instances. All Never and Always instantiations must provide a simple message.
2. Several functions that used to return the inlining results as boolean are changed to return InlineResult which carries the cause for negative decision.
3. Changed remark priniting and debug output messages to provide the additional messages and related inline cost.
4. Adjusted tests for changed printing.
Patch by: yrouban (Yevgeny Rouban)
Reviewers: craig.topper, sammccall, sgraenitz, NutshellySima, shchenz, chandlerc, apilipenko, javed.absar, tejohnson, dblaikie, sanjoy, eraman, xbolva00
Reviewed By: tejohnson, xbolva00
Subscribers: xbolva00, llvm-commits, arsenm, mehdi_amini, eraman, haicheng, steven_wu, dexonsmith
Differential Revision: https://reviews.llvm.org/D49412
llvm-svn: 338969
There are a bunch of edge cases and inconsistencies in how we're emitting sections
cause this warning to fire and it needs more work.
This reverts commit r335558.
llvm-svn: 338968
https://rise4fun.com/Alive/IT3
Comes up in the [most ugliest] signed int -> signed char case of
-fsanitize=implicit-conversion (https://reviews.llvm.org/D50250)
Not sure if we want to do it always, or only when it is free to invert.
llvm-svn: 338967
Summary:
Previously, in the NewPM pipeline, TailCallElim recalculates the DomTree when it modifies any instruction in the Function.
For example,
```
CallInst *CI = dyn_cast<CallInst>(&I);
...
CI->setTailCall();
Modified = true;
...
if (!Modified || ...)
return PreservedAnalyses::all();
```
After applying this patch, the DomTree only recalculates if needed (plus an extra insertEdge() + an extra deleteEdge() call).
When optimizing SQLite with `-passes="default<O3>"` pipeline of the newPM, the number of DomTree recalculation decreases by 6.2%, the number of nodes visited by DFS decreases by 2.9%. The time used by DomTree will decrease approximately 1%~2.5% after applying the patch.
Statistics:
```
Before the patch:
23010 dom-tree-stats - Number of DomTree recalculations
489264 dom-tree-stats - Number of nodes visited by DFS -- DomTree
After the patch:
21581 dom-tree-stats - Number of DomTree recalculations
475088 dom-tree-stats - Number of nodes visited by DFS -- DomTree
```
Reviewers: kuhar, dmgreen, brzycki, grosser, davide
Reviewed By: kuhar, brzycki
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D49982
llvm-svn: 338954
These tests were clearly auto-generated when they were converted to
FileCheck back in r80019 (2009), but we didn't have a fancy script to
keep them up to date then. I've reviewed the diff, and we should be
generating the exact same code sequences we used to.
After this, I plan to commit a change that changes our output slightly,
but in a way that is still correct. It will generate a large diff, and I
want it to be clearly correct, so I am regenerating these checks in
preparation for that.
llvm-svn: 338928
- Remove -asm-verbose=0 from every llc command. The tests still pass.
- Reorder the RUN lines to match CHECKs.
- Use -LABEL like update_llc_test_checks.py does.
llvm-svn: 338927
Put the LLVM IR at the bottom of the function instead of the top. In my
next patch, I will run update_llc_test_checks.py on this file, and I
want to only highlight the diffs in the CHECK lines. Hopefully by doing
this change first, the patch will be more understandable.
llvm-svn: 338926
At one point in time acquire implied mayLoad and mayStore as did release. Thus we needed separate pseudos that also carried that property. This appears to no longer be the case. I believe it was changed in 2012 with a comment saying that atomic memory accesses are marked volatile which preserves the ordering.
So from what I can tell we shouldn't need additional pseudos since they aren't carry any flags that are different from the normal instructions. The only thing I can think of is that we may consider them for load folding candidates in the peephole pass now where we didn't before. If that's important hopefully there's something in the memory operand we can check to prevent the folding without relying on pseudo instructions.
Differential Revision: https://reviews.llvm.org/D50212
llvm-svn: 338925
Add a parameter for testing specifically for
sNaNs - at least one instruction pattern on AMDGPU
needs to check specifically for this.
Also handle more cases, and add a target hook
for custom nodes, similar to the hooks for known
bits.
llvm-svn: 338910
Clang uses "ctpop & 1" to implement __builtin_parity. If the popcnt instruction isn't supported this generates a large amount of code to calculate the population count. Instead we can bisect the data down to a single byte using xor and then check the parity flag.
Even when popcnt is supported, its still a good idea to split 64-bit data on 32-bit targets using an xor in front of a single popcnt. Otherwise we get two popcnts and an add before the and.
I've specifically targeted this at the sizes supported by clang builtins, but we could generalize this if we think that's useful.
Differential Revision: https://reviews.llvm.org/D50165
llvm-svn: 338907
In r337830 I added SCEV checks to enable us to insert fewer bounds checks. Unfortunately, this sometimes crashes when multiple bounds checks are added due to SCEV caching issues. This patch splits the bounds checking pass into two phases, one that computes all the conditions (using SCEV checks) and the other that adds the new instructions.
Differential Revision: https://reviews.llvm.org/D49946
llvm-svn: 338902
We don't expect module names to be present in the index. This patch adds
DW_TAG_module to the blacklist.
Differential revision: https://reviews.llvm.org/D50237
llvm-svn: 338878
Some instructions expand to more than one decoder group.
This has been hitherto ignored, but is handled with this patch.
Review: Ulrich Weigand
https://reviews.llvm.org/D50187
llvm-svn: 338849
Basic pattern that leaves an unnecessary select on a rotation by zero result. This variant is trivial - the more general case with a compare+branch to prevent execution of undefined shifts is more tricky.
llvm-svn: 338833
There are a lot of permutations of types here generating a lot of patterns in the isel table. It's more efficient to just ReplaceUses and RemoveDeadNode from the Select function.
The test changes are because we have a some shuffle patterns that have a bitcast as their root node. But the behavior is identical to another instruction whose pattern doesn't start with a bitcast. So this isn't a functional change.
llvm-svn: 338824
Move all the patterns to X86InstrVecCompiler.td so we can keep SSE/AVX/AVX512 all in one place.
To save some patterns we'll use an existing DAG combine to convert f128 fand/for/fxor to integer when sse2 is enabled. This allows use to reuse all the existing patterns for v2i64.
I believe this now makes SHA instructions the only case where VEX/EVEX and legacy encoded instructions could be generated simultaneously.
llvm-svn: 338821
This is the second patch of the series which intends to enable jump threading for an inlined method whose return type is std::pair<int, bool> or std::pair<bool, int>.
The first patch is https://reviews.llvm.org/rL338485.
This patch handles code sequences that merges two values using `shl` and `or`, then extracts one value using `and`.
Differential Revision: https://reviews.llvm.org/D49981
llvm-svn: 338817
If the producing instruction is legacy encoded it doesn't implicitly zero the upper bits. This is important for the SHA instructions which don't have a VEX encoded version. We might also be able to hit this with the incomplete f128 support that hasn't been ported to VEX.
llvm-svn: 338812
This one requires a bit of explaination. It's not every day you simply delete code to implement an optimization. :)
The transform in question is sinking an instruction from a loop to the uses in loop exiting blocks. We know (from LCSSA) that all of the uses outside the loop must be phi nodes, and after predecessor splitting, we know all phi users must have a single operand. Since the use must be strictly dominated by the def, we know from the definition of dominance/ssa that the exit block must execute along a (non-strict) subset of paths which reach the def. As a result, duplicating a potentially faulting instruction can not *introduce* a fault that didn't previously exist in the program.
The full story is that this patch builds on "rL338671: [LICM] Factor out fault legality from canHoistOrSinkInst [NFC]" which pulled this logic out of a common helper routine. As best I can tell, this check was originally added to the helper function for hoisting legality, later an incorrect fastpath for loads/calls was added, and then the bug was fixed by duplicating the fault safety check in the hoist path. This left the redundant check in the common code to pessimize sinking for no reason. I split it out in an NFC, and am not removing the unneccessary check. I wanted there to be something easy to revert in case I missed something.
Reviewed by: Anna Thomas (in person)
llvm-svn: 338794
Summary:
With Mach-O, there is a flag requirement discrepancy between working with
universal binaries and thin binaries. Many flags that don't require the `-macho`
flag (for example `-private-headers` and `-disassemble`) fail to work on
universal binaries unless `-macho` is given. When this happens, the error
message is unhelpful, stating:
The file was not recognized as a valid object file.
Which can lead to confusion.
This change allows generic flags to be used on universal binaries with and
without the `-macho` flag. This means flags that can be used for thin files can
be used consistently with fat files too.
To do this, the universal binary support within `ParseInputMachO()` is extracted
into a new function. This new function is called directly from `DumpInput()`
when the input binary is universal. Additionally the `-arch` flag validation in
`ParseInputMachO()` was extracted to be reused.
Reviewers: compnerd
Reviewed By: compnerd
Subscribers: keith, llvm-commits
Differential Revision: https://reviews.llvm.org/D48702
llvm-svn: 338792
At least on ELF, it's impossible to tell from the object file whether
two globals with the same section marking were merged: the merged global
uses "private" linkage to hide its symbol, and the aliases look like
regular symbols. I can't think of any other reason to disallow it.
(Of course, we can only merge globals in the same section.)
The weird alignment handling matches AsmPrinter; our alignment handling
for global variables should probably be refactored.
Differential Revision: https://reviews.llvm.org/D49822
llvm-svn: 338791
Summary:
I encountered some problems with SIFixWWMLiveness when WWM is in a loop:
1. It sometimes gave invalid MIR where there is some control flow path
to the new implicit use of a register on EXIT_WWM that does not pass
through any def.
2. There were lots of false positives of registers that needed to have
an implicit use added to EXIT_WWM.
3. Adding an implicit use to EXIT_WWM (and adding an implicit def just
before the WWM code, which I tried in order to fix (1)) caused lots
of the values to be spilled and reloaded unnecessarily.
This commit is a rework of SIFixWWMLiveness, with the following changes:
1. Instead of considering any register with a def that can reach the WWM
code and a def that can be reached from the WWM code, it now
considers three specific cases that need to be handled.
2. A register that needs liveness over WWM to be synthesized now has it
done by adding itself as an implicit use to defs other than the
dominant one.
Also added the following fixmes:
FIXME: We should detect whether a register in one of the above
categories is already live at the WWM code before deciding to add the
implicit uses to synthesize its liveness.
FIXME: I believe this whole scheme may be flawed due to the possibility
of the register allocator doing live interval splitting.
Subscribers: arsenm, kzhuravl, wdng, nhaehnle, yaxunl, dstuttard, t-tye, llvm-commits
Differential Revision: https://reviews.llvm.org/D46756
Change-Id: Ie7fba0ede0378849181df3f1a9a7a39ed1a94a94
llvm-svn: 338783
Summary:
This fixes a problem where a load from global+idx generated incorrect
code on <=gfx7 when the index is divergent.
Subscribers: arsenm, kzhuravl, wdng, nhaehnle, yaxunl, dstuttard, t-tye, llvm-commits
Differential Revision: https://reviews.llvm.org/D47383
Change-Id: Ib4d177d6254b1dd3f8ec0203fdddec94bd8bc5ed
llvm-svn: 338779
This will remove suboptimal branching from the generated ll/sc loops.
The extra simplification pass affects a lot of testcases, which have
been modified to accommodate this change: either by modifying the
test to become immune to the CFG simplification, or (less preferablt)
by adding option -hexagon-initial-cfg-clenaup=0.
llvm-svn: 338774
Rather than allowing invalid bitcasts to be lowered to wasm
call instructions that won't validate, generate wrappers that
contain unreachable thereby delaying the error until runtime.
Differential Revision: https://reviews.llvm.org/D49517
llvm-svn: 338744
These instructions perform the same operation, but the semantic of which operand is destroyed is reversed. If the same register is used as both operands we can change the execution domain without worrying about this difference.
Unfortunately, this really only works in cases where the input register is killed by the instruction. If its not killed, the two address isntruction pass inserts a copy that will become a move instruction. This makes the instruction use different physical registers that contain the same data at the time the unpck/movhlps executes. I've considered using a unary pseudo instruction with tied operand to trick the two address instruction pass. We could then expand the pseudo post regalloc to get the same physical register on both inputs.
Differential Revision: https://reviews.llvm.org/D50157
llvm-svn: 338735
This adds the NAN checks suggested in PR37776:
https://bugs.llvm.org/show_bug.cgi?id=37776
If both operands to maxnum are NAN, that should get constant folded, so we don't
have to handle that case. This is the same assumption as other FP ops in this
function. Returning 'false' is always conservatively correct.
Copying from the bug report:
Currently, we have this for "when is cannotBeOrderedLessThanZero
(mustBePositiveOrNaN) true for maxnum":
L
-------------------
| Pos | Neg | NaN |
------------------------
|Pos | x | x | x |
------------------------
R |Neg | x | | x |
------------------------
|NaN | x | x | x |
------------------------
The cases with (Neg & NaN) are wrong. We should have:
L
-------------------
| Pos | Neg | NaN |
------------------------
|Pos | x | x | x |
------------------------
R |Neg | x | | |
------------------------
|NaN | x | | x |
------------------------
Differential Revision: https://reviews.llvm.org/D50081
llvm-svn: 338716
As a part of adding the tiny codemodel, we need to support ldr's with :got:
relocations on them. This seems to be mostly already done, just needs the
relocation type support.
Differential Revision: https://reviews.llvm.org/D50137
llvm-svn: 338673
In expansion of FCOPYSIGN, the shift node is missing when the two
operands of FCOPYSIGN are of the same size. We should always generate
shift node (if the required shift bit is not zero) to put the sign
bit into the right position, regardless of the size of underlying
types.
Differential Revision: https://reviews.llvm.org/D49973
llvm-svn: 338665
Adding the FP_ROUND nodes when combining FP_TO_[SU]INT of elements
feeding a BUILD_VECTOR into an FP_TO_[SU]INT of the built vector
loses precision. This patch removes the code that adds these nodes
to true f64 operands. It also adds patterns required to ensure
the code is still vectorized rather than converting individual
elements and inserting into a vector.
Fixes https://bugs.llvm.org/show_bug.cgi?id=38342
Differential Revision: https://reviews.llvm.org/D50121
llvm-svn: 338658
AArch64 ELF ABI does not define a static relocation type for TLS offset within
a module, which makes it impossible for compiler to generate a valid
DW_AT_location content for thread local variables. Currently LLVM generates an
invalid R_AARCH64_ABS64 relocation at the DW_AT_location field for a TLS
variable. That causes trouble for linker because thread local variable does
not have an absolute address at link time. AArch64 GCC solves the problem by
not generating DW_AT_location for thread local variables. We should do the
same in LLVM.
Differential Revision: https://reviews.llvm.org/D43860
llvm-svn: 338655
(Previously reverted in r338442)
I'm told that the breakage came from us using an x86 triple on configs
that didn't have x86 enabled. This is remedied by moving the
debugcounter test to an x86 directory (where there's also a
opt-bisect-isel.ll test for similar reasons).
I can't repro the reverse-iteration failure mentioned in the revert with
this patch, so I assume that a misconfiguration on my end is what caused
that.
Original commit message:
Add DebugCounters to DivRemPairs
For people who don't use DebugCounters, NFCI.
Patch by Zhizhou Yang!
Differential Revision: https://reviews.llvm.org/D50033
llvm-svn: 338653
Mutate the node type during selection when it
doesn't matter. This avoids an intermediate bitcast
node on targets with legal i16/f16.
Also fixes missing output modifiers on v_cvt_pkrtz_f32_f16,
which I assume are OK.
llvm-svn: 338619
Summary:
Added an option that allows to emit only '.loc' and '.file' kind debug
directives, but disables emission of the DWARF sections. Required for
NVPTX target to support profiling. It requires '.loc' and '.file'
directives, but does not require any DWARF sections for the profiler.
Reviewers: probinson, echristo, dblaikie
Subscribers: aprantl, JDevlieghere, llvm-commits
Differential Revision: https://reviews.llvm.org/D46021
llvm-svn: 338616
We now emit a move of -1 before the cmov and do the addition after the cmov just like the case with an extra addition.
This may be slightly worse for code size, but is more consistent with other compilers. And we might be able to hoist the mov -1 outside of loops.
llvm-svn: 338613
After we detected the presence of a template via ?$ we would proceed by
only demangling a simple unqualified name. This means we would fail on
templated operators (and perhaps other yet-to-be-determined things)
This was discovered while doing some refactoring to store richer
semantic information about the demangled types to pave the way for
overhauling the way we handle backreferences. (Specifically, we need to
defer recording or resolving back-references until a symbol has been
completely demangled, because we need to use information that only
occurs later in the mangled string to decide whether a back-reference
should be recorded.)
Differential Revision: https://reviews.llvm.org/D50145
llvm-svn: 338608
Summary:
D25878, which added support for !absolute_symbol for normal X86 ISel,
did not add support for materializing references to absolute symbols for
X86 FastISel. This causes build failures because FastISel generates
PC-relative relocations for absolute symbols. Fall back to normal ISel
for references to !absolute_symbol GVs. Fix for PR38200.
Reviewers: pcc, craig.topper
Reviewed By: pcc
Subscribers: hiraditya, llvm-commits, kcc
Differential Revision: https://reviews.llvm.org/D50116
llvm-svn: 338599
I've put CMPXCHG8B/CMPXCHG16B in the same file, even though technically they are under separate CPUID bits all targets seem to support both (or neither).
llvm-svn: 338595
The bug is visible in the constant-folded x86 tests. We can't use the
negated shift amount when the type is not power-of-2:
https://rise4fun.com/Alive/US1r
...so in that case, use the regular lowering that includes a select
to guard against a shift-by-bitwidth. This path is improved by only
calculating the modulo shift amount once now.
Also, improve the rotate (with power-of-2 size) lowering to use
a negate rather than subtract from bitwidth. This improves the
codegen whether we have a rotate instruction or not (although
we can still see that we're not matching to a legal rotate in
all cases).
llvm-svn: 338592
Summary:
Add support for --rename-section flags from gnu objcopy.
Not all flags appear to have an effect for ELF objects, but allowing them would allow easier drop-in replacement. Other unrecognized flags are rejected.
This was only tested by comparing flags printed by "readelf -e <.o>" against the output of gnu vs llvm objcopy, it hasn't been tested to be valid beyond that.
Reviewers: jakehehrlich, alexshap
Subscribers: llvm-commits, paulsemel, alexshap
Differential Revision: https://reviews.llvm.org/D49870
llvm-svn: 338582
Clang support for the Armv8.2-A FP16 vector intrinsic was committed in
rC328277, but this was never followed up, i.e. the LLVM part is missing.
I've raised PR38404, and this is the first step to address this. I.e.,
this adds tests for the Armv8.2-A FP16 vector intrinsic, and thus shows
which intrinsics already work, and which need further work.
Differential Revision: https://reviews.llvm.org/D50142
llvm-svn: 338568
Getting the DWARF types section is only implemented for ELF object
files. We already disabled emitting debug types in clang (r337717), but
now we also report an fatal error (rather than crashing) when trying to
obtain this section in MC. Additionally we ignore the generate debug
types flag for unsupported target triples.
See PR38190 for more information.
Differential revision: https://reviews.llvm.org/D50057
llvm-svn: 338527
Summary:
Add _L to _LZ image intrinsic table mapping to table gen.
In ISelLowering check if image intrinsic has lod and if it's equal
to zero, if so remove lod and change opcode to equivalent mapped _LZ.
Change-Id: Ie24cd7e788e2195d846c7bd256151178cbb9ec71
Subscribers: arsenm, mehdi_amini, kzhuravl, wdng, nhaehnle, yaxunl, dstuttard, tpr, t-tye, steven_wu, dexonsmith, llvm-commits
Differential Revision: https://reviews.llvm.org/D49483
llvm-svn: 338523
The DAG combiner logic to simplify AND masks in shift counts is invalid.
While it is true that the SystemZ shift instructions ignore all but the
low 6 bits of the shift count, it is still invalid to simplify the AND
masks while the DAG still uses the standard shift operators (which are
*not* defined to match the SystemZ instruction behavior).
Instead, this patch performs equivalent operations during instruction
selection. For completely removing the AND, this now happens via
additional DAG match patterns implemented by a multi-alternative
PatFrags. For simplifying a 32-bit AND to a 16-bit AND, the existing DAG
patterns were already mostly OK, they just needed an output XForm to
actually truncate the immediate value.
Unfortunately, the latter change also exposed a bug in TableGen: it
seems XForms are currently only handled correctly for direct operands of
the outermost operation node. This patch also fixes that bug by simply
recurring through the whole pattern. This should be NFC for all other
targets.
Differential Revision: https://reviews.llvm.org/D50096
llvm-svn: 338521
Summary:
This patch improves Inliner to provide causes/reasons for negative inline decisions.
1. It adds one new message field to InlineCost to report causes for Always and Never instances. All Never and Always instantiations must provide a simple message.
2. Several functions that used to return the inlining results as boolean are changed to return InlineResult which carries the cause for negative decision.
3. Changed remark priniting and debug output messages to provide the additional messages and related inline cost.
4. Adjusted tests for changed printing.
Patch by: yrouban (Yevgeny Rouban)
Reviewers: craig.topper, sammccall, sgraenitz, NutshellySima, shchenz, chandlerc, apilipenko, javed.absar, tejohnson, dblaikie, sanjoy, eraman, xbolva00
Reviewed By: tejohnson, xbolva00
Subscribers: xbolva00, llvm-commits, arsenm, mehdi_amini, eraman, haicheng, steven_wu, dexonsmith
Differential Revision: https://reviews.llvm.org/D49412
llvm-svn: 338494
This revision implements support for generating DWARFv5 .debug_addr section.
The implementation is pretty straight-forward: we just check the dwarf version
and emit section header if needed.
Reviewers: aprantl, dblaikie, probinson
Reviewed by: dblaikie
Differential Revision: https://reviews.llvm.org/D50005
llvm-svn: 338487
This patch intends to enable jump threading when a method whose return type is std::pair<int, bool> or std::pair<bool, int> is inlined.
For example, jump threading does not happen for the if statement in func.
std::pair<int, bool> callee(int v) {
int a = dummy(v);
if (a) return std::make_pair(dummy(v), true);
else return std::make_pair(v, v < 0);
}
int func(int v) {
std::pair<int, bool> rc = callee(v);
if (rc.second) {
// do something
}
SROA executed before the method inlining replaces std::pair by i64 without splitting in both callee and func since at this point no access to the individual fields is seen to SROA.
After inlining, jump threading fails to identify that the incoming value is a constant due to additional instructions (like or, and, trunc).
This series of patch add patterns in InstructionSimplify to fold extraction of members of std::pair. To help jump threading, actually we need to optimize the code sequence spanning multiple BBs.
These patches does not handle phi by itself, but these additional patterns help NewGVN pass, which calls instsimplify to check opportunities for simplifying instructions over phi, apply phi-of-ops optimization to result in successful jump threading.
SimplifyDemandedBits in InstCombine, can do more general optimization but this patch aims to provide opportunities for other optimizers by supporting a simple but common case in InstSimplify.
This first patch in the series handles code sequences that merges two values using shl and or and then extracts one value using lshr.
Differential Revision: https://reviews.llvm.org/D48828
llvm-svn: 338485
EFLAGS copy lowering.
If you have a branch of LLVM, you may want to cherrypick this. It is
extremely unlikely to hit this case empirically, but it will likely
manifest as an "impossible" branch being taken somewhere, and will be
... very hard to debug.
Hitting this requires complex conditions living across complex control
flow combined with some interesting memory (non-stack) initialized with
the results of a comparison. Also, because you have to arrange for an
EFLAGS copy to be in *just* the right place, almost anything you do to
the code will hide the bug. I was unable to reduce anything remotely
resembling a "good" test case from the place where I hit it, and so
instead I have constructed synthetic MIR testing that directly exercises
the bug in question (as well as the good behavior for completeness).
The issue is that we would mistakenly assume any SETcc with a valid
condition and an initial operand that was a register and a virtual
register at that to be a register *defining* SETcc...
It isn't though....
This would in turn cause us to test some other bizarre register,
typically the base pointer of some memory. Now, testing this register
and using that to branch on doesn't make any sense. It even fails the
machine verifier (if you are running it) due to the wrong register
class. But it will make it through LLVM, assemble, and it *looks*
fine... But wow do you get a very unsual and surprising branch taken in
your actual code.
The fix is to actually check what kind of SETcc instruction we're
dealing with. Because there are a bunch of them, I just test the
may-store bit in the instruction. I've also added an assert for sanity
that ensure we are, in fact, *defining* the register operand. =D
llvm-svn: 338481
we aren't incorrectly generating any of it when doing SLH.
There was a bug that only occured with SLH that very much looked like it
could be caused by bad unwind info, and so this was a prime suspect.
Turns out that everything is fine, but this way we'll *see* if we end
up, for example, putting things we shouldn't inside the prolog.
llvm-svn: 338480
It is necessary to generate fixups in .debug_line as relaxation is
enabled due to the address delta may be changed after relaxation.
DWARF will record the mappings of lines and addresses in
.debug_line section. It will encode the information using special
opcodes, standard opcodes and extended opcodes in Line Number
Program. I use DW_LNS_fixed_advance_pc to encode fixed length
address delta and DW_LNE_set_address to encode absolute address
to make it possible to generate fixups in .debug_line section.
Differential Revision: https://reviews.llvm.org/D46850
llvm-svn: 338477
Previously we were just visiting the blocks in the function in IR order, which
is rather arbitrary. Therefore we wouldn't always visit defs before uses, but
the translation code relies on this assumption in some places.
Only codegen change seen in tests is an elision of a redundant copy.
Fixes PR38396
llvm-svn: 338476
Disable ARMCodeGenPrepare by default again. It is causing verifier
failues in V8 that look like:
Duplicate integer as switch case
switch i32 %trunc, label %if.end13 [
i32 0, label %cleanup36
i32 0, label %if.then8
], !dbg !4981
i32 0
fatal error: error in backend: Broken function found, compilation aborted!
I will continue reducing the test case and send it along.
llvm-svn: 338452
Summary:
See binutils-gdb/bfd/elf.c, GNU objcopy also strips .stab* (STABS)
.line* (DWARF 1) .gnu.linkonce.wi.* (linkonce section for .debug_info) but
I'm not sure we need to be compatible with it.
Reviewers: dblaikie, alexshap, jakehehrlich, jhenderson
Reviewed By: alexshap, jakehehrlich
Subscribers: aprantl, JDevlieghere, jakehehrlich, llvm-commits
Differential Revision: https://reviews.llvm.org/D50100
llvm-svn: 338443
When lowering calling conventions, prefer to decompose vectors
into the constitute register types. This avoids artifical constraints
to satisfy a wide super-register.
This improves code quality because now optimizations don't need to
deal with the super-register constraint. For example the immediate
folding code doesn't deal with 4 component reg_sequences, so by
breaking the register down earlier the existing immediate folding
code is able to work.
This also avoids the need for the shader input processing code
to manually split vector types.
llvm-svn: 338416
As was done for vector rotations, we can efficiently use ISD::MULHU for vXi8/vXi16 ISD::SRL lowering.
Shift-by-zero cases are still problematic (mainly on v32i8 due to extra AND/ANDN/OR or VPBLENDVB blend masks but v8i16/v16i16 aren't great either if PBLENDW fails) so I've limited this first patch to known non-zero cases if we can't easily use PBLENDW.
Differential Revision: https://reviews.llvm.org/D49562
llvm-svn: 338407
These aren't exhaustive, but cover some instructions that are only available in 32-bit mode (where would we be without good BCD math performance?).
llvm-svn: 338404
Summary:
Similar to D49636, but for PMADDUBSW. This instruction has the additional complexity that the addition of the two products saturates to 16-bits rather than wrapping around. And one operand is treated as signed and the other as unsigned.
A C example that triggers this pattern
```
static const int N = 128;
int8_t A[2*N];
uint8_t B[2*N];
int16_t C[N];
void foo() {
for (int i = 0; i != N; ++i)
C[i] = MIN(MAX((int16_t)A[2*i]*(int16_t)B[2*i] + (int16_t)A[2*i+1]*(int16_t)B[2*i+1], -32768), 32767);
}
```
Reviewers: RKSimon, spatel, zvi
Reviewed By: RKSimon, zvi
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D49829
llvm-svn: 338402
This commit fixes two issues with the liveness information after the
call:
1) The code always spills RCX and RDX if InProlog == true, which results
in an use of undefined phys reg.
2) FinalReg, JoinReg, RoundedReg, SizeReg are not added as live-ins to
the basic blocks that use them, therefore they are seen undefined.
https://llvm.org/PR38376
Differential Revision: https://reviews.llvm.org/D50020
llvm-svn: 338400
Builder clang-cmake-armv8-full failed due to the assembly 'comment'
notation is not '#' in the target. So, I use CHECK-SAME to avoid to
check the comment notation in the same line in the test case.
llvm-svn: 338398
Workaround bug where the InstCombine pass was asserting on the IR added in lit
test, where we have a bitcast instruction after a GEP from an addrspace cast.
The second bitcast in the test was getting combined into
`bitcast <16 x i32>* %0 to <16 x i32> addrspace(3)*`, which looks like it should
be an addrspace cast instruction instead. Otherwise if control flow is allowed
to continue as it is now we create a GEP instruction
`<badref> = getelementptr inbounds <16 x i32>, <16 x i32>* %0, i32 0`. However
because the type of this instruction doesn't match the address space we hit an
assert when replacing the bitcast with that GEP.
```
void llvm::Value::doRAUW(llvm::Value*, bool): Assertion `New->getType() == getType() && "replaceAllUses of value with new value of different type!"' failed.
```
Differential Revision: https://reviews.llvm.org/D50058
llvm-svn: 338395
Summary:
When inserting lcssa Phi Nodes in the exit block
mak sure to preserve the original instructions DL.
Reviewers: vsk
Subscribers: JDevlieghere, llvm-commits
Differential Revision: https://reviews.llvm.org/D50009
llvm-svn: 338391
There are two forms for label debug information in DWARF format.
1. Labels in a non-inlined function:
DW_TAG_label
DW_AT_name
DW_AT_decl_file
DW_AT_decl_line
DW_AT_low_pc
2. Labels in an inlined function:
DW_TAG_label
DW_AT_abstract_origin
DW_AT_low_pc
We will collect label information from DBG_LABEL. Before every DBG_LABEL,
we will generate a temporary symbol to denote the location of the label.
The symbol could be used to get DW_AT_low_pc afterwards. So, we create a
mapping between 'inlined label' and DBG_LABEL MachineInstr in DebugHandlerBase.
The DBG_LABEL in the mapping is used to query the symbol before it.
The AbstractLabels in DwarfCompileUnit is used to process labels in inlined
functions.
We also keep a mapping between scope and labels in DwarfFile to help to
generate correct tree structure of DIEs.
It also generates label debug information under global isel.
Differential Revision: https://reviews.llvm.org/D45556
llvm-svn: 338390
Summary:
This patch improves Inliner to provide causes/reasons for negative inline decisions.
1. It adds one new message field to InlineCost to report causes for Always and Never instances. All Never and Always instantiations must provide a simple message.
2. Several functions that used to return the inlining results as boolean are changed to return InlineResult which carries the cause for negative decision.
3. Changed remark priniting and debug output messages to provide the additional messages and related inline cost.
4. Adjusted tests for changed printing.
Patch by: yrouban (Yevgeny Rouban)
Reviewers: craig.topper, sammccall, sgraenitz, NutshellySima, shchenz, chandlerc, apilipenko, javed.absar, tejohnson, dblaikie, sanjoy, eraman, xbolva00
Reviewed By: tejohnson, xbolva00
Subscribers: xbolva00, llvm-commits, arsenm, mehdi_amini, eraman, haicheng, steven_wu, dexonsmith
Differential Revision: https://reviews.llvm.org/D49412
llvm-svn: 338387
This is being done in order to make GVN able to better optimize certain inputs.
MemDep doesn't use PhiValues directly, but does need to notifiy it when things
get invalidated.
Differential Revision: https://reviews.llvm.org/D48489
llvm-svn: 338384
Summary:
If the ExtractElement instructions can be optimized out during the
vectorization and we need to reshuffle the parent vector, this
ShuffleInstruction may be inserted in the wrong place causing compiler
to produce incorrect code.
Reviewers: spatel, RKSimon, mkuper, hfinkel, javed.absar
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D49928
llvm-svn: 338380
We could choose a free 0 for this, but this
matches the behavior for fmul undef, 1.0. Also,
the NaN use is more useful for folding use operations
although if it's not eliminated it is more expensive
in terms of code size.
llvm-svn: 338376
This patch teaches llvm-mca how to identify dependency breaking instructions on
btver2.
An example of dependency breaking instructions is the zero-idiom XOR (example:
`XOR %eax, %eax`), which always generates zero regardless of the actual value of
the input register operands.
Dependency breaking instructions don't have to wait on their input register
operands before executing. This is because the computation is not dependent on
the inputs.
Not all dependency breaking idioms are also zero-latency instructions. For
example, `CMPEQ %xmm1, %xmm1` is independent on
the value of XMM1, and it generates a vector of all-ones.
That instruction is not eliminated at register renaming stage, and its opcode is
issued to a pipeline for execution. So, the latency is not zero.
This patch adds a new method named isDependencyBreaking() to the MCInstrAnalysis
interface. That method takes as input an instruction (i.e. MCInst) and a
MCSubtargetInfo.
The default implementation of isDependencyBreaking() conservatively returns
false for all instructions. Targets may override the default behavior for
specific CPUs, and return a value which better matches the subtarget behavior.
In future, we should teach to Tablegen how to automatically generate the body of
isDependencyBreaking from scheduling predicate definitions. This would allow us
to expose the knowledge about dependency breaking instructions to the machine
schedulers (and, potentially, other codegen passes).
Differential Revision: https://reviews.llvm.org/D49310
llvm-svn: 338372
Since z13, the max group size will be 2 if any μop has more than 3 register
sources.
This has been ignored sofar in the SystemZHazardRecognizer, but is now
handled by recognizing those instructions and adjusting the tracking of
decoding and the cost heuristic for grouping.
Review: Ulrich Weigand
https://reviews.llvm.org/D49847
llvm-svn: 338368
This fold was written in an odd way and tried to avoid
an endless loop by bailing out on all constants instead
of the supposedly problematic case of -1. But (X & -1)
should always be simplified before we reach here, so I'm
not sure how that is a problem.
There were no tests for the commuted patterns, so I added
those at rL338364.
llvm-svn: 338367
Contrary to ELF, we don't add any markers that distinguish data generated
with .short/.long from normal instructions, so the .inst directive only
adds compatibility with assembly that uses it.
Differential Revision: https://reviews.llvm.org/D49936
llvm-svn: 338356
Contrary to ELF, we don't add any markers that distinguish data generated
with .long from normal instructions, so the .inst directive only adds
compatibility with assembly that uses it.
Differential Revision: https://reviews.llvm.org/D49935
llvm-svn: 338355
In one place we checked X86Subtarget.slowLEA() to decide if the pass should run. But to decide what the pass should we only check isSLM. This resulted in Goldmont going down the Bonnell path.
llvm-svn: 338342
This patch fixes demangling of template aliases as template-template
arguments, and also fixes function pointers and references as
not type template parameters. All of these can be properly
demangled now, so I've ported over the test
clang/test/CodeGenCXX/ms-template-callbacks.cpp. All of these
tests pass
llvm-svn: 338340
Also refactors some existing code to materialize addresses for the large code
model so it can be shared between G_GLOBAL_VALUE and G_BLOCK_ADDR.
This implements PR36390.
Differential Revision: https://reviews.llvm.org/D49903
llvm-svn: 338337
This patch adds support for demangling r-value references, new
operators such as the ""_foo operator, lambdas, alias types,
nullptr_t, and various other C++11'isms.
There is 1 failing test remaining in this file, which appears to
be related to back-referencing. This type of problem has the
potential to get ugly so I'd rather fix it in a separate patch.
Differential Revision: https://reviews.llvm.org/D50013
llvm-svn: 338324
This is exchanging a sub-of-1 with add-of-minus-1:
https://rise4fun.com/Alive/plKAH
This is another step towards improving select-of-constants codegen (see D48970).
x86 is the motivating target, and those diffs all appear to be wins. PPC and AArch64 look neutral.
I've limited this to early combining (!LegalOperations) in case a target wants to reverse it, but
I think canonicalizing to 'add' is more likely to produce further transforms because we have more
folds for 'add'.
Differential Revision: https://reviews.llvm.org/D49924
llvm-svn: 338317
Summary:
Normally, inling does not happen if caller does not have
"null-pointer-is-valid"="true" attibute but callee has it.
However, alwaysinline may force callee to be inlined.
In this case, if the caller has the "null-pointer-is-valid"="true"
attribute, copy the attribute to caller.
Reviewers: efriedma, a.elovikov, lebedev.ri, jyknight
Reviewed By: efriedma
Subscribers: eraman, llvm-commits
Differential Revision: https://reviews.llvm.org/D50000
llvm-svn: 338292
This teaches the outliner to save LR to a register rather than the stack when
possible. This allows us to avoid bumping the stack in outlined functions in
some cases. By doing this, in a later patch, we can teach the outliner to do
something like this:
f1:
...
bl OUTLINED_FUNCTION
...
f2:
...
move LR's contents to a register
bl OUTLINED_FUNCTION
move the register's contents back
instead of falling back to saving LR in both cases.
llvm-svn: 338278
Previously, I thought this was a Windows failure. Then I realized it failed on
every bot that used the verifier. This makes it use the verifier always, and
adds that pass to the pipeline checks so that it's consistent across all bots.
llvm-svn: 338272
Summary:
Attempt to extract a shrl from a udiv or a shl from a mul if this allows a rotate to be formed. This targets cases where the input to a rotate pattern was a mul or udiv by a constant and InstCombine merged one of the shifts with the op.
Patch by: sameconrad (Sam Conrad)
Reviewers: RKSimon, craig.topper, spatel, lebedev.ri, javed.absar
Reviewed By: lebedev.ri
Subscribers: efriedma, kparzysz, llvm-commits
Differential Revision: https://reviews.llvm.org/D47681
llvm-svn: 338270
This reapplies commit r338206 reverted by r338214 since the bug that
r338206 uncovered has been fixed in r338268.
Add support for inline assembly with matching input operand that do not
naturally go in the register class it is constrained to (eg. double in a
32-bit GPR). Note that regular input is already handled by existing
code.
llvm-svn: 338269
It seems like the pass pipeline on Windows is slightly different than on Linux
and macOS. As a result, the arm64-opt-remarks-lazy-bfi test has been failing.
This switches a CHECK-NEXT to a CHECK-DAG to try and get this running properly
again.
It'd be nice to switch it back to a CHECK-NEXT if possible, but the CHECK-NEXT
lines following the line we care about (the optimization remark emitter)
do a pretty good job of enforcing the ordering we want.
Hopefully this works, since I don't have a Windows machine. ;)
Example failure: http://lab.llvm.org:8011/builders/llvm-clang-x86_64-expensive-checks-win/builds/11295
llvm-svn: 338267
This patch enables instructions that are destructive on their
destination- and first source operand, to be prefixed with a
MOVPRFX instruction.
This patch also adds a variety of tests:
- positive tests for all instructions and forms that accept a
movprfx for either or both predicated and unpredicated forms.
- negative tests for all instructions and forms that do not accept
an unpredicated or predicated movprfx.
- negative tests for the diagnostics that get emitted when a MOVPRFX
instruction is used incorrectly.
This is patch [2/2] in a series to add MOVPRFX instructions:
- Patch [1/2]: https://reviews.llvm.org/D49592
- Patch [2/2]: https://reviews.llvm.org/D49593
Reviewers: rengolin, SjoerdMeijer, samparker, fhahn, javed.absar
Reviewed By: SjoerdMeijer
Differential Revision: https://reviews.llvm.org/D49593
llvm-svn: 338261
The combination of r338240 and r338242 causes the opt pass pipeline tests to
fail because of how r338242 makes BasicAA be invalidated more often. Adjust the
tests to reflect this.
llvm-svn: 338250
By using PhiValuesAnalysis we can get all the values reachable from a phi, so
we can be more precise instead of giving up when a phi has phi operands. We
can't make BaseicAA directly use PhiValuesAnalysis though, as the user of
BasicAA may modify the function in ways that PhiValuesAnalysis can't cope with.
For this optional usage to work correctly BasicAAWrapperPass now needs to be not
marked as CFG-only (i.e. it is now invalidated even when CFG is preserved) due
to how the legacy pass manager handles dependent passes being invalidated,
namely the depending pass still has a pointer to the now-dead dependent pass.
Differential Revision: https://reviews.llvm.org/D44564
llvm-svn: 338242
The machine verifier asserts with:
Assertion failed: (isMBB() && "Wrong MachineOperand accessor"), function getMBB, file ../include/llvm/CodeGen/MachineOperand.h, line 542.
It calls analyzeBranch which tries to call getMBB if the opcode is
JMP_1, but in this case we do:
JMP_1 @OUTLINED_FUNCTION
I believe we have to use TAILJMPd64 instead of JMP_1 since JMP_1 is used
with brtarget8.
Differential Revision: https://reviews.llvm.org/D49299
llvm-svn: 338237
Summary:
These instructions interact with hardware blocks outside the shader core,
and they can have "scalar" side effects even when EXEC = 0. We don't
want these scalar side effects to occur when all lanes want to skip
these instructions, so always add the execz skip branch instruction
for basic blocks that contain them.
Also ensure that we skip scalar stores / atomics, though we don't
code-gen those yet.
Reviewers: arsenm, rampitec
Subscribers: kzhuravl, wdng, yaxunl, dstuttard, tpr, t-tye, llvm-commits
Differential Revision: https://reviews.llvm.org/D48431
Change-Id: Ieaeb58352e2789ffd64745603c14970c60819d44
llvm-svn: 338235
Code in `CC_ARM_AAPCS_Custom_Aggregate()` is responsible for handling
homogeneous aggregates for `CC_ARM_AAPCS_VFP`. When an aggregate ends up
fully on stack, the function tries to pack all resulting items of the
aggregate as tightly as possible according to AAPCS.
Once the first item was laid out, the alignment used for consecutive
items was the size of one item. This logic went wrong for 128-bit
vectors because their alignment is normally only 64 bits, and so could
result in inserting unexpected padding between the first and second
element.
The patch fixes the problem by updating the alignment with the item size
only if this results in reducing it.
Differential Revision: https://reviews.llvm.org/D49720
llvm-svn: 338233
There are a couple of issues you run into when you start getting into
more complex names, especially with regards to function local statics.
When you've got something like:
int x() {
static int n = 0;
return n;
}
Then this needs to demangle to something like
int `int __cdecl x()'::`1'::n
The nested mangled symbols (e.g. `int __cdecl x()` in the above
example) also share state with regards to back-referencing, so
we need to be able to re-use the demangler in the middle of
demangling a symbol while sharing back-ref state.
To make matters more complicated, there are a lot of ambiguities
when demangling a symbol's qualified name, because a function local
scope pattern (usually something like `?1??name?`) looks suspiciously
like many other possible things that can occur, such as `?1` meaning
the second back-ref and disambiguating these cases is rather
interesting. The `?1?` in a local scope pattern is actually a special
case of the more general pattern of `? + <encoded number> + ?`, where
"encoded number" can itself have embedded `@` symbols, which is a
common delimeter in mangled names. So we have to take care during the
disambiguation, which is the reason for the overly complicated
`isLocalScopePattern` function in this patch.
I've added some pretty obnoxious tests to exercise all of this, which
exposed several other problems related to back-referencing, so those
are fixed here as well. Finally, I've uncommented some tests that were
previously marked as `FIXME`, since now these work.
Differential Revision: https://reviews.llvm.org/D49965
llvm-svn: 338226
These are reassociated versions of the same pattern and
similar transforms as in rL338200 and rL338118.
The motivation is identical to those commits:
Patterns with add/sub combos can be improved using
'not' ops. This is better for analysis and may lead
to follow-on transforms because 'xor' and 'add' are
commutative/associative. It can also help codegen.
llvm-svn: 338221
Dsymutil's update functionality was broken on Windows because we tried
to rename a file while we're holding open handles to that file. TempFile
provides a solution for this through its keep(Twine) method. This patch
changes dsymutil to make use of that functionality.
Differential revision: https://reviews.llvm.org/D49860
llvm-svn: 338216
The WHILE instructions generate a predicate that is true while the
comparison of the first scalar operand (incremented for each predicate
element) with the second scalar operand is true and false thereafter.
WHILELE While incrementing signed scalar less than or equal to scalar
WHILELO While incrementing unsigned scalar lower than scalar
WHILELS While incrementing unsigned scalar lower than or same as scalar
WHILELT While incrementing signed scalar less than scalar
e.g.
whilele p0.s, x0, x1
generates predicate p0 (for 32bit elements) by incrementing
(signed) x0 and comparing that vector to splat(x1).
llvm-svn: 338211
The instructions added in this patch permit active elements within
a vector to be processed sequentially without unpacking the vector.
PFIRST Set the first active element to true.
PNEXT Find next active element in predicate.
CTERMEQ Compare and terminate loop when equal.
CTERMNE Compare and terminate loop when not equal.
llvm-svn: 338210
Add support for inline assembly with matching input operand that do not
naturally go in the register class it is constrained to (eg. double in a
32-bit GPR). Note that regular input is already handled by existing
code.
llvm-svn: 338206
https://rise4fun.com/Alive/jDd
Patterns with add/sub combos can be improved using
'not' ops. This is better for analysis and may lead
to follow-on transforms because 'xor' and 'add' are
commutative/associative. It can also help codegen.
llvm-svn: 338200
This patch adds PFALSE (unconditionally sets all elements of
the predicate to false) and PTEST (set the status flags for the
predicate).
llvm-svn: 338198
SelectionDAGBuilder widens v3i32/v3f32 arguments to
to v4i32/v4f32 which consume an additional register.
In addition to wasting argument space, this produces extra
instructions since now it appears the 4th vector component has
a meaningful value to most combines.
llvm-svn: 338197
This patch adds support for instructions that partition a predicate
based on data-dependent termination conditions in a loop.
BRKA Break after the first true condition
BRKAS Break after the first true condition, setting condition flags
BRKB Break before the first true condition
BRKBS Break before the first true condition, setting condition flags
BRKPA Break after the first true condition, propagating from the
previous partition
BRKPAS Break after the first true condition, propagating from the
previous partition, setting condition flags
BRKPB Break before the first true condition, propagating from the
previous partition
BRKPBS Break before the first true condition, propagating from the
previous partition, setting condition flags
BRKN Propagate break to next partition
BKRNS Propagate break to next partition, setting condition flags
llvm-svn: 338196
We now, from clang, can turn arrays of
static short g_data[] = {16, 16, 16, 16, 16, 16, 16, 16, 0, 0, 0, 0, 0, 0, 0, 0};
into structs of the form
@g_data = internal global <{ [8 x i16], [8 x i16] }> ...
GlobalOpt will incorrectly SROA it, not realising that the access to the first
element may overflow into the second. This fixes it by checking geps more
thoroughly.
I believe this makes the globalsra-partial.ll test case invalid as the %i value
could be out of bounds. I've re-purposed it as a negative test for this case.
Differential Revision: https://reviews.llvm.org/D49816
llvm-svn: 338192
Summary:
Moved Explicit Locals pass to last.
Made that pass obligatory.
Made it convert from register to stack based instructions, and removed the registers.
Fixes to related code that was expecting register based instructions.
Added the correct testing flag to all tests, depending on what the
format they were expecting so far.
Translated one test to stack format as example: reg-stackify-stack.ll
tested:
llvm-lit -v `find test -name WebAssembly`
unittests/MC/*
Reviewers: dschuff, sunfish
Subscribers: sbc100, jgravelle-google, eraman, aheejin, llvm-commits
Differential Revision: https://reviews.llvm.org/D49160
llvm-svn: 338164
Fixed the ASAN failure from before in r338148, so recommiting.
This patch enables the MachineOutliner by default in AArch64 under -Oz.
The MachineOutliner offers around a 4.5% improvement on the current -Oz code
size improvements.
We have done work into improving the debuggability of outlined code, so that
users of -Oz won't be surprised by the optimization. We have also been executing
the LLVM test suite and common external tests such as the SPEC suites
continuously with no issue. The outliner has a low compile-time overhead of
roughly 1%. At this point, the outliner would be a really good addition to the
-Oz pass pipeline!
llvm-svn: 338160
The tests with a constant sub operand were added with rL338143,
but the potential transform doesn't have that requirement, so
adding more tests with variable operands.
llvm-svn: 338150
This feature enables the fusion of such operations on Cortex A57 and Cortex
A72, as recommended in their Software Optimisation Guides, sections 4.14 and
4.11, respectively.
Differential revision: https://reviews.llvm.org/D49563
llvm-svn: 338147
Errors like the following are reported by:
https://urldefense.proofpoint.com/v2/url?u=http-3A__lab.llvm.org-3A8011_builders_llvm-2Dclang-2Dx86-5F64-2Dexpensive-2Dchecks-2Dwin_builds_11261&d=DwIBAg&c=5VD0RTtNlTh3ycd41b3MUw&r=DA8e1B5r073vIqRrFz7MRA&m=929oWPCf7Bf2qQnir4GBtowB8ZAlIRWsAdTfRkDaK-g&s=9k-wbEUVpUm474hhzsmAO29VXVvbxJPWD9RTgCD71fQ&e=
*** Bad machine code: Explicit definition marked as use ***
- function: cal_align1
- basic block: %bb.0 entry (0x47edd98)
- instruction: LDB $r3, $r2, 0
- operand 0: $r3
This is because RegState info was missing for ScratchReg inside
expandMEMCPY. This caused incomplete register usage information to
MachineInstr verifier which then would complain as there could be potential
code-gen issue if the complained MachineInstr is used in place where
register usage information matters even though the memcpy expanding is not
in such case as it happens at the last stage of IR optimization pipeline.
We should always specify those register usage information which compiler
couldn't deduct automatically whenever we add a hardware register manually.
Reported-by: Builder llvm-clang-x86_64-expensive-checks-win Build #11261
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Reviewed-by: Yonghong Song <yhs@fb.com>
llvm-svn: 338134
This patch enables the MachineOutliner by default in AArch64 under -Oz.
The MachineOutliner offers around a 4.5% improvement on the current -Oz code
size improvements.
We have done work into improving the debuggability of outlined code, so that
users of -Oz won't be surprised by the optimization. We have also been executing
the LLVM test suite and common external tests such as the SPEC suites
continuously with no issue. The outliner has a low compile-time overhead of
roughly 1%. At this point, the outliner would be a really good addition to the
-Oz pass pipeline!
llvm-svn: 338133
This is a follow-up suggested in D48970.
Alive proofs:
https://rise4fun.com/Alive/sII
We can eliminate an instruction in the usual select-of-constants
to bit hack transform by adjusting the add/sub with constant.
This is always a win.
There are more transforms that are likely wins, but they may need
target hooks in case some targets do not benefit.
This is another step towards making up for canonicalizing to
select-of-constants in rL331486.
llvm-svn: 338132
R600 can't handle immediates for BFE, these will be eliminated later.
Fixes powr/pow regressions n r600 since r334817
Differential Revision: https://reviews.llvm.org/D49641
llvm-svn: 338127
This patch adds support for various integer reduction operations:
SADDV signed add reduction to scalar
UADDV unsigned add reduction to scalar
SMAXV signed maximum reduction to scalar
SMINV signed minimum reduction to scalar
UMAXV unsigned maximum reduction to scalar
UMINV unsigned minimum reduction to scalar
ANDV logical AND reduction to scalar
ORV logical OR reduction to scalar
EORV logical EOR reduction to scalar
The reduction is predicated, e.g.
smaxv s0, p0, z1.s
performs a signed maximum reduction on active elements in z1,
and stores the (signed max value) result in s0.
llvm-svn: 338126
This patch adds support for various floating-point
reduction operations:
FADDA strictly-ordered add reduction, accumulating in scalar
FADDV recursive add reduction to scalar
FMAXV recursive max reduction to scalar
FMINV recursive min reduction to scalar
FMAXNMV recursive max number reduction to scalar
FMINNMV recursive min number reduction to scalar
The reduction is predicated, e.g.
fadda d0, p0, d0, z1.d
performs the add-reduction in strict order on active elements
in z1, accumulating into d0.
faddv d0, p0, z1.d
performs the add-reduction (not in strict order)
on active elements in z1, storing the result in d0.
llvm-svn: 338123
This patch adds support for transcendental acceleration
instructions 'FEXPA' (exponential accelerator) and 'FTSSEL'
(trigonometric select coefficient).
llvm-svn: 338121
The tests with constants show a missing optimization.
Analysis for adds is better than subs, so this can also
help with other transforms. And codegen is better with
adds for targets like x86 (destructive ops, no sub-from).
https://rise4fun.com/Alive/llK
llvm-svn: 338118
This is a follow-up for the patch rL335020. When we replace compares against
trunc with compares against wide IV, we can also replace signed predicates with
unsigned where it is legal.
Reviewed By: reames
Differential Revision: https://reviews.llvm.org/D48763
llvm-svn: 338115
This commit includes unit tests for D48828, which enhances InstSimplify to enable jump threading with a method whose return type is std::pair<int, bool> or std::pair<bool, int>.
I am going to commit the actual transformation later.
llvm-svn: 338107
Not sure why they were being explicitly excluded, but I believe all the math inside the if works. I changed the absolute value to be uint64_t instead of int64_t so INT64_MIN+1 wouldn't be signed wrap.
llvm-svn: 338101
Summary:
Some links were failing with "Global is external, but doesn't have
external or weak linkage!" in ThinLTO builds with debug
information. This happened when we elide the body of a global that is
referenced by debug info. This results in a declaration, which we
would then internalize - but declarations cannot be internal. This
change avoids the problem by not internalizing these declarations.
Fixes PR38046.
Reviewers: pcc, tejohnson
Subscribers: mehdi_amini, aprantl, hiraditya, JDevlieghere, steven_wu, dexonsmith, llvm-commits
Differential Revision: https://reviews.llvm.org/D49777
llvm-svn: 338100
Summary:
This is the pattern you get from the loop vectorizer for something like this
int16_t A[1024];
int16_t B[1024];
int32_t C[512];
void pmaddwd() {
for (int i = 0; i != 512; ++i)
C[i] = (A[2*i]*B[2*i]) + (A[2*i+1]*B[2*i+1]);
}
In this case we will have (add (mul (build_vector), (build_vector)), (mul (build_vector), (build_vector))). This is different than the pattern we currently match which has the build_vectors between an add and a single multiply. I'm not sure what C code would get you that pattern.
Reviewers: RKSimon, spatel, zvi
Reviewed By: zvi
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D49636
llvm-svn: 338097
If this happens the operands aren't updated and the existing node is returned. Make sure we pass this existing node up to the DAG combiner so that a proper replacement happens. Otherwise we get stuck in an infinite loop with an unoptimized node.
llvm-svn: 338090
Masked loads are calling DAG.getRoot rather than calling SelectionDAGBuilder::getRoot, which means the PendingLoads weren't emptied to update the root and create any needed TokenFactor. So it would be incorrect to call setRoot for the masked load.
This patch instead adds the masked load to PendingLoads so that the root doesn't get update until a store or scatter or something happens.. Alternatively, we could call SelectionDAGBuilder::getRoot before it, but that would create unnecessary serialization.
llvm-svn: 338085
Summary:
r262157 added ELF-specific logic to put a comdat on the __profc_*
globals created for available_externally functions. We should be able to
generalize that logic to all object file formats that support comdats,
i.e. everything other than MachO. This fixes duplicate symbol errors,
since on COFF, linkonce_odr doesn't make the symbol weak.
Fixes PR38251.
Reviewers: davidxl, xur
Subscribers: hiraditya, dmajor, llvm-commits, aheejin
Differential Revision: https://reviews.llvm.org/D49882
llvm-svn: 338082
The test failure was caused by the compiler not emitting a __debug_ranges section with DWARF 4 and
earlier when no ranges are needed. The test checks for the existence regardless.
llvm-svn: 338081
Properly demangle function parameter back-references.
Previously we treated lists of function parameters and template
parameters the same. There are some important differences with regards
to back-references, and some less important differences regarding which
characters can appear before or after the name.
The important differences are that with a given type T, all instances of
a function parameter list share the same global back-ref table.
Specifically, if X and Y are function pointers, then there are 3
entities in the declaration X func(Y) which all affect and are affected
by the master parameter back-ref table:
1) The parameter list of X's function type
2) the parameter list of func itself
3) The parameter list of Y's function type.
The previous code would create a back-reference table that was local to
a single parameter list, so it would not be shared across parameter
lists.
This was discovered when porting ms-back-references.test from clang's
mangling tests. All of these tests should now pass with the new changes.
In doing so, I split the function for parsing template and function
parameters into two separate functions. This makes the template
parameter list parsing code in particular very small and easy to
understand now.
Differential Revision: https://reviews.llvm.org/D49875
llvm-svn: 338075
Summary:
In non-integral address spaces, we're not allowed to introduce inttoptr/ptrtoint
intrinsics. Instead, we need to expand any pointer arithmetic as geps on the
base pointer. Luckily this is a common task for SCEV, so all we have to do here
is hook up the corresponding helper function and add test case.
Fixes PR38290
Reviewers: sanjoy
Differential Revision: https://reviews.llvm.org/D49832
llvm-svn: 338073
LowerDbgDeclare inserts a dbg.value before each use of an address
described by a dbg.declare. When inserting a dbg.value before a CallInst
use, however, it fails to append DW_OP_deref to the DIExpression.
The DW_OP_deref is needed to reflect the fact that a dbg.value describes
a source variable directly (as opposed to a dbg.declare, which relies on
pointer indirection).
This patch adds in the DW_OP_deref where needed. This results in the
correct values being shown during a debug session for a program compiled
with ASan and optimizations (see https://reviews.llvm.org/D49520). Note
that ConvertDebugDeclareToDebugValue is already correct -- no changes
there were needed.
One complication is that SelectionDAG is unable to distinguish between
direct and indirect frame-index (FRAMEIX) SDDbgValues. This patch also
fixes this long-standing issue in order to not regress integration tests
relying on the incorrect assumption that all frame-index SDDbgValues are
indirect. This is a necessary fix: the newly-added DW_OP_derefs cannot
be lowered properly otherwise. Basically the fix prevents a direct
SDDbgValue with DIExpression(DW_OP_deref) from being dereferenced twice
by a debugger. There were a handful of tests relying on this incorrect
"FRAMEIX => indirect" assumption which actually had incorrect
DW_AT_locations: these are all fixed up in this patch.
Testing:
- check-llvm, and an end-to-end test using lldb to debug an optimized
program.
- Existing unit tests for DIExpression::appendToStack fully cover the
new DIExpression::append utility.
- check-debuginfo (the debug info integration tests)
Differential Revision: https://reviews.llvm.org/D49454
llvm-svn: 338069
For function pointers, we would print something like
int __cdecl (*)(int)
We need to move the calling convention inside, and print
int (__cdecl *)(int)
This patch implements this change for regular function pointers as
well as member function pointers.
llvm-svn: 338068
This converts the arg qualifier mangling tests from
clang/CodeGenCXX/mangle-ms-arg-qualifiers.cpp to demangling tests.
Most tests already pass, so this patch doesn't come with any
functional change, just the addition of new tests. The few tests
that don't pass are left in with a FIXME label so that they don't
run but serve as documentation about what still doesn't work.
llvm-svn: 338067
None of these tests pass yet so they are commented out, but I'm
adding them with a FIXME label so that they don't get lost when
copying tests over from clang's mangling tests. Currently these
tests are all commented out.
llvm-svn: 338066
After this patch, we can now properly demangle pointers to member
functions. The calling convention is located in the wrong place,
but this will be fixed in a followup since it also affects non
member function pointers.
Differential Revision: https://reviews.llvm.org/D49639
llvm-svn: 338065
Even though gas doesn't document it, it has been supported there for
a very long time.
This produces the 32 bit relative virtual address (aka image relative
address) for a given symbol. ".rva foo" is essentially equal to
".long foo@imgrel".
Differential Revision: https://reviews.llvm.org/D49821
llvm-svn: 338063
Summary:
These two cases will trigger a dereference on a nullptr, since the
SymbolTable can be nonexistent for a given library, in addition to just
being empty.
Reviewers: alexshap
Reviewed By: alexshap
Subscribers: meikeb, kongyi, chh, jakehehrlich, llvm-commits, pirama
Differential Revision: https://reviews.llvm.org/D49534
llvm-svn: 338062
Scale the offset of VGPR spills by the wave size when it cannot fit in the
12-bit offset immediate field and so is added to the soffset SGPR. This
accounts for hardware swizzling of scratch memory.
Differential Revision: https://reviews.llvm.org/D49448
llvm-svn: 338060
- Save/restore only registers that are used.
This includes Callee saved registers and Caller saved registers
(arguments and temporaries) for integer and FP registers.
- If there is a call in the interrupt handler, save/restore all
Caller saved registers (arguments and temporaries) and all FP registers.
- Emit special return instructions depending on "interrupt"
attribute type.
Based on initial patch by Zhaoshi Zheng.
Reviewers: asb
Reviewed By: asb
Subscribers: rkruppe, the_o, MartinMosbeck, brucehoult, rbar, johnrusso, simoncook, sabuasal, niosHD, kito-cheng, shiva0217, zzheng, edward-jones, mgrang, rogfer01, llvm-commits
Differential Revision: https://reviews.llvm.org/D48411
llvm-svn: 338047
When fusing instructions A and B, we must add all predecessors of B as
predecessors of A to avoid instructions getting scheduling in between.
There is a special case involving ExitSU: Every other node must be
scheduled before it by design and we don't need to make this explicit in
the graph, however when fusing with a different node we need to schedule
every othere node before the fused node too and we need to make this
explicit now: This patch adds a dependency from the fused node to all
roots in the graph.
Differential Revision: https://reviews.llvm.org/D49830
llvm-svn: 338046
Summary:
A follow-up for D49266 / rL337166.
At least one of these cases is more canonical,
so we really do have to handle it.
https://godbolt.org/g/pkzP3Xhttps://rise4fun.com/Alive/pQyhZZ
We won't get to these cases with I1 being -1,
as that will be constant-folded to true or false.
I'm also not sure we actually hit the 'ule' case,
but i think the worst think that could happen is that being dead code.
Reviewers: spatel, craig.topper, RKSimon, javed.absar, efriedma
Reviewed By: spatel
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D49497
llvm-svn: 338044
Summary:
NVPTX target dos not use register-based frame information. Instead it
relies on the artificial local_depot that is used instead of the frame
and the data for variables must be emitted relatively to this
local_depot.
Reviewers: tra, jlebar, echristo
Subscribers: jholewinski, aprantl, JDevlieghere, llvm-commits
Differential Revision: https://reviews.llvm.org/D45963
llvm-svn: 338039
This fold is mentioned in PR38239:
https://bugs.llvm.org/show_bug.cgi?id=38239
The general case probably belongs in -reassociate, but given that we do
basic reassociation optimizations similar to this in instcombine already,
we might as well be consistent within instcombine and handle this pattern?
llvm-svn: 338038
Summary:
For NVPTX target the value of `DW_AT_frame_base` attribute must be set
to `DW_OP_call_frame_cfa`.
Reviewers: tra, jlebar, echristo
Subscribers: jholewinski, JDevlieghere, llvm-commits
Differential Revision: https://reviews.llvm.org/D45785
llvm-svn: 338036
Apparently, the issue with dsymutil update functionality on Windows was
that Windows doesn't like dsymutil renaming files that have open handles
to them. This disables the new accelerator test and updates the comment
in the other two test.
We should be able to enable the tests again once we updated the
implementation to use TempFile::keep() to keep the temporary files in
MachOUtils.
A big thank you to Jeremy Morse from Sony for figuring this out and
bringing it to my attention.
llvm-svn: 338030
- Some of the v8.3 pointer authentication instruction inhabit the Hint space
- These instructions can be assembled to hint instructions which act as NOP instructions prior to v8.3
- This patch permits using the hint instructions for all v8a targets
- Also, correct the RETA{A,B} instructions to match the instruction attributes of RET (set isTerminator and isBarrier)
Differential Revision: https://reviews.llvm.org/D49786
llvm-svn: 338029
Override getTypeForExtReturn so that functions returning
an i32 typed value have it sign extended on MIPS64.
Also provide patterns to get rid of unneeded sign extensions
for arithmetic instructions which implicitly sign extend
their results.
Differential Revision: https://reviews.llvm.org/D48374
llvm-svn: 338019
This reverts commit r337951.
While that kind of shared constant generally works fine in a MinGW
setting, it broke some cases of inline assembly that worked before:
$ cat const-asm.c
int MULH(int a, int b) {
int rt, dummy;
__asm__ (
"imull %3"
:"=d"(rt), "=a"(dummy)
:"a"(a), "rm"(b)
);
return rt;
}
int func(int a) {
return MULH(a, 1);
}
$ clang -target x86_64-win32-gnu -c const-asm.c -O2
const-asm.c:4:9: error: invalid variant '00000001'
"imull %3"
^
<inline asm>:1:15: note: instantiated into assembly here
imull __real@00000001(%rip)
^
A similar error is produced for i686 as well. The same test with a
target of x86_64-win32-msvc or i686-win32-msvc works fine.
llvm-svn: 338018
Update the dSYM bundle in place when swapping out the accelerator
tables. This should unbreak the windows bot that have been failing with
an access denied.
llvm-svn: 338014
This adds MC support for the crypto instructions that were made optional
extensions in Armv8.2-A (AArch64 only).
Differential Revision: https://reviews.llvm.org/D49370
llvm-svn: 338010
--strip-trailing-cr is a diffutils option which is also available on
BSD-licensed diff introduced in FreeBSD 11.2, however, it has a bug
comparing files mixing \r and \r\n. Use -b (POSIX) instead.
llvm-svn: 338008
I'm not sure if this was trying to avoid optimizing the new nodes further or what. Or maybe to prevent a cycle if something tried to reform the multiply? But I don't think its a reliable way to do that. If the user of the expanded multiply is visited by the DAGCombiner after this conversion happens, the DAGCombiner will check its operands, see that they haven't been visited by the DAGCombiner before and it will then add the first node to the worklist. This process will repeat until all the new nodes are visited.
So this seems like an unreliable prevention at best. So this patch just returns the new nodes like any other combine. If this starts causing problems we can try to add target specific nodes or something to more directly prevent optimizations.
Now that we handle the combine normally, we can combine any negates the mul expansion creates into their users since those will be visited now.
llvm-svn: 338007
This patch add support for emitting DWARF5 accelerator tables
(.debug_names) from dsymutil. Just as with the Apple style accelerator
tables, it's possible to update existing dSYMs. This patch includes a
test that show how you can convert back and forth between the two types.
If no kind of table is specified, dsymutil will default to generating
Apple-style accelerator tables whenever it finds those in its input. The
same is true when there are no accelerator tables at all. Finally, in
the remaining case, where there's at least one DWARF v5 table and no
Apple ones, the output will contains a DWARF accelerator tables
(.debug_names).
Differential revision: https://reviews.llvm.org/D49137
llvm-svn: 337980
Some BPF JIT backends would want to optimize memcpy in their own
architecture specific way.
However, at the moment, there is no way for JIT backends to see memcpy
semantics in a reliable way. This is due to LLVM BPF backend is expanding
memcpy into load/store sequences and could possibly schedule them apart from
each other further. So, BPF JIT backends inside kernel can't reliably
recognize memcpy semantics by peephole BPF sequence.
This patch introduce new intrinsic expand infrastructure to memcpy.
To get stable in-order load/store sequence from memcpy, we first lower
memcpy into BPF::MEMCPY node which then expanded into in-order load/store
sequences in expandPostRAPseudo pass which will happen after instruction
scheduling. By this way, kernel JIT backends could reliably recognize
memcpy through scanning BPF sequence.
This new memcpy expand infrastructure is gated by a new option:
-bpf-expand-memcpy-in-order
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
llvm-svn: 337977
Reuse the handling for llvm.used, and don't transform such globals.
Fixes a failure on the asan buildbot caused by my previous commit.
llvm-svn: 337973
If the DAGCombiner's rotate matching was working as expected,
I don't think we'd see any test diffs here.
This sidesteps the issue of custom lowering for rotates raised in PR38243:
https://bugs.llvm.org/show_bug.cgi?id=38243
...by only dealing with legal operations.
llvm-svn: 337966
In some cases LSV sees (load/store _ (select _ <pointer expression>
<pointer expression>)) patterns in input IR, often due to sinking and
other forms of CFG simplification, sometimes interspersed with
bitcasts and all-constant-indices GEPs. With this
patch`areConsecutivePointers` method would attempt to handle select
instructions. This leads to an increased number of successful
vectorizations.
Technically, select instructions could appear in index arithmetic as
well, however, we don't see those in our test suites / benchmarks.
Also, there is a lot more freedom in IR shapes computing integral
indices in general than in what's common in pointer computations, and
it appears that it's quite unreliable to do anything short of making
select instructions first class citizens of Scalar Evolution, which
for the purposes of this patch is most definitely an overkill.
Reviewed By: rampitec
Differential Revision: https://reviews.llvm.org/D49428
llvm-svn: 337965
Instead of depending on implicit padding from the structure layout code,
use a packed struct and emit the padding explicitly.
Differential Revision: https://reviews.llvm.org/D49710
llvm-svn: 337961
GNU binutils tools have no problems with this kind of shared constants,
provided that we actually hook it up completely in AsmPrinter and
produce a global symbol.
This effectively reverts SVN r335918 by hooking the rest of it up
properly.
This feature was implemented originally in SVN r213006, with no reason
for why it can't be used for MinGW other than the fact that GCC doesn't
do it while MSVC does.
Differential Revision: https://reviews.llvm.org/D49646
llvm-svn: 337951
In SVN r334523, the first half of comdat constant pool handling was
hoisted from X86WindowsTargetObjectFile (which despite the name only
was used for msvc targets) into the arch independent
TargetLoweringObjectFileCOFF, but the other half of the handling was
left behind in X86AsmPrinter::GetCPISymbol.
With only half of the handling in place, inconsistent comdat
sections/symbols are created, causing issues with both GNU binutils
(avoided for X86 in SVN r335918) and with the MS linker, which
would complain like this:
fatal error LNK1143: invalid or corrupt file: no symbol for COMDAT section 0x4
Differential Revision: https://reviews.llvm.org/D49644
llvm-svn: 337950
Saves materializing the immediate for the "ands".
Corresponding patterns exist for lsrs+lsls, but that seems less common
in practice.
Now implemented as a DAGCombine.
Differential Revision: https://reviews.llvm.org/D49585
llvm-svn: 337945
as well as sext(C + x + ...) -> (D + sext(C-D + x + ...))<nuw><nsw>
similar to the equivalent transformation for zext's
if the top level addition in (D + (C-D + x * n)) could be proven to
not wrap, where the choice of D also maximizes the number of trailing
zeroes of (C-D + x * n), ensuring homogeneous behaviour of the
transformation and better canonicalization of such AddRec's
(indeed, there are 2^(2w) different expressions in `B1 + ext(B2 + Y)` form for
the same Y, but only 2^(2w - k) different expressions in the resulting `B3 +
ext((B4 * 2^k) + Y)` form, where w is the bit width of the integral type)
This patch generalizes sext(C1 + C2*X) --> sext(C1) + sext(C2*X) and
sext{C1,+,C2} --> sext(C1) + sext{0,+,C2} transformations added in
r209568 relaxing the requirements the following way:
1. C2 doesn't have to be a power of 2, it's enough if it's divisible by 2
a sufficient number of times;
2. C1 doesn't have to be less than C2, instead of extracting the entire
C1 we can split it into 2 terms: (00...0XXX + YY...Y000), keep the
second one that may cause wrapping within the extension operator, and
move the first one that doesn't affect wrapping out of the extension
operator, enabling further simplifications;
3. C1 and C2 don't have to be positive, splitting C1 like shown above
produces a sum that is guaranteed to not wrap, signed or unsigned;
4. in AddExpr case there could be more than 2 terms, and in case of
AddExpr the 2nd and following terms and in case of AddRecExpr the
Step component don't have to be in the C2*X form or constant
(respectively), they just need to have enough trailing zeros,
which in turn could be guaranteed by means other than arithmetics,
e.g. by a pointer alignment;
5. the extension operator doesn't have to be a sext, the same
transformation works and profitable for zext's as well.
Apparently, optimizations like SLPVectorizer currently fail to
vectorize even rather trivial cases like the following:
double bar(double *a, unsigned n) {
double x = 0.0;
double y = 0.0;
for (unsigned i = 0; i < n; i += 2) {
x += a[i];
y += a[i + 1];
}
return x * y;
}
If compiled with `clang -std=c11 -Wpedantic -Wall -O3 main.c -S -o - -emit-llvm`
(!{!"clang version 7.0.0 (trunk 337339) (llvm/trunk 337344)"})
it produces scalar code with the loop not unrolled with the unsigned `n` and
`i` (like shown above), but vectorized and unrolled loop with signed `n` and
`i`. With the changes made in this commit the unsigned version will be
vectorized (though not unrolled for unclear reasons).
How it all works:
Let say we have an AddExpr that looks like (C + x + y + ...), where C
is a constant and x, y, ... are arbitrary SCEVs. Let's compute the
minimum number of trailing zeroes guaranteed of that sum w/o the
constant term: (x + y + ...). If, for example, those terms look like
follows:
i
XXXX...X000
YYYY...YY00
...
ZZZZ...0000
then the rightmost non-guaranteed-zero bit (a potential one at i-th
position above) can change the bits of the sum to the left (and at
i-th position itself), but it can not possibly change the bits to the
right. So we can compute the number of trailing zeroes by taking a
minimum between the numbers of trailing zeroes of the terms.
Now let's say that our original sum with the constant is effectively
just C + X, where X = x + y + .... Let's also say that we've got 2
guaranteed trailing zeros for X:
j
CCCC...CCCC
XXXX...XX00 // this is X = (x + y + ...)
Any bit of C to the left of j may in the end cause the C + X sum to
wrap, but the rightmost 2 bits of C (at positions j and j - 1) do not
affect wrapping in any way. If the upper bits cause a wrap, it will be
a wrap regardless of the values of the 2 least significant bits of C.
If the upper bits do not cause a wrap, it won't be a wrap regardless
of the values of the 2 bits on the right (again).
So let's split C to 2 constants like follows:
0000...00CC = D
CCCC...CC00 = (C - D)
and represent the whole sum as D + (C - D + X). The second term of
this new sum looks like this:
CCCC...CC00
XXXX...XX00
----------- // let's add them up
YYYY...YY00
The sum above (let's call it Y)) may or may not wrap, we don't know,
so we need to keep it under a sext/zext. Adding D to that sum though
will never wrap, signed or unsigned, if performed on the original bit
width or the extended one, because all that that final add does is
setting the 2 least significant bits of Y to the bits of D:
YYYY...YY00 = Y
0000...00CC = D
----------- <nuw><nsw>
YYYY...YYCC
Which means we can safely move that D out of the sext or zext and
claim that the top-level sum neither sign wraps nor unsigned wraps.
Let's run an example, let's say we're working in i8's and the original
expression (zext's or sext's operand) is 21 + 12x + 8y. So it goes
like this:
0001 0101 // 21
XXXX XX00 // 12x
YYYY Y000 // 8y
0001 0101 // 21
ZZZZ ZZ00 // 12x + 8y
0000 0001 // D
0001 0100 // 21 - D = 20
ZZZZ ZZ00 // 12x + 8y
0000 0001 // D
WWWW WW00 // 21 - D + 12x + 8y = 20 + 12x + 8y
therefore zext(21 + 12x + 8y) = (1 + zext(20 + 12x + 8y))<nuw><nsw>
This approach could be improved if we move away from using trailing
zeroes and use KnownBits instead. For instance, with KnownBits we could
have the following picture:
i
10 1110...0011 // this is C
XX X1XX...XX00 // this is X = (x + y + ...)
Notice that some of the bits of X are known ones, also notice that
known bits of X are interspersed with unknown bits and not grouped on
the rigth or left.
We can see at the position i that C(i) and X(i) are both known ones,
therefore the (i + 1)th carry bit is guaranteed to be 1 regardless of
the bits of C to the right of i. For instance, the C(i - 1) bit only
affects the bits of the sum at positions i - 1 and i, and does not
influence if the sum is going to wrap or not. Therefore we could split
the constant C the following way:
i
00 0010...0011 = D
10 1100...0000 = (C - D)
Let's compute the KnownBits of (C - D) + X:
XX1 1 = carry bit, blanks stand for known zeroes
10 1100...0000 = (C - D)
XX X1XX...XX00 = X
--- -----------
XX X0XX...XX00
Will this add wrap or not essentially depends on bits of X. Adding D
to this sum, however, is guaranteed to not to wrap:
0 X
00 0010...0011 = D
sX X0XX...XX00 = (C - D) + X
--- -----------
sX XXXX XX11
As could be seen above, adding D preserves the sign bit of (C - D) +
X, if any, and has a guaranteed 0 carry out, as expected.
The more bits of (C - D) we constrain, the better the transformations
introduced here canonicalize expressions as it leaves less freedom to
what values the constant part of ((C - D) + x + y + ...) can take.
Reviewed By: mzolotukhin, efriedma
Differential Revision: https://reviews.llvm.org/D48853
llvm-svn: 337943
When VectorLegalizer::LegalizeOp creates a new SDValue after iterating
over its arguments, we need to refer to the same result number of the
new node that the original value used.
Reviewed by: cameron.mcinally
Differential Revision: https://reviews.llvm.org/D49805
llvm-svn: 337939
Currently ComputeNumSignBits does early exit while processing some
of the operations (add, sub, mul, and select). This prevents the
function from using AssumptionCacheTracker if passed.
Differential Revision: https://reviews.llvm.org/D49759
llvm-svn: 337936
For example v = <2 x i1> is represented as bbbbaaaa in a predicate register,
where b = v[1], a = v[0]. Extracting v[1] is equivalent to extracting bit 4
from the predicate register.
llvm-svn: 337934
Add support for lowering pointer arguments.
Changing type from pointer to integer is already done in
MipsTargetLowering::getRegisterTypeForCallingConv.
Patch by Petar Avramovic.
Differential Revision: https://reviews.llvm.org/D49419
llvm-svn: 337912
r337828 resolves a PredicateInfo issue with unnamed types.
Original message:
This patch updates IPSCCP to use PredicateInfo to propagate
facts to true branches predicated by EQ and to false branches
predicated by NE.
As a follow up, we should be able to extend it to also propagate additional
facts about nonnull.
Reviewers: davide, mssimpso, dberlin, efriedma
Reviewed By: davide, dberlin
llvm-svn: 337904
Add support for inline assembly with output operand that do not
naturally go in the register class it is constrained to (eg. double in a
32-bit GPR as in the PR).
llvm-svn: 337903
Helpers are available to make this option file format independant. This
patch adds the feature for Wasm file format. It doesn't change the
behavior of the other file format handling.
Differential Revision: https://reviews.llvm.org/D49545
llvm-svn: 337896
The target independent AsmParser doesn't recognise .hword, .word, .dword
which are required for Mips. Currently MipsAsmParser recognises these
through dispatch to MipsAsmParser::parseDataDirective. This contains
equivalent logic to AsmParser::parseDirectiveValue. This patch allows
reuse of AsmParser::parseDirectiveValue by making use of
addAliasForDirective to support .hword, .word and .dword.
Original patch provided by Alex Bradbury at D47001 was modified to fix
handling of microMIPS symbols. The `AsmParser::parseDirectiveValue`
calls either `EmitIntValue` or `EmitValue`. In this patch we override
`EmitIntValue` in the `MipsELFStreamer` to clear a pending set of
microMIPS symbols.
Differential revision: https://reviews.llvm.org/D49539
llvm-svn: 337893
against v1.2 BCBS attacks directly.
Attacks using spectre v1.2 (a subset of BCBS) are described in the paper
here:
https://people.csail.mit.edu/vlk/spectre11.pdf
The core idea is to speculatively store over the address in a vtable,
jumptable, or other target of indirect control flow that will be
subsequently loaded. Speculative execution after such a store can
forward the stored value to subsequent loads, and if called or jumped
to, the speculative execution will be steered to this potentially
attacker controlled address.
Up until now, this could be mitigated by enableing retpolines. However,
that is a relatively expensive technique to mitigate this particular
flavor. Especially because in most cases SLH will have already mitigated
this. To fully mitigate this with SLH, we need to do two core things:
1) Unfold loads from calls and jumps, allowing the loads to be post-load
hardened.
2) Force hardening of incoming registers even if we didn't end up
needing to harden the load itself.
The reason we need to do these two things is because hardening calls and
jumps from this particular variant is importantly different from
hardening against leak of secret data. Because the "bad" data here isn't
a secret, but in fact speculatively stored by the attacker, it may be
loaded from any address, regardless of whether it is read-only memory,
mapped memory, or a "hardened" address. The only 100% effective way to
harden these instructions is to harden the their operand itself. But to
the extent possible, we'd like to take advantage of all the other
hardening going on, we just need a fallback in case none of that
happened to cover the particular input to the control transfer
instruction.
For users of SLH, currently they are paing 2% to 6% performance overhead
for retpolines, but this mechanism is expected to be substantially
cheaper. However, it is worth reminding folks that this does not
mitigate all of the things retpolines do -- most notably, variant #2 is
not in *any way* mitigated by this technique. So users of SLH may still
want to enable retpolines, and the implementation is carefuly designed to
gracefully leverage retpolines to avoid the need for further hardening
here when they are enabled.
Differential Revision: https://reviews.llvm.org/D49663
llvm-svn: 337878
Summary: truncateToMinimalBitWidths() doesn't handle all Instructions and the worst case is compiler crash via llvm_unreachable(). Fix is to add a case to handle PHINode and changed the worst case to NO-OP (from compiler crash).
Reviewers: sbaranga, mssimpso, hsaito
Reviewed By: hsaito
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D49461
llvm-svn: 337861
if the top level addition in (D + (C-D + x + ...)) could be proven to
not wrap, where the choice of D also maximizes the number of trailing
zeroes of (C-D + x + ...), ensuring homogeneous behaviour of the
transformation and better canonicalization of such expressions.
This enables better canonicalization of expressions like
1 + zext(5 + 20 * %x + 24 * %y) and
zext(6 + 20 * %x + 24 * %y)
which get both transformed to
2 + zext(4 + 20 * %x + 24 * %y)
This pattern is common in address arithmetics and the transformation
makes it easier for passes like LoadStoreVectorizer to prove that 2 or
more memory accesses are consecutive and optimize (vectorize) them.
Reviewed By: mzolotukhin
Differential Revision: https://reviews.llvm.org/D48853
llvm-svn: 337859
We generated a subtract for the power of 2 minus one then negated the result. The negate can be optimized away by swapping the subtract operands, but DAG combine doesn't know how to do that and we don't add any of the new nodes to the worklist anyway.
This patch makes use explicitly emit the swapped subtract.
llvm-svn: 337858
Use a left shift and 2 subtracts like we do for 30. Move this out from behind the slow lea check since it doesn't even use an LEA.
Use this for multiply by 14 as well.
llvm-svn: 337856
Summary:
Currently all wasm atomic memory access instructions are sequentially
consistent, so even if LLVM IR specifies weaker orderings than that, we
should upgrade them to sequential ordering and treat them in the same
way.
Reviewers: dschuff
Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits
Differential Revision: https://reviews.llvm.org/D49194
llvm-svn: 337854
Mul by constant can expand to a sequence that ends with a negate. If the next instruction is an add or sub we might be able to fold the negate away.
We currently fail to do this because we explicitly don't add anything to the DAG combine worklist when we expand multiplies. This is primarily to keep the multipy from being reformed, but we should consider adding the users to worklist.
llvm-svn: 337843
This patch uses SCEV to avoid inserting some bounds checks when they are not needed. This slightly improves the performance of code compiled with the bounds check sanitizer.
Differential Revision: https://reviews.llvm.org/D49602
llvm-svn: 337830
This is a workaround and it would be better to fix this generally, but
doing it generally is quite tricky. See D48541 and PR38117.
Doing it in PredicateInfo directly allows us to use the type address to
differentiate different unnamed types, because neither the created
declarations nor the ssa_copy calls should be visible after
PredicateInfo got destroyed.
Reviewers: efriedma, davide
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D49126
llvm-svn: 337828
For the final DTPREL addition, rather than a lui/daddiu/daddu triple,
LLVM was erronously emitting a daddiu/daddiu pair, treating the %dtprel_hi
as if it were a %dtprel_lo, since Mips::Hi expands unshifted for Sym64.
Instead, use a new TlsHi node and, although unnecessary due to the exact
structure of the nodes emitted, use TlsHi for local exec too to prevent
future bugs. Also garbage-collect the unused TprelLo and TlsGd nodes,
and TprelHi since its functionality is provided by the new common TlsHi node.
Patch by James Clarke.
Differential revision: https://reviews.llvm.org/D49259
llvm-svn: 337827
ARM Stage 2 builders have been suspiciously broken since the pass was
committed. Disabling to hopefully fix the bots and give me time to
debug.
llvm-svn: 337821
This test was already checking microscopic behavior of tail call under
specific conditions. This just makes the CHECK lines much more
consistent, clear, and easily updated when intentional changes are made.
I've also switched the test to consistently name the entry block and to
order the helper declarations and comments for specific tests in the
more usual locations.
llvm-svn: 337806
There are two forms for label debug information in DWARF format.
1. Labels in a non-inlined function:
DW_TAG_label
DW_AT_name
DW_AT_decl_file
DW_AT_decl_line
DW_AT_low_pc
2. Labels in an inlined function:
DW_TAG_label
DW_AT_abstract_origin
DW_AT_low_pc
We will collect label information from DBG_LABEL. Before every DBG_LABEL,
we will generate a temporary symbol to denote the location of the label.
The symbol could be used to get DW_AT_low_pc afterwards. So, we create a
mapping between 'inlined label' and DBG_LABEL MachineInstr in DebugHandlerBase.
The DBG_LABEL in the mapping is used to query the symbol before it.
The AbstractLabels in DwarfCompileUnit is used to process labels in inlined
functions.
We also keep a mapping between scope and labels in DwarfFile to help to
generate correct tree structure of DIEs.
Differential Revision: https://reviews.llvm.org/D45556
Patch by Hsiangkai Wang.
llvm-svn: 337799
Add a -debugify-export option to opt. This exports per-pass `debugify`
loss statistics to a file in CSV format.
For some interesting numbers on debug value loss during an -O2 build
of the sqlite3 amalgamation, see the review thread.
Differential Revision: https://reviews.llvm.org/D49003
llvm-svn: 337787
The intent is to use it for location list tables as well. Change is almost NFC with the exception
of the spelling of some strings used during dumping (all lowercase now).
Reviewer: JDevlieghere
Differential Revision: https://reviews.llvm.org/D49500
llvm-svn: 337763
Summary:
Similar to what lld already does for dllimport symbols which are
prefaced with __imp_ (see lld patch r240620), strip off the __imp_
prefix in LTO. Otherwise we can get 2 separate GlobalResolution for
a single symbol, the dllimport declaration, and the definition, which
leads to incorrect LTO handling.
Fixes PR38105.
Reviewers: pcc
Subscribers: mehdi_amini, inglorion, steven_wu, dexonsmith, llvm-commits
Differential Revision: https://reviews.llvm.org/D49138
llvm-svn: 337762
Since SVN r335286, the .xdata sections are produced without an attached
symbol, which requires using a different syntax when printing assembly
output.
Instead of the usual syntax of '.section <name>,"dr",discard,<symbol>',
use '.section <name>,"dr"' + '.linkonce discard' (which is what GCC
uses for all assembly output).
This fixes PR38254.
Differential Revision: https://reviews.llvm.org/D49651
llvm-svn: 337756
This matches the structure used on X86 and ARM. This requires
a little bit of duplication of the parts that are equal in both
AArch64 COFF variants though.
Before SVN r335286, these classes didn't add anything that MCAsmInfoCOFF
didn't, but now they do.
This makes AArch64 match X86 in how comdat is used for float constants
for MinGW.
Differential Revision: https://reviews.llvm.org/D49637
llvm-svn: 337755
Summary:
Without this change, the WholeProgramDevirt pass, which requires the
TargetLibraryInfo, will construct one from the default triple.
Fixes PR38139.
Reviewers: pcc
Subscribers: mehdi_amini, inglorion, steven_wu, dexonsmith, llvm-commits
Differential Revision: https://reviews.llvm.org/D49278
llvm-svn: 337750
Summary:
Check if the parent basic block and caller exists
before calling CS.getCaller when constant folding
strip.invariant.group instrinsic.
This avoids a crash when the function containing the intrinsic
is being inlined. The instruction is checked for any simplifiction
but has not yet been added to a basic block.
Reviewers: Prazek, rsmith, efriedma
Reviewed By: efriedma
Subscribers: eraman, llvm-commits
Differential Revision: https://reviews.llvm.org/D49690
llvm-svn: 337742
Don't try to generate large PIC code for non-ELF targets. Neither COFF
nor MachO have relocations for large position independent code, and
users have been using "large PIC" code models to JIT 64-bit code for a
while now. With this change, if they are generating ELF code, their
JITed code will truly be PIC, but if they target MachO or COFF, it will
contain 64-bit immediates that directly reference external symbols. For
a JIT, that's perfectly fine.
llvm-svn: 337740
Dynamic section holds a table, so the sh_entsize might be set. As the
dynamic section entry size never changes, we can default it to the size
of a dynamic entry.
Differential Revision: https://reviews.llvm.org/D49619
llvm-svn: 337725
Arm specific codegen prepare is implemented to perform type promotion
on icmp operands, which can enable the removal of uxtb and uxth
(unsigned extend) instructions. This is possible because performing
type promotion before ISel alleviates this duty from the DAG builder
which has to perform legalisation, but has a limited view on data
ranges.
The pass visits any instruction operand of an icmp and creates a
worklist to traverse the use-def tree to determine whether the values
can simply be promoted. Our concern is values in the registers
overflowing the narrow (i8, i16) data range, so instructions marked
with nuw can be promoted easily. For add and sub instructions, we are
able to use the parallel dsp instructions to operate on scalar data
types and avoid overflowing bits. Underflowing adds and subs are also
permitted when the result is only used by an unsigned icmp.
Differential Revision: https://reviews.llvm.org/D48832
llvm-svn: 337687
In ConstructSSAForLoadSet if an available value is actually the load that we're
doing SSA construction to eliminate, then we can omit it as SSAUpdate will add
in the value for the phi that will be replacing it anyway. This can result in
simpler IR which can allow further optimisation.
Differential Revision: https://reviews.llvm.org/D44160
llvm-svn: 337686
Bug fix for PR37445. The underlying problem and its fix are similar to PR37808.
The bug lies in MemorySSAUpdater::getPreviousDefRecursive(), where PhiOps is
computed before the call to tryRemoveTrivialPhi() and it ends up being out of
date, pointing to stale data. We have now turned each of the PhiOps into a
TrackingVH<MemoryAccess>.
Differential Revision: https://reviews.llvm.org/D49425
llvm-svn: 337680
Summary:
Pretty mechanical follow-up for D49196.
As microarchitecture.pdf notes, "20 AMD Ryzen pipeline",
"20.8 Register renaming and out-of-order schedulers":
The integer register file has 168 physical registers of 64 bits each.
The floating point register file has 160 registers of 128 bits each.
"20.14 Partial register access":
The processor always keeps the different parts of an integer register together.
...
An instruction that writes to part of a register will therefore have a false dependence
on any previous write to the same register or any part of it.
Reviewers: andreadb, courbet, RKSimon, craig.topper, GGanesh
Reviewed By: GGanesh
Subscribers: gbedwell, llvm-commits
Differential Revision: https://reviews.llvm.org/D49393
llvm-svn: 337676
Bug fix for PR36787. When reasoning if it's safe to hoist a load we
want to make sure that the defining memory access dominates the new
insertion point of the hoisted instruction. safeToHoistLdSt calls
firstInBB(InsertionPoint,DefiningAccess) which returns false if
InsertionPoint == DefiningAccess, and therefore it falsely thinks
it's safe to hoist.
Differential Revision: https://reviews.llvm.org/D49555
llvm-svn: 337674
a call, and then again as a return.
Also added a comment to try and explain better why we would be doing
what we're doing when hardening the (non-call) returns.
llvm-svn: 337673
This specifically covers different ways of making indirect calls and
jumps. There are some bugs in SLH that I will be fixing in subsequent
patches where the diff in the generated instructions makes the bug fix
much more clear, so just checking in a baseline of this test to start.
I'm also going to be adding direct mitigation for variant 1.2 which this
file very specifically tests in the various forms it can arise on x86.
Again, the diff to the generated instructions should make the change for
that much more clear, so having the test as a baseline seems useful.
llvm-svn: 337672
This seems to be a net improvement. There's still an issue under avx512f where we have a 512-bit vpaddd, but not vpmaddwd so we end up doing two 256-bit vpmaddwds and inserting the results before a 512-bit vpaddd. It might be better to do two 512-bits paddds with zeros in the upper half. Same number of instructions, but breaks a dependency.
llvm-svn: 337656
This is a follow-up to the rL335185. Those commit adds some WrapperPat
patterns for microMIPS target. But declaration of the WrapperPat class
is under the NotInMicroMips predicate and microMIPS patterns cannot be
selected because predicate (Subtarget->inMicroMipsMode()) &&
(!Subtarget->inMicroMipsMode()) is always false.
This change move out the WrapperPat class declaration from the
NotInMicroMips predicate and enables microMIPS WrapperPat patterns.
Differential revision: https://reviews.llvm.org/D49533
llvm-svn: 337646
This reapplies commit r337489 reverted by r337541
Additionally, this commit contains a speculative fix to the issue reported in r337541
(the report does not contain an actionable reproducer, just a stack trace)
llvm-svn: 337606
A DAG-NOT-DAG is a CHECK-DAG group, X, followed by a CHECK-NOT group,
N, followed by a CHECK-DAG group, Y. Let y be the initial directive
of Y. This patch makes the following changes to the behavior:
1. Directives in N can no longer match within part of Y's match
range just because y happens not to be the earliest match from
Y. Specifically, this patch withdraws N's search range end
from y's match range start to Y's match range start.
2. y can no longer match within X's match range, where a y match
produced a reordering complaint, which is thus no longer
possible. Specifically, this patch withdraws y's search range
start from X's permitted range start to X's match range end,
which was already the search range start for other members of
Y.
Both of these changes can only increase the number of test passes: #1
constrains the ability of CHECK-NOTs to match, and #2 expands the
ability of CHECK-DAGs to match without complaints.
These changes are based on discussions at:
<http://lists.llvm.org/pipermail/llvm-dev/2018-May/123550.html>
<https://reviews.llvm.org/D47106>
which conclude that:
1. These changes simplify the FileCheck conceptual model. First,
it makes search ranges for DAG-NOT-DAG more consistent with
other cases. Second, it was confusing that y was treated
differently from the rest of Y.
2. These changes add theoretical use cases for DAG-NOT-DAG that
had no obvious means to be expressed otherwise. We can justify
the first half of this assertion with the observation that
these changes can only increase the number of test passes.
3. Reordering detection for DAG-NOT-DAG had no obvious real
benefit.
We don't have evidence from real uses cases to help us debate
conclusions #2 and #3, but #1 at least seems intuitive.
Reviewed By: probinson
Differential Revision: https://reviews.llvm.org/D48986
llvm-svn: 337605
Summary:
Add basic support for --rename-section=old=new to llvm-objcopy.
A full replacement for GNU objcopy requires also modifying flags (i.e. --rename-section=old=new,flag1,flag2); I'd like to keep that in a separate change to keep this simple.
Reviewers: jakehehrlich, alexshap
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D49576
llvm-svn: 337604
Sanjay Patel