constant-offsets of a common base using the generic GEP-walking logic
I added for computing pointer differences in the same situation.
llvm-svn: 153419
inbounds GEPs. This isn't really necessary for simplifying pointer
differences, but I'm planning to re-use the same code to simplify
pointer comparisons where it is necessary. Since real code almost
exclusively uses inbounds GEPs, it doesn't seem worth it to support the
extra complexity of turning it on and off. If anyone would like that
back, feel free to shout. Note that instcombine will still catch any of
these patterns.
llvm-svn: 153418
aggressively. There are lots of dire warnings about this being expensive
that seem to predate switching to the TrackingVH-based value remapper
that is automatically updated on RAUW. This makes it easy to not just
prune single-entry PHIs, but to fully simplify PHIs, and to recursively
simplify the newly inlined code to propagate PHINode simplifications.
This introduces a bit of a thorny problem though. We may end up
simplifying a branch condition to a constant when we fold PHINodes, and
we would like to nuke any dead blocks resulting from this so that time
isn't wasted continually analyzing them, but this isn't easy. Deleting
basic blocks *after* they are fully cloned and mapped into the new
function currently requires manually updating the value map. The last
piece of the simplification-during-inlining puzzle will require either
switching to WeakVH mappings or some other piece of refactoring. I've
left a FIXME in the testcase about this.
llvm-svn: 153410
* Removed test/lib/llvm.exp - it is no longer needed
* Deleted the dg.exp reading code from test/lit.cfg. There are no dg.exp files
left in the test suite so this code is no longer required. test/lit.cfg is
now much shorter and clearer
* Removed a lot of duplicate code in lit.local.cfg files that need access to
the root configuration, by adding a "root" attribute to the TestingConfig
object. This attribute is dynamically computed to provide the same
information as was previously provided by the custom getRoot functions.
* Documented the config.root attribute in docs/CommandGuide/lit.pod
llvm-svn: 153408
to instead rely on much more generic and powerful instruction
simplification in the function cloner (and thus inliner).
This teaches the pruning function cloner to use instsimplify rather than
just the constant folder to fold values during cloning. This can
simplify a large number of things that constant folding alone cannot
begin to touch. For example, it will realize that 'or' and 'and'
instructions with certain constant operands actually become constants
regardless of what their other operand is. It also can thread back
through the caller to perform simplifications that are only possible by
looking up a few levels. In particular, GEPs and pointer testing tend to
fold much more heavily with this change.
This should (in some cases) have a positive impact on compile times with
optimizations on because the inliner itself will simply avoid cloning
a great deal of code. It already attempted to prune proven-dead code,
but now it will be use the stronger simplifications to prove more code
dead.
llvm-svn: 153403
regressed seriously here, we are no longer removing allocas during
inline cleanup. This appears to be because of lifetime markers "using"
them. =/ I'll look into this shortly.
llvm-svn: 153394
The PPC64 SVR4 ABI requires integer stack arguments, and thus the var. args., that
are smaller than 64 bits be zero extended to 64 bits.
llvm-svn: 153373
same basic block, and it's not safe to insert code in the successor
blocks if the edges are critical edges. Splitting those edges is
possible, but undesirable, especially on the unwind side. Instead,
make the bottom-up code motion to consider invokes to be part of
their successor blocks, rather than part of their parent blocks, so
that it doesn't push code past them and onto the edges. This fixes
PR12307.
llvm-svn: 153343
(and hopefully on Windows). The bots have been down most of the day
because of this, and it's not clear to me what all will be required to
fix it.
The commits started with r153205, then r153207, r153208, and r153221.
The first commit seems to be the real culprit, but I couldn't revert
a smaller number of patches.
When resubmitting, r153207 and r153208 should be folded into r153205,
they were simple build fixes.
llvm-svn: 153241
execution-time regression for nsieve-bits on the ARMv7 -O0 -g nightly tester.
This may also improve compile-time on architectures that would otherwise
generate a libcall for urem (e.g., ARM) or fall back to the DAG selector.
rdar://10810716
llvm-svn: 153230
These changes allow us to compile big endian from the command line for 32 bit
Mips targets. This patch will result in code and data actually being produced
in the correct endianess.
llvm-svn: 153153
Do not call SplitBlockPredecessors on a loop preheader when one of the
predecessors is an indirectbr. Otherwise, you will hit this assert:
!isa<IndirectBrInst>(Preds[i]->getTerminator()) && "Cannot split an edge from an IndirectBrInst"
llvm-svn: 153134
instead of skipping the current loop.
My prior fix was incomplete because of an overzealous compile-time optimization:
Better fix for: <rdar://problem/11049788> Segmentation fault: 11 in LoopStrengthReduce
llvm-svn: 153131
This results in things such as
vmovups 16(%rdi), %xmm0
vinsertf128 $1, %xmm0, %ymm0, %ymm0
to be combined to
vinsertf128 $1, 16(%rdi), %ymm0, %ymm0
rdar://11076953
llvm-svn: 153092
i128). In that case, we may not be able to print out the MCExpr as an
expression. For instance, we could have an MCExpr like this:
0xBEEF0000BEEF0000 | (0xBEEF0000BEEF0000 << 64)
The MCExpr printer handles sizes up to 64-bits, but this expression would
require 128-bits. In this situation, try to evaluate the constant expression and
emit that as the value into 64-bit chunks.
<rdar://problem/11070338>
llvm-svn: 153081
X86InstrCompiler.td.
It also adds –mcpu-generic to the legalize-shift-64.ll test so the test
will pass if run on an Intel Atom CPU, which would otherwise
produce an instruction schedule which differs from that which the test expects.
llvm-svn: 153033
It's not a good style idea, as the registers will be laid down in memory in
numerical order, not the order they're in the list, but it's legal. vldm/vstm
are stricter.
rdar://11064740
llvm-svn: 152943
alignment. If that's the case, then we want to make sure that we don't increase
the alignment of the store instruction. Because if we increase it to be "more
aligned" than the pointer, code-gen may use instructions which require a greater
alignment than the pointer guarantees.
<rdar://problem/11043589>
llvm-svn: 152907
It was added in 2007 as the first cut at supporting no-inline
attributes, but we didn't have function attributes of any form at the
time. However, it was added without any mention in the LangRef or other
documentation.
Later on, in 2008, Devang added function notes for 'inline=never' and
then turned them into proper function attributes. From that point
onward, as far as I can tell, the world moved on, and no one has touched
'llvm.noinline' in any meaningful way since.
It's time has now come. We have had better mechanisms for doing this for
a long time, all the frontends I'm aware of use them, and this is just
holding back progress. Given that it was never a documented feature of
the IR, I've provided no auto-upgrade support. If people know of real,
in-the-wild bitcode that relies on this, yell at me and I'll add it, but
I *seriously* doubt anyone cares.
llvm-svn: 152904
Only record IVUsers that are dominated by simplified loop
headers. Otherwise SCEVExpander will crash while looking for a
preheader.
I previously tried to work around this in LSR itself, but that was
insufficient. This way, LSR can continue to run if some uses are not
in simple loops, as long as we don't attempt to analyze those users.
Fixes <rdar://problem/11049788> Segmentation fault: 11 in LoopStrengthReduce
llvm-svn: 152892
out the DW_AT_name. Older gdbs unfortunately still use it to
disambiguate member functions in templated classes (gdb.cp/templates.exp).
rdar://11043421 (which is now deferred for a bit)
llvm-svn: 152782
This results in things such as
vmovaps -96(%rbx), %xmm1
vinsertf128 $1, %xmm1, %ymm0, %ymm0
to be combined to
vinsertf128 $1, -96(%rbx), %ymm0, %ymm0
rdar://10643481
llvm-svn: 152762
correlated pairs of pointer arguments at the callsite. This is designed
to recognize the common C++ idiom of begin/end pointer pairs when the
end pointer is a constant offset from the begin pointer. With the
C-based idiom of a pointer and size, the inline cost saw the constant
size calculation, and this provides the same level of information for
begin/end pairs.
In order to propagate this information we have to search for candidate
operations on a pair of pointer function arguments (or derived from
them) which would be simplified if the pointers had a known constant
offset. Then the callsite analysis looks for such pointer pairs in the
argument list, and applies the appropriate bonus.
This helps LLVM detect that half of bounds-checked STL algorithms
(such as hash_combine_range, and some hybrid sort implementations)
disappear when inlined with a constant size input. However, it's not
a complete fix due the inaccuracy of our cost metric for constants in
general. I'm looking into that next.
Benchmarks showed no significant code size change, and very minor
performance changes. However, specific code such as hashing is showing
significantly cleaner inlining decisions.
llvm-svn: 152752
output (we're emitting a specification already and the information
isn't changing).
Saves 1% on the debug information for a build of llvm.
Fixes rdar://11043421
llvm-svn: 152697
(i16 load $addr+c*sizeof(i16)) and replace uses of (i32 vextract) with the
i16 load. It should issue an extload instead: (i32 extload $addr+c*sizeof(i16)).
rdar://11035895
llvm-svn: 152675
candidate set for subsequent inlining, try to simplify the arguments to
the inner call site now that inlining has been performed.
The goal here is to propagate and fold constants through deeply nested
call chains. Without doing this, we loose the inliner bonus that should
be applied because the arguments don't match the exact pattern the cost
estimator uses.
Reviewed on IRC by Benjamin Kramer.
llvm-svn: 152556
Typically instcombine has handled this, but pointer differences show up
in several contexts where we would like to get constant folding, and
cannot afford to run instcombine. Specifically, I'm working on improving
the constant folding of arguments used in inline cost analysis with
instsimplify.
Doing this in instsimplify implies some algorithm changes. We have to
handle multiple layers of all-constant GEPs because instsimplify cannot
fold them into a single GEP the way instcombine can. Also, we're only
interested in all-constant GEPs. The result is that this doesn't really
replace the instcombine logic, it's just complimentary and focused on
constant folding.
Reviewed on IRC by Benjamin Kramer.
llvm-svn: 152555
The 'CmpInst::isFalseWhenEqual' function returns 'false' for values other than
simply equality. For instance, it returns 'false' for <= or >=. This isn't the
correct behavior for this transformation, which is checking for strict equality
and non-equality. It was causing the gcc.c-torture/execute/frame-address.c test
to fail because it would completely (and incorrectly) optimize a whole function
into a 'ret i32 0'.
llvm-svn: 152497
* Add enums and structures for GNU version information.
* Implement extraction of that information on a per-symbol basis (ELFObjectFile::getSymbolVersion).
* Implement a generic interface, GetELFSymbolVersion(), for getting the symbol version from the ObjectFile (hides the templating).
* Have llvm-readobj print out the version, when available.
* Add a test for the new feature: readobj-elf-versioning.test
llvm-svn: 152436
traversal, consider nodes for which the only successors are backedges
which the traversal is ignoring to be exit nodes. This fixes a problem
where the bottom-up traversal was failing to visit split blocks along
split loop backedges. This fixes rdar://10989035.
llvm-svn: 152421
introduced. Specifically, there are cost reductions for all
constant-operand icmp instructions against an alloca, regardless of
whether the alloca will in fact be elligible for SROA. That means we
don't want to abort the icmp reduction computation when we abort the
SROA reduction computation. That in turn frees us from the need to keep
a separate worklist and defer the ICmp calculations.
Use this new-found freedom and some judicious function boundaries to
factor the innards of computing the cost factor of any given instruction
out of the loop over the instructions and into static helper functions.
This greatly simplifies the code, and hopefully makes it more clear what
is happening here.
Reviewed by Eric Christopher. There is some concern that we'd like to
ensure this doesn't get out of hand, and I plan to benchmark the effects
of this change over the next few days along with some further fixes to
the inline cost.
llvm-svn: 152368
Original commit message from r147481:
DAGCombine for transforming 128->256 casts into a vmovaps, rather
then a vxorps + vinsertf128 pair if the original vector came from a load.
Fix:
Unaligned loads need to generate a vmovups.
rdar://10974078
llvm-svn: 152366
When an instruction only writes sub-registers, it is still necessary to
add an <imp-def> operand for the super-register. When reloading into a
virtual register, rewriting will add the operand, but when loading
directly into a virtual register, the <imp-def> operand is still
necessary.
llvm-svn: 152095
The fpscr register contains both flags (set by FP operations/comparisons) and
control bits. The control bits (FPSCR) should be reserved, since they're always
available and needn't be defined before use. The flag bits (FPSCR_NZCV) should
like to be unreserved so they can be hoisted by MachineCSE. This fixes PR12165.
llvm-svn: 152076
This was testing the handling of sub-register coalescing followed by
remat. The original problem was caused by the extra <imp-def> operands
added by sub-register coalescing. Those <imp-def> operands are not
added any longer, and the test case passes even when the original patch
is reverted.
llvm-svn: 152040
In this update:
- I assumed neon2 does not imply vfpv4, but neon and vfpv4 imply neon2.
- I kept setting .fpu=neon-vfpv4 code attribute because that is what the
assembler understands.
Patch by Ana Pazos <apazos@codeaurora.org>
llvm-svn: 152036
MachineOperands that define part of a virtual register must have an
<undef> flag if they are not intended as read-modify-write operands.
The old trick of adding an <imp-def> operand doesn't work any longer.
Fixes PR12177.
llvm-svn: 152008
equalities into phi node operands for which the equality is known to
hold in the incoming basic block. That's because replaceAllDominatedUsesWith
wasn't handling phi nodes correctly in general (that this didn't give wrong
results was just luck: the specific way GVN uses replaceAllDominatedUsesWith
precluded wrong changes to phi nodes).
llvm-svn: 152006
Some BBs can become dead after codegen preparation. If we delete them here, it
could help enable tail-call optimizations later on.
<rdar://problem/10256573>
llvm-svn: 152002
This could probably be made a lot smarter, but this is a common case and doesn't require LVI to scan a lot
of code. With this change CVP can optimize away the "shift == 0" case in Hashing.h that only gets hit when
"shift" is in a range not containing 0.
llvm-svn: 151919
In this instance we are generating the tail-call during legalizeDAG. The 2nd
floor call can't be a tail call because it clobbers %xmm1, which is defined by
the first floor call. The first floor call can't be a tail-call because it's
not in the tail position. The only reasonable way I could think to fix this
in a target-independent manner was to check for glue logic on the copy reg.
rdar://10930395
llvm-svn: 151877
The inline table needs to be constructed ahead of time so that it doesn't try to
create new strings while we're emitting everything.
This reverts commit a8ff9bccb399183cdd5f1c3cec2bda763664b4b0.
llvm-svn: 151864
floating point equality comparisons into integer ones with -ffast-math. The
issue is the optimization causes +0.0 != -0.0.
Now the optimization is only done when one side is known to be 0.0. The other
side's sign bit is masked off for the comparison.
rdar://10964603
llvm-svn: 151861
fixups that are being used to determine section offsets. Reduces
the total number of fixups by 50% for a non-trivial testcase.
Part of rdar://10413936
llvm-svn: 151852
and stores was added.
- SelectAddr should return false if Parent is an unaligned f32 load or store.
- Only aligned load and store nodes should be matched to select reg+imm
floating point instructions.
- MIPS does not have support for f64 unaligned load or store instructions.
llvm-svn: 151843
so that the test will not fail when run on an Intel Atom
processor, due to the Atom scheduler producing an instruction sequence that is
different from that which is normally expected.
llvm-svn: 151832
* Add begin_dynamic_table() / end_dynamic_table() private interface to ELFObjectFile.
* Add begin_libraries_needed() / end_libraries_needed() interface to ObjectFile, for grabbing the list of needed libraries for a shared object or dynamic executable.
* Implement this new interface completely for ELF, leave stubs for COFF and MachO.
* Add 'llvm-readobj' tool for dumping ObjectFile information.
llvm-svn: 151785
Without this hook, functions w/ a completely empty body (including no
epilogue) will cause an MCEmitter assertion failure.
For example,
define internal fastcc void @empty_function() {
unreachable
}
rdar://10947471
llvm-svn: 151673
debug info for assembly files. We were already doing the right thing when
producing debug info for C/C++.
ELF linkers don't know dwarf, so they depend on these relocations to produce
valid dwarf output.
llvm-svn: 151655
To avoid problems with zero shifts when getting the bits that move between words
we use a trick: first shift the by amount-1, then do another shift by one. When
amount is 0 (and size 32) we first shift by 31, then by one, instead of by 32.
Also fix a latent bug that emitted the low and high words in the wrong order
when shifting right.
Fixes PR12113.
llvm-svn: 151637
When the GEP index is a vector of pointers, the code that calculated the size
of the element started from the vector type, and not the contained pointer type.
As a result, instead of looking at the data element pointed by the vector, this
code used the size of the vector. This works for 32bit members (on 32bit
systems), but not for other types. Added code to peel the vector type and
added a test.
llvm-svn: 151626
the processor keeps a return addresses stack (RAS) which stores the address
and the instruction execution state of the instruction after a function-call
type branch instruction.
Calling a "noreturn" function with normal call instructions (e.g. bl) can
corrupt RAS and causes 100% return misprediction so LLVM should use a
unconditional branch instead. i.e.
mov lr, pc
b _foo
The "mov lr, pc" is issued in order to get proper backtrace.
rdar://8979299
llvm-svn: 151623
When an outgoing call takes more than 2k of arguments on the stack, we
don't allocate that call frame in the prolog, but adjust the stack
pointer immediately before the call instead.
This causes problems with the emergency spill slot because PEI can't
track stack pointer adjustments on the second pass, and if the outgoing
arguments are too big, SP can't be used to reach the emergency spill
slot at all.
Work around these problems by ensuring there is a base or frame pointer
that can be used to access the emergency spill slot.
<rdar://problem/10917166>
llvm-svn: 151604
We on the linker to resolve calls to the appropriate BL/BLX instruction
to make interworking function correctly. It uses the symbol in the
relocation to do that, so we need to be careful about being too clever.
To enable this for ARM mode, split the BL/BLX fixup kind off from the
unconditional-branch fixups.
rdar://10927209
llvm-svn: 151571
%cmp (eg: A==B) we already replace %cmp with "true" under the true edge, and
with "false" under the false edge. This change enhances this to replace the
negated compare (A!=B) with "false" under the true edge and "true" under the
false edge. Reported to improve perlbench results by 1%.
llvm-svn: 151517
verifier does. This correctly handles invoke.
Thanks to Duncan, Andrew and Chris for the comments.
Thanks to Joerg for the early testing.
llvm-svn: 151469
Reverting this because it breaks static linking on ppc64. Specifically, it may be linkonce_odr functions that are the problem.
With this patch, if you link statically, calls to some functions end up calling their descriptor addresses instead
of calling to their entry points. This causes the execution to fail with SIGILL (b/c the descriptor address just
has some pointers, not code).
llvm-svn: 151433
[Joe Groff] Hi everyone. My previous patch applied as r151382 had a few problems:
Clang raised a warning, and X86 LowerOperation would assert out for
fptoui f64 to i32 because it improperly lowered to an illegal
BUILD_PAIR. Here's a patch that addresses these issues. Let me know if
any other changes are necessary. Thanks.
llvm-svn: 151432
reserving a physical register ($gp or $28) for that purpose.
This will completely eliminate loads that restore the value of $gp after every
function call, if the register allocator assigns a callee-saved register, or
eliminate unnecessary loads if it assigns a temporary register.
example:
.cpload $25 // set $gp.
...
.cprestore 16 // store $gp to stack slot 16($sp).
...
jalr $25 // function call. clobbers $gp.
lw $gp, 16($sp) // not emitted if callee-saved reg is chosen.
...
lw $2, 4($gp)
...
jalr $25 // function call.
lw $gp, 16($sp) // not emitted if $gp is not live after this instruction.
...
llvm-svn: 151402
variable declaration as an argument because we want that address
anyhow for our debug information.
This seems to fix rdar://9965111, at least we have more debug
information than before and from reading the assembly it appears
to be the correct location.
llvm-svn: 151335
The tied source operand of tMUL is the second source operand, not the
first like every other two-address thumb instruction. Special case it
in the size reduction pass to make sure we create the tMUL instruction
properly.
llvm-svn: 151315
rdar://10873652
As part of this I updated the llvm-mc disassembler C API to always call the
SymbolLookUp call back even if there is no getOpInfo call back. If there is a
getOpInfo call back that is tried first and then if that gets no information
then the SymbolLookUp is called. I also made the code more robust by
memset(3)'ing to zero the LLVMOpInfo1 struct before then setting
SymbolicOp.Value before for the call to getOpInfo. And also don't use any
values from the LLVMOpInfo1 struct if getOpInfo returns 0. And also don't
use any of the ReferenceType or ReferenceName values from SymbolLookUp if it
returns NULL. rdar://10873563 and rdar://10873683
For the X86 target also fixed bugs so the annotations get printed.
Also fixed a few places in the ARM target that was not producing symbolic
operands for some instructions. rdar://10878166
llvm-svn: 151267
value is zero. Instead of a cmov + op, issue an conditional op instead. e.g.
cmp r9, r4
mov r4, #0
moveq r4, #1
orr lr, lr, r4
should be:
cmp r9, r4
orreq lr, lr, #1
That is, optimize (or x, (cmov 0, y, cond)) to (or.cond x, y). Similarly extend
this to xor as well as (and x, (cmov -1, y, cond)) => (and.cond x, y).
It's possible to extend this to ADD and SUB but I don't think they are common.
rdar://8659097
llvm-svn: 151224
The standard function epilog includes a .size directive, but ppc64 uses
an alternate local symbol to tag the actual start of each function.
Until recently, binutils accepted the .size directive as:
.size test1, .Ltmp0-test1
however, using this directive with recent binutils will result in the error:
.size expression for XXX does not evaluate to a constant
so we must use the label which actually tags the start of the function.
llvm-svn: 151200
Add some data structures to represent for loops. These will be
referenced during object processing to do any needed iteration and
instantiation.
Add foreach keyword support to the lexer.
Add a mode to indicate that we're parsing a foreach loop. This allows
the value parser to early-out when processing the foreach value list.
Add a routine to parse foreach iteration declarations. This is
separate from ParseDeclaration because the type of the named value
(the iterator) doesn't match the type of the initializer value (the
value list). It also needs to add two values to the foreach record:
the iterator and the value list.
Add parsing support for foreach.
Add the code to process foreach loops and create defs based
on iterator values.
Allow foreach loops to be matched at the top level.
When parsing an IDValue check if it is a foreach loop iterator for one
of the active loops. If so, return a VarInit for it.
Add Emacs keyword support for foreach.
Add VIM keyword support for foreach.
Add tests to check foreach operation.
Add TableGen documentation for foreach.
Support foreach with multiple objects.
Support non-braced foreach body with one object.
Do not require types for the foreach declaration. Assume the iterator
type from the iteration list element type.
llvm-svn: 151164
This test case was way too strict, matching the entire assembly output.
Every non-trivial change to the ppc backend or -O0 pipeline required
the test to be updated.
It should be replaced with a test of the specific vaarg feature.
llvm-svn: 151105
they'll be simple enough to simulate, and to reduce the chance we'll encounter
equal but different simple pointer constants.
This removes the symptoms from PR11352 but is not a full fix. A proper fix would
either require a guarantee that two constant objects we simulate are folded
when equal, or a different way of handling equal pointers (ie., trying a
constantexpr icmp on them to see whether we know they're equal or non-equal or
unsure).
llvm-svn: 151093
This transformation is not safe in some pathological cases (signed icmp of pointers should be an
extremely rare thing, but it's valid IR!). Add an explanatory comment.
Kudos to Duncan for pointing out this edge case (and not giving up explaining it until I finally got it).
llvm-svn: 151055
ecx = mov eax
al = mov ch
The second copy is not a nop because the sub-indices of ecx,ch is not the
same of that of eax/al.
Re-enabled machine-cp.
PR11940
llvm-svn: 151002
- Ignore pointer casts.
- Also expand GEPs that aren't constantexprs when they have one use or only constant indices.
- We now compile "&foo[i] - &foo[j]" into "i - j".
llvm-svn: 150961
the cast. If we do, we can end up with
inst1
--------------- < Insertion point
dbg inst
new inst
instead of the desired
inst1
new inst
--------------- < Insertion point
dbg inst
Another option would be for InsertNoopCastOfTo (or its callers) to move the
insertion point and we would end up with
inst1
dbg inst
new inst
--------------- < Insertion point
but that complicates the callers. This fixes PR12018 (and firefox's build).
llvm-svn: 150884
metadata may still unwind, but only in ways that the ARC
optimizer doesn't need to consider. This permits more
aggressive optimization.
llvm-svn: 150829
useful to represent a variable that is const in the source but can't be constant
in the IR because of a non-trivial constructor. If globalopt evaluates the
constructor, and there was an invariant.start with no matching invariant.end
possible, it will mark the global constant afterwards.
llvm-svn: 150794
processor, due to the Atom scheduler producing an instruction sequence that is
different from that which is expected.
Patch by Michael Spencer!
llvm-svn: 150736
that are greater than the vector element type. For example BUILD_VECTOR
of type <1 x i1> with a constant i8 operand.
This patch fixes the assertion.
llvm-svn: 150477
This folds a simple loop tail into a loop latch. It covers the common (in fortran) case of postincrement loops. It's a "free" way to expose this type of loop to downstream loop optimizations that bail out on non-canonical loops (getLoopLatch is a heavily used check).
llvm-svn: 150439
If the DEC node had more than one user, it was doing this lowering but
leaving the original DEC node around and so decrementing twice.
Fixes PR11964.
llvm-svn: 150356
v8i8 -> v8i32 on AVX machines. The codegen often scalarizes ANY_EXTEND nodes.
The DAGCombiner has two optimizations that can mitigate the problem. First,
if all of the operands of a BUILD_VECTOR node are extracted from an ZEXT/ANYEXT
nodes, then it is possible to create a new simplified BUILD_VECTOR which uses
UNDEFS/ZERO values to eliminate the scalar ZEXT/ANYEXT nodes.
Second, another dag combine optimization lowers BUILD_VECTOR into a shuffle
vector instruction.
In the case of zext v8i8->v8i32 on AVX, a value in an XMM register is to be
shuffled into a wide YMM register.
This patch modifes the second optimization and allows the creation of
shuffle vectors even when the newly generated vector and the original vector
from which we extract the values are of different types.
llvm-svn: 150340
Module flags are key-value pairs associated with the module. They include a
'behavior' value, indicating how module flags react when mergine two
files. Normally, it's just the union of the two module flags. But if two module
flags have the same key, then the resulting flags are dictated by the behaviors.
Allowable behaviors are:
Error
Emits an error if two values disagree.
Warning
Emits a warning if two values disagree.
Require
Emits an error when the specified value is not present
or doesn't have the specified value. It is an error for
two (or more) llvm.module.flags with the same ID to have
the Require behavior but different values. There may be
multiple Require flags per ID.
Override
Uses the specified value if the two values disagree. It
is an error for two (or more) llvm.module.flags with the
same ID to have the Override behavior but different
values.
llvm-svn: 150300
This allows BBVectorize to check the "unknown instruction" list in the
alias sets. This is important to prevent instruction fusing from reordering
function calls. Resolves PR11920.
llvm-svn: 150250
is that patterns no longer match for vectors of booleans, because you only get
ConstantDataVector when the vector element type is i8, i16, etc, not when it is
i1). Original commit message:
Remove some dead code and tidy things up now that vectors use ConstantDataVector
instead of always using ConstantVector.
llvm-svn: 150246
Creates a configurable regalloc pipeline.
Ensure specific llc options do what they say and nothing more: -reglloc=... has no effect other than selecting the allocator pass itself. This patch introduces a new umbrella flag, "-optimize-regalloc", to enable/disable the optimizing regalloc "superpass". This allows for example testing coalscing and scheduling under -O0 or vice-versa.
When a CodeGen pass requires the MachineFunction to have a particular property, we need to explicitly define that property so it can be directly queried rather than naming a specific Pass. For example, to check for SSA, use MRI->isSSA, not addRequired<PHIElimination>.
CodeGen transformation passes are never "required" as an analysis
ProcessImplicitDefs does not require LiveVariables.
We have a plan to massively simplify some of the early passes within the regalloc superpass.
llvm-svn: 150226
GlobalOpt runs early in the pipeline (before inlining) and complex class
hierarchies often introduce bitcasts or GEPs which weren't optimized away.
Teach it to ignore side-effect free instructions instead of depending on
other passes to remove them.
llvm-svn: 150174
* Most of the transforms come through intact by having each transformed load or
store copy the ordering and synchronization scope of the original.
* The transform that turns a global only accessed in main() into an alloca
(since main is non-recursive) with a store of the initial value uses an
unordered store, since it's guaranteed to be the first thing to happen in main.
(Threads may have started before main (!) but they can't have the address of a
function local before the point in the entry block we insert our code.)
* The heap-SRoA transforms are disabled in the face of atomic operations. This
can probably be improved; it seems odd to have atomic accesses to an alloca
that doesn't have its address taken.
AnalyzeGlobal keeps track of the strongest ordering found in any use of the
global. This is more information than we need right now, but it's cheap to
compute and likely to be useful.
llvm-svn: 149847
logic by half: isOnlyReachableViaThisEdge was trying to be clever and
handle the case of a branch to a basic block which is contained in a
loop. This costs a domtree lookup and is completely useless due to
GVN's position in the pass pipeline: all loops have preheaders at this
point, which means it is enough for isOnlyReachableViaThisEdge to check
that Dst has only one predecessor. (I checked this theoretical argument
by running over the entire nightly testsuite, and indeed it is so!).
llvm-svn: 149838
By default, boost the chain depth contribution of loads and stores. This will allow a load/store pair to vectorize even when it would not otherwise be long enough to satisfy the chain depth requirement.
llvm-svn: 149761
In this patch we optimize this pattern and convert the sequence into extract op of a narrow type.
This allows the BUILD_VECTOR dag optimizations to construct efficient shuffle operations in many cases.
llvm-svn: 149692
needed to emit a 64-bit gp-relative relocation entry. Make changes necessary
for emitting jump tables which have entries with directive .gpdword. This patch
does not implement the parts needed for direct object emission or JIT.
llvm-svn: 149668
PHI nodes which were matched, rather than climbing up the
original PHI node's operands to rediscover PHI nodes for
recording, since the PHI nodes found that are not
necessarily part of the matched set.
This fixes rdar://10589171.
llvm-svn: 149654
more than two adjacent ranges needed to be merged. The new version should be
able to handle an arbitrary sequence of adjancent ranges.
llvm-svn: 149588
Adds an instruction itinerary to all x86 instructions, giving each a default latency of 1, using the InstrItinClass IIC_DEFAULT.
Sets specific latencies for Atom for the instructions in files X86InstrCMovSetCC.td, X86InstrArithmetic.td, X86InstrControl.td, and X86InstrShiftRotate.td. The Atom latencies for the remainder of the x86 instructions will be set in subsequent patches.
Adds a test to verify that the scheduler is working.
Also changes the scheduling preference to "Hybrid" for i386 Atom, while leaving x86_64 as ILP.
Patch by Preston Gurd!
llvm-svn: 149558
This new scheduler plugs into the existing selection DAG scheduling framework. It is a top-down critical path scheduler that tracks register pressure and uses a DFA for pipeline modeling.
Patch by Sergei Larin!
llvm-svn: 149547
This is the initial checkin of the basic-block autovectorization pass along with some supporting vectorization infrastructure.
Special thanks to everyone who helped review this code over the last several months (especially Tobias Grosser).
llvm-svn: 149468
Changing arguments from being passed as fixed to varargs is unsafe, as
the ABI may require they be handled differently (stack vs. register, for
example).
Remove two tests which rely on the bitcast being folded into the direct
call, which is exactly the transformation that's unsafe.
llvm-svn: 149457
symbol from an assignment. In this case the symbol did not have a fragment so
MCObjectWriter::IsSymbolRefDifferenceFullyResolved() should not have been
calling IsSymbolRefDifferenceFullyResolvedImpl() with a NULL fragment and should
just have returned false in that case.
llvm-svn: 149442
vectors of all one bits to be printed more cleverly in the AsmPrinter.
Unfortunately, the byte value for all one bits is the same with
-fsigned-char as the error return of '-1'. Force this to be the unsigned
byte value when returning it to avoid this problem, and update the test
case for the shiny new behavior.
Yay for building LLVM and Clang with -funsigned-char.
Chris, please review, and let me know if there is any reason to not
desire this change. It seems good on the surface, and certainly intended
based on the code written.
llvm-svn: 149299
The Win64 calling convention has xmm6-15 as callee-saved while still
clobbering all ymm registers.
Add a YMM_HI_6_15 pseudo-register that aliases the clobbered part of the
ymm registers, and mark that as call-clobbered. This allows live xmm
registers across calls.
This hack wouldn't be necessary with RegisterMask operands representing
the call clobbers, but they are not quite operational yet.
llvm-svn: 149088
MachineBasicBlock::canFallThrough(). We're interested in the state of the
instruction (i.e., is this a barrier or not?), not if the instruction is
predicable or not.
rdar://10501092
llvm-svn: 149070
The live range of the source register may be extended when a redundant
copy is eliminated. Make sure any kill flags between the two copies are
cleared.
This fixes PR11765.
llvm-svn: 149069
This enables the linker to match concrete relocation types (absolute or relative) with whatever library or C++ support code is being linked against.
llvm-svn: 149057
. "fptosi" and "fptoui" IR instructions are defined with round-to-zero rounding mode.
. Currently for AVX mode for <4xdouble> and <8xdouble> the "VCVTPD2DQ.128" and "VCVTPD2DQ.256" instructions are selected (for .fp_to_sint. DAG node operation ) by AVX codegen. However they use round-to-nearest-even rounding mode.
. Consequently, the conversion produces incorrect numbers.
The fix is to replace selection of VCVTPD2DQ instructions with VCVTTPD2DQ instructions. The latter use truncate (i.e. round-to-zero) rounding mode.
As .fp_to_sint. DAG node operation is used only for lowering of "fptosi" and "fptoui" IR instructions, the fix in X86InstrSSE.td definition file doesn.t have an impact on other LLVM flows.
The patch includes changes in the .td file, LIT test for the changes and a fix in a legacy LIT test (which produced asm code conflicting with LLVN IR spec).
llvm-svn: 149056
This boils down to using MachineOperand::readsReg() more.
This fixes PR11829 where a use ended up after the first def when
lowering REG_SEQUENCE instructions involving IMPLICIT_DEFs.
llvm-svn: 148996
"Although a Thumb2 instruction, the IT mnemonic shall be permitted in
ARM mode, and the condition verified to match the condition code(s)
on the following instruction(s)."
PR11853
llvm-svn: 148969
savings from a pointer argument becoming an alloca. Sometimes callees will even
compare a pointer to null and then branch to an otherwise unreachable block!
Detect these cases and compute the number of saved instructions, instead of
bailing out and reporting no savings.
llvm-svn: 148941
- Use MipsAnalyzeImmediate to expand immediates that do not fit in 16-bit.
- Change the types of variables so that they are sufficiently large to handle
64-bit pointers.
- Emit instructions to set register $28 in a function prologue after
instructions which store callee-saved registers have been emitted.
llvm-svn: 148917
A REG_SEQUENCE instruction is lowered into a sequence of partial defs:
%vreg7:ssub_0<def,undef> = COPY %vreg20:ssub_0
%vreg7:ssub_1<def> = COPY %vreg2
%vreg7:ssub_2<def> = COPY %vreg2
%vreg7:ssub_3<def> = COPY %vreg2
The first def needs an <undef> flag to indicate it is the beginning of
the live range, while the other defs are read-modify-write. Previously,
we depended on LiveIntervalAnalysis to notice and fix the missing
<def,undef>, but that solution was never robust, it was causing problems
with ProcessImplicitDefs and the lowering of chained REG_SEQUENCE
instructions.
This fixes PR11841.
llvm-svn: 148879
When not using subsections via symbols, the assembler can resolve
symbol differences (including pcrel references) to non-local
labels at assembly time, not just those in the same atom.
llvm-svn: 148865
This change adds an new option --arm-enable-ehabi-descriptors that
enables emitting unwinding descriptors. This provides a mode with a
working backtrace() without the (currently broken) exception support.
llvm-svn: 148800
violation -- MC cannot depend on CodeGen.
Specifically, the MCTargetDesc component of each target is actually
a subcomponent of the MC library. As such, it cannot depend on the
target-independent code generator, because MC itself cannot depend on
the target-independent code generator. This change moved a flag from the
ARM MCTargetDesc file ARMMCAsmInfo.cpp to the CodeGen layer in
ARMException.cpp, leaving behind an 'extern' to refer back to it. That
layering order isn't viable givin the constraints outlined above.
Commandline flags are designed to be static specifically to avoid these
types of bugs.
Fixing this is likely going to require some non-trivial refactoring.
llvm-svn: 148759
This change adds an new value to the --arm-enable-ehabi option that
disables emitting unwinding descriptors. This mode gives a working
backtrace() without the (currently broken) exception support.
llvm-svn: 148686
returns false in the event the computation feeding into the pointer is
unreachable, which maybe ought to be true -- but this is at least consistent
with undef->isDereferenceablePointer().) Fixes PR11825!
llvm-svn: 148671
We have patterns for vector sext and zext operations but were missing
anyext. Without those patterns, codegen will fail when the selection DAG
has any_extend nodes.
llvm-svn: 148568
For bit patterns that aren't representable using the 8-bit floating point
representation for vmov.f32, but are representable via vmov.i32, treat
the .f32 syntax as an alias. Most importantly, this covers the case
'vmov.f32 Vd, #0.0'.
rdar://10616677
llvm-svn: 148556
can't handle. Also don't produce non-zero results for things which won't be
transformed by SROA at all just because we saw the loads/stores before we saw
the use of the address.
llvm-svn: 148536
LSR has gradually been improved to more aggressively reuse existing code, particularly existing phi cycles. This exposed problems with the SCEVExpander's sloppy treatment of its insertion point. I applied some rigor to the insertion point problem that will hopefully avoid an endless bug cycle in this area. Changes:
- Always used properlyDominates to check safe code hoisting.
- The insertion point provided to SCEV is now considered a lower bound. This is usually a block terminator or the use itself. Under no cirumstance may SCEVExpander insert below this point.
- LSR is reponsible for finding a "canonical" insertion point across expansion of different expressions.
- Robust logic to determine whether IV increments are in "expanded" form and/or can be safely hoisted above some insertion point.
Fixes PR11783: SCEVExpander assert.
llvm-svn: 148535
When the non-local symbol in the expression is in the same fragment
as the second symbol, the assembler can still evaluate the expression
without needing a relocation.
For example, on ARM:
_foo:
ldr lr, (_foo - 4)
rdar://10348687
llvm-svn: 148341
implementation.
Currently lit still executes ExecutionEngine tests with JIT (not MCJIT) by
default. MCJIT tests can be executed manually by calling llvm-lit with
--param jit_impl=mcjit
llvm-svn: 148299
In CanXFormVExtractWithShuffleIntoLoad we assumed that EXTRACT_VECTOR_ELT can be later handled by the DAGCombiner.
However, in some cases on AVX, the EXTRACT_VECTOR_ELT is legalized to EXTRACT_SUBVECTOR + EXTRACT_VECTOR_ELT, which
currently is not handled by the DAGCombiner. In this patch I added a check that we only extract from the XMM part.
llvm-svn: 148298
It's becoming clear that LoopSimplify needs to unconditionally create loop preheaders. But that is a bigger fix. For now, continuing to hack LSR.
Fixes rdar://10701050 "Cannot split an edge from an IndirectBrInst" assert.
llvm-svn: 148288
We know that the blend instructions only use the MSB, so if the mask is
sign-extended then we can convert it into a SHL instruction. This is a
common pattern because the type-legalizer sign-extends the i1 type which
is used by the LLVM-IR for the condition.
Added a new optimization in SimplifyDemandedBits for SIGN_EXTEND_INREG -> SHL.
llvm-svn: 148225
live across BBs before register allocation. This miscompiled 197.parser
when a cmp + b are optimized to a cbnz instruction even though the CPSR def
is live-in a successor.
cbnz r6, LBB89_12
...
LBB89_12:
ble LBB89_1
The fix consists of two parts. 1) Teach LiveVariables that some unallocatable
registers might be liveouts so don't mark their last use as kill if they are.
2) ARM constantpool island pass shouldn't form cbz / cbnz if the conditional
branch does not kill CPSR.
rdar://10676853
llvm-svn: 148168
overly conservative. It was concerned about cases where it would prohibit
folding simple [r, c] addressing modes. e.g.
ldr r0, [r2]
ldr r1, [r2, #4]
=>
ldr r0, [r2], #4
ldr r1, [r2]
Change the logic to look for such cases which allows it to form indexed memory
ops more aggressively.
rdar://10674430
llvm-svn: 148086
the optimizer doesn't eliminate objc_retainBlock calls which are needed
for their side effect of copying blocks onto the heap.
This implements rdar://10361249.
llvm-svn: 148076
lc: X86ISelLowering.cpp:6480: llvm::SDValue llvm::X86TargetLowering::LowerVECTOR_SHUFFLE(llvm::SDValue, llvm::SelectionDAG&) const: Assertion `V1.getOpcode() != ISD::UNDEF&& "Op 1 of shuffle should not be undef"' failed.
Added a test.
llvm-svn: 148044
When we load the v12i32 type, the GenWidenVectorLoads method generates two loads: v8i32 and v4i32
and attempts to use CONCAT_VECTORS to join them. In this fix I concat undef values to widen
the smaller value. The test "widen_load-2.ll" also exposes this bug on AVX.
llvm-svn: 147964
hoped this would revive one of the llvm-gcc selfhost build bots, but it
didn't so it doesn't appear that my transform is the culprit.
If anyone else is seeing failures, please let me know!
llvm-svn: 147957
directives was in the wrong place and getting triggered incorectly with a
cpp .file directive. This change fixes that and adds a test case.
llvm-svn: 147951
strange build bot failures that look like a miscompile into an infloop.
I'll investigate this tomorrow, but I'd both like to know whether my
patch is the culprit, and get the bots back to green.
llvm-svn: 147945
detect a pattern which can be implemented with a small 'shl' embedded in
the addressing mode scale. This happens in real code as follows:
unsigned x = my_accelerator_table[input >> 11];
Here we have some lookup table that we look into using the high bits of
'input'. Each entity in the table is 4-bytes, which means this
implicitly gets turned into (once lowered out of a GEP):
*(unsigned*)((char*)my_accelerator_table + ((input >> 11) << 2));
The shift right followed by a shift left is canonicalized to a smaller
shift right and masking off the low bits. That hides the shift right
which x86 has an addressing mode designed to support. We now detect
masks of this form, and produce the longer shift right followed by the
proper addressing mode. In addition to saving a (rather large)
instruction, this also reduces stalls in Intel chips on benchmarks I've
measured.
In order for all of this to work, one part of the DAG needs to be
canonicalized *still further* than it currently is. This involves
removing pointless 'trunc' nodes between a zextload and a zext. Without
that, we end up generating spurious masks and hiding the pattern.
llvm-svn: 147936
1. Size heuristics changed. Now we calculate number of unswitching
branches only once per loop.
2. Some checks was moved from UnswitchIfProfitable to
processCurrentLoop, since it is not changed during processCurrentLoop
iteration. It allows decide to skip some loops at an early stage.
Extended statistics:
- Added total number of instructions analyzed.
llvm-svn: 147935
Allow LDRD to be formed from pairs with different LDR encodings. This was the original intention of the pass. Somewhere along the way, the LDR opcodes were refined which broke the optimization. We really don't care what the original opcodes are as long as they both map to the same LDRD and the immediate still fits.
Fixes rdar://10435045 ARMLoadStoreOptimization cannot handle mixed LDRi8/LDRi12
llvm-svn: 147922
Consider this code:
int h() {
int x;
try {
x = f();
g();
} catch (...) {
return x+1;
}
return x;
}
The variable x is undefined on the first edge to the landing pad, but it
has the f() return value on the second edge to the landing pad.
SplitAnalysis::getLastSplitPoint() would assume that the return value
from f() was live into the landing pad when f() throws, which is of
course impossible.
Detect these cases, and treat them as if the landing pad wasn't there.
This allows spill code to be inserted after the function call to f().
<rdar://problem/10664933>
llvm-svn: 147912
with other symbols.
An object in the __cfstring section is suppoed to be filled with CFString
objects, which have a pointer to ___CFConstantStringClassReference followed by a
pointer to a __cstring. If we allow the object in the __cstring section to be
merged with another global, then it could end up in any section. Because the
linker is going to remove these symbols in the final executable, we shouldn't
bother to merge them.
<rdar://problem/10564621>
llvm-svn: 147899
This function runs after all constant islands have been placed, and may
shrink some instructions to their 2-byte forms. This can actually cause
some constant pool entries to move out of range because of growing
alignment padding.
Treat instructions that may be shrunk the same as inline asm - they
erode the known alignment bits.
Also reinstate an old assertion in verify(). It is correct now that
basic block offsets include alignments.
Add a single large test case that will hopefully exercise many parts of
the constant island pass.
<rdar://problem/10670199>
llvm-svn: 147885
assembly source when it generates the TAG_subprogram dwarf debug info for
the labels that have nothing between them as in this bit of assembly source:
% cat ZeroLength.s
_func1:
_func2:
nop
One solution would be to not emit the subsequent labels with the same address
and use the next label with a different address or the end of the section for
the AT_high_pc value of the TAG_subprogram.
Turns out in llvm-mc it is not possible in all cases to determine of two
symbols have the same value at the point we put out the TAG_subprogram dwarf
debug info.
So we will have llvm-mc instead of putting out TAG_subprogram's put out
DW_TAG_label's. And the DW_TAG_label does not have a AT_high_pc value which
avoids the problem.
This commit is only the functional change to make the diffs clear as to what is
really being changed. The next commit will be to clean up the names of such
things like MCGenDwarfSubprogramEntry to something like MCGenDwarfLabelEntry.
rdar://10666925
llvm-svn: 147860
define physical registers. It's currently very restrictive, only catching
cases where the CE is in an immediate (and only) predecessor. But it catches
a surprising large number of cases.
rdar://10660865
llvm-svn: 147827
These heuristics are sufficient for enabling IV chains by
default. Performance analysis has been done for i386, x86_64, and
thumbv7. The optimization is rarely important, but can significantly
speed up certain cases by eliminating spill code within the
loop. Unrolled loops are prime candidates for IV chains. In many
cases, the final code could still be improved with more target
specific optimization following LSR. The goal of this feature is for
LSR to make the best choice of induction variables.
Instruction selection may not completely take advantage of this
feature yet. As a result, there could be cases of slight code size
increase.
Code size can be worse on x86 because it doesn't support postincrement
addressing. In fact, when chains are formed, you may see redundant
address plus stride addition in the addressing mode. GenerateIVChains
tries to compensate for the common cases.
On ARM, code size increase can be mitigated by using postincrement
addressing, but downstream codegen currently misses some opportunities.
llvm-svn: 147826
After collecting chains, check if any should be materialized. If so,
hide the chained IV users from the LSR solver. LSR will only solve for
the head of the chain. GenerateIVChains will then materialize the
chained IV users by computing the IV relative to its previous value in
the chain.
In theory, chained IV users could be exposed to LSR's solver. This
would be considerably complicated to implement and I'm not aware of a
case where we need it. In practice it's more important to
intelligently prune the search space of nontrivial loops before
running the solver, otherwise the solver is often forced to prune the
most optimal solutions. Hiding the chained users does this well, so
that LSR is more likely to find the best IV for the chain as a whole.
llvm-svn: 147801
LoopSimplify may not run on some outer loops, e.g. because of indirect
branches. SCEVExpander simply cannot handle outer loops with no preheaders.
Fixes rdar://10655343 SCEVExpander segfault.
llvm-svn: 147718
file error checking. Use that to error on an unfinished cfi_startproc.
The error is not nice, but is already better than a segmentation fault.
llvm-svn: 147717
opportunities that only present themselves after late optimizations
such as tail duplication .e.g.
## BB#1:
movl %eax, %ecx
movl %ecx, %eax
ret
The register allocator also leaves some of them around (due to false
dep between copies from phi-elimination, etc.)
This required some changes in codegen passes. Post-ra scheduler and the
pseudo-instruction expansion passes have been moved after branch folding
and tail merging. They were before branch folding before because it did
not always update block livein's. That's fixed now. The pass change makes
independently since we want to properly schedule instructions after
branch folding / tail duplication.
rdar://10428165
rdar://10640363
llvm-svn: 147716
This eliminates a lot of constant pool entries for -O0 builds of code
with many global variable accesses.
This speeds up -O0 codegen of consumer-typeset by 2x because the
constant island pass no longer has to look at thousands of constant pool
entries.
<rdar://problem/10629774>
llvm-svn: 147712
present in the bottom of the CFG triangle, as the transformation isn't
ever valuable if the branch can't be eliminated.
Also, unify some heuristics between SimplifyCFG's multiple
if-converters, for consistency.
This fixes rdar://10627242.
llvm-svn: 147630
code can incorrectly move the load across a store. This never
happens in practice today, but only because the current
heuristics accidentally preclude it.
llvm-svn: 147623
a combined-away node and the result of the combine isn't substantially
smaller than the input, it's just canonicalized. This is the first part
of a significant (7%) performance gain for Snappy's hot decompression
loop.
llvm-svn: 147604
Testing: passed 'make check' including LIT tests for all sequences being handled (both SSE and AVX)
Reviewers: Evan Cheng, David Blaikie, Bruno Lopes, Elena Demikhovsky, Chad Rosier, Anton Korobeynikov
llvm-svn: 147601
Now that canRealignStack() understands frozen reserved registers, it is
safe to use it for aligned spill instructions.
It will only return true if the registers reserved at the beginning of
register allocation allow for dynamic stack realignment.
<rdar://problem/10625436>
llvm-svn: 147579
(x > y) ? x : y
=>
(x >= y) ? x : y
So for something like
(x - y) > 0 : (x - y) ? 0
It will be
(x - y) >= 0 : (x - y) ? 0
This makes is possible to test sign-bit and eliminate a comparison against
zero. e.g.
subl %esi, %edi
testl %edi, %edi
movl $0, %eax
cmovgl %edi, %eax
=>
xorl %eax, %eax
subl %esi, $edi
cmovsl %eax, %edi
rdar://10633221
llvm-svn: 147512
This patch caused a miscompilation of oggenc because a frame pointer was
suddenly needed halfway through register allocation.
<rdar://problem/10625436>
llvm-svn: 147487
The failure seen on win32, when i64 type is illegal.
It happens on stage of conversion VECTOR_SHUFFLE to BUILD_VECTOR.
The failure message is:
llc: SelectionDAG.cpp:784: void VerifyNodeCommon(llvm::SDNode*): Assertion `(I->getValueType() == EltVT || (EltVT.isInteger() && I->getValueType().isInteger() && EltVT.bitsLE(I->getValueType()))) && "Wrong operand type!"' failed.
I added a special test that checks vector shuffle on win32.
llvm-svn: 147445
The failure seen on win32, when i64 type is illegal.
It happens on stage of conversion VECTOR_SHUFFLE to BUILD_VECTOR.
The failure message is:
llc: SelectionDAG.cpp:784: void VerifyNodeCommon(llvm::SDNode*): Assertion `(I->getValueType() == EltVT || (EltVT.isInteger() && I->getValueType().isInteger() && EltVT.bitsLE(I->getValueType()))) && "Wrong operand type!"' failed.
I added a special test that checks vector shuffle on win32.
llvm-svn: 147399
1. The ST*UX instructions that store and update the stack pointer did not set define/kill on R1. This became a problem when I activated post-RA scheduling (and had incorrectly adjusted the Frames-large test).
2. eliminateFrameIndex did not kill its scavenged temporary register, and this could cause the scavenger to exhaust all available registers (and its emergency spill slot) when there were a lot of CR values to spill. The 2010-02-12-saveCR test has been adjusted to check for this.
llvm-svn: 147359
captured. This allows the tracker to look at the specific use, which may be
especially interesting for function calls.
Use this to fix 'nocapture' deduction in FunctionAttrs. The existing one does
not iterate until a fixpoint and does not guarantee that it produces the same
result regardless of iteration order. The new implementation builds up a graph
of how arguments are passed from function to function, and uses a bottom-up walk
on the argument-SCCs to assign nocapture. This gets us nocapture more often, and
does so rather efficiently and independent of iteration order.
llvm-svn: 147327
This has the obvious advantage of being commutable and is always a win on x86 because
const - x wastes a register there. On less weird architectures this may lead to
a regression because other arithmetic doesn't fuse with it anymore. I'll address that
problem in a followup.
llvm-svn: 147254
LZCNT instructions are available. Force promotion to i32 to get
a smaller encoding since the fix-ups necessary are just as complex for
either promoted type
We can't do standard promotion for CTLZ when lowering through BSR
because it results in poor code surrounding the 'xor' at the end of this
instruction. Essentially, if we promote the entire CTLZ node to i32, we
end up doing the xor on a 32-bit CTLZ implementation, and then
subtracting appropriately to get back to an i8 value. Instead, our
custom logic just uses the knowledge of the incoming size to compute
a perfect xor. I'd love to know of a way to fix this, but so far I'm
drawing a blank. I suspect the legalizer could be more clever and/or it
could collude with the DAG combiner, but how... ;]
llvm-svn: 147251
my C-brain happy. Remove the unnecessary bits of pedantic IR fluff like
nounwind. Remove stray uses comments. Name things semantically rather
than tN so that adding a new test in the middle doesn't cause pain, and
so that new tests can be grouped semantically.
This exposes how little systematic testing is going on here. I noticed
this by finding several bugs via inspection and wondering why this test
wasn't catching any of them. =[
llvm-svn: 147248
'bsf' instructions here.
This one is actually debatable to my eyes. It's not clear that any chip
implementing 'tzcnt' would have a slow 'bsf' for any reason, and unless
EFLAGS or a zero input matters, 'tzcnt' is just a longer encoding.
Still, this restores the old behavior with 'tzcnt' enabled for now.
llvm-svn: 147246
X86ISelLowering C++ code. Because this is lowered via an xor wrapped
around a bsr, we want the dagcombine which runs after isel lowering to
have a chance to clean things up. In particular, it is very common to
see code which looks like:
(sizeof(x)*8 - 1) ^ __builtin_clz(x)
Which is trying to compute the most significant bit of 'x'. That's
actually the value computed directly by the 'bsr' instruction, but if we
match it too late, we'll get completely redundant xor instructions.
The more naive code for the above (subtracting rather than using an xor)
still isn't handled correctly due to the dagcombine getting confused.
Also, while here fix an issue spotted by inspection: we should have been
expanding the zero-undef variants to the normal variants when there is
an 'lzcnt' instruction. Do so, and test for this. We don't want to
generate unnecessary 'bsr' instructions.
These two changes fix some regressions in encoding and decoding
benchmarks. However, there is still a *lot* to be improve on in this
type of code.
llvm-svn: 147244
ARM targets with NEON units have access to aligned vector loads and
stores that are potentially faster than unaligned operations.
Add support for spilling the callee-saved NEON registers to an aligned
stack area using 16-byte aligned NEON loads and store.
This feature is off by default, controlled by an -align-neon-spills
command line option.
llvm-svn: 147211
time regressions. In general, it is beneficial to compile-time.
Original commit message:
Fix for bug #11429: Wrong behaviour for switches. Small improvement for code
size heuristics.
llvm-svn: 147175
probability wouldn't be considered "hot" in some weird loop structures
or other compounding probability patterns. This makes it much harder to
confuse, but isn't really a principled fix. I'd actually like it if we
could model a zero probability, as it would make this much easier to
reason about. Suggestions for how to do this better are welcome.
llvm-svn: 147142
performance regressions (both execution-time and compile-time) on our
nightly testers.
Original commit message:
Fix for bug #11429: Wrong behaviour for switches. Small improvement for code
size heuristics.
llvm-svn: 147131
Use the spill slot alignment as well as the local variable alignment to
determine when the stack needs to be realigned. This works now that the
ARM target can always realign the stack by using a base pointer.
Still respect the ARMBaseRegisterInfo::canRealignStack() function
vetoing a realigned stack. Don't use aligned spill code in that case.
llvm-svn: 146997
use the zero-undefined variants of CTTZ and CTLZ. These are just simple
patterns for now, there is more to be done to make real world code using
these constructs be optimized and codegen'ed properly on X86.
The existing tests are spiffed up to check that we no longer generate
unnecessary cmov instructions, and that we generate the very important
'xor' to transform bsr which counts the index of the most significant
one bit to the number of leading (most significant) zero bits. Also they
now check that when the variant with defined zero result is used, the
cmov is still produced.
llvm-svn: 146974
We used to rely on the *eh_sjlj_setjmp instructions to mark that a function
with setjmp/longjmp exception handling clobbers all the registers. But with
the recent reorganization of ARM EH, those eh_sjlj_setjmp instructions are
expanded away earlier, before PEI can see them to determine what registers to
save and restore. Mark the dispatchsetup instruction in the same way, since
that instruction cannot be expanded early. This also more accurately reflects
when the registers are clobbered.
llvm-svn: 146949
"mov r1, r2, lsl #0" should assemble as "mov r1, r2" even though it's
not strictly legal UAL syntax. It's a common extension and the friendly
thing to do.
rdar://10604663
llvm-svn: 146937
merging types by name when we can. We still don't guarantee type name linkage
but we do it when obviously the right thing to do. This makes LTO type names
easier to read, for example.
llvm-svn: 146932
This change reduces the number of instructions generated.
For example,
(load (add (sub $n0, $n1), (MipsLo got(s))))
results in the following sequence of instructions:
1. sub $n2, $n0, $n1
2. lw got(s)($n2)
Previously, three instructions were needed.
1. sub $n2, $n0, $n1
2. addiu $n3, $n2, got(s)
3. lw 0($n3)
llvm-svn: 146888
internal nightly testers. Original commit message:
By popular demand, link up types by name if they are isomorphic and one is an
autorenamed version of the other. This makes the IR easier to read, because
we don't end up with random renamed versions of the types after LTO'ing a large
app.
llvm-svn: 146838
autorenamed version of the other. This makes the IR easier to read, because
we don't end up with random renamed versions of the types after LTO'ing a large app.
llvm-svn: 146728
into Analysis as a standalone function, since there's no need for
it to be in VMCore. Also, update it to use isKnownNonZero and
other goodies available in Analysis, making it more precise,
enabling more aggressive optimization.
llvm-svn: 146610
On ARM, peephole optimization for ABS creates a trivial cfg triangle which tempts machine sink to sink instructions in code which is really straight line code. Sometimes this sinking may alter register allocator input such that use and def of a reg is divided by a branch in between, which may result in extra spills. Now mahine sink avoids sinking if final sink destination is post dominator.
Radar 10266272.
llvm-svn: 146604
Work in progress. Parsing for non-writeback, single spaced register lists
works now. The rest have the representations better factored, but still
need more to be able to parse properly.
llvm-svn: 146579
When 'cmp rn #imm' doesn't match due to the immediate not being representable,
but 'cmn rn, #-imm' does match, use the latter in place of the former, as
it's equivalent.
rdar://10552389
llvm-svn: 146567
to finalize MI bundles (i.e. add BUNDLE instruction and computing register def
and use lists of the BUNDLE instruction) and a pass to unpack bundles.
- Teach more of MachineBasic and MachineInstr methods to be bundle aware.
- Switch Thumb2 IT block to MI bundles and delete the hazard recognizer hack to
prevent IT blocks from being broken apart.
llvm-svn: 146542
test cases where there were a lot of relocations applied relative to a large
rodata section. Gas would create a symbol for each of these whereas we would
be relative to the beginning of the rodata section. This change mimics what
gas does.
Patch by Jack Carter.
llvm-svn: 146468
These modifiers simply select either the low or high D subregister of a Neon
Q register. I've also removed the unimplemented 'p' modifier, which turns out
to be a bit different than the comment here suggests and as far as I can tell
was only intended for internal use in Apple's version of gcc.
llvm-svn: 146417
I followed three heuristics for deciding whether to set 'true' or
'false':
- Everything target independent got 'true' as that is the expected
common output of the GCC builtins.
- If the target arch only has one way of implementing this operation,
set the flag in the way that exercises the most of codegen. For most
architectures this is also the likely path from a GCC builtin, with
'true' being set. It will (eventually) require lowering away that
difference, and then lowering to the architecture's operation.
- Otherwise, set the flag differently dependending on which target
operation should be tested.
Let me know if anyone has any issue with this pattern or would like
specific tests of another form. This should allow the x86 codegen to
just iteratively improve as I teach the backend how to differentiate
between the two forms, and everything else should remain exactly the
same.
llvm-svn: 146370
intrinsic syntax.
Now that this is explicitly covered, I plan to upgrade the existing test
suite to use an explicit immediate. Note that I plan to specify 'true'
in most places rather than the auto-upgraded value as that is the far
more common value to end up here as that is the value coming from GCC's
builtins. The only place I'm likely to put a 'false' in is when testing
x86 which actually has different instructions for the two variants.
llvm-svn: 146369
does. The _GLOBAL_OFFSET_TABLE_ is still magical in that we get a R_386_GOTPC,
but it doesn't change the immediate in the same way as when the expression
has no right hand side symbol.
llvm-svn: 146311
When the immediate operand of an AND or BIC instruction isn't representable
in the immediate field of the instruction, but the bitwise negation of the
immediate is, assemble the instruction as the inverse operation instead
with the inverted immediate as the operand.
rdar://10550057
llvm-svn: 146283
Refactor the instructions into fixed writeback and register-stride
writeback variants to simplify the offset operand (no more optional
register operand using reg0). This is a simpler representation and allows
the assembly parser to more easily handle these instructions.
Add tests for the instruction variants now supported.
llvm-svn: 146278
generates the dwarf Compile Unit DIE and a dwarf subprogram DIE for each
non-temporary label.
The next part will be to get the clang driver to enable this when assembling
a .s file. rdar://9275556
llvm-svn: 146262
Patch by Brendon Cahoon!
This extends the existing LoopUnroll and LoopUnrollPass. Brendon
measured no regressions in the llvm test suite with -unroll-runtime
enabled. This implementation works by using the existing loop
unrolling code to unroll the loop by a power-of-two (default 8). It
generates an if-then-else sequence of code prior to the loop to
execute the extra iterations before entering the unrolled loop.
llvm-svn: 146245
We must not issue a bitcast operation for integer-promotion of vector types, because the
location of the values in the vector may be different.
llvm-svn: 146150
When the file isn't being built with subsections-via-symbols, symbol
differences involving non-local symbols can be resolved more aggressively.
Needed for gas compatibility.
llvm-svn: 146054
It's always good to prune early, but formulae that are unsatisfactory
in their own right need to be removed before running any other pruning
heuristics. We easily avoid generating such formulae, but we need them
as an intermediate basis for forming other good formulae.
llvm-svn: 145906
Previously, all ARM::CONSTPOOL_ENTRY instructions had a hardwired
alignment of 4 bytes emitted by ARMAsmPrinter. Now the same alignment
is set on the basic block.
This is in preparation of supporting ARM constant pool islands with
different alignments.
llvm-svn: 145890
libgcc sets the stack limit field in TCB to 256 bytes above the actual
allocated stack limit. This means if the function's stack frame needs
less than 256 bytes, we can just compare the stack pointer with the
stack limit. This should result in lesser calls to __morestack.
llvm-svn: 145766
Currently LLVM pads the call to __morestack with a add and sub of 8
bytes to esp. This isn't correct since __morestack expects the call
to be followed directly by a ret.
This commit also adjusts the relevant test-case.
llvm-svn: 145765
argument value type. Otherwise, the sign/zero-extend has no effect on arguments
passed via the stack (i.e., undefined high-order bits).
rdar://10515467
llvm-svn: 145701
Like V_SET0, these instructions are expanded by ExpandPostRA to xorps /
vxorps so they can participate in execution domain swizzling.
This also makes the AVX variants redundant.
llvm-svn: 145440
weak variable are compiled by different compilers, such as GCC and LLVM, while
LLVM may increase the alignment to the preferred alignment there is no reason to
think that GCC will use anything more than the ABI alignment. Since it is the
GCC version that might end up in the final program (as the linkage is weak), it
is wrong to increase the alignment of loads from the global up to the preferred
alignment as the alignment might only be the ABI alignment.
Increasing alignment up to the ABI alignment might be OK, but I'm not totally
convinced that it is. It seems better to just leave the alignment of weak
globals alone.
llvm-svn: 145413
as MC is the only assembler we support.
This splits MS/Windows and GNU/Windows ASM infos into two seperate classes.
While there is currently only one difference, full MS C++ ABI support will
require many more.
llvm-svn: 145409
Conservatively returns zero when the GV does not specify an alignment nor is it
initialized. Previously it returns ABI alignment for type of the GV. However, if
the type is a "packed" type, then the under-specified alignments is attached to
the load / store instructions. In that case, the alignment of the type cannot be
trusted.
rdar://10464621
llvm-svn: 145300
than ABI alignment. These are loads / stores from / to "packed" data structures.
Their alignments are intentionally under-specified.
rdar://10301431
llvm-svn: 145273
was centered around the premise of laying out a loop in a chain, and
then rotating that chain. This is good for preserving contiguous layout,
but bad for actually making sane rotations. In order to keep it safe,
I had to essentially make it impossible to rotate deeply nested loops.
The information needed to correctly reason about a deeply nested loop is
actually available -- *before* we layout the loop. We know the inner
loops are already fused into chains, etc. We lose information the moment
we actually lay out the loop.
The solution was the other alternative for this algorithm I discussed
with Benjamin and some others: rather than rotating the loop
after-the-fact, try to pick a profitable starting block for the loop's
layout, and then use our existing layout logic. I was worried about the
complexity of this "pick" step, but it turns out such complexity is
needed to handle all the important cases I keep teasing out of benchmarks.
This is, I'm afraid, a bit of a work-in-progress. It is still
misbehaving on some likely important cases I'm investigating in Olden.
It also isn't really tested. I'm going to try to craft some interesting
nested-loop test cases, but it's likely to be extremely time consuming
and I don't want to go there until I'm sure I'm testing the correct
behavior. Sadly I can't come up with a way of getting simple, fine
grained test cases for this logic. We need complex loop structures to
even trigger much of it.
llvm-svn: 145183
heavily on AnalyzeBranch. That routine doesn't behave as we want given
that rotation occurs mid-way through re-ordering the function. Instead
merely check that there are not unanalyzable branching constructs
present, and then reason about the CFG via successor lists. This
actually simplifies my mental model for all of this as well.
The concrete result is that we now will rotate more loop chains. I've
added a test case from Olden highlighting the effect. There is still
a bit more to do here though in order to regain all of the performance
in Olden.
llvm-svn: 145179
pass. This is designed to achieve one of the important optimizations
that the old code placement pass did, but more simply.
This is a somewhat rough and *very* conservative version of the
transform. We could get a lot fancier here if there are profitable cases
to do so. In particular, this only looks for a single pattern, it
insists that the loop backedge being rotated away is the last backedge
in the chain, and it doesn't provide any means of doing better in-loop
placement due to the rotation. However, it appears that it will handle
the important loops I am finding in the LLVM test suite.
llvm-svn: 145158
was returning incorrect values in rare cases, and incorrectly marking
exact conversions as inexact in some more common cases. Fixes PR11406, and a
missed optimization in test/CodeGen/X86/fp-stack-O0.ll.
llvm-svn: 145141
need lots of fanciness around retaining a reference to a Chain's slot in
the BlockToChain map, but that's all gone now. We can just go directly
to allocating the new chain (which will update the mapping for us) and
using it.
Somewhat gross mechanically generated test case replicates the issue
Duncan spotted when actually testing this out.
llvm-svn: 145120
conflicts, we should only be adding the first block of the chain to the
list, lest we try to merge into the middle of that chain. Most of the
places we were doing this we already happened to be looking at the first
block, but there is no reason to assume that, and in some cases it was
clearly wrong.
I've added a couple of tests here. One already worked, but I like having
an explicit test for it. The other is reduced from a test case Duncan
reduced for me and used to crash. Now it is handled correctly.
llvm-svn: 145119
and positive: positive, because it could be directly computed to be positive;
negative, because the nsw flags means it is either negative or undefined (the
multiplication always overflowed).
llvm-svn: 145104
Before:
movabsq $4294967296, %rax ## encoding: [0x48,0xb8,0x00,0x00,0x00,0x00,0x01,0x00,0x00,0x00]
testq %rax, %rdi ## encoding: [0x48,0x85,0xf8]
jne LBB0_2 ## encoding: [0x75,A]
After:
btq $32, %rdi ## encoding: [0x48,0x0f,0xba,0xe7,0x20]
jb LBB0_2 ## encoding: [0x72,A]
btq is usually slower than testq because it doesn't fuse with the jump, but here we're better off
saving one register and a giant movabsq.
llvm-svn: 145103
further. This invariant just wasn't going to work in the face of
unanalyzable branches; we need to be resillient to the phenomenon of
chains poking into a loop and poking out of a loop. In fact, we already
were, we just needed to not assert on it.
This was found during a bootstrap with block placement turned on.
llvm-svn: 145100
successors, they just are all landing pad successors. We handle this the
same way as no successors. Comments attached for the next person to wade
through here and another lovely test case courtesy of Benjamin Kramer's
bugpoint reduction.
llvm-svn: 145098
This was a bug in keeping track of the available domains when merging
domain values.
The wrong domain mask caused ExecutionDepsFix to try to move VANDPSYrr
to the integer domain which is only available in AVX2.
Also add an assertion to catch future attempts at emitting AVX2
instructions.
llvm-svn: 145096
reversed in the function's original ordering, and we happened to
encounter it while handling an outer unnatural CFG structure.
Thanks to the test case reduced from GCC's source by Benjamin Kramer.
This may also fix a crasher in gzip that Duncan reduced for me, but
I haven't yet gotten to testing that one.
llvm-svn: 145094
updateTerminator code didn't correctly handle EH terminators in one very
specific case. AnalyzeBranch would find no terminator instruction, and
so the fallback in updateTerminator is to assume fallthrough. This is
correct, but the destination of the fallthrough was assumed to be the
first successor.
This is *almost always* true, but in certain cases the loop
transformations will cause the landing pad to be the first successor!
Instead of this brittle logic, actually look through the successors for
a non-landing-pad accessor, and to assert if more than one is found.
This will hopefully fix some (if not all) of the self host miscompiles
with block placement. Thanks to Benjamin Kramer for reporting, Nick
Lewycky for an initial stab at a reduction, and Duncan for endless
advice on EH (which I know nothing about) as well as reviewing the
actual fix.
llvm-svn: 145062
properly account for the *global* probability of the edge being taken.
This manifested as a very large number of unconditional branches to
blocks being merged against the CFG even though they weren't
particularly hot within the CFG.
The fix is to check whether the edge being merged is both locally hot
relative to other successors for the source block, and globally hot
compared to other (unmerged) predecessors of the destination block.
This introduces a new crasher on GCC single-source, but it's currently
behind a flag, and Ben has offered to work on the reduction. =]
llvm-svn: 145010
is actually being tested. Also add some FileCheck goodness to much more
carefully ensure that the result is the desired result. Before this test
would only have failed through an assert failure if the underlying fix
were reverted.
Also, add some weight metadata and a comment explaining exactly what is
going on to a trick section of the test case. Originally, we were
getting very unlucky and trying to form a block chain that isn't
actually profitable. I'm working on a fix to avoid forming these
unprofitable chains, and that would also have masked any failure from
this test case. The easy solution is to add some metadata that makes it
*really* profitable to form the bad chain here.
llvm-svn: 145006
formation phase and into the initial walk of the basic blocks. We
essentially pre-merge all blocks where unanalyzable fallthrough exists,
as we won't be able to update the terminators effectively after any
reorderings. This is quite a bit more principled as there may be CFGs
where the second half of the unanalyzable pair has some analyzable
predecessor that gets placed first. Then it may get placed next,
implicitly breaking the unanalyzable branch even though we never even
looked at the part that isn't analyzable. I've included a test case that
triggers this (thanks Benjamin yet again!), and I'm hoping to synthesize
some more general ones as I dig into related issues.
Also, to make this new scheme work we have to be able to handle branches
into the middle of a chain, so add this check. We always fallback on the
incoming ordering.
Finally, this starts to really underscore a known limitation of the
current implementation -- we don't consider broken predecessors when
merging successors. This can caused major missed opportunities, and is
something I'm planning on looking at next (modulo more bug reports).
llvm-svn: 144994
The loop tree's inclusive block lists are painful and expensive to
update. (I have no idea why they're inclusive). The design was
supposed to handle this case but the implementation missed it and my
unit tests weren't thorough enough.
Fixes PR11335: loop unroll update.
llvm-svn: 144970
The right way to check for a binary operation is
cast<BinaryOperator>. The original check: cast<Instruction> &&
numOperands() == 2 would match phi "instructions", leading to an
infinite loop in extreme corner case: a useless phi with operands
[self, constant] that prior optimization passes failed to remove,
being used in the loop by another useless phi, in turn being used by an
lshr or udiv.
Fixes PR11350: runaway iteration assertion.
llvm-svn: 144935
ADDs. MaxOffs is used as a threshold to limit the size of the offset. Tradeoffs
being: (1) If we can't materialize the large constant then we'll cause fast-isel
to bail. (2) Too large of an offset can't be directly encoded in the ADD
resulting in a MOV+ADD. Generally not a bad thing because otherwise we would
have had ADD+ADD, but on Thumb this turns into a MOVS+MOVT+ADD. Working on a fix
for that. (3) Conversely, too low of a threshold we'll miss opportunities to
coalesce ADDs.
rdar://10412592
llvm-svn: 144886
We don't (yet) have the granularity in the fixups to be specific about which
bitranges are affected. That's a future cleanup, but we're not there yet.
llvm-svn: 144852
For example,
vld1.f64 {d2-d5}, [r2,:128]!
Should be equivalent to:
vld1.f64 {d2,d3,d4,d5}, [r2,:128]!
It's not documented syntax in the ARM ARM, but it is consistent with what's
accepted for VLDM/VSTM and is unambiguous in meaning, so it's a good thing to
support.
rdar://10451128
llvm-svn: 144727
When the 3rd operand is not a low-register, and the first two operands are
the same low register, the parser was incorrectly trying to use the 16-bit
instruction encoding.
rdar://10449281
llvm-svn: 144679
has a reference to it. Unfortunately, that doesn't work for codegen passes
since we don't get notified of MBB's being deleted (the original BB stays).
Use that fact to our advantage and after printing a function, check if
any of the IL BBs corresponds to a symbol that was not printed. This fixes
pr11202.
llvm-svn: 144674
block sequence when recovering from unanalyzable control flow
constructs, *always* use the function sequence. I'm not sure why I ever
went down the path of trying to use the loop sequence, it is
fundamentally not the correct sequence to use. We're trying to preserve
the incoming layout in the cases of unreasonable control flow, and that
is only encoded at the function level. We already have a filter to
select *exactly* the sub-set of blocks within the function that we're
trying to form into a chain.
The resulting code layout is also significantly better because of this.
In several places we were ending up with completely unreasonable control
flow constructs due to the ordering chosen by the loop structure for its
internal storage. This change removes a completely wasteful vector of
basic blocks, saving memory allocation in the common case even though it
costs us CPU in the fairly rare case of unnatural loops. Finally, it
fixes the latest crasher reduced out of GCC's single source. Thanks
again to Benjamin Kramer for the reduction, my bugpoint skills failed at
it.
llvm-svn: 144627
Two new TargetInstrInfo hooks lets the target tell ExecutionDepsFix
about instructions with partial register updates causing false unwanted
dependencies.
The ExecutionDepsFix pass will break the false dependencies if the
updated register was written in the previoius N instructions.
The small loop added to sse-domains.ll runs twice as fast with
dependency-breaking instructions inserted.
llvm-svn: 144602
and stores capture) to permit the caller to see each capture point and decide
whether to continue looking.
Use this inside memdep to do an analysis that basicaa won't do. This lets us
solve another devirtualization case, fixing PR8908!
llvm-svn: 144580
instructions of the two-address operands) in order to avoid inserting copies.
This fixes the few regressions introduced when the two-address hack was
disabled (without regressing the improvements).
rdar://10422688
llvm-svn: 144559
the sum of the edge weights not overflowing uint32, and crashed when
they did. This is generally safe as BranchProbabilityInfo tries to
provide this guarantee. However, the CFG can get modified during codegen
in a way that grows the *sum* of the edge weights. This doesn't seem
unreasonable (imagine just adding more blocks all with the default
weight of 16), but it is hard to come up with a case that actually
triggers 32-bit overflow. Fortuately, the single-source GCC build is
good at this. The solution isn't very pretty, but its no worse than the
previous code. We're already summing all of the edge weights on each
query, we can sum them, check for an overflow, compute a scale, and sum
them again.
I've included a *greatly* reduced test case out of the GCC source that
triggers it. It's a pretty lame test, as it clearly is just barely
triggering the overflow. I'd like to have something that is much more
definitive, but I don't understand the fundamental pattern that triggers
an explosion in the edge weight sums.
The buggy code is duplicated within this file. I'll colapse them into
a single implementation in a subsequent commit.
llvm-svn: 144526
get loop info structures associated with them, and so we need some way
to make forward progress selecting and placing basic blocks. The
technique used here is pretty brutal -- it just scans the list of blocks
looking for the first unplaced candidate. It keeps placing blocks like
this until the CFG becomes tractable.
The cost is somewhat unfortunate, it requires allocating a vector of all
basic block pointers eagerly. I have some ideas about how to simplify
and optimize this, but I'm trying to get the logic correct first.
Thanks to Benjamin Kramer for the reduced test case out of GCC. Sadly
there are other bugs that GCC is tickling that I'm reducing and working
on now.
llvm-svn: 144516
second algorithm, but only loosely. It is more heavily based on the last
discussion I had with Andy. It continues to walk from the inner-most
loop outward, but there is a key difference. With this algorithm we
ensure that as we visit each loop, the entire loop is merged into
a single chain. At the end, the entire function is treated as a "loop",
and merged into a single chain. This chain forms the desired sequence of
blocks within the function. Switching to a single algorithm removes my
biggest problem with the previous approaches -- they had different
behavior depending on which system triggered the layout. Now there is
exactly one algorithm and one basis for the decision making.
The other key difference is how the chain is formed. This is based
heavily on the idea Andy mentioned of keeping a worklist of blocks that
are viable layout successors based on the CFG. Having this set allows us
to consistently select the best layout successor for each block. It is
expensive though.
The code here remains very rough. There is a lot that needs to be done
to clean up the code, and to make the runtime cost of this pass much
lower. Very much WIP, but this was a giant chunk of code and I'd rather
folks see it sooner than later. Everything remains behind a flag of
course.
I've added a couple of tests to exercise the issues that this iteration
was motivated by: loop structure preservation. I've also fixed one test
that was exhibiting the broken behavior of the previous version.
llvm-svn: 144495
SimplifyAddress to handle either a 12-bit unsigned offset or the ARM +/-imm8
offsets (addressing mode 3). This enables a load followed by an integer
extend to be folded into a single load.
For example:
ldrb r1, [r0] ldrb r1, [r0]
uxtb r2, r1 =>
mov r3, r2 mov r3, r1
llvm-svn: 144488
It was off by default.
The new register allocators don't have the problems that made it
necessary to reallocate registers during stack slot coloring.
llvm-svn: 144481
instance and a concrete inlined instance are the use of DW_TAG_subprogram
instead of DW_TAG_inlined_subroutine and the who owns the tree.
We were also omitting DW_AT_inline from the abstract roots. To fix this,
make sure we mark abstract instance roots with DW_AT_inline even when
we have only out-of-line instances referring to them with DW_AT_abstract_origin.
FileCheck is not a very good tool for tests like this, maybe we should add
a -verify mode to llvm-dwarfdump.
llvm-svn: 144441
lead to it trying to re-mark a value marked as a constant with a different value. It also appears to trigger very rarely.
Fixes PR11357.
llvm-svn: 144352
Get the source register that isn't tied to the destination register correct,
even when the assembly source operand order is backwards.
rdar://10428630
llvm-svn: 144322
instruction lower optimization" in the pre-RA scheduler.
The optimization, rather the hack, was done before MI use-list was available.
Now we should be able to implement it in a better way, perhaps in the
two-address pass until a MI scheduler is available.
Now that the scheduler has to backtrack to handle call sequences. Adding
artificial scheduling constraints is just not safe. Furthermore, the hack
is not taking all the other scheduling decisions into consideration so it's just
as likely to pessimize code. So I view disabling this optimization goodness
regardless of PR11314.
llvm-svn: 144267
The TII.foldMemoryOperand hook preserves implicit operands from the
original instruction. This is not what we want when those implicit
operands refer to the register being spilled.
Implicit operands referring to other registers are preserved.
This fixes PR11347.
llvm-svn: 144247
Currently checks alignment and killing stores on a power of 2 boundary as this is likely
to trim the size of the earlier store without breaking large vector stores into scalar ones.
Fixes <rdar://problem/10140300>
llvm-svn: 144239
dragonegg self-host buildbot will recover (it is complaining about object
files differing between different build stages). Original commit message:
Add a hack to the scheduler to disable pseudo-two-address dependencies in
basic blocks containing calls. This works around a problem in which
these artificial dependencies can get tied up in calling seqeunce
scheduling in a way that makes the graph unschedulable with the current
approach of using artificial physical register dependencies for calling
sequences. This fixes PR11314.
llvm-svn: 144188
During the initial RPO traversal of the basic blocks, remember the ones
that are incomplete because of back-edges from predecessors that haven't
been visited yet.
After the initial RPO, revisit all those loop headers so the incoming
DomainValues on the back-edges can be properly collapsed.
This will properly fix execution domains on software pipelined code,
like the included test case.
llvm-svn: 144151
basic blocks containing calls. This works around a problem in which
these artificial dependencies can get tied up in calling seqeunce
scheduling in a way that makes the graph unschedulable with the current
approach of using artificial physical register dependencies for calling
sequences. This fixes PR11314.
llvm-svn: 144124
Add support for trimming constants to GetDemandedBits. This fixes some funky
constant generation that occurs when stores are expanded for targets that don't
support unaligned stores natively.
llvm-svn: 144102
callee's responsibility to sign or zero-extend the return value. The additional
test case just checks to make sure the calls are selected (i.e., -fast-isel-abort
doesn't assert).
llvm-svn: 144047
DomainValues that are only used by "don't care" instructions are now
collapsed to the first possible execution domain after all basic blocks
have been processed. This typically means the PS domain on x86.
For example, the vsel_i64 and vsel_double functions in sse2-blend.ll are
completely collapsed to the PS domain instead of containing a mix of
execution domains created by isel.
llvm-svn: 144037
The xorps instruction is smaller than pxor, so prefer that encoding.
The ExecutionDepsFix pass will switch the encoding to pxor and xorpd
when appropriate.
llvm-svn: 143996
zero-extend the constant integer encoding. Test case provides testing for
both call parameters and materialization of i1, i8, and i16 types.
llvm-svn: 143821
Only currently done if the later store is writing to a power of 2 address or
has the same alignment as the earlier store as then its likely to not break up
large stores into smaller ones
Fixes <rdar://problem/10140300>
llvm-svn: 143630
We've been hitting asserts in this code due to the many supported
combintions of modes (iv-rewrite/no-iv-rewrite) and IV types. This
second rewrite of the code attempts to deal with these cases systematically.
llvm-svn: 143546
it is separating the directory part from the basename of the FileName. Noticed
that this:
.file 1 "dir/foo"
when assembled got the two parts switched. Using the Mac OS X dwarfdump tool
it can be seen easily:
% dwarfdump -a a.out
include_directories[ 1] = 'foo'
Dir Mod Time File Len File Name
---- ---------- ---------- ---------------------------
file_names[ 1] 1 0x00000000 0x00000000 dir
...
Which should be:
...
include_directories[ 1] = 'dir'
Dir Mod Time File Len File Name
---- ---------- ---------- ---------------------------
file_names[ 1] 1 0x00000000 0x00000000 foo
llvm-svn: 143521
with the given predicate, it matches any condition and returns the
predicate - d'oh! Original commit message:
The expression icmp eq (select (icmp eq x, 0), 1, x), 0 folds to false.
Spotted by my super-optimizer in 186.crafty and 450.soplex. We really
need a proper infrastructure for handling generalizations of this kind
of thing (which occur a lot), however this case is so simple that I decided
to go ahead and implement it directly.
llvm-svn: 143318
On x86: (shl V, 1) -> add V,V
Hardware support for vector-shift is sparse and in many cases we scalarize the
result. Additionally, on sandybridge padd is faster than shl.
llvm-svn: 143311
Spotted by my super-optimizer in 186.crafty and 450.soplex. We really
need a proper infrastructure for handling generalizations of this kind
of thing (which occur a lot), however this case is so simple that I decided
to go ahead and implement it directly.
llvm-svn: 143214
fixes: Use a separate register, instead of SP, as the
calling-convention resource, to avoid spurious conflicts with
actual uses of SP. Also, fix unscheduling of calling sequences,
which can be triggered by pseudo-two-address dependencies.
llvm-svn: 143206
Outside an IT block, "add r3, #2" should select a 32-bit wide encoding
rather than generating an error indicating the 16-bit encoding is only
legal in an IT block (outside, the 'S' suffic is required for the 16-bit
encoding).
rdar://10348481
llvm-svn: 143201
Don't assume APInt::getRawData() would hold target-aware endianness nor host-compliant endianness. rawdata[0] holds most lower i64, even on big endian host.
FIXME: Add a testcase for big endian target.
FIXME: Ditto on CompileUnit::addConstantFPValue() ?
llvm-svn: 143194
it fixes the dragonegg self-host (it looks like gcc is miscompiled).
Original commit messages:
Eliminate LegalizeOps' LegalizedNodes map and have it just call RAUW
on every node as it legalizes them. This makes it easier to use
hasOneUse() heuristics, since unneeded nodes can be removed from the
DAG earlier.
Make LegalizeOps visit the DAG in an operands-last order. It previously
used operands-first, because LegalizeTypes has to go operands-first, and
LegalizeTypes used to be part of LegalizeOps, but they're now split.
The operands-last order is more natural for several legalization tasks.
For example, it allows lowering code for nodes with floating-point or
vector constants to see those constants directly instead of seeing the
lowered form (often constant-pool loads). This makes some things
somewhat more complicated today, though it ought to allow things to be
simpler in the future. It also fixes some bugs exposed by Legalizing
using RAUW aggressively.
Remove the part of LegalizeOps that attempted to patch up invalid chain
operands on libcalls generated by LegalizeTypes, since it doesn't work
with the new LegalizeOps traversal order. Instead, define what
LegalizeTypes is doing to be correct, and transfer the responsibility
of keeping calls from having overlapping calling sequences into the
scheduler.
Teach the scheduler to model callseq_begin/end pairs as having a
physical register definition/use to prevent calls from having
overlapping calling sequences. This is also somewhat complicated, though
there are ways it might be simplified in the future.
This addresses rdar://9816668, rdar://10043614, rdar://8434668, and others.
Please direct high-level questions about this patch to management.
Delete #if 0 code accidentally left in.
llvm-svn: 143188
on every node as it legalizes them. This makes it easier to use
hasOneUse() heuristics, since unneeded nodes can be removed from the
DAG earlier.
Make LegalizeOps visit the DAG in an operands-last order. It previously
used operands-first, because LegalizeTypes has to go operands-first, and
LegalizeTypes used to be part of LegalizeOps, but they're now split.
The operands-last order is more natural for several legalization tasks.
For example, it allows lowering code for nodes with floating-point or
vector constants to see those constants directly instead of seeing the
lowered form (often constant-pool loads). This makes some things
somewhat more complicated today, though it ought to allow things to be
simpler in the future. It also fixes some bugs exposed by Legalizing
using RAUW aggressively.
Remove the part of LegalizeOps that attempted to patch up invalid chain
operands on libcalls generated by LegalizeTypes, since it doesn't work
with the new LegalizeOps traversal order. Instead, define what
LegalizeTypes is doing to be correct, and transfer the responsibility
of keeping calls from having overlapping calling sequences into the
scheduler.
Teach the scheduler to model callseq_begin/end pairs as having a
physical register definition/use to prevent calls from having
overlapping calling sequences. This is also somewhat complicated, though
there are ways it might be simplified in the future.
This addresses rdar://9816668, rdar://10043614, rdar://8434668, and others.
Please direct high-level questions about this patch to management.
llvm-svn: 143177
Benjamin Kramer