The MachineFunction wasn't used in getOptimalMemOpType, but more importantly,
this allows reuse of findOptimalMemOpLowering that is calling getOptimalMemOpType.
This is the groundwork for the changes in D59766 and D59787, that allows
implementation of TTI::getMemcpyCost.
Differential Revision: https://reviews.llvm.org/D59785
llvm-svn: 359537
This patch teach getTestBitOperand to look through ANY_EXTENDs when the extended bits aren't used. The test case changed here is based what D60358 did to test16 in tbz-tbnz.ll. So this patch will avoid that regression.
Differential Revision: https://reviews.llvm.org/D60482
llvm-svn: 358108
This patch follows some ideas from r352866 to optimize the floating
point materialization even further. It changes isFPImmLegal to
considere up to 2 mov instruction or up to 5 in case subtarget has
fused literals.
The rationale is the cost is the same for mov+fmov vs. adrp+ldr; but
the mov+fmov sequence is always better because of the reduced d-cache
pressure. The timings are still the same if you consider movw+movk+fmov
vs. adrp+ldr will be fused (although one instruction longer).
Reviewers: efriedma
Differential Revision: https://reviews.llvm.org/D58460
llvm-svn: 356390
This allows better code size for aarch64 floating point materialization
in a future patch.
Reviewers: evandro
Differential Revision: https://reviews.llvm.org/D58690
llvm-svn: 356389
Switch BIC immediate creation for vector ANDs from custom lowering
to a DAG combine, which gives generic DAG combines a change to
apply first. In particular this avoids (and x, -1) being turned into
a (bic x, 0) instead of being eliminated entirely.
Differential Revision: https://reviews.llvm.org/D59187
llvm-svn: 356299
Fixes https://bugs.llvm.org/show_bug.cgi?id=36796.
Implement basic legalizations (PromoteIntRes, PromoteIntOp,
ExpandIntRes, ScalarizeVecOp, WidenVecOp) for VECREDUCE opcodes.
There are more legalizations missing (esp float legalizations),
but there's no way to test them right now, so I'm not adding them.
This also includes a few more changes to make this work somewhat
reasonably:
* Add support for expanding VECREDUCE in SDAG. Usually
experimental.vector.reduce is expanded prior to codegen, but if the
target does have native vector reduce, it may of course still be
necessary to expand due to legalization issues. This uses a shuffle
reduction if possible, followed by a naive scalar reduction.
* Allow the result type of integer VECREDUCE to be larger than the
vector element type. For example we need to be able to reduce a v8i8
into an (nominally) i32 result type on AArch64.
* Use the vector operand type rather than the scalar result type to
determine the action, so we can control exactly which vector types are
supported. Also change the legalize vector op code to handle
operations that only have vector operands, but no vector results, as
is the case for VECREDUCE.
* Default VECREDUCE to Expand. On AArch64 (only target using VECREDUCE),
explicitly specify for which vector types the reductions are supported.
This does not handle anything related to VECREDUCE_STRICT_*.
Differential Revision: https://reviews.llvm.org/D58015
llvm-svn: 355860
This is a follow up to D48580 and D48581 which allows reserving
arbitrary general purpose registers with the exception of registers
with special purpose (X8, X16-X18, X29, X30) and registers used by LLVM
(X0, X19). This change also generalizes some of the existing logic to
rely entirely on values generated from tablegen.
Differential Revision: https://reviews.llvm.org/D56305
llvm-svn: 353957
AArch64 NEON has a bunch of instructions with a "2" suffix that extract
the top half of the source vectors, instead of the bottom half. We have
some DAGCombines to try to take advantage of that. However, they
assumed that any EXTRACT_VECTOR was extracting the high half of the
vector in question.
This issue has apparently existed since the AArch64 backend was merged.
Fixes https://bugs.llvm.org/show_bug.cgi?id=40632 .
Differential Revision: https://reviews.llvm.org/D57862
llvm-svn: 353486
This patch improves code generation for some AArch64 ACLE intrinsics. It adds
support to CGP to duplicate and sink operands to their user, if they can be
folded into a target instruction, like zexts and sub into usubl. It adds a
TargetLowering hook shouldSinkOperands, which looks at the operands of
instructions to see if sinking is profitable.
I decided to add a new target hook, as for the sinking to be profitable,
at least on AArch64, we have to look at multiple operands of an
instruction, instead of looking at the users of a zext for example.
The sinking is done in CGP, because it works around an instruction
selection limitation. If instruction selection is not limited to a
single basic block, this patch should not be needed any longer.
Alternatively this could be done in the LoopSink pass, which tries to
undo LICM for instructions in blocks that are not executed frequently.
Note that we do not force the operands to sink to have a single user,
because we duplicate them before sinking. Therefore this is only
desirable if they really can be done for free. Additionally we could
consider the impact on live ranges later on.
This should fix https://bugs.llvm.org/show_bug.cgi?id=40025.
As for performance, we have internal code that uses intrinsics and can
be speed up by 10% by this change.
Reviewers: SjoerdMeijer, t.p.northover, samparker, efriedma, RKSimon, spatel
Reviewed By: samparker
Differential Revision: https://reviews.llvm.org/D57377
llvm-svn: 353152
Summary: This fixes using the correct stack registers for SEH when stack realignment is needed or when variable size objects are present.
Reviewers: rnk, efriedma, ssijaric, TomTan
Reviewed By: rnk, efriedma
Subscribers: javed.absar, kristof.beyls, llvm-commits
Differential Revision: https://reviews.llvm.org/D57183
llvm-svn: 352923
This cleans up all GetElementPtr creation in LLVM to explicitly pass a
value type rather than deriving it from the pointer's element-type.
Differential Revision: https://reviews.llvm.org/D57173
llvm-svn: 352913
This cleans up all CallInst creation in LLVM to explicitly pass a
function type rather than deriving it from the pointer's element-type.
Differential Revision: https://reviews.llvm.org/D57170
llvm-svn: 352909
This patch changes isFPImmLegal to return if the value can be enconded
as the immediate operand of a logical instruction besides checking if
for immediate field for fmov.
This optimizes some floating point materization, inclusive values
used on isinf lowering.
Reviewed By: rengolin, efriedma, evandro
Differential Revision: https://reviews.llvm.org/D57044
llvm-svn: 352866
Recommit r352791 after tweaking DerivedTypes.h slightly, so that gcc
doesn't choke on it, hopefully.
Original Message:
The FunctionCallee type is effectively a {FunctionType*,Value*} pair,
and is a useful convenience to enable code to continue passing the
result of getOrInsertFunction() through to EmitCall, even once pointer
types lose their pointee-type.
Then:
- update the CallInst/InvokeInst instruction creation functions to
take a Callee,
- modify getOrInsertFunction to return FunctionCallee, and
- update all callers appropriately.
One area of particular note is the change to the sanitizer
code. Previously, they had been casting the result of
`getOrInsertFunction` to a `Function*` via
`checkSanitizerInterfaceFunction`, and storing that. That would report
an error if someone had already inserted a function declaraction with
a mismatching signature.
However, in general, LLVM allows for such mismatches, as
`getOrInsertFunction` will automatically insert a bitcast if
needed. As part of this cleanup, cause the sanitizer code to do the
same. (It will call its functions using the expected signature,
however they may have been declared.)
Finally, in a small number of locations, callers of
`getOrInsertFunction` actually were expecting/requiring that a brand
new function was being created. In such cases, I've switched them to
Function::Create instead.
Differential Revision: https://reviews.llvm.org/D57315
llvm-svn: 352827
This reverts commit f47d6b38c7 (r352791).
Seems to run into compilation failures with GCC (but not clang, where
I tested it). Reverting while I investigate.
llvm-svn: 352800
The FunctionCallee type is effectively a {FunctionType*,Value*} pair,
and is a useful convenience to enable code to continue passing the
result of getOrInsertFunction() through to EmitCall, even once pointer
types lose their pointee-type.
Then:
- update the CallInst/InvokeInst instruction creation functions to
take a Callee,
- modify getOrInsertFunction to return FunctionCallee, and
- update all callers appropriately.
One area of particular note is the change to the sanitizer
code. Previously, they had been casting the result of
`getOrInsertFunction` to a `Function*` via
`checkSanitizerInterfaceFunction`, and storing that. That would report
an error if someone had already inserted a function declaraction with
a mismatching signature.
However, in general, LLVM allows for such mismatches, as
`getOrInsertFunction` will automatically insert a bitcast if
needed. As part of this cleanup, cause the sanitizer code to do the
same. (It will call its functions using the expected signature,
however they may have been declared.)
Finally, in a small number of locations, callers of
`getOrInsertFunction` actually were expecting/requiring that a brand
new function was being created. In such cases, I've switched them to
Function::Create instead.
Differential Revision: https://reviews.llvm.org/D57315
llvm-svn: 352791
Summary:
Avoids duplicating generated static helpers for calling convention
analysis.
This also means you can modify AArch64CallingConv.td without recompiling
the AArch64ISelLowering.cpp monolith, so it provides faster incremental
rebuilds.
Saves 12K in llc.exe, but adds a new object file, which is large.
Reviewers: efriedma, t.p.northover
Subscribers: mgorny, javed.absar, kristof.beyls, hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D56948
llvm-svn: 352430
This broke the RISCV build, and even with that fixed, one of the RISCV
tests behaves surprisingly differently with asserts than without,
leaving there no clear test pattern to use. Generally it seems bad for
hte IR to differ substantially due to asserts (as in, an alloca is used
with asserts that isn't needed without!) and nothing I did simply would
fix it so I'm reverting back to green.
This also required reverting the RISCV build fix in r351782.
llvm-svn: 351796
to reflect the new license.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
llvm-svn: 351636
Summary:
This patch supports MS SEH extensions __try/__except/__finally. The intrinsics localescape and localrecover are responsible for communicating escaped static allocas from the try block to the handler.
We need to preserve frame pointers for SEH. So we create a new function/property HasLocalEscape.
Reviewers: rnk, compnerd, mstorsjo, TomTan, efriedma, ssijaric
Reviewed By: rnk, efriedma
Subscribers: smeenai, jrmuizel, alex, majnemer, ssijaric, ehsan, dmajor, kristina, javed.absar, kristof.beyls, chrib, llvm-commits
Differential Revision: https://reviews.llvm.org/D53540
llvm-svn: 351370
Otherwise, with D56544, the intrinsic will be expanded to an integer
csel, which is probably not what the user expected. This matches the
general convention of using "v1" types to represent scalar integer
operations in vector registers.
While I'm here, also add some error checking so we don't generate
illegal ABS nodes.
Differential Revision: https://reviews.llvm.org/D56616
llvm-svn: 351141
Summary:
This patch changes the legalization action for some half-precision floating-
point vector intrinsics (FSIN, FLOG, etc.) from Promote to Expand. These ops
are not supported in hardware for half-precision vectors, but promotion is
not always possible (for v8f16 operands). Changing the action to Expand fixes
an assertion failure in the legalizer when the frontend produces such ops.
In addition, a quick microbenchmark shows that, in the v4f16 case,
expanding introduces fewer spills and is therefore slightly faster than
promoting.
Reviewers: t.p.northover, SjoerdMeijer
Reviewed By: SjoerdMeijer
Subscribers: javed.absar, kristof.beyls, llvm-commits
Differential Revision: https://reviews.llvm.org/D56296
llvm-svn: 350825
We have code to split vector splats (of zero and non-zero) for performance
reasons, but it ignores the fact that a store might be truncating.
Actually, truncating stores are formed for vNi8 and vNi16 types. Since the
truncation is from a legal type, the size of the store is always <= 64-bits and
so they don't actually benefit from being split up anyway, so this patch just
disables that transformation.
llvm-svn: 350620
The pass implements tracking of control flow miss-speculation into a "taint"
register. That taint register can then be used to mask off registers with
sensitive data when executing under miss-speculation, a.k.a. "transient
execution".
This pass is aimed at mitigating against SpectreV1-style vulnarabilities.
At the moment, it implements the tracking of miss-speculation of control
flow into a taint register, but doesn't implement a mechanism yet to then
use that taint register to mask off vulnerable data in registers (something
for a follow-on improvement). Possible strategies to mask out vulnerable
data that can be implemented on top of this are:
- speculative load hardening to automatically mask of data loaded
in registers.
- using intrinsics to mask of data in registers as indicated by the
programmer (see https://lwn.net/Articles/759423/).
For AArch64, the following implementation choices are made.
Some of these are different than the implementation choices made in
the similar pass implemented in X86SpeculativeLoadHardening.cpp, as
the instruction set characteristics result in different trade-offs.
- The speculation hardening is done after register allocation. With a
relative abundance of registers, one register is reserved (X16) to be
the taint register. X16 is expected to not clash with other register
reservation mechanisms with very high probability because:
. The AArch64 ABI doesn't guarantee X16 to be retained across any call.
. The only way to request X16 to be used as a programmer is through
inline assembly. In the rare case a function explicitly demands to
use X16/W16, this pass falls back to hardening against speculation
by inserting a DSB SYS/ISB barrier pair which will prevent control
flow speculation.
- It is easy to insert mask operations at this late stage as we have
mask operations available that don't set flags.
- The taint variable contains all-ones when no miss-speculation is detected,
and contains all-zeros when miss-speculation is detected. Therefore, when
masking, an AND instruction (which only changes the register to be masked,
no other side effects) can easily be inserted anywhere that's needed.
- The tracking of miss-speculation is done by using a data-flow conditional
select instruction (CSEL) to evaluate the flags that were also used to
make conditional branch direction decisions. Speculation of the CSEL
instruction can be limited with a CSDB instruction - so the combination of
CSEL + a later CSDB gives the guarantee that the flags as used in the CSEL
aren't speculated. When conditional branch direction gets miss-speculated,
the semantics of the inserted CSEL instruction is such that the taint
register will contain all zero bits.
One key requirement for this to work is that the conditional branch is
followed by an execution of the CSEL instruction, where the CSEL
instruction needs to use the same flags status as the conditional branch.
This means that the conditional branches must not be implemented as one
of the AArch64 conditional branches that do not use the flags as input
(CB(N)Z and TB(N)Z). This is implemented by ensuring in the instruction
selectors to not produce these instructions when speculation hardening
is enabled. This pass will assert if it does encounter such an instruction.
- On function call boundaries, the miss-speculation state is transferred from
the taint register X16 to be encoded in the SP register as value 0.
Future extensions/improvements could be:
- Implement this functionality using full speculation barriers, akin to the
x86-slh-lfence option. This may be more useful for the intrinsics-based
approach than for the SLH approach to masking.
Note that this pass already inserts the full speculation barriers if the
function for some niche reason makes use of X16/W16.
- no indirect branch misprediction gets protected/instrumented; but this
could be done for some indirect branches, such as switch jump tables.
Differential Revision: https://reviews.llvm.org/D54896
llvm-svn: 349456
The code emitting AND-subtrees used to check whether any of the operands
was an OR in order to figure out if the result needs to be negated.
However the OR could be hidden in further subtrees and not immediately
visible.
Change the code so that canEmitConjunction() determines whether the
result of the generated subtree needs to be negated. Cleanup emission
logic to use this. I also changed the code a bit to make all negation
decisions early before we actually emit the subtrees.
This fixes http://llvm.org/PR39550
Differential Revision: https://reviews.llvm.org/D54137
llvm-svn: 348444
I believe we should be legalizing these with the rest of vector binary operations. If any custom lowering is required for these nodes, this will give the DAG combine between LegalizeVectorOps and LegalizeDAG to run on the custom code before constant build_vectors are lowered in LegalizeDAG.
I've moved MULHU/MULHS handling in AArch64 from Lowering to isel. Moving the lowering earlier caused build_vector+extract_subvector simplifications to kick in which made the generated code worse.
Differential Revision: https://reviews.llvm.org/D54276
llvm-svn: 347902
A consequence of r347274 is that SCALAR_TO_VECTOR can be converted into
BUILD_VECTOR by SimplifyDemandedBits, but LowerBUILD_VECTOR can turn
BUILD_VECTOR into SCALAR_TO_VECTOR so we get an infinite loop.
Fix this by making LowerBUILD_VECTOR not do this transformation for those
vectors that would get transformed back, i.e. BUILD_VECTOR of a single-element
constant vector. Doing that means we get a DUP, which we then need to recognise
in ISel as a copy.
llvm-svn: 347456
This is a long-awaited follow-up suggested in D33578. Since then, we've picked up even more
opportunities for vector narrowing from changes like D53784, so there are a lot of test diffs.
Apart from 2-3 strange cases, these are all wins.
I've structured this to be no-functional-change-intended for any target except for x86
because I couldn't tell if AArch64, ARM, and AMDGPU would improve or not. All of those
targets have existing regression tests (4, 4, 10 files respectively) that would be
affected. Also, Hexagon overrides the shouldReduceLoadWidth() hook, but doesn't show
any regression test diffs. The trade-off is deciding if an extra vector load is better
than a single wide load + extract_subvector.
For x86, this is almost always better (on paper at least) because we often can fold
loads into subsequent ops and not increase the official instruction count. There's also
some unknown -- but potentially large -- benefit from using narrower vector ops if wide
ops are implemented with multiple uops and/or frequency throttling is avoided.
Differential Revision: https://reviews.llvm.org/D54073
llvm-svn: 346595
This patch adds support for funclets in frame lowering and ISel
lowering. Together with D50288 and D50166, it enables C++ exception
handling.
Patch by Sanjin Sijaric, with some fixes by me.
Differential Revision: https://reviews.llvm.org/D51524
llvm-svn: 346568
Cleanup CCMP pattern matching code in preparation for review/bugfix:
- Rename `isConjunctionDisjunctionTree()` to `canEmitConjunction()`
(it won't accept arbitrary disjunctions and is really about whether we
can transform the subtree into a conjunction that we can emit).
- Rename `emitConjunctionDisjunctionTree()` to `emitConjunction()`
llvm-svn: 346203
The main caller of this already has an MVT and several targets called getSimpleVT inside without checking isSimple. This makes the simpleness explicit.
llvm-svn: 346180
This was added in r330630. GCC's -Wimplicit-fallthrough seems to not
fire when the previous case contains a switch itself.
This fallthrough was bening because the helper function implementing the
case used dyn_cast to re-check the type of the node in question. After
fixing the fallthrough, we can strengthen the cast.
llvm-svn: 345864
Mandeep Singh Grang