The value is always an immediate and can never be in a register.
This the kind of thing TargetConstant is for.
Saves a step GenDAGISel to convert a Constant to a TargetConstant.
This patch allows PRE of the following type of loads:
```
preheader:
br label %loop
loop:
br i1 ..., label %merge, label %clobber
clobber:
call foo() // Clobbers %p
br label %merge
merge:
...
br i1 ..., label %loop, label %exit
```
Into
```
preheader:
%x0 = load %p
br label %loop
loop:
%x.pre = phi(x0, x2)
br i1 ..., label %merge, label %clobber
clobber:
call foo() // Clobbers %p
%x1 = load %p
br label %merge
merge:
x2 = phi(x.pre, x1)
...
br i1 ..., label %loop, label %exit
```
So instead of loading from %p on every iteration, we load only when the actual clobber happens.
The typical pattern which it is trying to address is: hot loop, with all code inlined and
provably having no side effects, and some side-effecting calls on cold path.
The worst overhead from it is, if we always take clobber block, we make 1 more load
overall (in preheader). It only matters if loop has very few iteration. If clobber block is not taken
at least once, the transform is neutral or profitable.
There are several improvements prospect open up:
- We can sometimes be smarter in loop-exiting blocks via split of critical edges;
- If we have block frequency info, we can handle multiple clobbers. The only obstacle now is that
we don't know if their sum is colder than the header.
Differential Revision: https://reviews.llvm.org/D99926
Reviewed By: reames
This recognizes the case when Hi is (sra Lo, 31). We can use
SPLAT_VECTOR_I64 rather than splatting the high bits and
combining them in the vector register.
Summary: The original logic seems to be we could collecting a CoroBegin
if one of the terminators could be dominated by one of coro.destroy,
which doesn't make sense.
This patch rewrites the logics to collect CoroBegin if all of
terminators are dominated by one coro.destroy. If there is no such
coro.destroy, we would call hasEscapePath to evaluate if we should
collect it.
Test Plan: check-llvm
Reviewed by: lxfind
Differential Revision: https://reviews.llvm.org/D100614
Don't phrase the semantics in terms of the optimizer. Instead have a
more straightforward execution based semantic.
Reviewed By: ebrevnov
Differential Revision: https://reviews.llvm.org/D63439
This revision simplifies Clang codegen for parallel regions in OpenMP GPU target offloading and corresponding changes in libomptarget: SPMD/non-SPMD parallel calls are unified under a single `kmpc_parallel_51` runtime entry point for parallel regions (which will be commonized between target, host-side parallel regions), data sharing is internalized to the runtime. Tests have been auto-generated using `update_cc_test_checks.py`. Also, the revision contains changes to OpenMPOpt for remark creation on target offloading regions.
Reviewed By: jdoerfert, Meinersbur
Differential Revision: https://reviews.llvm.org/D95976
Each of the cases marked as legal here have an imported pattern in
AArch64GenGlobalISel.inc. So, if we mark them as legal, we get selection for
free.
Technically this is only supposed to happen if we have NEON support. But, we
fall back if we don't have that in the legalizer right now. I suppose it'd be
better to have a FIXME so we can write the testcase when the time comes.
(Plus, it'd just fall back in selection if NEON isn't available, so it's not
*wrong*, I guess?)
This fixes some fallbacks in the test suite.
(Also use `isScalar` from LegalityPredicates.cpp while we're here just to tidy
things a little bit.)
Differential Revision: https://reviews.llvm.org/D100916
Report dangling probes for frames that have real samples collected. Dangling probes are the probes associated to an empty block. When reported, sample count on a dangling probe will not be trusted by the compiler and we will rely on the counts inference algorithm to get the probe a reasonable count. This actually fixes a bug where previously only those dangling probes with samples collected were reported.
This patch also fixes two existing issues. Pseudo probes are stored in `Address2ProbesMap` and their pointers are used in `PseudoProbeInlineTree`. Previously `std::vector` was used to store probes and the pointers to probes may get obsolete as the vector grows. I'm changing `std::vector` to `std::list` instead.
The other issue is that all outlined functions shared the same inline frame previously due to the unchanged `Index` value as the dummy inlineSite identifier.
Good results seen for SPEC2017 in general regarding profile quality.
Reviewed By: wenlei, wlei
Differential Revision: https://reviews.llvm.org/D100235
On ELF targets, if a function has uwtable or personality, or does not have
nounwind (`needsUnwindTableEntry`), it marks that `.eh_frame` is needed in the module.
Then, a function gets `.eh_frame` if `needsUnwindTableEntry` or `-g[123]` is specified.
(i.e. If -g[123], every function gets `.eh_frame`.
This behavior is strange but that is the status quo on GCC and Clang.)
Let's take asan as an example. Other sanitizers are similar.
`asan.module_[cd]tor` has no attribute. `needsUnwindTableEntry` returns true,
so every function gets `.eh_frame` if `-g[123]` is specified.
This is the root cause that
`-fno-exceptions -fno-asynchronous-unwind-tables -g` produces .debug_frame
while
`-fno-exceptions -fno-asynchronous-unwind-tables -g -fsanitize=address` produces .eh_frame.
This patch
* sets the nounwind attribute on sanitizer module ctor/dtor.
* let Clang emit a module flag metadata "uwtable" for -fasynchronous-unwind-tables. If "uwtable" is set, sanitizer module ctor/dtor additionally get the uwtable attribute.
The "uwtable" mechanism is generic: synthesized functions not cloned/specialized
from existing ones should consider `Function::createWithDefaultAttr` instead of
`Function::create` if they want to get some default attributes which
have more of module semantics.
Other candidates: "frame-pointer" (https://github.com/ClangBuiltLinux/linux/issues/955https://github.com/ClangBuiltLinux/linux/issues/1238), dso_local, etc.
Differential Revision: https://reviews.llvm.org/D100251
This change adds debug information about whether PGO is being used or
not.
Microsoft performance tooling (e.g. xperf, WPA) uses this information to
show whether functions are optimized with PGO or not, as well as whether
PGO information is invalid.
This information is useful for validating whether training scenarios are
providing good coverage of real world scenarios, showing if profile data
is out of date, etc.
Reviewed By: rnk
Differential Revision: https://reviews.llvm.org/D99994
This previously made references to 2.3-draft which was a short
lived version number in 2017. It was replaced by date based
versions leading up to ratification.
This patch uses the latest ratified version number and just says
what the behavior is. Nothing here is in flux.
Reviewed By: frasercrmck
Differential Revision: https://reviews.llvm.org/D100878
This was checked in some asserts, but not enforced by the
instruction matching.
There's still a second bug that we don't check that vt and vd
are different registers, but that will require custom checking.
Differential Revision: https://reviews.llvm.org/D100928
This fixed issue introduced in 16af97393346ad636298605930a8b503a55eb40a
and 796feb61637c407aefcc0d462f24a1cc41f350d8.
Differential Revision: https://reviews.llvm.org/D100909
This makes the memcpy-memcpy and memcpy-memset optimizations work for
variable sizes as long as they are equal, relaxing the old restriction
that they are constant integers. If they're not equal, the old
requirement that they are constant integers with certain size
restrictions is used.
The implementation works by pushing the length tests further down in the
code, which reveals some places where it's enough that the lengths are
equal (but not necessarily constant).
Differential Revision: https://reviews.llvm.org/D100870
Trying to evaluate a GEP would assert with
"Ty == cast<PointerType>(C->getType()->getScalarType())->getElementType()"
because the type of the pointer we would evaluate the GEP argument to
would be a different type than the GEP was expecting. We should treat
pointer stripping as a bitcast.
The test adds a redundant GEP that would crash due to type mismatch.
Reviewed By: rnk
Differential Revision: https://reviews.llvm.org/D100970
This reverts commit 9423f78240a216e3f38b394a41fe3427dee22c26.
A performance regression with this patch has been reported at
https://reviews.llvm.org/rG9423f78240a2#990953. Reverting for now.
Discovered during attributor testing comparing stats with
and without the attributor. Willreturn should not be inferred
for nonexact definitions.
Differential Revision: https://reviews.llvm.org/D100988
Fix for PR49984
This was discovered during Attributor testing.
Memset was always created with alignment of 1
and in case when strncpy alignment was changed
it triggered an assertion in the AttrBuilder.
Memset will now be created with appropriate alignment.
Differential Revision: https://reviews.llvm.org/D100875
PR50049 demonstrated an infinite loop between OR(SHUFFLE,SHUFFLE) <-> BLEND(SHUFFLE,SHUFFLE) patterns.
The UNDEF elements were allowing a combined shuffle mask to be widened which lost the undef element, resulting us needing to use the BLEND pattern (as the undef element would need to be zero for the OR pattern). But then bitcast folds would re-expose the undef element allowing us to use OR again.....
Let it work on a very small kernels only. Measurements showed
the performance benefit is not worth the compile time.
Differential Revision: https://reviews.llvm.org/D100904
- Previously, https://reviews.llvm.org/D72680 introduced a new attribute called `AllowSymbolAtNameStart` (in relation to the MAsmParser changes) in `MCAsmInfo.h` which (according to the comment in the header) allows the following behaviour:
```
/// This is true if the assembler allows $ @ ? characters at the start of
/// symbol names. Defaults to false.
```
- However, the usage of this field in AsmLexer.cpp doesn't seem completely accurate* for a couple of reasons.
```
default:
if (MAI.doesAllowSymbolAtNameStart()) {
// Handle Microsoft-style identifier: [a-zA-Z_$.@?][a-zA-Z0-9_$.@#?]*
if (!isDigit(CurChar) &&
isIdentifierChar(CurChar, MAI.doesAllowAtInName(),
AllowHashInIdentifier))
return LexIdentifier();
}
```
1. The Dollar and At tokens, when occurring at the start of the string, are treated as separate tokens (AsmToken::Dollar and AsmToken::At respectively) and not lexed as an Identifier.
2. I'm not too sure why `MAI.doesAllowAtInName()` is used when `AllowAtInIdentifier` could be used. For X86 platforms, afaict, this shouldn't be an issue, since the `CommentString` attribute isn't "@". (alternatively the call to the setter can be set anywhere else as needed). The `AllowAtInName` does have an additional important meaning, but in the context of AsmLexer, shouldn't mean anything different compared to `AllowAtInIdentifier`
My proposal is the following:
- Introduce 3 new fields called `AllowQuestionTokenAtStartOfString`, `AllowDollarTokenAtStartOfString` and `AllowAtTokenAtStartOfString` in MCAsmInfo.h which will encapsulate the previously documented behaviour of "allowing $, @, ? characters at the start of symbol names")
- Introduce these fields where "$", "@" are lexed, and treat them as identifiers depending on whether `Allow[Dollar|At]TokenAtStartOfString` is set.
- For the sole case of "?", append it to the existing logic for treating a "default" token as an Identifier.
z/OS (HLASM) will also make use of some of these fields in follow up patches.
completely accurate* - This was based on the comments and the intended behaviour the code. I might have completely misinterpreted it, and if that is the case my sincere apologies. We can close this patch if necessary, if there are no changes to be made :)
Depends on https://reviews.llvm.org/D99374
Reviewed By: Jonathan.Crowther
Differential Revision: https://reviews.llvm.org/D99889
CommandLine.h is indirectly included in ~50% of TUs when building
clang, and VirtualFileSystem.h is large.
(Already remarked by jhenderson on D70769.)
No behavior change.
Differential Revision: https://reviews.llvm.org/D100957
This patch changes the lowering of SELECT_CC from Legal to Expand for scalable
vector and adds support for scalable vectors in performSelectCombine.
When selecting the nodes to lower in visitSELECT it checks if it is possible to
use SELECT_CC in cases where SETCC is followed by SELECT. visistSELECT checks
if SELECT_CC is legal or custom to replace SELECT by SELECT_CC.
SELECT_CC used to be legal for scalable vector, so the node changes to
SELECT_CC. This used to crash the compiler as there is no support for SELECT_CC
with scalable vectors. So now the compiler lowers to VSELECT instead of
SELECT_CC.
Differential Revision: https://reviews.llvm.org/D100485
If you gave clang the options `--target=arm-pc-windows-msvc` and
`-march=armv8-a+crypto` together, the crypto extension would not be
enabled in the compilation, and you'd see the following warning
message suggesting that the 'armv8-a' had been ignored:
clang: warning: ignoring extension 'crypto' because the 'armv7-a' architecture does not support it [-Winvalid-command-line-argument]
This happens because Triple::getARMCPUForArch(), for the Win32 OS,
unconditionally returns "cortex-a9" (an Armv7 CPU) regardless of
MArch, which overrides the architecture setting on the command line.
I don't think that the combination of Windows and AArch32 _should_
unconditionally outlaw the use of the crypto extension. MSVC itself
doesn't think so: you can perfectly well compile Thumb crypto code
using its AArch32-targeted compiler.
All the other default CPUs in the same switch statement are
conditional on a particular MArch setting; this is the only one that
returns a particular CPU _regardless_ of MArch. So I've fixed this one
by adding a condition, so that if you ask for an architecture *above*
v7, the default of Cortex-A9 no longer overrides it.
Reviewed By: mstorsjo
Differential Revision: https://reviews.llvm.org/D100937
This patch adds incrementally-better support for SPLAT_VECTOR in a
handful of vector combines by changing a few more
isBuildVectorAllOnes/isBuildVectorAllZeros to the equivalent
isConstantSplatVectorAllOnes/Zeros calls.
Reviewed By: paulwalker-arm
Differential Revision: https://reviews.llvm.org/D100851
This patch fixes a case missed out by D100574, in which RVV scalable
stack offset computations may require three live registers in the case
where the offset's fixed component is 12 bits or larger and has a
scalable component.
Instead of adding an additional emergency spill slot, this patch further
optimizes the scalable stack offset computation sequences to reduce
register usage.
By emitting the sequence to compute the scalable component before the
fixed component, we can free up one scratch register to be reallocated
by the sequence for the fixed component. Doing this saves one register
and thus one additional emergency spill slot.
Compare:
$x5 = LUI 1
$x1 = ADDIW killed $x5, -1896
$x1 = ADD $x2, killed $x1
$x5 = PseudoReadVLENB
$x6 = ADDI $x0, 50
$x5 = MUL killed $x5, killed $x6
$x1 = ADD killed $x1, killed $x5
versus:
$x5 = PseudoReadVLENB
$x1 = ADDI $x0, 50
$x5 = MUL killed $x5, killed $x1
$x1 = LUI 1
$x1 = ADDIW killed $x1, -1896
$x1 = ADD $x2, killed $x1
$x1 = ADD killed $x1, killed $x5
Reviewed By: HsiangKai
Differential Revision: https://reviews.llvm.org/D100847
When llvm-rc invokes clang for preprocessing, it uses a target
triple derived from the default target. The test verifies that
e.g. _WIN32 is defined when preprocessing.
If running clang with e.g. -target ppc64le-windows-msvc, that
particular arch/OS combination isn't hooked up, so _WIN32 doesn't
get defined in that configuration. Therefore, the preprocessing
test fails.
Instead make llvm-rc inspect the architecture of the default target.
If it's one of the known supported architectures, use it as such,
otherwise set a default one (x86_64). (Clang can run preprocessing
with an x86_64 target triple, even if the x86 backend isn't
enabled.)
Also remove superfluous llvm:: specifications on enums in llvm-rc.cpp.
Allow opting out from preprocessing with a command line argument.
Update tests to pass -no-preprocess to make it not try to use clang
(which isn't a build level dependency of llvm-rc), but add a test that
does preprocessing under clang/test/Preprocessor.
Update a few options to allow them both joined (as -DFOO) and separate
(-D BR), as rc.exe allows both forms of them.
With the verbose flag set, this prints the preprocessing command
used (which differs from what rc.exe does).
Tests under llvm/test/tools/llvm-rc only test constructing the
preprocessor commands, while tests under clang/test/Preprocessor test
actually running the preprocessor.
Differential Revision: https://reviews.llvm.org/D100755
Don't use createBinary() but call the WindowsResource class directly.
The createBinary() function references all supported object file
types and ends up pulling way more from all the underlying libraries
than what is necessary.
This shrinks a stripped llvm-cvtres from 4.6 MB to 463 KB.
Differential Revision: https://reviews.llvm.org/D100833
