Philip Reames [Mon, 5 Aug 2019 22:34:59 +0000 (22:34 +0000)]
Add a note to the release not about a potentially breaking optimization
This has come up twice already (once in pr42763 and once in the commit thread), so give warning of a new way in which UB can result in unexpected program behavior.
Keno Fischer [Mon, 5 Aug 2019 21:36:09 +0000 (21:36 +0000)]
[WebAssembly] Fix conflict between ret legalization and sjlj
Summary:
When the WebAssembly backend encounters a return type that doesn't
fit within i32, SelectionDAG performs sret demotion, adding an
additional argument to the start of the function that contains
a pointer to an sret buffer to use instead. However, this conflicts
with the emscripten sjlj lowering pass. There we translate calls like:
```
call {i32, i32} @foo()
```
into (in pseudo-llvm)
```
%addr = @foo
call {i32, i32} @__invoke_{i32,i32}(%addr)
```
i.e. we perform an indirect call through an extra function.
However, the sret transform now transforms this into
the equivalent of
```
%addr = @foo
%sret = alloca {i32, i32}
call {i32, i32} @__invoke_{i32,i32}(%sret, %addr)
```
(while simultaneously translation the implementation of @foo as well).
Unfortunately, this doesn't work out. The __invoke_ ABI expected
the function address to be the first argument, causing crashes.
There is several possible ways to fix this:
1. Implementing the sret rewrite at the IR level as well and performing
it as part of lowering to __invoke
2. Fixing the wasm backend to recognize that __invoke has a special ABI
3. A change to the binaryen/emscripten ABI to recognize this situation
This revision implements the middle option, teaching the backend to
treat __invoke_ functions specially in sret lowering. This is achieved
by
1) Introducing a new CallingConv ID for invoke functions
2) When this CallingConv ID is seen in the backend and the first argument
is marked as sret (a function pointer would never be marked as sret),
swapping the first two arguments.
[Attributor][Fix] Do not remove instructions during manifestation
When we remove instructions cached references could still be live. This
patch avoids removing invoke instructions that are replaced by calls and
instead keeps them around but in a dead block.
[Attributor][Fix] Keep invokes if handlers catch asynchronous exceptions
Similar to other places where we transform invokes to calls we need to
be careful if the handler (=personality) can catch asynchronous
exceptions as they are not modeled as part of nounwind.
BMI2 support is indicated in bit eight of EBX, not nine.
See Intel SDM, Vol 2A, Table 3-8:
https://www.intel.com/content/dam/www/public/us/en/documents/manuals/64-ia-32-architectures-software-developer-vol-2a-manual.pdf#page=296
llvm-symbolizer: Untag addresses in object files by default.
Any addresses that we pass to llvm-symbolizer are going to be untagged,
while any HWASAN instrumented globals are going to be tagged in the
symbol table. Therefore we need to untag the addresses before using them.
Daniel Sanders [Mon, 5 Aug 2019 19:50:25 +0000 (19:50 +0000)]
Register/MCRegister: Add conversion operators to avoid use of implicit convert to unsigned. NFC
Summary:
This has no functional effect but makes it more obvious which parts of the
compiler do not use Register/MCRegister when you mark the implicit conversion
deprecated.
Implicit conversions for comparisons accounted for ~20% (~3k of ~13k) of
the implicit conversions when I first measured it. I haven't maintained
those numbers as other patches have landed though so it may be out of date.
Louis Dionne [Mon, 5 Aug 2019 18:29:14 +0000 (18:29 +0000)]
[libc++] Take 2: Integrate the PSTL into libc++
Summary:
This commit allows specifying LIBCXX_ENABLE_PARALLEL_ALGORITHMS when
configuring libc++ in CMake. When that option is enabled, libc++ will
assume that the PSTL can be found somewhere on the CMake module path,
and it will provide the C++17 parallel algorithms based on the PSTL
(that is assumed to be available).
The commit also adds support for running the PSTL tests as part of
the libc++ test suite.
The first attempt to commit this failed because it exposed a bug in the
tests for modules. Now that this has been fixed, it should be safe to
commit this.
Craig Topper [Mon, 5 Aug 2019 18:25:36 +0000 (18:25 +0000)]
[X86] Enable -x86-experimental-vector-widening-legalization by default.
This patch changes our defualt legalization behavior for 16, 32, and
64 bit vectors with i8/i16/i32/i64 scalar types from promotion to
widening. For example, v8i8 will now be widened to v16i8 instead of
promoted to v8i16. This keeps the elements widths the same and pads
with undef elements. We believe this is a better legalization strategy.
But it carries some issues due to the fragmented vector ISA. For
example, i8 shifts and multiplies get widened and then later have
to be promoted/split into vXi16 vectors.
This has the potential to cause regressions so we wanted to get
it in early in the 10.0 cycle so we have plenty of time to
address them.
Next steps will be to merge tests that explicitly test the command
line option. And then we can remove the option and its associated
code.
Philip Reames [Mon, 5 Aug 2019 18:25:08 +0000 (18:25 +0000)]
Robustify update_test_checks.py to non-autogened tests, and add a mode to skip non-autogenerated ones
Intended use case is:
./utils/update_test_checks.py test/Transform/PassDir/* --update-only
(i.e. rapidly be able to see changes in autogened filed, before handing non-autogened tests individually)
Evandro Menezes [Mon, 5 Aug 2019 18:09:14 +0000 (18:09 +0000)]
[AArch64] Expand bcmp() for small block lengths
Patch D56593 by @courbet results in calls to `bcmp()` in some cases, should
the target support the it. Unless `TTI::MemCmpExpansionOptions()`
is overridden by the target.
In a proprietary benchmark we see a performance drop of about 12% on PNG
compression before this patch, though it passes all tests.
This patch mirrors X86 for AArch64 and initializes
`TTI::MemCmpExpansionOptions()` to then expand calls to `bcmp()` when
appropriate. No tuning of the parameters was performed, but, at this point,
it's enough to recover the performance drop above.
This problem also exists on ARM. Once a consensus is reached for AArch64, we
can work to fix ARM as well.
Chris Bieneman [Mon, 5 Aug 2019 17:50:08 +0000 (17:50 +0000)]
NATIVE tablegen needs to depend on target tablegen
This dependency was removed in r357486, which has lead to a stream of difficult to diagnose bugs.
Without this dependency, when building with `LLVM_OPTIMIZED_TABLEGEN=On` the native tablegen executible may not be rebuilt at all, and often won't get rebuilt before targets that use the tablegen headers. In the best case this results in a build-time failure, in the worst case it results in runtime failures.
Pablo Barrio [Mon, 5 Aug 2019 17:38:58 +0000 (17:38 +0000)]
[AArch64] Set preferred function alignment to 16 bytes on Neoverse N1
Summary:
The Arm Neoverse N1 Software Optimization Guide [1], Section "4.8 Branch
instruction alignment" states:
"Consider aligning subroutine entry points and branch targets to 32B
boundaries, within the bounds of the code-density requirements of the
program."
This patch sets the preferred function alignment on Neoverse N1 to 2^4=16B.
This was already the case in some of the latest Cortex-A CPUs. Benchmarking
in previous Cortex-A CPUs suggested that 16B alignment is already better
than the default. See commit d04ee305.
The reason we don't set it to 32B right now (as the optimisation guide
suggests) is that this will impact code size and perhaps the instruction
cache performance. Therefore we need benchmark numbers first.
I have also added testing for A75 and A76 that we were missing.
Sanjay Patel [Mon, 5 Aug 2019 16:59:58 +0000 (16:59 +0000)]
[InstCombine] combine mul+shl separated by zext
This appears to slightly help patterns similar to what's
shown in PR42874:
https://bugs.llvm.org/show_bug.cgi?id=42874
...but not in the way requested.
That fix will require some later IR and/or backend pass to
decompose multiply/shifts into something more optimal per
target. Those transforms already exist in some basic forms,
but probably need enhancing to catch more cases.
Tom Stellard [Mon, 5 Aug 2019 16:08:44 +0000 (16:08 +0000)]
AMDGPU/LoadStoreOptimizer: Set the correct offset whem merging MMOs
Summary:
This is a follow up to r367237. MachineFunction::getMachineMemOperand()
adds the offset parameter to the existing offset instead of resetting it.
So we need to reset the offset to the correct value after calling this
function.
Summary:
Core files have different descriptions for note values. llvm-readelf currently prints the generic note type, which is wrong when using it to read a core file.
To verify the constants/strings, see:
Values: https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;a=blob;f=include/elf/common.h;h=75c4fb7e9d7c0f780d635ac305f579546b7b071b;hb=HEAD#l571
Strings: https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;a=blob;f=binutils/readelf.c;h=c31a5c1266b7bb62a485895b01b49e1f832ade35;hb=HEAD#l16881
Note: this does not handle printing the note data for NT_FILE, it just fixes the descriptions.
Matt Arsenault [Mon, 5 Aug 2019 14:40:26 +0000 (14:40 +0000)]
AMDGPU/GlobalISel: Alternative mappings for constants
Without context we assume SGPR. Allowing VGPR constants theoretically
helps avoid a copy. This seems to not actually work now, and the
choice isn't based on the use bank.
Matt Arsenault [Mon, 5 Aug 2019 14:40:23 +0000 (14:40 +0000)]
AMDGPU/GlobalISel: Don't reject shader types
I'm not sure what complications these present, but the current
argument lowering is pretty much directly copied from the DAG
lowering, so I assume these work as they should.
No tests because I'm lazy and things are getting pretty close to the
point where the existing calling-conventions.ll can be shared with
SelectionDAG.
Hubert Tong [Mon, 5 Aug 2019 13:55:41 +0000 (13:55 +0000)]
[yaml2obj][tests] Fix overly restrictive od output check
Summary:
rL364517 introduced further instances of `od` output checking of the
kind previously corrected by rL363829. This patch corrects the issue by
suppressing output of the input offset. The check remains sufficiently
sensitive to test for the intended value of the specific byte since the
relevant byte value is the only output we are expecting from `od`.
Cullen Rhodes [Mon, 5 Aug 2019 13:44:10 +0000 (13:44 +0000)]
[AArch64] Implement initial SVE calling convention support
Summary:
This patch adds initial support for the SVE calling convention such that
SVE types can be passed as arguments and return values to/from a
subroutine.
The SVE AAPCS states [1]:
z0-z7 are used to pass scalable vector arguments to a subroutine,
and to return scalable vector results from a function. If a
subroutine takes arguments in scalable vector or predicate
registers, or if it is a function that returns results in such
registers, it must ensure that the entire contents of z8-z23 are
preserved across the call. In other cases it need only preserve the
low 64 bits of z8-z15, as described in §5.1.2.
p0-p3 are used to pass scalable predicate arguments to a subroutine
and to return scalable predicate results from a function. If a
subroutine takes arguments in scalable vector or predicate
registers, or if it is a function that returns results in these
registers, it must ensure that p4-p15 are preserved across the call.
In other cases it need not preserve any scalable predicate register
contents.
SVE predicate and data registers are passed indirectly (i.e. spilled to the
stack and pass the address) if they exceed the registers used for argument
passing defined by the PCS referenced above. Until SVE stack support is merged
we can't spill SVE registers to the stack, so currently an llvm_unreachable is
used where we will eventually handle this.
Hans Wennborg [Mon, 5 Aug 2019 13:04:12 +0000 (13:04 +0000)]
test-release.sh: Perform the sed substitution on both files (PR42739)
The comparison would otherwise fail if Phase2 occurrs naturally in the
object file. It would get replaced with Phase3 in the one .o, but not
in the other.
We were already running both files through sed to have them processed in
this same way; this is a logical extension of that.
Sanjay Patel [Mon, 5 Aug 2019 11:27:07 +0000 (11:27 +0000)]
[DAGCombiner][x86] prevent infinite loop from truncate/extend transforms
The test case is based on the example from the post-commit thread for:
https://reviews.llvm.org/rGc9171bd0a955
This replaces the x86-specific simple-type check from:
rL367766
with a check in the DAGCombiner. Adding the check isn't
strictly necessary after the fix from:
rL367768
...but it seems likely that we're heading for trouble if
we are creating weird types in this transform.
I combined the earlier legality check into the initial
clause to simplify the code.
So we should only try the trunc/sext transform at the
earliest combine stage, but we limit the transform to
simple types anyway because the TLI hook is probably
too lax about what it considers a free truncate.
This method is dead. It was introduced in D47989,
but now the logic from D63475 is used in llvm-readobj instead.
Also it has a problem: it returns the first matching section,
even if there are multiple sections with the same name.
Summary:
This is patch is part of a serie to introduce an Alignment type.
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html
See this patch for the introduction of the type: https://reviews.llvm.org/D64790
[LLVM][Alignment] Introduce Alignment In CallingConv
Summary:
This is patch is part of a serie to introduce an Alignment type.
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html
See this patch for the introduction of the type: https://reviews.llvm.org/D64790
Oliver Stannard [Mon, 5 Aug 2019 09:04:10 +0000 (09:04 +0000)]
Reland: Fix and test inter-procedural register allocation for ARM
Add an explicit construction of the ArrayRef, gcc 5 and earlier don't
seem to select the ArrayRef constructor which takes a C array when the
construction is implicit.
Original commit message:
- Avoid a crash when IPRA calls ARMFrameLowering::determineCalleeSaves
with a null RegScavenger. Simply not updating the register scavenger
is fine because IPRA only cares about the SavedRegs vector, the acutal
code of the function has already been generated at this point.
- Add a new hook to TargetRegisterInfo to get the set of registers which
can be clobbered inside a call, even if the compiler can see both
sides, by linker-generated code.
[LLVM][Alignment] Introduce Alignment Type in DataLayout
Summary:
This is patch is part of a serie to introduce an Alignment type.
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html
See this patch for the introduction of the type: https://reviews.llvm.org/D64790
Michael Pozulp [Mon, 5 Aug 2019 08:52:28 +0000 (08:52 +0000)]
Revert "[llvm-objdump] Re-commit r367284."
This reverts r367776 (git commit d34099926e909390cb0254bebb4b7f5cf15467c7).
My changes to llvm-objdump tests caused them to fail on windows:
http://lab.llvm.org:8011/builders/llvm-clang-lld-x86_64-scei-ps4-windows10pro-fast/builds/27368
Craig Topper [Mon, 5 Aug 2019 03:48:31 +0000 (03:48 +0000)]
[X86] Fix a bad early out in combineExtInVec that prevented recursive shuffle combining from running with -x86-experimental-vector-widening-legalization.
Summary:
This contains various fixes:
- Explicitly determine and return the next noreturn instruction.
- If an invoke calls a noreturn function which is not nounwind we
keep the unwind destination live. This also means we require an
invoke. Though we can still add the unreachable to the normal
destination block.
- Check if the return instructions are dead after we look for calls
to avoid triggering an optimistic fixpoint in the presence of
assumed liveness information.
- Make the interface work with "const" pointers.
- Some simplifications
While additional tests are included, full coverage is achieved only with
D59978.
[Attributor][NFC] Simplify common pattern wrt. fixpoints
When a fixpoint is indicated the change status is known due to the
fixpoint kind. This simplifies a common code pattern by making the
connection explicit.
[Attributor][NFC] Invalid DerefState is at fixpoint
Summary:
If the DerefBytesState (and thereby the DerefState) is invalid, we
reached a fixpoint for the whole DerefState as we will not
manifest/provide information then.
Craig Topper [Sun, 4 Aug 2019 17:30:41 +0000 (17:30 +0000)]
[TargetLowering][X86] Teach SimplifyDemandedVectorElts to replace the base vector of INSERT_SUBVECTOR with undef if none of the elements are demanded even if the node has other users.
Summary:
The SimplifyDemandedVectorElts function can replace with undef
when no elements are demanded, but due to how it interacts with
TargetLoweringOpts, it can only do this when the node has
no other users.
Remove a now unneeded DAG combine from the X86 backend.
David Green [Sun, 4 Aug 2019 10:18:15 +0000 (10:18 +0000)]
[ARM] MVE big endian bitcasts
This adds big endian MVE patterns for bitcasts. They are defined in llvm as
being the same as a store of the existing type and the load into the new. This
means that they have to become a VREV between the two types, working in the
same way that NEON works in big-endian. This also adds some example tests for
bigendian, showing where code is and isn't different.
The main difference, especially from a testing perspective is that vectors are
passed as v2f64, and so are VREV into and out of call arguments, and the
parameters are passed in a v2f64 format. Same happens for inline assembly where
the register class is used, so it is VREV to a v16i8.
So some of this is probably not correct yet, but it is (mostly) self-consistent
and seems to be consistent with how llvm treats vectors. The rest we can
hopefully fix later. More details about big endian neon can be found in
https://llvm.org/docs/BigEndianNEON.html.
Yonghong Song [Sat, 3 Aug 2019 23:41:26 +0000 (23:41 +0000)]
[Transforms] Do not drop !preserve.access.index metadata
Currently, when a GVN or CSE optimization happens,
the llvm.preserve.access.index metadata is dropped.
This caused a problem for BPF AbstructMemberOffset phase
as it relies on the metadata (debuginfo types).
This patch added proper hooks in lib/Transforms to
preserve !preserve.access.index metadata. A test
case is added to ensure metadata is preserved under CSE.
Sanjay Patel [Sat, 3 Aug 2019 21:46:27 +0000 (21:46 +0000)]
[x86] change free truncate hook to handle only simple types (PR42880)
This avoids the crash from:
https://bugs.llvm.org/show_bug.cgi?id=42880
...and I think it's a proper constraint for the TLI hook.
But that example raises questions about what happens to get us
into this situation (created i29 types) and what happens later
(why does legalization die on those types), so I'm not sure if
we will resolve the bug based on this change.
Keno Fischer [Sat, 3 Aug 2019 21:38:19 +0000 (21:38 +0000)]
[WebAssembly] Fix allocsize attribute in sjlj lowering
Summary:
The allocsize attribute refers to call parameters by index.
Thus, when we add the extra parameter in sjlj lowering, we
need to increment the referenced paramater in the allocsize
attribute to avoid angering the Verifier.
Lang Hames [Sat, 3 Aug 2019 20:17:10 +0000 (20:17 +0000)]
[JITLink] Add support for MachO/x86-64 UNSIGNED relocs with length=2.
MachO/x86-64 UNSIGNED relocs are almost always 64-bit (length=3), but UNSIGNED
relocs of length=2 are allowed if the target resides in the low 32-bits. This
patch adds support for such relocations in JITLink (previously they would have
triggered an unsupported relocation error).
Hubert Tong [Sat, 3 Aug 2019 18:52:45 +0000 (18:52 +0000)]
[yaml2obj][tests] Replace 8-byte `od` conversion with 1-byte conversion
Summary:
`od` on AIX does not seem to implement 8-byte integer conversions. Work
around this by using 1-byte conversions, which can be used in this case
since the value is byte-order insensitive.
Nikita Popov [Sat, 3 Aug 2019 06:47:23 +0000 (06:47 +0000)]
[Thumb] Fix invalid symbol redefinition due to duplicated jumptable (PR42760)
Fix for https://bugs.llvm.org/show_bug.cgi?id=42760. A tBR_JTr
instruction is duplicated by tail duplication, which results in
the same jumptable with the same label being emitted twice.
Fix this by marking tBR_JTr as not duplicable. The corresponding
ARM/Thumb instructions are already marked as not duplicable.
Additionally also mark tTBB_JT and tTBH_JT to be consistent with
Thumb2, even though this shouldn't be strictly necessary.
Joel E. Denny [Sat, 3 Aug 2019 06:08:19 +0000 (06:08 +0000)]
[lit] Print internal env commands
Without this patch, the internal `env` command removes `env` and its
args from the command line while parsing it. This patch modifies a
copy instead so that the original command line is printed.
projects / llvm / log