34 Commits

Author SHA1 Message Date
Nikita Popov
c23b4fbdbb
[IR] Remove size argument from lifetime intrinsics (#150248)
Now that #149310 has restricted lifetime intrinsics to only work on
allocas, we can also drop the explicit size argument. Instead, the size
is implied by the alloca.

This removes the ability to only mark a prefix of an alloca alive/dead.
We never used that capability, so we should remove the need to handle
that possibility everywhere (though many key places, including stack
coloring, did not actually respect this).
2025-08-08 11:09:34 +02:00
jofrn
15d36aa4ce
[clang][CodeGen] Preserve addrspace of enqueue_kernel builtin. (#148062)
__enqueue_kernel_varargs' last parameter is in addrspace(5), but CodeGen
currently misses this qualifier. This commit fixes the code to preserve
the qualifier by referencing Alloca, which has its casts removed, rather
than TmpPtr.
2025-07-11 17:00:28 -04:00
Matt Arsenault
a11d86461e
clang: Fix broken implicit cast to generic address space (#138863)
This fixes emitting undefined behavior where a 64-bit generic
pointer is written to a 32-bit slot allocated for a private pointer.
This can be seen in test/CodeGenOpenCL/amdgcn-automatic-variable.cl's
wrong_pointer_alloca.
2025-05-08 07:51:57 +02:00
Aniket Lal
c3ce5684a8
[Clang][OpenCL][AMDGPU] OpenCL Kernel stubs should be assigned alwaysinline attribute (#137769)
OpenCL Kernels body is emitted as stubs and the kernel is emitted as
call to respective stub.
(https://github.com/llvm/llvm-project/pull/115821).
The stub function should be alwaysinlined, since call to stub can cause
performance drop.

Co-authored-by: anikelal <anikelal@amd.com>
2025-05-07 15:42:23 +05:30
Aniket Lal
642481a428
[Clang][OpenCL][AMDGPU] Allow a kernel to call another kernel (#115821)
This feature is currently not supported in the compiler.
To facilitate this we emit a stub version of each kernel
function body with different name mangling scheme, and
replaces the respective kernel call-sites appropriately.
    
Fixes https://github.com/llvm/llvm-project/issues/60313
    
D120566 was an earlier attempt made to upstream a solution
for this issue.

---------

Co-authored-by: anikelal <anikelal@amd.com>
2025-04-08 10:29:30 +05:30
Joseph Huber
772173f548
[Clang][AMDGPU] Remove special handling for COV4 libraries (#132870)
Summary:
When we were first porting to COV5, this lead to some ABI issues due to
a change in how we looked up the work group size. Bitcode libraries
relied on the builtins to emit code, but this was changed between
versions. This prevented the bitcode libraries, like OpenMP or libc,
from being used for both COV4 and COV5. The solution was to have this
'none' functionality which effectively emitted code that branched off of
a global to resolve to either version.

This isn't a great solution because it forced every TU to have this
variable in it. The patch in
https://github.com/llvm/llvm-project/pull/131033 removed support for
COV4 from OpenMP, which was the only consumer of this functionality.
Other users like HIP and OpenCL did not use this because they linked the
ROCm Device Library directly which has its own handling (The name was
borrowed from it after all).

So, now that we don't need to worry about backward compatibility with
COV4, we can remove this special handling. Users can still emit COV4
code, this simply removes the special handling used to make the OpenMP
device runtime bitcode version agnostic.
2025-03-28 07:35:16 -05:00
Shilei Tian
f1ac2afe21
Reapply "[AMDGPU] Use COV6 by default (#118515)" (#130963)
This reverts commit 68bcba6d7a1cc18996c0bcb7c62267c62d2040d0.
2025-03-21 15:26:45 -04:00
Matt Arsenault
0d2c55cb96
AMDGPU: Move enqueued block handling into clang (#128519)
The previous implementation wasn't maintaining a faithful IR
representation of how this really works. The value returned by
createEnqueuedBlockKernel wasn't actually used as a function, and
hacked up later to be a pointer to the runtime handle global
variable. In reality, the enqueued block is a struct where the first
field is a pointer to the kernel descriptor, not the kernel itself. We
were also relying on passing around a reference to a global using a
string attribute containing its name. It's better to base this on a
proper IR symbol reference during final emission.

This now avoids using a function attribute on kernels and avoids using
the additional "runtime-handle" attribute to populate the final
metadata. Instead, associate the runtime handle reference to the
kernel with the !associated global metadata. We can then get a final,
correctly mangled name at the end.

I couldn't figure out how to get rename-with-external-symbol behavior
using a combination of comdats and aliases, so leaves an IR pass to
externalize the runtime handles for codegen. If anything breaks, it's
most likely this, so leave avoiding this for a later step. Use a
special section name to enable this behavior. This also means it's
possible to declare enqueuable kernels in source without going through
the dedicated block syntax or other dedicated compiler support.

We could move towards initializing the runtime handle in the
compiler/linker. I have a working patch where the linker sets up the
first field of the handle, avoiding the need to export the block
kernel symbol for the runtime. We would need new relocations to get
the private and group sizes, but that would avoid the runtime's
special case handling that requires the device_enqueue_symbol metadata
field.

https://reviews.llvm.org/D141700
2025-03-10 19:54:04 +07:00
Matt Arsenault
bfea84946d
clang: Hack around opencl enqueue_block using wrong ABI for aggregrate (#130011)
EmitAggExprToLValue started wrapping the temporary alloca in an
addrspacecast
at some point. We take the direct type from this as the pointer argument
for the
runtime function type, but this isn't correct. Technically, we should be
querying
the target's ABI for what IR to produce for this sequence. The
assumption seems to
always have been that this will be indirectly passed with byval (or
byref).

I started working on a patch to go through the ABI handling, but it
seems to
require more time and/or clang expertise than I have at the moment.
2025-03-06 23:13:28 +07:00
Florian Hahn
77d3f8a925
[TBAA] Don't emit pointer-tbaa for void pointers. (#122116)
While there are no special rules in the standards regarding void
pointers and strict aliasing, emitting distinct tags for void pointers
break some common idioms and there is no good alternative to re-write
the code without strict-aliasing violations. An example is to count the
entries in an array of pointers:

    int count_elements(void * values) {
      void **seq = values;
      int count;
      for (count = 0; seq && seq[count]; count++);
      return count;
    }

https://clang.godbolt.org/z/8dTv51v8W

An example in the wild is from
https://github.com/llvm/llvm-project/issues/119099

This patch avoids emitting distinct tags for void pointers, to avoid
those idioms causing mis-compiles for now.

Fixes https://github.com/llvm/llvm-project/issues/119099.
Fixes https://github.com/llvm/llvm-project/issues/122537.

PR: https://github.com/llvm/llvm-project/pull/122116
2025-01-31 11:38:14 +00:00
Florian Hahn
7954a0514b
[Clang] Enable -fpointer-tbaa by default. (#117244)
Support for more precise TBAA metadata has been added a while ago
(behind the -fpointer-tbaa flag). The more precise TBAA metadata allows
treating accesses of different pointer types as no-alias.

This helps to remove more redundant loads and stores in a number of
workloads.

Some highlights on the impact across llvm-test-suite's MultiSource,
SPEC2006 & SPEC2017 include:
 * +2% more NoAlias results for memory accesses
 * +3% more stores removed by DSE,
 * +4% more loops vectorized.

This closes a relatively big gap to GCC, which has been supporting
disambiguating based on pointer types for a long time.
(https://clang.godbolt.org/z/K7Wbhrz4q)

Pointer-TBAA support for pointers to builtin types has been added in
https://github.com/llvm/llvm-project/pull/76612.

Support for user-defined types has been added in
https://github.com/llvm/llvm-project/pull/110569.

There are 2 recent PRs with bug fixes for special cases uncovered during
testing:
 * https://github.com/llvm/llvm-project/pull/116991
 * https://github.com/llvm/llvm-project/pull/116596

PR: https://github.com/llvm/llvm-project/pull/117244
2024-12-04 20:55:18 +00:00
Shilei Tian
68bcba6d7a Revert "[AMDGPU] Use COV6 by default (#118515)"
This reverts commit 410cbe3cf28913cca2fc61b3437306b841d08172 because some
buildbots are not ready yet.
2024-12-03 20:17:06 -05:00
Shilei Tian
410cbe3cf2
[AMDGPU] Use COV6 by default (#118515) 2024-12-03 19:38:35 -05:00
Shilei Tian
4b50ec43d0
[Clang] Avoid Using byval for ndrange_t when emitting __enqueue_kernel_basic (#116435)
AMDGPU disabled the use of `byval` for struct argument passing in commit
d77c620. However, when emitting `__enqueue_kernel_basic`, Clang still
adds the
`byval` attribute by default. Emitting the `byval` attribute by default
in this
context doesn’t seem like a good idea, as argument-passing conventions
are
highly target-dependent, and assumptions here could lead to issues. This
PR
removes the addition of the `byval` attribute, aligning the behavior
with other
`__enqueue_kernel_*` functions.
2024-11-15 16:54:29 -05:00
Alex Voicu
6e0b0038cd
[clang][OpenCL][CodeGen][AMDGPU] Do not use private as the default AS for when generic is available (#112442)
Currently, for AMDGPU, when compiling for OpenCL, we unconditionally use
`private` as the default address space. This is wrong for cases where
the `generic` address space is available, and is corrected via this
patch. In general, this AS map abuse is a bad hack and we should re-work
it altogether, but at least after this patch we will stop being
incorrect for e.g. OpenCL 2.0.
2024-10-22 12:05:48 +01:00
Hari Limaye
94473f4db6
[IRBuilder] Generate nuw GEPs for struct member accesses (#99538)
Generate nuw GEPs for struct member accesses, as inbounds + non-negative
implies nuw.

Regression tests are updated using update scripts where possible, and by
find + replace where not.
2024-08-09 13:25:04 +01:00
Emma Pilkington
4490003a22
[AMDGPU] Rename COV module flag to amdhsa_code_object_version (#79905)
The previous name 'amdgpu_code_object_version', was misleading since
this is really a property of the HSA OS. The new spelling also matches
the asm directive I added in bc82cfb.
2024-03-06 09:51:48 -05:00
Saiyedul Islam
082f87c9d4
[AMDGPU] Change default AMDHSA Code Object version to 5 (#79038)
Also update LIT tests and docs.
For more details, see
https://llvm.org/docs/AMDGPUUsage.html#code-object-v5-metadata

Corresponding llvm-objdump AMDGPU lit tests are updated
in a follow-up PR.
2024-01-23 17:08:18 +05:30
Saiyedul Islam
466a8149b3
Revert "[AMDGPU] Make default AMDHSA Code Object Version to be 5 (#65410)" (#66060)
This reverts commit 0a8d17e79b02a92814a2a788d79df1f54d70ec3e.
2023-09-12 15:13:59 +05:30
Saiyedul Islam
0a8d17e79b
[AMDGPU] Make default AMDHSA Code Object Version to be 5 (#65410)
Also update LIT tests and docs.
For more details, see
https://llvm.org/docs/AMDGPUUsage.html#code-object-v5-metadata

Reviewed By: arsenm, jhuber6

Github PR: #65410

Differential Revision: https://reviews.llvm.org/D129818
2023-09-12 13:53:31 +05:30
Matt Arsenault
647925648a clang/OpenCL: Apply default attributes to enqueued blocks
This was missing important environment context, like denormal-fp-math
and target-features. Curiously this seems to be losing nounwind. Note
this only fixes the actual invoke kernel. The invoke function is
already setting the default attribute set for internal
functions. However that is still buggy since it's not applying any use
function attributes (it's also missing uniform-work-group-size).

There seem to be too many different functions for setting attributes
with inconsistent behavior. The Function overload of
addDefaultFunctionAttributes seems to miss the target-cpu and
target-features. The AttrBuilder one seems to miss optnone (but that
seems to be disallowed on blocks anyway). Neither one calls
setTargetAttributes, when it probably should. uniform-work-group-size
is also set through AMDGPU code when it should be emitting generically
as a language property.

I also noticed update_cc_test_checks for attributes seem to not
connect the captured attribute variables to the attributes at the end
(although I think the numbers happen to work out correctly).
2023-01-30 15:03:15 -04:00
Matt Arsenault
d12ee4bf7c clang/OpenCL: Extend tests for enqueued block attributes
Baseline tests showing that enqueued blocks are not getting the
correct attributes applied.
2023-01-30 15:03:15 -04:00
Matt Arsenault
00f6a7f02f clang/OpenCL: Fix not setting convergent on block invoke kernels
Yet another example how convergent not being the default is dangerous
and backwards.
2023-01-30 15:03:14 -04:00
Sven van Haastregt
1495210914 [OpenCL] Always add nounwind attribute for OpenCL
Neither OpenCL nor C++ for OpenCL support exceptions, so add the
`nounwind` attribute unconditionally for those languages.

Differential Revision: https://reviews.llvm.org/D142033
2023-01-20 12:01:22 +00:00
Matt Arsenault
f9559b1e30 clang: Convert test to generated checks and opaque pointers 2023-01-10 20:35:49 -05:00
Nikita Popov
532dc62b90 [OpaquePtrs][Clang] Add -no-opaque-pointers to tests (NFC)
This adds -no-opaque-pointers to clang tests whose output will
change when opaque pointers are enabled by default. This is
intended to be part of the migration approach described in
https://discourse.llvm.org/t/enabling-opaque-pointers-by-default/61322/9.

The patch has been produced by replacing %clang_cc1 with
%clang_cc1 -no-opaque-pointers for tests that fail with opaque
pointers enabled. Worth noting that this doesn't cover all tests,
there's a remaining ~40 tests not using %clang_cc1 that will need
a followup change.

Differential Revision: https://reviews.llvm.org/D123115
2022-04-07 12:09:47 +02:00
Fangrui Song
fd739804e0 [test] Add {{.*}} to make ELF tests immune to dso_local/dso_preemptable/(none) differences
For a default visibility external linkage definition, dso_local is set for ELF
-fno-pic/-fpie and COFF and Mach-O. Since default clang -cc1 for ELF is similar
to -fpic ("PIC Level" is not set), this nuance causes unneeded binary format differences.

To make emitted IR similar, ELF -cc1 -fpic will default to -fno-semantic-interposition,
which sets dso_local for default visibility external linkage definitions.

To make this flip smooth and enable future (dso_local as definition default),
this patch replaces (function) `define ` with `define{{.*}} `,
(variable/constant/alias) `= ` with `={{.*}} `, or inserts appropriate `{{.*}} `.
2020-12-31 00:27:11 -08:00
Tim Northover
a009a60a91 IR: print value numbers for unnamed function arguments
For consistency with normal instructions and clarity when reading IR,
it's best to print the %0, %1, ... names of function arguments in
definitions.

Also modifies the parser to accept IR in that form for obvious reasons.

llvm-svn: 367755
2019-08-03 14:28:34 +00:00
Sven van Haastregt
da3b632057 Revert r326937 "[OpenCL] Remove block invoke function from emitted block literal struct"
This reverts r326937 as it broke block argument handling in OpenCL.
See the discussion on https://reviews.llvm.org/D43783 .

The next commit will add a test case that revealed the issue.

llvm-svn: 343582
2018-10-02 13:02:24 +00:00
Yaxun Liu
cb35e9fa94 [OpenCL] Remove block invoke function from emitted block literal struct
OpenCL runtime tracks the invoke function emitted for
any block expression. Due to restrictions on blocks in
OpenCL (v2.0 s6.12.5), it is always possible to know the
block invoke function when emitting call of block expression
or __enqueue_kernel builtin functions. Since __enqueu_kernel
already has an argument for the invoke function, it is redundant
to have invoke function member in the llvm block literal structure.

This patch removes invoke function from the llvm block literal
structure. It also removes the bitcast of block invoke function
to the generic block literal type which is useless for OpenCL.

This will save some space for the kernel argument, and also
eliminate some store instructions.

Differential Revision: https://reviews.llvm.org/D43783

llvm-svn: 326937
2018-03-07 19:32:58 +00:00
Yaxun Liu
fa13d015a3 [OpenCL] Fix __enqueue_block for block with captures
The following test case causes issue with codegen of __enqueue_block

void (^block)(void) = ^{ callee(id, out); };

enqueue_kernel(queue, 0, ndrange, block);
Clang first does codegen for block expression in the first line and deletes its block info.
Clang then tries to do codegen for the same block expression again for the second line,
and fails because the block info is gone.

The fix is to do normal codegen for both lines. Introduce an API to OpenCL runtime to
record llvm block invoke function and llvm block literal emitted for each AST block
expression, and use the recorded information for generating the wrapper kernel.

The EmitBlockLiteral APIs are cleaned up to minimize changes to the normal codegen
of blocks.

Another minor issue is that some clean up AST expression is generated for block
with captures, which can be stripped by IgnoreImplicit.

Differential Revision: https://reviews.llvm.org/D43240

llvm-svn: 325264
2018-02-15 16:39:19 +00:00
Yaxun Liu
f5f45e5e63 [AMDGPU] Switch to the new addr space mapping by default
This requires corresponding llvm change.

Differential Revision: https://reviews.llvm.org/D40956

llvm-svn: 324102
2018-02-02 16:08:24 +00:00
Yaxun Liu
f2127d1728 [AMDGPU] Fix bug in enqueued block codegen due to an extra line
llvm-svn: 316165
2017-10-19 15:56:13 +00:00
Yaxun Liu
c2a87a05f1 [OpenCL] Emit enqueued block as kernel
In OpenCL the kernel function and non-kernel function has different calling conventions.
For certain targets they have different argument ABIs. Also kernels have special function
attributes and metadata for runtime to launch them.

The blocks passed to enqueue_kernel is supposed to be executed as kernels. As such,
the block invoke function should be emitted as kernel with proper calling convention and
argument ABI.

This patch emits enqueued block as kernel. If a block is both called directly and passed
to enqueue_kernel, separate functions will be generated.

Differential Revision: https://reviews.llvm.org/D38134

llvm-svn: 315804
2017-10-14 12:23:50 +00:00