It (introduced by 556d713c70) appears to be
related to the removed dragonegg project. In addition, the feature was a bit
misnamed and may lur users to unnecessarily use it.
[clang][amdgpu] Use implicit code object version
At present, clang always passes amdhsa-code-object-version on to -cc1. That is
great for certainty over what object version is being used when debugging.
Unfortunately, the command line argument is in AMDGPUBaseInfo.cpp in the amdgpu
target. If clang is used with an llvm compiled with DLLVM_TARGETS_TO_BUILD
that excludes amdgpu, this will be diagnosed (as discovered via D98658):
- Unknown command line argument '--amdhsa-code-object-version=4'
This means that clang, built only for X86, can be used to compile the nvptx
devicertl for openmp but not the amdgpu one. That would shortly spawn fragile
logic in the devicertl cmake to try to guess whether the clang used will work.
This change omits the amdhsa-code-object-version parameter when it matches the
default that AMDGPUBaseInfo.cpp specifies, with a comment to indicate why. As
this is the only part of clang's codegen for amdgpu that depends on the target
in the back end it suffices to build the openmp runtime on most (all?) systems.
It is a non-functional change, though observable in the updated tests and when
compiling with -###. It may cause minor disruption to the amd-stg-open branch.
Revision of D98746, builds on refactor in D101077
Reviewed By: yaxunl
Differential Revision: https://reviews.llvm.org/D101095
[NFC] Use regex for code object version in hip tests
Extracted from D93258. Makes tests robust to changes in default
code object version.
Reviewed By: t-tye
Differential Revision: https://reviews.llvm.org/D93398
Currently HIP toolchain calls clang to emit bitcode then calls opt/llc for device compilation for the default -fno-gpu-rdc
case, which is unnecessary since clang is able to compile a single source file to ISA.
This patch fixes the HIP action builder and toolchain so that the default -fno-gpu-rdc can be done like a canonical
toolchain, i.e. one clang -cc1 invocation to compile source code to ISA.
This can avoid unnecessary processes to speed up the compilation, and avoid redundant LLVM passes which are
performed in clang -cc1 and opt.
Differential Revision: https://reviews.llvm.org/D81627
Summary:
The HIP toolchain invokes `llc` without an explicit opt-level, meaning
it always uses the default (-O2). This makes it impossible to use -O1,
for example. The HIP toolchain also coerces -Os/-Oz to -O2 even when
invoking opt, and it coerces -Og to -O2 rather than -O1.
Forward the opt-level to `llc` as well as `opt`, and only coerce levels
where it is required.
Subscribers: cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D70987
Fangrui Song