Add O3 flag to VLS and VLA test-suite flags

[MattDevereau]

Summary

A missing O3 flag in the VLS and VLA buildbots was resulting
in some false positives slipping through. e.g., CLAMR fails when
running LNT with O3 but passes without it.

[peterwaller-arm]

This looks right to me but please allow time to pass for other reviewers to chime in before submitting.

[maxim-kuvyrkov]

Hi @MattDevereau ,
Thanks.

Could you elaborate in the commit log about the false positives?

Does it make sense to add -O3 to other bots?

[MattDevereau]

@maxim-kuvyrkov I've expanded the commit message a bit.

AFAIK these 4 bot configs were created on request of ARM specifically for testing VLA/VLS with SVE enabled machines. Changing other bots might interfere with other peoples work so its probably best to keep it simple here.

[DavidSpickett]

I've expanded the commit message a bit.

If you're using arc it won't update the commit message on Phab for you, you have to do that manually.

[MattDevereau]

closed in commit 3ddb899dea13cab48f1c79587f9eb5ec836b5459

[peterwaller-arm]

By the way you can update the commit message in Phabricator to match what you have locally with arc diff --verbatim.

So far as I can tell any commit message clarification appears to not have made it into Git or Phabriactor(?). So to clarify, the "false positives" Matt refers to are that we encountered LNT failures due to SVE VLS code-generation where Buildbot was green. As far as we can tell, the reason is that Buildbot was not exercising vector codegen at the default optimization level, and therefore, was of limited use as a VLS builder.

[DavidSpickett]

By the way you can update the commit message in Phabricator to match what you have locally with arc diff --verbatim.

TIL this exists. Has always bugged me.

Matt refers to are that we encountered LNT failures due to SVE VLS code-generation where Buildbot was green.

Got it, somehow I thought that you were seeing failures on the bot that I wasn't. But yeah makes total sense, the bot wasn't generating any vector code but your testing elsewhere was.

[gkistanova]

If tests require -O3 shouldn’t those tests enforce the right flags in the RUN instead? Sounds like an issue with the tests in question.
I don’t mind running these builders with -O3, though.

buildbot/osuosl/master/config/builders.py

# Clang builders.
     'tags'  : ["clang"],
     'workernames' : ["linaro-clang-aarch64-sve-vla"],
     'builddir': "clang-aarch64-sve-vla",
     'factory' : ClangBuilder.getClangCMakeBuildFactory(
                     clean=False,
                     checkout_flang=True,
                     runTestSuite=True,
                     testsuite_flags=[
-                        '--cppflags', '-mcpu=a64fx -mllvm -scalable-vectorization=preferred -mllvm -treat-scalable-fixed-error-as-warning=false',
+                        '--cppflags', '-mcpu=a64fx -mllvm -scalable-vectorization=preferred -mllvm -treat-scalable-fixed-error-as-warning=false -O3',
                         '--threads=48', '--build-threads=48'],
                     extra_cmake_args=[
                         "-DCMAKE_C_FLAGS='-mcpu=a64fx'",
                         "-DCMAKE_CXX_FLAGS='-mcpu=a64fx'",
                         "-DLLVM_ENABLE_LLD=True"])},
 
     # AArch64 Clang+LLVM+RT+LLD check-all + flang + test-suite 2-stage w/SVE-Vector-Length-Agnostic
     {'name' : "clang-aarch64-sve-vla-2stage",
     'tags'  : ["clang"],
     'workernames' : ["linaro-clang-aarch64-sve-vla-2stage"],
     'builddir': "clang-aarch64-sve-vla-2stage",
     'factory' : ClangBuilder.getClangCMakeBuildFactory(
                     clean=False,
                     checkout_flang=True,
                     useTwoStage=True,
                     testStage1=False,
                     runTestSuite=True,
                     testsuite_flags=[
-                        '--cppflags', '-mcpu=a64fx -mllvm -scalable-vectorization=preferred -mllvm -treat-scalable-fixed-error-as-warning=false',
+                        '--cppflags', '-mcpu=a64fx -mllvm -scalable-vectorization=preferred -mllvm -treat-scalable-fixed-error-as-warning=false -O3',
                         '--threads=48', '--build-threads=48'],
                     extra_cmake_args=[
                         "-DCMAKE_C_FLAGS='-mcpu=a64fx -mllvm -scalable-vectorization=preferred -mllvm -treat-scalable-fixed-error-as-warning=false'",
                         "-DCMAKE_CXX_FLAGS='-mcpu=a64fx -mllvm -scalable-vectorization=preferred -mllvm -treat-scalable-fixed-error-as-warning=false'",
                         "-DLLVM_ENABLE_LLD=True"])},
 
     # AArch64 Clang+LLVM+RT+LLD check-all + flang + test-suite w/SVE-Vector-Length-Specific
     {'name' : "clang-aarch64-sve-vls",
     'tags'  : ["clang"],
     'workernames' : ["linaro-clang-aarch64-sve-vls"],
     'builddir': "clang-aarch64-sve-vls",
     'factory' : ClangBuilder.getClangCMakeBuildFactory(
                     clean=False,
                     checkout_flang=True,
                     runTestSuite=True,
                     testsuite_flags=[
-                        '--cppflags', '-mcpu=a64fx -msve-vector-bits=512 -mllvm -treat-scalable-fixed-error-as-warning=false',
+                        '--cppflags', '-mcpu=a64fx -msve-vector-bits=512 -mllvm -treat-scalable-fixed-error-as-warning=false -O3',
                         '--threads=48', '--build-threads=48'],
                     extra_cmake_args=[
                         "-DCMAKE_C_FLAGS='-mcpu=a64fx'",
                         "-DCMAKE_CXX_FLAGS='-mcpu=a64fx'",
                         "-DLLVM_ENABLE_LLD=True"])},
 
     # AArch64 Clang+LLVM+RT+LLD check-all + flang + test-suite 2-stage w/SVE-Vector-Length-Specific
     {'name' : "clang-aarch64-sve-vls-2stage",
     'tags'  : ["clang"],
     'workernames' : ["linaro-clang-aarch64-sve-vls-2stage"],
     'builddir': "clang-aarch64-sve-vls-2stage",
     'factory' : ClangBuilder.getClangCMakeBuildFactory(
                     clean=False,
                     checkout_flang=True,
                     useTwoStage=True,
                     testStage1=False,
                     runTestSuite=True,
                     testsuite_flags=[
-                        '--cppflags', '-mcpu=a64fx -msve-vector-bits=512 -mllvm -treat-scalable-fixed-error-as-warning=false',
+                        '--cppflags', '-mcpu=a64fx -msve-vector-bits=512 -mllvm -treat-scalable-fixed-error-as-warning=false -O3',
                         '--threads=48', '--build-threads=48'],
                     extra_cmake_args=[
                         "-DCMAKE_C_FLAGS='-mcpu=a64fx -msve-vector-bits=512 -mllvm -treat-scalable-fixed-error-as-warning=false'",
                         "-DCMAKE_CXX_FLAGS='-mcpu=a64fx -msve-vector-bits=512 -mllvm -treat-scalable-fixed-error-as-warning=false'",
                         "-DLLVM_ENABLE_LLD=True"])},
 
     {'name' : "clang-arm64-windows-msvc-2stage",
     'tags'  : ["clang"],