[compiler-rt] [scudo] Use -mcrc32 on x86 when available
authorMichał Górny <mgorny@moritz.systems>
Thu, 31 Mar 2022 07:55:25 +0000 (09:55 +0200)
committerMichał Górny <mgorny@moritz.systems>
Thu, 31 Mar 2022 15:49:42 +0000 (17:49 +0200)
commit09b53121c323f260ab97cecd067d4e7b3be1bf7c
tree55dc6b5a003ef97bb05ef6fe3b5fafeca34d7bca
parent97417e0300719f4bc9e8599ecc68ef97170524f8
[compiler-rt] [scudo] Use -mcrc32 on x86 when available

Update the hardware CRC32 logic in scudo to support using `-mcrc32`
instead of `-msse4.2`.  The CRC32 intrinsics use the former flag
in the newer compiler versions, e.g. in clang since 12fa608af44a.
With these compilers, passing `-msse4.2` is insufficient to enable
the instructions and causes build failures when `-march` does not enable
CRC32:

    /var/tmp/portage/sys-libs/compiler-rt-sanitizers-14.0.0/work/compiler-rt/lib/scudo/scudo_crc32.cpp:20:10: error: always_inline function '_mm_crc32_u32' requires target feature 'crc32', but would be inlined into function 'computeHardwareCRC32' that is compiled without support for 'crc32'
      return CRC32_INTRINSIC(Crc, Data);
             ^
    /var/tmp/portage/sys-libs/compiler-rt-sanitizers-14.0.0/work/compiler-rt/lib/scudo/scudo_crc32.h:27:27: note: expanded from macro 'CRC32_INTRINSIC'
    #  define CRC32_INTRINSIC FIRST_32_SECOND_64(_mm_crc32_u32, _mm_crc32_u64)
                              ^
    /var/tmp/portage/sys-libs/compiler-rt-sanitizers-14.0.0/work/compiler-rt/lib/scudo/../sanitizer_common/sanitizer_platform.h:132:36: note: expanded from macro 'FIRST_32_SECOND_64'
    #  define FIRST_32_SECOND_64(a, b) (a)
                                       ^
    1 error generated.

For backwards compatibility, use `-mcrc32` when available and fall back
to `-msse4.2`.  The `<smmintrin.h>` header remains in use as it still
works and is compatible with GCC, while clang's `<crc32intrin.h>`
is not.

Originally reported in https://bugs.gentoo.org/835870.

Differential Revision: https://reviews.llvm.org/D122789
compiler-rt/cmake/config-ix.cmake
compiler-rt/lib/scudo/CMakeLists.txt
compiler-rt/lib/scudo/scudo_allocator.cpp
compiler-rt/lib/scudo/scudo_crc32.cpp
compiler-rt/lib/scudo/scudo_crc32.h
compiler-rt/lib/scudo/standalone/CMakeLists.txt
compiler-rt/lib/scudo/standalone/checksum.h
compiler-rt/lib/scudo/standalone/chunk.h
compiler-rt/lib/scudo/standalone/crc32_hw.cpp