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build: detect GNU Assembler AVX-512 bug and disable AVX-512 variants if needed

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Type: fix
Change-Id: I098f6c79be3c2e4db001edc0cf0a229bf6e0b13d
Signed-off-by: Damjan Marion <damarion@cisco.com>
This commit is contained in:
Damjan Marion
2020-04-29 15:15:45 +02:00
committed by Florin Coras
parent 5a7f2f1224
commit 6e39ff03a6
1 changed files with 24 additions and 4 deletions
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28
src/cmake/cpu.cmake
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@ -55,6 +55,22 @@ endif()
set(VPP_LOG2_CACHE_LINE_SIZE ${VPP_LOG2_CACHE_LINE_SIZE}
CACHE STRING "Target CPU cache line size (power of 2)")
##############################################################################
# Gnu Assembler AVX-512 bug detection
# - see: https://sourceware.org/bugzilla/show_bug.cgi?id=23465
##############################################################################
if(CMAKE_SYSTEM_PROCESSOR MATCHES "amd64.*|x86_64.*|AMD64.*")
if (CMAKE_C_COMPILER_ID STREQUAL "GNU")
set(pfx ${CMAKE_CURRENT_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/gas_avx512_bug_test)
file(WRITE ${pfx}.s "vmovaps 0x40(,%rax), %zmm0\n")
execute_process(COMMAND ${CMAKE_C_COMPILER} -c ${pfx}.s -o ${pfx}.o)
execute_process(COMMAND objdump -s ${pfx}.o OUTPUT_VARIABLE _output)
if (NOT _output MATCHES "62f17c48 28040540 000000")
set(GNU_ASSEMBLER_AVX512_BUG 1)
endif()
endif()
endif()
##############################################################################
# CPU optimizations and multiarch support
##############################################################################
@ -64,10 +80,14 @@ if(CMAKE_SYSTEM_PROCESSOR MATCHES "amd64.*|x86_64.*|AMD64.*")
if(compiler_flag_march_core_avx2)
list(APPEND MARCH_VARIANTS "avx2\;-march=core-avx2 -mtune=core-avx2")
endif()
check_c_compiler_flag("-march=skylake-avx512" compiler_flag_march_skylake_avx512)
check_c_compiler_flag("-march=icelake-client" compiler_flag_march_icelake_client)
if(compiler_flag_march_skylake_avx512)
list(APPEND MARCH_VARIANTS "avx512\;-march=skylake-avx512 -mtune=skylake-avx512")
if (GNU_ASSEMBLER_AVX512_BUG)
message(WARNING "AVX-512 multiarch variant(s) disabled due to GNU Assembler bug")
else()
check_c_compiler_flag("-march=skylake-avx512" compiler_flag_march_skylake_avx512)
check_c_compiler_flag("-march=icelake-client" compiler_flag_march_icelake_client)
if(compiler_flag_march_skylake_avx512)
list(APPEND MARCH_VARIANTS "avx512\;-march=skylake-avx512 -mtune=skylake-avx512")
endif()
endif()
elseif(CMAKE_SYSTEM_PROCESSOR MATCHES "^(aarch64.*|AARCH64.*)")
set(CMAKE_C_FLAGS "-march=armv8-a+crc ${CMAKE_C_FLAGS}")