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authorDamjan Marion <damarion@cisco.com>2020-04-29 15:15:45 +0200
committerFlorin Coras <florin.coras@gmail.com>2020-04-29 20:04:03 +0000
commit6e39ff03a6fa28a2655d767454394413252a269d (patch)
tree9f6baa9fabadc2c48fda2e68b0a2d066895bb853
parent5a7f2f1224716130b50e48232e4c276fbebe63bc (diff)
build: detect GNU Assembler AVX-512 bug and disable AVX-512 variants if needed
Type: fix Change-Id: I098f6c79be3c2e4db001edc0cf0a229bf6e0b13d Signed-off-by: Damjan Marion <damarion@cisco.com>
-rw-r--r--src/cmake/cpu.cmake28
1 files changed, 24 insertions, 4 deletions
diff --git a/src/cmake/cpu.cmake b/src/cmake/cpu.cmake
index e407978ea37..916fe0d1ddd 100644
--- a/src/cmake/cpu.cmake
+++ b/src/cmake/cpu.cmake
@@ -56,6 +56,22 @@ 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
##############################################################################
if(CMAKE_SYSTEM_PROCESSOR MATCHES "amd64.*|x86_64.*|AMD64.*")
@@ -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}")