build: detect GNU Assembler bug and disable variants if needed
Type: fix
@@ -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
##############################################################################
@@ -64,11 +80,15 @@ 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()
+ 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}")
check_c_compiler_flag("-march=armv8-a+crc+crypto -mtune=qdf24xx" compiler_flag_march_core_qdf24xx)
