diff options
Diffstat (limited to 'meson.build')
| -rw-r--r-- | meson.build | 22 |
1 files changed, 15 insertions, 7 deletions
diff --git a/meson.build b/meson.build index ff3848b1d85..6bc3bb51dc0 100644 --- a/meson.build +++ b/meson.build @@ -2211,14 +2211,19 @@ endif # If we are targeting a processor that has Intel SSE 4.2 instructions, we can # use the special CRC instructions for calculating CRC-32C. If we're not # targeting such a processor, but we can nevertheless produce code that uses -# the SSE intrinsics, perhaps with some extra CFLAGS, compile both -# implementations and select which one to use at runtime, depending on whether -# SSE 4.2 is supported by the processor we're running on. +# the SSE intrinsics, compile both implementations and select which one to use +# at runtime, depending on whether SSE 4.2 is supported by the processor we're +# running on. # # Similarly, if we are targeting an ARM processor that has the CRC # instructions that are part of the ARMv8 CRC Extension, use them. And if # we're not targeting such a processor, but can nevertheless produce code that # uses the CRC instructions, compile both, and select at runtime. +# +# Note that we do not use __attribute__((target("..."))) for the ARM CRC +# instructions because until clang 16, using the ARM intrinsics still requires +# special -march flags. Perhaps we can re-evaluate this decision after some +# time has passed. ############################################################### have_optimized_crc = false @@ -2234,6 +2239,9 @@ if host_cpu == 'x86' or host_cpu == 'x86_64' prog = ''' #include <nmmintrin.h> +#if defined(__has_attribute) && __has_attribute (target) +__attribute__((target("sse4.2"))) +#endif int main(void) { unsigned int crc = 0; @@ -2244,16 +2252,16 @@ int main(void) } ''' - if cc.links(prog, name: '_mm_crc32_u8 and _mm_crc32_u32 without -msse4.2', + if not cc.links(prog, name: '_mm_crc32_u8 and _mm_crc32_u32', args: test_c_args) + # Do not use Intel SSE 4.2 + elif (cc.get_define('__SSE4_2__') != '') # Use Intel SSE 4.2 unconditionally. cdata.set('USE_SSE42_CRC32C', 1) have_optimized_crc = true - elif cc.links(prog, name: '_mm_crc32_u8 and _mm_crc32_u32 with -msse4.2', - args: test_c_args + ['-msse4.2']) + else # Use Intel SSE 4.2, with runtime check. The CPUID instruction is needed for # the runtime check. - cflags_crc += '-msse4.2' cdata.set('USE_SSE42_CRC32C', false) cdata.set('USE_SSE42_CRC32C_WITH_RUNTIME_CHECK', 1) have_optimized_crc = true |