Hi! As shown in the testcase below, if a function has multiple target attributes (rather than a single one with one or more arguments) or if a function gets one target attribute on one declaration and another one on another declaration, on x86 their effect is not combined into DECL_FUNCTION_SPECIFIC_TARGET, but instead only the last processed target attribute wins. aarch64 handles this right, the following patch follows what it does, i.e. only start with target_option_default_node if DECL_FUNCTION_SPECIFIC_TARGET is previously NULL (i.e. the first target attribute being processed on a function) and otherwise start from the previous DECL_FUNCTION_SPECIFIC_TARGET.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk? 2021-11-20 Jakub Jelinek <ja...@redhat.com> PR c++/101180 * config/i386/i386-options.c (ix86_valid_target_attribute_p): If fndecl already has DECL_FUNCTION_SPECIFIC_TARGET, use that as base instead of target_option_default_node. * gcc.target/i386/pr101180.c: New test. --- gcc/config/i386/i386-options.c.jj 2021-11-19 12:48:56.507415161 +0100 +++ gcc/config/i386/i386-options.c 2021-11-19 13:04:31.618044781 +0100 @@ -1443,8 +1443,11 @@ ix86_valid_target_attribute_p (tree fnde /* Initialize func_options to the default before its target options can be set. */ + tree old_target = DECL_FUNCTION_SPECIFIC_TARGET (fndecl); + if (old_target == NULL_TREE) + old_target = target_option_default_node; cl_target_option_restore (&func_options, &func_options_set, - TREE_TARGET_OPTION (target_option_default_node)); + TREE_TARGET_OPTION (old_target)); /* FLAGS == 1 is used for target_clones attribute. */ new_target --- gcc/testsuite/gcc.target/i386/pr101180.c.jj 2021-11-19 13:24:19.334132937 +0100 +++ gcc/testsuite/gcc.target/i386/pr101180.c 2021-11-19 13:23:56.676454806 +0100 @@ -0,0 +1,12 @@ +/* PR c++/101180 */ +/* { dg-do compile } */ +/* { dg-options "-O2 -mno-avx -mno-crc32" } */ + +#include <x86intrin.h> + +__attribute__((target ("avx"))) __attribute__((target ("crc32"))) void +foo (__m256 *p, unsigned int *q) +{ + __m256 c = _mm256_and_ps (p[0], p[1]); + *q = __crc32b (*q, 0x55); +} Jakub