Hi! The arch= handling in target attribute right now clears almost all isa_flags and all isa_flags2, so that later call to ix86_option_override_internal can set just the isa options for the specific arch and nothing else. Unfortunately, it doesn't work, because next to the ix86_isa_flags{,2} we have also ix86_isa_flags{,2}_explicit bitmask and in ix86_option_override_internal and say for arch=x86_64 will not try to set sse2 isa when we cleared it in ix86_isa_flags but kept it set in ix86_isa_flags_explicit. So, the testcase works fine with -O2, but doesn't work with -O2 -msse2, in the former case ix86_isa_flags_explicit doesn't have MASK_SSE2 bit set, but in the latter case it does, so in the former case we end up with MASK_SSE2 in ix86_isa_flags, in the latter not in the function with target attribute.
The following patch thus clears both ix86_isa_flags{,2} and corresponding ix86_isa_flags{,2}_explicit. Also, so that say target ("arch=x86_64", "avx") works, the clearing is done when actually seeing the arch=, not at the end. target ("avx", "arch=x86_64") will still not enable avx, like before, though. Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk? 2019-11-19 Jakub Jelinek <ja...@redhat.com> PR target/90867 * config/i386/i386-options.c (ix86_valid_target_attribute_tree): Don't clear opts->x_ix86_isa_flags{,2} here... (ix86_valid_target_attribute_inner_p): ... but here when seeing arch=. Also clear opts->x_ix86_isa_flags{,2}_explicit. * gcc.target/i386/pr90867.c: New test. --- gcc/config/i386/i386-options.c.jj 2019-11-18 12:07:54.672405129 +0100 +++ gcc/config/i386/i386-options.c 2019-11-19 18:43:36.426606458 +0100 @@ -1147,7 +1147,25 @@ ix86_valid_target_attribute_inner_p (tre ret = false; } else - p_strings[opt] = xstrdup (p + opt_len); + { + p_strings[opt] = xstrdup (p + opt_len); + if (opt == IX86_FUNCTION_SPECIFIC_ARCH) + { + /* If arch= is set, clear all bits in x_ix86_isa_flags, + except for ISA_64BIT, ABI_64, ABI_X32, and CODE16 + and all bits in x_ix86_isa_flags2. */ + opts->x_ix86_isa_flags &= (OPTION_MASK_ISA_64BIT + | OPTION_MASK_ABI_64 + | OPTION_MASK_ABI_X32 + | OPTION_MASK_CODE16); + opts->x_ix86_isa_flags_explicit &= (OPTION_MASK_ISA_64BIT + | OPTION_MASK_ABI_64 + | OPTION_MASK_ABI_X32 + | OPTION_MASK_CODE16); + opts->x_ix86_isa_flags2 = 0; + opts->x_ix86_isa_flags2_explicit = 0; + } + } } else if (type == ix86_opt_enum) @@ -1225,18 +1243,8 @@ ix86_valid_target_attribute_tree (tree f /* If we are using the default tune= or arch=, undo the string assigned, and use the default. */ if (option_strings[IX86_FUNCTION_SPECIFIC_ARCH]) - { - opts->x_ix86_arch_string - = ggc_strdup (option_strings[IX86_FUNCTION_SPECIFIC_ARCH]); - - /* If arch= is set, clear all bits in x_ix86_isa_flags, - except for ISA_64BIT, ABI_64, ABI_X32, and CODE16. */ - opts->x_ix86_isa_flags &= (OPTION_MASK_ISA_64BIT - | OPTION_MASK_ABI_64 - | OPTION_MASK_ABI_X32 - | OPTION_MASK_CODE16); - opts->x_ix86_isa_flags2 = 0; - } + opts->x_ix86_arch_string + = ggc_strdup (option_strings[IX86_FUNCTION_SPECIFIC_ARCH]); else if (!orig_arch_specified) opts->x_ix86_arch_string = NULL; --- gcc/testsuite/gcc.target/i386/pr90867.c.jj 2019-11-19 18:49:11.746592189 +0100 +++ gcc/testsuite/gcc.target/i386/pr90867.c 2019-11-19 18:48:17.271406789 +0100 @@ -0,0 +1,30 @@ +/* PR target/90867 */ +/* { dg-do run { target lp64 } } */ +/* { dg-options "-O2 -msse2" } */ + +unsigned long long freq = 3600000000UL; /* 3.6 GHz = 3600.0 MHz */ + +__attribute__((noipa)) void +bar (double x) +{ + static double d = 3600000000.0; + if (x != d) + __builtin_abort (); + d /= 1000.0; +} + +__attribute__ ((target ("arch=x86-64"))) int +foo () +{ + bar ((double) freq); + bar (1e-3 * freq); + bar (1e-6 * freq); + bar (1e-9 * freq); + return 0; +} + +int +main () +{ + return foo (); +} Jakub