On Wed, 23 Aug 2017, Uros Bizjak wrote: > On Wed, Aug 23, 2017 at 11:40 AM, Uros Bizjak <ubiz...@gmail.com> wrote: > > On Wed, Aug 23, 2017 at 11:22 AM, Richard Biener <rguent...@suse.de> wrote: > >>> > /* If the machine does not have a case insn that compares the bounds, > >>> > Index: gcc/config/i386/i386.c > >>> > =================================================================== > >>> > --- gcc/config/i386/i386.c (revision 251275) > >>> > +++ gcc/config/i386/i386.c (working copy) > >>> > @@ -7369,7 +7369,8 @@ ix86_valid_target_attribute_tree (tree a > >>> > || opts->x_target_flags != def->x_target_flags > >>> > || option_strings[IX86_FUNCTION_SPECIFIC_ARCH] > >>> > || option_strings[IX86_FUNCTION_SPECIFIC_TUNE] > >>> > - || enum_opts_set.x_ix86_fpmath) > >>> > + || enum_opts_set.x_ix86_fpmath > >>> > + || !TARGET_64BIT_P (opts->x_ix86_isa_flags)) > >>> > >>> You should use (!TARGET_64BIT_P ... && TARGET_SSE_P ...) to match the > >>> condition in the special fpmath processing part. (BTW: The comment in > >>> that part is wrong, we need SSE, not sse2 on 32-bit targets to use SSE > >>> math.) > >> > >> Hmpf, with the change I again run into the libgo bootstrap fail > >> (appearantly my reduced testcase is incomplete) > >> > >> libtool: compile: /abuild/rguenther/obj2/./gcc/xgcc > >> -B/abuild/rguenther/obj2/./gcc/ -B/usr/local/x86_64-pc-linux-gnu/bin/ > >> -B/usr/local/x86_64-pc-linux-gnu/lib/ -isystem > >> /usr/local/x86_64-pc-linux-gnu/include -isystem > >> /usr/local/x86_64-pc-linux-gnu/sys-include -m32 -DHAVE_CONFIG_H -I. > >> -I/space/rguenther/src/svn/trunk2/libgo -I > >> /space/rguenther/src/svn/trunk2/libgo/runtime > >> -I/space/rguenther/src/svn/trunk2/libgo/../libffi/include > >> -I../libffi/include -pthread -fexceptions -fnon-call-exceptions > >> -fplan9-extensions -fsplit-stack -Wall -Wextra -Wwrite-strings -Wcast-qual > >> -Werror -minline-all-stringops -D_GNU_SOURCE -D_LARGEFILE_SOURCE > >> -D_FILE_OFFSET_BITS=64 -I /space/rguenther/src/svn/trunk2/libgo/../libgcc > >> -I /space/rguenther/src/svn/trunk2/libgo/../libbacktrace -I > >> ../../../gcc/include -g -O2 -m32 -MT aeshash.lo -MD -MP -MF > >> .deps/aeshash.Tpo -c > >> /space/rguenther/src/svn/trunk2/libgo/runtime/aeshash.c -fPIC -DPIC -o > >> .libs/aeshash.o > >> In file included from > >> /space/rguenther/src/svn/trunk2/libgo/runtime/aeshash.c:17:0: > >> /space/rguenther/src/svn/trunk2/libgo/runtime/aeshash.c: In function > >> ‘aeshashbody’: > >> /abuild/rguenther/obj2/./gcc/include/emmintrin.h:700:1: error: inlining > >> failed in call to always_inline ‘_mm_loadu_si128’: target specific option > >> mismatch > >> _mm_loadu_si128 (__m128i_u const *__P) > >> ^~~~~~~~~~~~~~~ > >> /space/rguenther/src/svn/trunk2/libgo/runtime/aeshash.c:387:11: note: > >> called from here > >> mseed ^= _mm_loadu_si128(aeskeysched.__values); > >> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > >> > >> that appens even with making the if a if (1). The check we run into > >> is somehow still > >> > >> else if (caller_opts->x_ix86_fpmath != callee_opts->x_ix86_fpmath) > >> ret = false; > >> > >> ah ... > >> > >> #ifndef __SSE__ > >> #pragma GCC push_options > >> #pragma GCC target("sse") > >> #define __DISABLE_SSE__ > >> #endif /* __SSE__ */ > >> > >> but on x86_64 when building with -m32 we _do_ have __SSE__ set so > >> the intrinsics get target_option_default_node which doesn't have > >> fmpath=sse. So x86_64 -m32 -march=i586 enables SSE math for > >> the intrinsics while x86_64 -m32 [-march=x86-64] does not... > > > > IMO target_default_node should already enable fpmath=sse. When SSE is > > available, fpmath should be set to SSE, unless there is fpmath option > > specified. > > Following part from ix86_option_override_internal looks a bit mismatched: > > --cut here-- > /* For all chips supporting SSE2, -mfpmath=sse performs better than > fpmath=387. The second is however default at many targets since the > extra 80bit precision of temporaries is considered to be part of ABI. > Overwrite the default at least for -ffast-math. > TODO: -mfpmath=both seems to produce same performing code with bit > smaller binaries. It is however not clear if register allocation is > ready for this setting. > Also -mfpmath=387 is overall a lot more compact (bout 4-5%) than SSE > codegen. We may switch to 387 with -ffast-math for size optimized > functions. */ > else if (fast_math_flags_set_p (&global_options) > && TARGET_SSE2_P (opts->x_ix86_isa_flags)) > opts->x_ix86_fpmath = FPMATH_SSE; > --cut here-- > > We probably have to set fpmath to SSE also for (!TARGET_64BIT_P ... && > TARGET_SSE_P ...).
The comment says we can't because 387 math is considered part of the ABI. Richard.