x86_64 extended the sse2 movnti instruction to support 64-bit integer registers as well. i don't see any builtin for generating this... nor is there an intrinsic listed in the intel manuals or apparently in icc 10.0.023 header files either. the natural name would be _mm_stream_si64 -- which fortunately does not conflict with _mm_stream_pi, the mmx 64-bit store version. on a whim i tried this: void foo(unsigned long *d, unsigned long v) { __builtin_ia32_movntq((unsigned long long *)d, v); } results in this code: 0000000000000000 <foo>: 0: 48 89 74 24 f8 mov %rsi,0xfffffffffffffff8(%rsp) 5: 0f 6f 44 24 f8 movq 0xfffffffffffffff8(%rsp),%mm0 a: 0f e7 07 movntq %mm0,(%rdi) d: c3 retq perhaps this builtin could be overloaded to generate the "movnti %rsi,(%rdi)" directly instead of shuffling through the mmx reg file? (note if i throw in -mtune=core2 it eliminates the trip through the stack) -dean /home/odo/gcc/bin/gcc -v Using built-in specs. Target: x86_64-unknown-linux-gnu Configured with: ../gcc/configure --prefix=/home/odo/gcc --disable-multilib --disable-biarch x86_64-unknown-linux-gnu --enable-languages=c Thread model: posix gcc version 4.3.0 20071029 (experimental) (GCC)
A patch is posted at http://gcc.gnu.org/ml/gcc-patches/2011-11/msg01938.html
Author: hjl Date: Fri Nov 18 19:02:45 2011 New Revision: 181491 URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=181491 Log: Add _mm_stream_si64. 2011-11-18 H.J. Lu <hongjiu.lu@intel.com> PR target/33944 * doc/extend.texi: Document __builtin_ia32_movnti64. * config/i386/emmintrin.h (_mm_stream_si64): New. * config/i386/i386-builtin-types.def: Add VOID_FTYPE_PLONGLONG_LONGLONG. * config/i386/i386.c (ix86_builtins): Add IX86_BUILTIN_MOVNTI64. (bdesc_special_args): Update __builtin_ia32_movnti. Add __builtin_ia32_movnti64. (ix86_expand_special_args_builtin): Handle VOID_FTYPE_PLONGLONG_LONGLONG. * config/i386/i386.md (UNSPEC_MOVNTI): New. * config/i386/sse.md (sse2_movntsi): Renamed to ... (sse2_movnti<mode>): This. Modified: trunk/gcc/ChangeLog trunk/gcc/config/i386/emmintrin.h trunk/gcc/config/i386/i386-builtin-types.def trunk/gcc/config/i386/i386.c trunk/gcc/config/i386/i386.md trunk/gcc/config/i386/sse.md trunk/gcc/doc/extend.texi
(In reply to hjl@gcc.gnu.org from comment #2) > Author: hjl > Date: Fri Nov 18 19:02:45 2011 > New Revision: 181491 > > URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=181491 > Log: > Add _mm_stream_si64. > > 2011-11-18 H.J. Lu <hongjiu.lu@intel.com> > > PR target/33944 > * doc/extend.texi: Document __builtin_ia32_movnti64. > > * config/i386/emmintrin.h (_mm_stream_si64): New. > > * config/i386/i386-builtin-types.def: Add VOID_FTYPE_PLONGLONG_LONGLONG. > > * config/i386/i386.c (ix86_builtins): Add IX86_BUILTIN_MOVNTI64. > (bdesc_special_args): Update __builtin_ia32_movnti. Add > __builtin_ia32_movnti64. > (ix86_expand_special_args_builtin): Handle > VOID_FTYPE_PLONGLONG_LONGLONG. > > * config/i386/i386.md (UNSPEC_MOVNTI): New. > > * config/i386/sse.md (sse2_movntsi): Renamed to ... > (sse2_movnti<mode>): This. > > Modified: > trunk/gcc/ChangeLog > trunk/gcc/config/i386/emmintrin.h > trunk/gcc/config/i386/i386-builtin-types.def > trunk/gcc/config/i386/i386.c > trunk/gcc/config/i386/i386.md > trunk/gcc/config/i386/sse.md > trunk/gcc/doc/extend.texi Did this fix it?
Fixed for 4.7.0.