On 2017-11-27 00:13, Rostislav Pehlivanov wrote: > On 26 November 2017 at 22:51, James Darnley <james.darn...@gmail.com> wrote: >> @@ -123,7 +123,10 @@ RET >> %endmacro >> >> %macro PMINSQ 3 >> - pcmpgtq %3, %2, %1 >> + mova %3, %2 >> + ; We cannot use the 3-operand format because the memory location >> cannot be >> + ; the second operand, only the third. >> + pcmpgtq %3, %1 >> > > I don't get it, how did it work before then?
Easy. 3-operand instructions were never generated using it meaning it was always emulated with a move. >> @@ -197,8 +200,20 @@ mova [rsp], m4 ; save sign extend mask >> xor negj, negj >> >> .looporder1: >> +%if cpuflag(avx) >> + vbroadcastss m2, [coefsq+posj*4] >> +%else >> movd m2, [coefsq+posj*4] ; c = coefs[j] >> SPLATD m2 >> +%endif >> +%if cpuflag(avx) >> + vpmuldq m1, m2, [smpq+negj*4-4] >> + vpmuldq m5, m2, [smpq+negj*4-4+mmsize] >> + vpmuldq m7, m2, [smpq+negj*4-4+mmsize*2] >> + vpaddq m0, m1 >> + vpaddq m4, m5 >> + vpaddq m6, m7 >> > > Why force VEX encoding for these instructions, on avx no less? Not sure. Legacy code written before I knew what I was doing? Perhaps some issue arose with the assembler or x86inc at that time and this is how I worked around it. _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
