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scientica · Jan 4th, 2005, 12:28 PM

well don't forget:
3. To make use of cool stuff such as MMX,SSE[1-3],3Dnow!, etc -- stuff that many compilers can't make use of, well, not in a sane way at least... (I wonder if any comiler can make use of the parallellism of SIMD (single instruction, multiple data - eg, do 2-8 integer additions with one instruction with saturation (ie values 255+1 = 255 for bytes, normal add instruction make 255+1 = 0 for byte, btw)))
:ph34r: showoff: paddusb (~"Add unsigned with saturation on byte") will do 8 byte additions in one(sic) instruction cycle (MMX instruction) - actually, it's not that hard to "decode" the MMX instructions, once one has learned it, one way to describe the packed add instruction is (unless I'm misstaken): /padd([u]?[s]?[bw]|[bwd])/

Jan 4th, 2005, 12:28 PM	#7
scientica Newbie Join Date: Apr 2004 Location: Sweden Posts: 10 Rep Power: 0	well don't forget: 3. To make use of cool stuff such as MMX,SSE[1-3],3Dnow!, etc -- stuff that many compilers can't make use of, well, not in a sane way at least... (I wonder if any comiler can make use of the parallellism of SIMD (single instruction, multiple data - eg, do 2-8 integer additions with one instruction with saturation (ie values 255+1 = 255 for bytes, normal add instruction make 255+1 = 0 for byte, btw))) :ph34r: showoff: paddusb (~"Add unsigned with saturation on byte") will do 8 byte additions in one(sic) instruction cycle (MMX instruction) - actually, it's not that hard to "decode" the MMX instructions, once one has learned it, one way to describe the packed add instruction is (unless I'm misstaken): /padd([u]?[s]?[bw]\|[bwd])/ __________________ Regards Scienitca (registered user #335819 - http://counter.li.org ) -- Together in diversity, we each according to ability, to each according to needs, will help this world (to) become better - who did you help today?