digitalmars.D - question: prefer SSE over x87 asm code?
- dennis luehring (10/10) Jan 21 2011 hello all,
- Don (7/20) Jan 21 2011 At the present time, SSE and x87 are the same speed in most cases (most
- bearophile (5/8) Jan 21 2011 SSE-something also allow some other operations, sqrt, etc. Even with GCC...
- Trass3r (1/1) Jan 23 2011 Note that SSE is less precise than x87.
hello all, i've read that on newer architectures SSE code should be prefered over x87 - because of speed and i saw masses of SSE code in the math stuff of microsoft and intel compiler generated code i know that the current fpu/sse support of DMD isn't that good, but are there any attemps to use SSE code insinde of std.math implementation wouldn't give SSE better results here (beside that someone needs to implement it)? just as a question
Jan 21 2011
dennis luehring wrote:hello all, i've read that on newer architectures SSE code should be prefered over x87 - because of speed and i saw masses of SSE code in the math stuff of microsoft and intel compiler generated codeAt the present time, SSE and x87 are the same speed in most cases (most operations take just one cycle) -- except of course that you can do two or four operations at once with SSE.i know that the current fpu/sse support of DMD isn't that good, but are there any attemps to use SSE code insinde of std.math implementation wouldn't give SSE better results here (beside that someone needs to implement it)? just as a questionNot for 32-bit. Even the last AMD 32-bit processors didn't support SSE2. For 64-bit, it makes sense, since all x86-64 processors can do SSE2. It will definitely happen for 64.
Jan 21 2011
Don:At the present time, SSE and x87 are the same speed in most cases (most operations take just one cycle) -- except of course that you can do two or four operations at once with SSE.SSE-something also allow some other operations, sqrt, etc. Even with GCC I've seen some performance improvements using SSE-something instructions. I suggest people to start looking at AVX instructions too. Bye, bearophile
Jan 21 2011