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ä 2012/2/9 18:29, Andrew Haley åé:And I think it's related with -funsafe-math-optimizationsOn 02/09/2012 10:20 AM, xunxun wrote:I think so. I don't know whether I may change main.c 's sin to expI use the code main.c (test sin speed)
On Win7 64bit, gcc 4.6.2 32bit
gcc -O3 -ffast-math main.c -o main.exe
run main.exe will cost 6.853s.
When linking with intel libM no fastmath
gcc -O3 main.c -o main.exe libmmt.lib libircmt.lib
run main.exe will cost 4.367s.Ah okay, I get it now, its sin, not exp. I suspect that it's the argument reduction step that's slowing you down.
Andrew.
It will be also slow.
-- Best Regards, xunxun
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