GCC's -ffast-math behavior

[xunxun]

于 2012/2/9 18:10, Andrew Haley 写道:
>
> Okay.  Can you tell us how much faster than the builtins the Intel lib
> actually, is, and how you measured that?
>
> Andrew.
>
I 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.

ps : libmmt.lib and libircmt.lib comes from Intel C/C++ Compiler.

-- 
Best Regards,
xunxun

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