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Re: The state of glibc libm


On 03/14/2012 10:30 AM, Joseph S. Myers wrote:

I'd say that "better performance with the potential loss of accuracy" should be covered by -ffast-math - that GCC should generate direct use of fsin/fcos instructions for sin/cos for -O2 -funsafe-math-optimizations on x86_64, as it does on x86, unless there is some reason to think they would perform worse than the out-of-line implementation.
The better performance with potential loss of accuracy is an across the board request, it's not just a sin/cos issue. All the trig, exp, pow, log, etc, which I don't think are necessarily covered by using the old x87 fp unit.

Jeff


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