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Re: PATCH: [darwin] Always turn on FP_SAVE_INLINE at -O3
Caroline Tice wrote:
Yes you are both right, I accidentally attached an intermediate patch
version to the email
I sent out. The final version of the patch will contain the
definition (from Apple's version):
#define FP_SAVE_INLINE(FIRST_REG) \
(optimize >= 3 \
|| ((FIRST_REG) > 60 && (FIRST_REG) < 64)
*This* version will, as pointed out below, do something. In
particular, on the mesa SPEC Fp
benchmark, we see roughly a 1% performance improvement.
The reason for adding the "((FIRST_REG) > 60" clause, as I understand
it (it was done long
before I got here) was to reduce code size somewhat, while having a
minimal impact on
performance.
Yup. The general observation is that on Darwin and Mac OS X, smaller
code wins so much with the VM that it's worth a few extra instruction
executions to get sizes down. Almost the entire system is built -Os.
Stan