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[PATCH, i386]: Use reciprocal sequences for vectorized SFmode division and sqrtf(x) for -ffast-math


Hello!

This patch builds on recent patch by Michael (that implemented
fine-grained control on -mrecip option) and with -ffast-math emits
reciprocal sequences with additional NR step for vectorized SFmode
division and vectorized sqrtf(x).

2011-10-20  Uros Bizjak  <ubizjak@gmail.com>

	* config/i386/i386.h (RECIP_MASK_DEFAULT): New define.
	* config/i386/i386.op (recip_mask): Initialize with RECIP_MASK_DEFAULT.
	* doc/invoke.texi (mrecip): Document that GCC implements vectorized
	single float division and vectorized sqrtf(x) with reciprocal sequence
	with additional Newton-Raphson step with -ffast-math.

The patch was tested on x86_64-pc-linux-gnu, but I would like Joseph
to check if I didn't mess something with options handling.

The effect of the patch is 7% faster gas_dyn from polyhedron testsuite
on corei7-avx.

Uros.

Attachment: p.diff.txt
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