Commit Graph

2 Commits

Author SHA1 Message Date
Craig Topper 2dca3b287b [X86] Make the FMA3 instruction names consistent between VEX and EVEX encoded versions.
This places the 132/213/231 form number in front of the SS/SD/PS/PD. Move the Y for 256-bit versions to be after the PS/PD. Change the AVX512 scalar forms to include a Z in the their name. This new format should be consistent with the general naming of instructions.

llvm-svn: 276559
2016-07-24 08:26:38 +00:00
Sanjay Patel f664f3a578 [DAG] Remove redundant FMUL in Newton-Raphson SQRT code
When calculating a square root using Newton-Raphson with two constants,
a naive implementation is to use five multiplications (four muls to calculate
reciprocal square root and another one to calculate the square root itself).
However, after some reassociation and CSE the same result can be obtained
with only four multiplications. Unfortunately, there's no reliable way to do
such a reassociation in the back-end. So, the patch modifies NR code itself
so that it directly builds optimal code for SQRT and doesn't rely on any
further reassociation.

Patch by Nikolai Bozhenov!

Differential Revision: http://reviews.llvm.org/D21127

llvm-svn: 272920
2016-06-16 16:58:54 +00:00