Commit Graph

4 Commits

Author SHA1 Message Date
Simon Pilgrim 1fc483d991 [X86][SSE] Vector integer to float conversion memory folding
Added missing memory folding for the (V)CVTDQ2PS instructions - we can safely fold these (but not the (V)CVTDQ2PD versions which have a register/memory size discrepancy in the source operand). I've added a test case demonstrating that stack folding now works.

Differential Revision: http://reviews.llvm.org/D5981

llvm-svn: 221407
2014-11-05 22:28:25 +00:00
Simon Pilgrim 2f9548a3ef [X86] Memory folding for commutative instructions (updated)
This patch improves support for commutative instructions in the x86 memory folding implementation by attempting to fold a commuted version of the instruction if the original folding fails - if that folding fails as well the instruction is 're-commuted' back to its original order before returning.

Updated version of r219584 (reverted in r219595) - the commutation attempt now explicitly ensures that neither of the commuted source operands are tied to the destination operand / register, which was the source of all the regressions that occurred with the original patch attempt.

Added additional regression test case provided by Joerg Sonnenberger.

Differential Revision: http://reviews.llvm.org/D5818

llvm-svn: 220239
2014-10-20 22:14:22 +00:00
NAKAMURA Takumi 75a0240056 Revert r219584, "[X86] Memory folding for commutative instructions."
It broke i686 selfhosting.

llvm-svn: 219595
2014-10-13 04:17:34 +00:00
Simon Pilgrim 77ac26d279 [X86] Memory folding for commutative instructions.
This patch improves support for commutative instructions in the x86 memory folding implementation by attempting to fold a commuted version of the instruction if the original folding fails - if that folding fails as well the instruction is 're-commuted' back to its original order before returning.

This mainly helps the stack inliner better fold reloads of 3 (or more) operand instructions (VEX encoded SSE etc.) but by performing this in the lowest foldMemoryOperandImpl implementation it also replaces the X86InstrInfo::optimizeLoadInstr version and is now used by FastISel too.

Differential Revision: http://reviews.llvm.org/D5701

llvm-svn: 219584
2014-10-12 10:52:55 +00:00