2 Commits

Author SHA1 Message Date
Chad Rosier 580c45b12d [InstCombine] Gating select arithmetic optimization.
These changes faciliate positive behavior for arithmetic based select
expressions that match its translation criteria, keeping code size gated to
neutral or improved scenarios.

Patch by Michael Berg <michael_c_berg@apple.com>!

Differential Revision: https://reviews.llvm.org/D38263

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@314320 91177308-0d34-0410-b5e6-96231b3b80d8
2017-09-27 17:16:51 +00:00
Quentin Colombet 9a4ebf5dc9 [InstCombine] Add select simplifications
In these cases, two selects have constant selectable operands for
both the true and false components and have the same conditional
expression.
We then create two arithmetic operations of the same type and feed a
final select operation using the result of the true arithmetic for the true
operand and the result of the false arithmetic for the false operand and reuse
the original conditionl expression.
The arithmetic operations are naturally folded as a consequence, leaving
only the newly formed select to replace the old arithmetic operation.

Patch by: Michael Berg <michael_c_berg@apple.com>
Differential Revision: https://reviews.llvm.org/D37019

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@313774 91177308-0d34-0410-b5e6-96231b3b80d8
2017-09-20 17:32:16 +00:00