Commit Graph

3 Commits

Author SHA1 Message Date
Tim Northover 5745b6ac3b ARM: use target-specific SUBS node when combining cmp with cmov.
This has two positive effects. First, using a custom node prevents
recombination leading to an infinite loop since the output DAG is notionally a
little more complex than the input one. Using a flag-setting instruction also
allows the subtraction to be folded with the related comparison more easily.

https://reviews.llvm.org/D53190

llvm-svn: 348122
2018-12-03 11:16:21 +00:00
Roger Ferrer Ibanez d41059a9f6 [ARM] Materialise some boolean values to avoid a branch
This patch combines some cases of ARMISD::CMOV for integers that arise in comparisons of the form

  a != b ? x : 0
  a == b ? 0 : x

and that currently (e.g. in Thumb1) are emitted as branches.

Differential Revision: https://reviews.llvm.org/D34515

llvm-svn: 325323
2018-02-16 09:23:59 +00:00
Sam Parker ccb209bb97 [ARM] Swap cmp operands for automatic shifts
Swap the compare operands if the lhs is a shift and the rhs isn't,
as in arm and T2 the shift can be performed by the compare for its
second operand.

Differential Revision: https://reviews.llvm.org/D39004

llvm-svn: 316562
2017-10-25 08:33:06 +00:00