Commit Graph

3 Commits

Author SHA1 Message Date
Nirav Dave d6351340bb [DAGCombiner] If a TokenFactor would be merged into its user, consider the user later.
Summary:
A number of optimizations are inhibited by single-use TokenFactors not
being merged into the TokenFactor using it. This makes we consider if
we can do the merge immediately.

Most tests changes here are due to the change in visitation causing
minor reorderings and associated reassociation of paired memory
operations.

CodeGen tests with non-reordering changes:

  X86/aligned-variadic.ll -- memory-based add folded into stored leaq
  value.

  X86/constant-combiners.ll -- Optimizes out overlap between stores.

  X86/pr40631_deadstore_elision -- folds constant byte store into
  preceding quad word constant store.

Reviewers: RKSimon, craig.topper, spatel, efriedma, courbet

Reviewed By: courbet

Subscribers: dylanmckay, sdardis, nemanjai, jvesely, nhaehnle, javed.absar, eraman, hiraditya, kbarton, jrtc27, atanasyan, jsji, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D59260

llvm-svn: 356068
2019-03-13 17:07:09 +00:00
David Green 01e0f25a9f [ARM] Fix issue with large xor constants.
Fixup to rL325573 for large xor constants.

Thanks to Eli Friedman for the catch.

Differential revision: https://reviews.llvm.org/D43549

llvm-svn: 325761
2018-02-22 09:38:57 +00:00
David Green 056476497e [ARM] Mark -1 as cheap in xor's for thumb1
We can always convert xor %a, -1 into MVN, even in thumb 1 where the -1
would not otherwise be considered a cheap constant. This prevents the
-1's from being pulled out into constants and potentially hoisted.

Differential Revision: https://reviews.llvm.org/D43451

llvm-svn: 325573
2018-02-20 11:07:35 +00:00