Commit Graph

4 Commits

Author SHA1 Message Date
Sanjay Patel 5a48aef3f0 [x86, MemCmpExpansion] allow 2 pairs of loads per block (PR33325)
This is the last step needed to fix PR33325:
https://bugs.llvm.org/show_bug.cgi?id=33325

We're trading branch and compares for loads and logic ops. 
This makes the code smaller and hopefully faster in most cases.

The 24-byte test shows an interesting construct: we load the trailing scalar 
elements into vector registers and generate the same pcmpeq+movmsk code that 
we expected for a pair of full vector elements (see the 32- and 64-byte tests).

Differential Revision: https://reviews.llvm.org/D41714

llvm-svn: 321934
2018-01-06 16:16:04 +00:00
Clement Courbet 063bed9baf re-land [ExpandMemCmp] Split ExpandMemCmp from CodeGen into its own pass."
Fix undefined references: ExpandMemCmp belongs to CodeGen/, not Scalar/.

llvm-svn: 317318
2017-11-03 12:12:27 +00:00
Clement Courbet 82bade615b Revert "[ExpandMemCmp] Split ExpandMemCmp from CodeGen into its own pass."
undefined reference to `llvm::TargetPassConfig::ID' on
clang-ppc64le-linux-multistage

This reverts commit eea333c33fa73ad225ef28607795984829f65688.

llvm-svn: 317213
2017-11-02 15:53:10 +00:00
Clement Courbet 1dc37b9c3b [ExpandMemCmp] Split ExpandMemCmp from CodeGen into its own pass.
Summary:
This is mostly a noop (most of the test diffs are renamed blocks).
There are a few temporary register renames (eax<->ecx) and a few blocks are
shuffled around.

See the discussion in PR33325 for more details.

Reviewers: spatel

Subscribers: mgorny

Differential Revision: https://reviews.llvm.org/D39456

llvm-svn: 317211
2017-11-02 15:02:51 +00:00