Commit Graph

3 Commits

Author SHA1 Message Date
Geoff Berry 91e9a5cc23 [EarlyCSE] Make MemorySSA memory dependency check more aggressive.
Now that MemorySSA keeps track of whether MemoryUses are optimized, use
getClobberingMemoryAccess() to check MemoryUse memory dependencies since
it should no longer be so expensive.

This is a follow-up change to https://reviews.llvm.org/D25881

llvm-svn: 285080
2016-10-25 16:18:47 +00:00
Geoff Berry 6815468768 [EarlyCSE] Optimize MemoryPhis and reduce memory clobber queries w/ MemorySSA
Summary:
When using MemorySSA, re-optimize MemoryPhis when removing a store since
this may create MemoryPhis with all identical arguments.

Also, when using MemorySSA to check if two MemoryUses are reading from
the same version of the heap, use the defining access instead of calling
getClobberingAccess, since the latter can currently result in many more
AA calls.  Once the MemorySSA use optimization tracking changes are
done, we can remove this limitation, which should result in more loads
being CSE'd.

Reviewers: dberlin

Subscribers: mcrosier, llvm-commits

Differential Revision: https://reviews.llvm.org/D25881

llvm-svn: 284984
2016-10-24 15:54:00 +00:00
Geoff Berry 8d84605f25 [EarlyCSE] Optionally use MemorySSA. NFC.
Summary:
Use MemorySSA, if requested, to do less conservative memory dependency
checking.

This change doesn't enable the MemorySSA enhanced EarlyCSE in the
default pipelines, so should be NFC.

Reviewers: dberlin, sanjoy, reames, majnemer

Subscribers: mcrosier, llvm-commits

Differential Revision: http://reviews.llvm.org/D19821

llvm-svn: 280279
2016-08-31 19:24:10 +00:00