Commit Graph

3 Commits

Author SHA1 Message Date
Daniel Berlin b79f53669a NewGVN: Clean up how we handle the INITIAL class so that everything in
it is dead or unreachable, as it should be.
This also makes the leader of INITIAL undef, enabling us to handle
irreducibility properly.

Summary:
This lets us verify, more than we do now, that we didn't screw up
value numbering.

Reviewers: davide

Subscribers: Prazek, llvm-commits

Differential Revision: https://reviews.llvm.org/D29842

llvm-svn: 294844
2017-02-11 12:48:50 +00:00
Daniel Berlin c479686af2 NewGVN: Add basic dead and redundant store elimination
Summary:
This adds basic dead and redundant store elimination to
NewGVN.  Unlike our current DSE, it will happily do cross-block DSE if
it meets our requirements.

We get a bunch of DSE's simple.ll cases, and some stuff it doesn't.
Unlike DSE, however, we only try to eliminate stores of the same value
to the same memory location, not just general stores to the same
memory location.

Reviewers: davide

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D29149

llvm-svn: 293258
2017-01-27 02:37:11 +00:00
Daniel Berlin 32f8d560dd NewGVN: Make sure we properly lookup operand leaders while creating
congruence classes for stores, and then keep them up to date.  Add
testcases.

llvm-svn: 291351
2017-01-07 16:55:14 +00:00