]> git.ipfire.org Git - thirdparty/gcc.git/commit
tree-optimization/107569 - avoid wrecking earlier folding in FRE/PRE
authorRichard Biener <rguenther@suse.de>
Thu, 23 Mar 2023 13:52:01 +0000 (14:52 +0100)
committerRichard Biener <rguenther@suse.de>
Thu, 23 Mar 2023 16:22:02 +0000 (17:22 +0100)
commit41ade3399bd1ec9927be1bb818965831232eda4b
treeaa461d90bda457d9bde553ee06f28ef0962de892
parent25979b6761516b9039004385e08141e0925e1a17
tree-optimization/107569 - avoid wrecking earlier folding in FRE/PRE

The following avoids picking up dead code left over from folding
during FRE/PRE, effectively undoing propagations.

PR tree-optimization/107569
* tree-ssa-sccvn.cc (eliminate_dom_walker::eliminate_stmt):
Do not push SSA names with zero uses as available leader.
(process_bb): Likewise.

* g++.dg/opt/pr107569.C: New testcase.
gcc/testsuite/g++.dg/opt/pr107569.C [new file with mode: 0644]
gcc/tree-ssa-sccvn.cc