Commit Graph

3 Commits

Author SHA1 Message Date
Eric Christopher cee313d288 Revert "Temporarily Revert "Add basic loop fusion pass.""
The reversion apparently deleted the test/Transforms directory.

Will be re-reverting again.

llvm-svn: 358552
2019-04-17 04:52:47 +00:00
Eric Christopher a863435128 Temporarily Revert "Add basic loop fusion pass."
As it's causing some bot failures (and per request from kbarton).

This reverts commit r358543/ab70da07286e618016e78247e4a24fcb84077fda.

llvm-svn: 358546
2019-04-17 02:12:23 +00:00
Brian M. Rzycki 887865c1ad [JumpThreading] Fix incorrect fold conditional after indirectbr/callbr
Fixes bug 40992: https://bugs.llvm.org/show_bug.cgi?id=40992

There is potential for miscompiled code emitted from JumpThreading when
analyzing a block with one or more indirectbr or callbr predecessors. The
ProcessThreadableEdges() function incorrectly folds conditional branches
into an unconditional branch.

This patch prevents incorrect branch folding without fully pessimizing
other potential threading opportunities through the same basic block.

This IR shape was manually fed in via opt and is unclear if clang and the
full pass pipeline will ever emit similar code shapes.

Thanks to Matthias Liedtke for the bug report and simplified IR example.

Differential Revision: https://reviews.llvm.org/D60284

llvm-svn: 357930
2019-04-08 18:20:35 +00:00