Commit Graph

2 Commits

Author SHA1 Message Date
Florian Hahn 75be1a9e58 [ValueTracking] Fix recurrence detection to check both PHI operands.
Summary:
Currently we fail to compute known bits for recurrences where the
first incoming value is the start value of the recurrence.

Instead of exiting the loop when the first incoming value is not
the step of the recurrence, continue to check the second incoming
value.

The original code uses a loop to handle both cases, but incorrectly
exits instead of continuing.

Reviewers: lebedev.ri, spatel, nikic

Reviewed By: lebedev.ri

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D66216

llvm-svn: 369088
2019-08-16 09:15:02 +00:00
Florian Hahn 1bd898989c [InstCombine] Precommit test case for D66216
llvm-svn: 368978
2019-08-15 08:42:12 +00:00