Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

ScalarEvolution can introduce branch on poison #47113

Open
llvmbot opened this issue Oct 8, 2020 · 0 comments
Open

ScalarEvolution can introduce branch on poison #47113

llvmbot opened this issue Oct 8, 2020 · 0 comments
Labels
bugzilla Issues migrated from bugzilla llvm:SCEV Scalar Evolution miscompilation

Comments

@llvmbot
Copy link
Collaborator

llvmbot commented Oct 8, 2020

Bugzilla Link 47769
Version trunk
OS All
Reporter LLVM Bugzilla Contributor
CC @fhahn,@LebedevRI,@nunoplopes,@sparker-arm

Extended Description

Test: Transforms/LoopVectorize/pr30654-phiscev-sext-trunc.ll
Function: doit1
Reason: Source more defined than target

Example: https://godbolt.org/z/1nMsMT
LoopVectorize adds the block vector.scevcheck and uses SCEVExpander to generate checks that use %step. If %step is poison it introduces branch on poison.
@llvmbot llvmbot transferred this issue from llvm/llvm-bugzilla-archive Dec 10, 2021
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Assignees
No one assigned
Labels
bugzilla Issues migrated from bugzilla llvm:SCEV Scalar Evolution miscompilation
Projects
None yet
Milestone
No milestone
Development

No branches or pull requests
2 participants
@nunoplopes @llvmbot