This repository was archived by the owner on Feb 5, 2019. It is now read-only.
[PowerPC] Fix the calling convention for i1 arguments on PPC32 #127
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Summary: Integer types smaller than i32 must be extended to i32 by default. The feature "crbits" introduced at r202451 handles i1 as a special case, but it did not extend properly. The caller was, therefore, passing i1 stack arguments by writing 0/1 to the first byte of the 4-byte stack object and callee was reading the first byte for the value. "crbits" is enabled if the optimization level is greater than 1, which is very common in "release builds". Such discrepancies with ABI specification also introduces potential incompatibility with programs or libraries built with other compilers e.g. GCC. Fixes PR38661 Reviewers: hfinkel, cuviper Subscribers: sylvestre.ledru, glaubitz, nagisa, nemanjai, kbarton, llvm-commits Differential Revision: https://reviews.llvm.org/D51108
Sign up for free
to subscribe to this conversation on GitHub.
Already have an account?
Sign in.
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Summary:
Integer types smaller than i32 must be extended to i32 by default.
The feature "crbits" introduced at r202451 handles i1 as a special case,
but it did not extend properly.
The caller was, therefore, passing i1 stack arguments by writing 0/1 to
the first byte of the 4-byte stack object and callee was
reading the first byte for the value.
"crbits" is enabled if the optimization level is greater than 1,
which is very common in "release builds".
Such discrepancies with ABI specification also introduces
potential incompatibility with programs or libraries
built with other compilers e.g. GCC.
Fixes PR38661
Reviewers: hfinkel, cuviper
Subscribers: sylvestre.ledru, glaubitz, nagisa, nemanjai, kbarton, llvm-commits
Differential Revision: https://reviews.llvm.org/D51108