jdoerfert added a comment.
FWIW, I tried to solve something similar the other day. My solution sketch
looked like this: https://godbolt.org/z/bRQPjd
The idea would be that we teach DSE (and others) to remove the
`llvm.undef.init` intrinsic if the location is overwritten.
In the example above
jfb added a comment.
Overall I like this approach.
I think it needs three more things to make it:
- Better size optimizations. I measured the code size impact on a codebase
which deploys variable auto-init already, and it's a 0.5% code size hit.
Considering that auto-init itself was 1%, it
rsmith updated this revision to Diff 261511.
rsmith added a comment.
- The second operand of 'store' is the pointer, not the first.
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rsmith created this revision.
Herald added subscribers: llvm-commits, cfe-commits, jdoerfert, hiraditya.
Herald added projects: clang, LLVM.
rsmith updated this revision to Diff 261511.
rsmith added a comment.
- The second operand of 'store' is the pointer, not the first.
Add @llvm.trapping.()
