[PATCH] D27560: Always run GlobalDCE at O0
Chandler Carruth via Phabricator via llvm-commits
llvm-commits at lists.llvm.org
Tue Dec 13 17:45:06 PST 2016
chandlerc added a comment.
In https://reviews.llvm.org/D27560#621760, @mehdi_amini wrote:
> Another reason -O0 isn't great / enough to debug when LLVM is misbehaving is that it impacts the clang codegen (lifetime intrinsics, etc.).
But you're changing *opt*, not Clang.
I really think that we shouldn't add passes to -O0...
I am sympathetic to wanting a developer "friendly" mode in the compiler that does some cleanup by not too much so as to confuse things or slow anything down. But:
1. I don't think GlobalDCE is nearly enough.
2. I don't think it should be spelled '-O0'. I actually think this is what -O1 should be.
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