[PATCH] D48069: [cmake] Disable a GCC optimization when building LLVM for MIPS

[Simon Dardis via Phabricator via llvm-commits]

sdardis added a comment.

In D48069#1479260 <https://reviews.llvm.org/D48069#1479260>, @beanz wrote:

> Is there a specific version range of GCC that this miscompile occurs with?


Based on activity in the listed GCC PR/target there's been no activity on fixing the bug. GCC 4.9.2 was the version I had to hand when I posted this patch.

Looking at the blame history and a read through the GCC mailing lists shows that the current 'ghost gp' instruction implementation have been present on GCC trunk since Sept, 2009. So that'd probably mean every version since 4.5 could be affected. Older ones might not have the bug, but they're not supported for building LLVM.

I believe it would be safer to simply disable the shrink wrapping optimization outright until the issue in GCC is addressed.


Repository:
  rL LLVM

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