[PATCH] D36775: Increase tail dup threshold for -O3 from 3 to 4

[Matthias Braun via Phabricator via llvm-commits]

MatzeB added a comment.

For the record: This broke the greendragon "Project Clang Stage 1: cmake, RA, with expensive checks enabled" build (possibly hidden by other errors).

The output looks like something breaks instruction bundles into individual unbundled instructions while tail duplicating. This affects predicated ARMv7 code after if-conversion.

Given that it seems to be a pre-existing bug and only affects that one build I'd suggest to keep this commit in for now and I'll hopefully be able to fix the bug soon.


Repository:
  rL LLVM

https://reviews.llvm.org/D36775