[PATCH] D67638: Improve __builtin_constant_p lowering

[Joerg Sonnenberger via Phabricator via cfe-commits]

joerg created this revision.
joerg added a reviewer: rsmith.
Herald added subscribers: kristina, kbarton, nemanjai.
Herald added a project: clang.
Herald added a subscriber: wuzish.

__builtin_constant_p used to be short-cut evaluated to false when building with -O0. This is undesirable as it means that constant folding in the front-end can give different results than folding in the back-end.  It can also create conditional branches on constant conditions that don't get folded away. With the improvements to the llvm.is.constant handling on the LLVM side, the short-cut is no longer useful.

Adjust various codegen tests to not depend on the optimizations.


Repository:
  rC Clang

https://reviews.llvm.org/D67638

Files:
  lib/CodeGen/CGBuiltin.cpp
  test/CodeGen/builtin-constant-p.c
  test/CodeGen/ppc-emmintrin.c
  test/CodeGen/ppc-tmmintrin.c

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