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| author | Dan Gohman <dan433584@gmail.com> | 2013-01-28 21:45:32 +0000 |
|---|---|---|
| committer | Dan Gohman <dan433584@gmail.com> | 2013-01-28 21:45:32 +0000 |
| commit | c4e441804ebe5a2d0eadbd9b0840d4f1b12d5a6f (patch) | |
| tree | 8bd4b0329308d84bc0f55151e3b9c88c70d69c21 /include | |
| parent | ae70224a3e69db7d86db72cbf8f6ea0cf5ed192b (diff) | |
| download | external_llvm-c4e441804ebe5a2d0eadbd9b0840d4f1b12d5a6f.zip external_llvm-c4e441804ebe5a2d0eadbd9b0840d4f1b12d5a6f.tar.gz external_llvm-c4e441804ebe5a2d0eadbd9b0840d4f1b12d5a6f.tar.bz2 | |
Add a comment mentioning that InstructionSimplify routines do,
in fact, resolve undef uses.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173721 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'include')
| -rw-r--r-- | include/llvm/Analysis/InstructionSimplify.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/include/llvm/Analysis/InstructionSimplify.h b/include/llvm/Analysis/InstructionSimplify.h index b653e79..06e4432 100644 --- a/include/llvm/Analysis/InstructionSimplify.h +++ b/include/llvm/Analysis/InstructionSimplify.h @@ -14,6 +14,12 @@ // ("and i32 %x, %x" -> "%x"). If the simplification is also an instruction // then it dominates the original instruction. // +// These routines implicitly resolve undef uses. The easiest way to be safe when +// using these routines to obtain simplified values for existing instructions is +// to always replace all uses of the instructions with the resulting simplified +// values. This will prevent other code from seeing the same undef uses and +// resolving them to different values. +// //===----------------------------------------------------------------------===// #ifndef LLVM_ANALYSIS_INSTRUCTIONSIMPLIFY_H |