diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/passes/LocalCSE.cpp | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/src/passes/LocalCSE.cpp b/src/passes/LocalCSE.cpp index b55da976c..1ae77d155 100644 --- a/src/passes/LocalCSE.cpp +++ b/src/passes/LocalCSE.cpp @@ -422,6 +422,15 @@ struct Checker // away repeated apperances if it has any. EffectAnalyzer effects(options, getModule()->features, curr); + // We can ignore traps here, as we replace a repeating expression with a + // single appearance of it, a store to a local, and gets in the other + // locations, and so if the expression traps then the first appearance - + // that we keep around - would trap, and the others are never reached + // anyhow. (The other checks we perform here, including invalidation and + // determinism, will ensure that either all of the appearances trap, or + // none of them.) + effects.trap = false; + // We also cannot optimize away something that is intrinsically // nondeterministic: even if it has no side effects, if it may return a // different result each time, then we cannot optimize away repeats. |