[PATCH] D19210: Teach poison value tracking that certain calls always terminate

[Sanjoy Das via llvm-commits]

sanjoy added inline comments.

================
Comment at: lib/Analysis/ValueTracking.cpp:3289
@@ +3288,3 @@
+    // assumption (e.g. we will DCE readnone and readonly calls).
+    return CS.doesNotThrow() && CS.onlyReadsMemory();
+
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majnemer wrote:
> Couldn't this just be `!I->mayHaveSideEffects()` ?
Yeah, but I didn't want to write it that way -- IMO it is only "incidental" that `mayHaveSideEffects` and what I'm computing here are the same implementation.  IOW, the predicate in the two cases (`mayHaveSideEffects` vs. "guaranteed to transfer control flow to successor") are quite different, even if they have the same implementation.


http://reviews.llvm.org/D19210