[PATCH] D30712: [JumpThread] Try to fold SwitchInst before attempting to jumpthread it

[Xin Tong via Phabricator via llvm-commits]

trentxintong updated this revision to Diff 90906.
trentxintong added a comment.

efriedma is right about simplifycfg converting switch(i1) to condbr. so this patch is now
a comment change =).


https://reviews.llvm.org/D30712

Files:
  lib/Transforms/Scalar/JumpThreading.cpp


Index: lib/Transforms/Scalar/JumpThreading.cpp
===================================================================
--- lib/Transforms/Scalar/JumpThreading.cpp
+++ lib/Transforms/Scalar/JumpThreading.cpp
@@ -805,7 +805,9 @@
     // If we're branching on a conditional, LVI might be able to determine
     // it's value at the branch instruction.  We only handle comparisons
     // against a constant at this time.
-    // TODO: This should be extended to handle switches as well.
+    //
+    // Switch(i1) will be converted to CondBr by SimplifyCFG and therefore
+    // handled by the CondBr folding here..
     BranchInst *CondBr = dyn_cast<BranchInst>(BB->getTerminator());
     Constant *CondConst = dyn_cast<Constant>(CondCmp->getOperand(1));
     if (CondBr && CondConst) {


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