bit. This fixes Regression/Transforms/TailDup/MergeTest.ll
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@30237
91177308-0d34-0410-b5e6-
96231b3b80d8
// if (b)
// foo();
// Cloning the 'if b' block into the end of the first foo block is messy.
- return false;
+
+ // The messy case is when the fall-through block falls through to other
+ // blocks. This is what we would be preventing if we cloned the block.
+ DestI = Dest;
+ if (++DestI != Dest->getParent()->end()) {
+ BasicBlock *DestSucc = DestI;
+ // If any of Dest's successors are fall-throughs, don't do this xform.
+ for (succ_iterator SI = succ_begin(Dest), SE = succ_end(Dest);
+ SI != SE; ++SI)
+ if (*SI == DestSucc)
+ return false;
+ }
}
return true;