reenable the piece that turns trunc(zext(x)) -> x even if zext has multiple uses,
codegen has no apparent problem with the trunc version of this, because it turns
into a simple subreg idiom
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93202 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/InstCombine/InstCombineCasts.cpp b/lib/Transforms/InstCombine/InstCombineCasts.cpp
index b5da3e6..e018b35 100644
--- a/lib/Transforms/InstCombine/InstCombineCasts.cpp
+++ b/lib/Transforms/InstCombine/InstCombineCasts.cpp
@@ -327,9 +327,7 @@
// If this is an extension from the dest type, we can eliminate it, even if it
// has multiple uses.
- // FIXME: This is currently disabled until codegen can handle this without
- // pessimizing code, PR5997.
- if (0 && (isa<ZExtInst>(I) || isa<SExtInst>(I)) &&
+ if ((isa<ZExtInst>(I) || isa<SExtInst>(I)) &&
I->getOperand(0)->getType() == Ty)
return true;