Remove dead code. Improve llvm_unreachable text. Simplify some control flow.

[oota-llvm.git] / lib / CodeGen / UnreachableBlockElim.cpp

diff --git a/lib/CodeGen/UnreachableBlockElim.cpp b/lib/CodeGen/UnreachableBlockElim.cpp
index 48d8ab1658da5912076b98fd6fed7d6a7cece3fb..52693f03e82822e6bb9e87b98ef324b3c717ed78 100644 (file)
--- a/lib/CodeGen/UnreachableBlockElim.cpp
+++ b/lib/CodeGen/UnreachableBlockElim.cpp
@@ -196,8 +196,11 @@ bool UnreachableMachineBlockElim::runOnMachineFunction(MachineFunction &F) {
         temp->eraseFromParent();
         ModifiedPHI = true;
 
-        if (Input != Output)
-          F.getRegInfo().replaceRegWith(Output, Input);
+        if (Input != Output) {
+          MachineRegisterInfo &MRI = F.getRegInfo();
+          MRI.constrainRegClass(Input, MRI.getRegClass(Output));
+          MRI.replaceRegWith(Output, Input);
+        }
 
         continue;
       }