[llvm-commits] CVS: llvm/lib/Transforms/Utils/SimplifyCFG.cpp

[Chris Lattner]

Changes in directory llvm/lib/Transforms/Utils:

SimplifyCFG.cpp updated: 1.52 -> 1.53
---
Log message:

Do not insert trivially dead select instructions, which allows us to 
potentially fold more in one pass.


---
Diffs of the changes:  (+11 -2)

Index: llvm/lib/Transforms/Utils/SimplifyCFG.cpp
diff -u llvm/lib/Transforms/Utils/SimplifyCFG.cpp:1.52 llvm/lib/Transforms/Utils/SimplifyCFG.cpp:1.53
--- llvm/lib/Transforms/Utils/SimplifyCFG.cpp:1.52	Wed Sep 15 12:06:42 2004
+++ llvm/lib/Transforms/Utils/SimplifyCFG.cpp	Wed Sep 29 00:43:32 2004
@@ -753,10 +753,19 @@
             FalseSucc->removePredecessor(BI->getParent());
 
             // Insert a new select instruction.
-            Value *NewRetVal = new SelectInst(BI->getCondition(), TrueValue,
-                                              FalseValue, "retval", BI);
+            Value *NewRetVal;
+            Value *BrCond = BI->getCondition();
+            if (TrueValue != FalseValue)
+              NewRetVal = new SelectInst(BrCond, TrueValue,
+                                         FalseValue, "retval", BI);
+            else
+              NewRetVal = TrueValue;
+
             new ReturnInst(NewRetVal, BI);
             BI->getParent()->getInstList().erase(BI);
+            if (BrCond->use_empty())
+              if (Instruction *BrCondI = dyn_cast<Instruction>(BrCond))
+                BrCondI->getParent()->getInstList().erase(BrCondI);
             return true;
           }
         }