[llvm-commits] CVS: llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp

[Chris Lattner]

Changes in directory llvm/lib/CodeGen/SelectionDAG:

SelectionDAG.cpp updated: 1.9 -> 1.10
---
Log message:

Simplify: truncate ({zero|sign}_extend (X))



---
Diffs of the changes:  (+9 -0)

Index: llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
diff -u llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp:1.9 llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp:1.10
--- llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp:1.9	Fri Jan  7 15:09:16 2005
+++ llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp	Fri Jan  7 15:56:24 2005
@@ -428,6 +428,15 @@
     if (Operand.getValueType() == VT) return Operand;   // noop truncate
     if (OpOpcode == ISD::TRUNCATE)
       return getNode(ISD::TRUNCATE, VT, Operand.Val->getOperand(0));
+    else if (OpOpcode == ISD::ZERO_EXTEND || OpOpcode == ISD::SIGN_EXTEND) {
+      // If the source is smaller than the dest, we still need an extend.
+      if (Operand.Val->getOperand(0).getValueType() < VT)
+        return getNode(OpOpcode, VT, Operand.Val->getOperand(0));
+      else if (Operand.Val->getOperand(0).getValueType() > VT)
+        return getNode(ISD::TRUNCATE, VT, Operand.Val->getOperand(0));
+      else
+        return Operand.Val->getOperand(0);
+    }
     break;
   }