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

[Nate Begeman]

Changes in directory llvm/lib/CodeGen/SelectionDAG:

SelectionDAG.cpp updated: 1.157 -> 1.158
---
Log message:

Fix optimization of select_cc seteq X, 0, 1, 0 -> srl (ctlz X), log2 X size


---
Diffs of the changes:  (+3 -3)

 SelectionDAG.cpp |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)


Index: llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
diff -u llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp:1.157 llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp:1.158
--- llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp:1.157	Tue Aug 23 00:41:12 2005
+++ llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp	Tue Aug 23 19:21:28 2005
@@ -854,9 +854,9 @@
   }
   
   // Check to see if this is the equivalent of seteq X, 0.
-  // select_cc seteq X, 0, 1, 0 -> setcc X, 0, seteq -> srl (ctlz X), size(X)-1
+  // select_cc eq X, 0, 1, 0 -> setcc X, 0, eq -> srl (ctlz X), log2(size(X))
   if (N2C && N2C->isNullValue() && N4C && N4C->isNullValue() &&
-      N3C && (N3C->getValue() == 1)) {
+      N3C && (N3C->getValue() == 1ULL) && CC == ISD::SETEQ) {
     MVT::ValueType XType = N1.getValueType();
     if (TLI.getOperationAction(ISD::SETCC, TLI.getSetCCResultTy()) == 
         TargetLowering::Legal) {
@@ -865,7 +865,7 @@
     if (TLI.getOperationAction(ISD::CTLZ, XType) == TargetLowering::Legal) {
       SDOperand Ctlz = getNode(ISD::CTLZ, XType, N1);
       return getNode(ISD::SRL, XType, Ctlz, 
-                     getConstant(MVT::getSizeInBits(XType)-1,
+                     getConstant(Log2_32(MVT::getSizeInBits(XType)),
                                  TLI.getShiftAmountTy()));
     }
   }