[llvm-commits] CVS: llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
Chris Lattner
lattner at cs.uiuc.edu
Tue Apr 12 19:58:29 PDT 2005
Changes in directory llvm/lib/CodeGen/SelectionDAG:
SelectionDAG.cpp updated: 1.77 -> 1.78
---
Log message:
add back the optimization that Nate added for shl X, (zext_inreg y)
---
Diffs of the changes: (+23 -2)
SelectionDAG.cpp | 25 +++++++++++++++++++++++--
1 files changed, 23 insertions(+), 2 deletions(-)
Index: llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
diff -u llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp:1.77 llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp:1.78
--- llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp:1.77 Tue Apr 12 21:47:57 2005
+++ llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp Tue Apr 12 21:58:13 2005
@@ -943,8 +943,18 @@
case ISD::SHL:
case ISD::SRL:
case ISD::SRA:
- if (N2.getOpcode() == ISD::SIGN_EXTEND_INREG)
+ if (N2.getOpcode() == ISD::SIGN_EXTEND_INREG &&
+ cast<MVTSDNode>(N2)->getExtraValueType() != MVT::i1)
return getNode(Opcode, VT, N1, N2.getOperand(0));
+ else if (N2.getOpcode() == ISD::AND)
+ if (ConstantSDNode *AndRHS = dyn_cast<ConstantSDNode>(N2.getOperand(1))) {
+ // If the and is only masking out bits that cannot effect the shift,
+ // eliminate the and.
+ unsigned NumBits = MVT::getSizeInBits(VT);
+ if ((AndRHS->getValue() & (NumBits-1)) == NumBits-1)
+ return getNode(Opcode, VT, N1, N2.getOperand(0));
+ }
+
break;
}
@@ -1040,8 +1050,19 @@
case ISD::SRA_PARTS:
case ISD::SRL_PARTS:
case ISD::SHL_PARTS:
- if (N3.getOpcode() == ISD::SIGN_EXTEND_INREG)
+ if (N3.getOpcode() == ISD::SIGN_EXTEND_INREG &&
+ cast<MVTSDNode>(N3)->getExtraValueType() != MVT::i1)
return getNode(Opcode, VT, N1, N2, N3.getOperand(0));
+ else if (N3.getOpcode() == ISD::AND)
+ if (ConstantSDNode *AndRHS = dyn_cast<ConstantSDNode>(N3.getOperand(1))) {
+ // If the and is only masking out bits that cannot effect the shift,
+ // eliminate the and.
+ unsigned NumBits = MVT::getSizeInBits(VT)*2;
+ if ((AndRHS->getValue() & (NumBits-1)) == NumBits-1)
+ return getNode(Opcode, VT, N1, N2, N3.getOperand(0));
+ }
+
+
break;
}
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