[SelectionDAG] Use the inlined APInt shift methods since we've already bounds checked...

The version that takes APInt is out of line. The 'unsigned' version optimizes for the common case of single word APInts.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@319628 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index b456b74abd3de5ccfe8726cdff48b42360865964..0b59af2fa108729405e09743eecf3621df301738 100644 (file)
--- a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -2463,27 +2463,30 @@ void SelectionDAG::computeKnownBits(SDValue Op, KnownBits &Known,
   case ISD::SHL:
     if (const APInt *ShAmt = getValidShiftAmountConstant(Op)) {
       computeKnownBits(Op.getOperand(0), Known, DemandedElts, Depth + 1);
-      Known.Zero <<= *ShAmt;
-      Known.One <<= *ShAmt;
+      unsigned Shift = ShAmt->getZExtValue();
+      Known.Zero <<= Shift;
+      Known.One <<= Shift;
       // Low bits are known zero.
-      Known.Zero.setLowBits(ShAmt->getZExtValue());
+      Known.Zero.setLowBits(Shift);
     }
     break;
   case ISD::SRL:
     if (const APInt *ShAmt = getValidShiftAmountConstant(Op)) {
       computeKnownBits(Op.getOperand(0), Known, DemandedElts, Depth + 1);
-      Known.Zero.lshrInPlace(*ShAmt);
-      Known.One.lshrInPlace(*ShAmt);
+      unsigned Shift = ShAmt->getZExtValue();
+      Known.Zero.lshrInPlace(Shift);
+      Known.One.lshrInPlace(Shift);
       // High bits are known zero.
-      Known.Zero.setHighBits(ShAmt->getZExtValue());
+      Known.Zero.setHighBits(Shift);
     }
     break;
   case ISD::SRA:
     if (const APInt *ShAmt = getValidShiftAmountConstant(Op)) {
       computeKnownBits(Op.getOperand(0), Known, DemandedElts, Depth + 1);
+      unsigned Shift = ShAmt->getZExtValue();
       // Sign extend known zero/one bit (else is unknown).
-      Known.Zero.ashrInPlace(*ShAmt);
-      Known.One.ashrInPlace(*ShAmt);
+      Known.Zero.ashrInPlace(Shift);
+      Known.One.ashrInPlace(Shift);
     }
     break;
   case ISD::SIGN_EXTEND_INREG: {