return DAG.getNode(ISD::SRL, N->getDebugLoc(), VT, N0.getOperand(0),
DAG.getConstant(c1 + c2, N1.getValueType()));
}
+
+ // fold (srl (shl x, c), c) -> (and x, cst2)
+ if (N1C && N0.getOpcode() == ISD::SHL && N0.getOperand(1) == N1 &&
+ N0.getValueSizeInBits() <= 64) {
+ uint64_t ShAmt = N1C->getZExtValue()+64-N0.getValueSizeInBits();
+ return DAG.getNode(ISD::AND, N->getDebugLoc(), VT, N0.getOperand(0),
+ DAG.getConstant(~0ULL >> ShAmt, VT));
+ }
+
// fold (srl (anyextend x), c) -> (anyextend (srl x, c))
if (N1C && N0.getOpcode() == ISD::ANY_EXTEND) {