Make legalize a bit more efficient, and canonicalize sub X, C -> add X, -C
llvm-svn: 21882
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index 3c3de2d..dbb933e 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -916,7 +916,7 @@
break;
case ISD::SUB:
if (!C2) return N1; // sub X, 0 -> X
- break;
+ return getNode(ISD::ADD, VT, N1, getConstant(-C2, VT));
case ISD::MUL:
if (!C2) return N2; // mul X, 0 -> 0
if (N2C->isAllOnesValue()) // mul X, -1 -> 0-X
@@ -1194,13 +1194,13 @@
// Memoize this node if possible.
SDNode *N;
- if (Opcode != ISD::ADJCALLSTACKDOWN) {
+ if (Opcode != ISD::ADJCALLSTACKDOWN && Opcode != ISD::ADJCALLSTACKUP) {
SDNode *&BON = BinaryOps[std::make_pair(Opcode, std::make_pair(N1, N2))];
if (BON) return SDOperand(BON, 0);
BON = N = new SDNode(Opcode, N1, N2);
} else {
- N = new SDNode(ISD::ADJCALLSTACKDOWN, N1, N2);
+ N = new SDNode(Opcode, N1, N2);
}
@@ -1213,11 +1213,12 @@
return SDOperand(N, 0);
}
-// setAdjCallChain - This method changes the token chain of an ADJCALLSTACKDOWN
-// node to be the specified operand.
+// setAdjCallChain - This method changes the token chain of an
+// ADJCALLSTACKDOWN/UP node to be the specified operand.
void SDNode::setAdjCallChain(SDOperand N) {
assert(N.getValueType() == MVT::Other);
- assert(getOpcode() == ISD::ADJCALLSTACKDOWN && "Cannot adjust this node!");
+ assert((getOpcode() == ISD::ADJCALLSTACKDOWN ||
+ getOpcode() == ISD::ADJCALLSTACKUP) && "Cannot adjust this node!");
Operands[0].Val->removeUser(this);
Operands[0] = N;