mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-08-17 21:29:20 +00:00
Implement a common missing fold, (add (add x, c1), c2) -> (add x, c1+c2).
This restores all of stanford to being identical with and without the dag combiner with the add folding turned off in sd.cpp. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23258 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
parent
c98d823649
commit
f89d78d7c7
@ -342,32 +342,38 @@ SDOperand DAGCombiner::visitADD(SDNode *N) {
|
||||
ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
|
||||
ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
|
||||
ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
|
||||
MVT::ValueType VT = N0.getValueType();
|
||||
|
||||
// fold (add c1, c2) -> c1+c2
|
||||
if (N0C && N1C)
|
||||
return DAG.getConstant(N0C->getValue() + N1C->getValue(),
|
||||
N->getValueType(0));
|
||||
return DAG.getConstant(N0C->getValue() + N1C->getValue(), VT);
|
||||
// fold (add x, 0) -> x
|
||||
if (N1C && N1C->isNullValue())
|
||||
return N0;
|
||||
// fold (add (add x, c1), c2) -> (add x, c1+c2)
|
||||
if (N1C && N0.getOpcode() == ISD::ADD &&
|
||||
N0.getOperand(1).getOpcode() == ISD::Constant)
|
||||
return DAG.getNode(ISD::ADD, VT, N0.getOperand(0),
|
||||
DAG.getConstant(N1C->getValue() +
|
||||
cast<ConstantSDNode>(N0.getOperand(1))->getValue(),
|
||||
VT));
|
||||
// fold floating point (add c1, c2) -> c1+c2
|
||||
if (N0CFP && N1CFP)
|
||||
return DAG.getConstantFP(N0CFP->getValue() + N1CFP->getValue(),
|
||||
N->getValueType(0));
|
||||
return DAG.getConstantFP(N0CFP->getValue() + N1CFP->getValue(), VT);
|
||||
// fold (A + (-B)) -> A-B
|
||||
if (N1.getOpcode() == ISD::FNEG)
|
||||
return DAG.getNode(ISD::SUB, N->getValueType(0), N0, N1.getOperand(0));
|
||||
return DAG.getNode(ISD::SUB, VT, N0, N1.getOperand(0));
|
||||
// fold ((-A) + B) -> B-A
|
||||
if (N0.getOpcode() == ISD::FNEG)
|
||||
return DAG.getNode(ISD::SUB, N->getValueType(0), N1, N0.getOperand(0));
|
||||
return DAG.getNode(ISD::SUB, VT, N1, N0.getOperand(0));
|
||||
// fold ((0-A) + B) -> B-A
|
||||
if (N0.getOpcode() == ISD::SUB && isa<ConstantSDNode>(N0.getOperand(0)) &&
|
||||
cast<ConstantSDNode>(N0.getOperand(0))->isNullValue())
|
||||
return DAG.getNode(ISD::SUB, N->getValueType(0), N1, N0.getOperand(1));
|
||||
return DAG.getNode(ISD::SUB, VT, N1, N0.getOperand(1));
|
||||
// fold (A + (0-B)) -> A-B
|
||||
if (N1.getOpcode() == ISD::SUB && isa<ConstantSDNode>(N1.getOperand(0)) &&
|
||||
cast<ConstantSDNode>(N1.getOperand(0))->isNullValue())
|
||||
return DAG.getNode(ISD::SUB, N->getValueType(0), N0, N1.getOperand(1));
|
||||
return DAG.getNode(ISD::SUB, VT, N0, N1.getOperand(1));
|
||||
// fold (A+(B-A)) -> B for non-fp types
|
||||
if (N1.getOpcode() == ISD::SUB && N0 == N1.getOperand(1) &&
|
||||
!MVT::isFloatingPoint(N1.getValueType()))
|
||||
|
Loading…
Reference in New Issue
Block a user