Lower add (mul a, b), c into MACCU / MACCS nodes which translate

directly to the maccu / maccs instructions. We handle this in
ExpandADDSUB since after type legalisation it is messy to
recognise these operations.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98150 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Richard Osborne 2010-03-10 11:41:08 +00:00
parent 1250ac8a09
commit ebc64cf780
4 changed files with 110 additions and 0 deletions

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@ -208,6 +208,18 @@ SDNode *XCoreDAGToDAGISel::Select(SDNode *N) {
return CurDAG->getMachineNode(XCore::LSUB_l5r, dl, MVT::i32, MVT::i32,
Ops, 3);
}
case XCoreISD::MACCU: {
SDValue Ops[] = { N->getOperand(0), N->getOperand(1),
N->getOperand(2), N->getOperand(3) };
return CurDAG->getMachineNode(XCore::MACCU_l4r, dl, MVT::i32, MVT::i32,
Ops, 4);
}
case XCoreISD::MACCS: {
SDValue Ops[] = { N->getOperand(0), N->getOperand(1),
N->getOperand(2), N->getOperand(3) };
return CurDAG->getMachineNode(XCore::MACCS_l4r, dl, MVT::i32, MVT::i32,
Ops, 4);
}
// Other cases are autogenerated.
}
}

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@ -54,6 +54,8 @@ getTargetNodeName(unsigned Opcode) const
case XCoreISD::RETSP : return "XCoreISD::RETSP";
case XCoreISD::LADD : return "XCoreISD::LADD";
case XCoreISD::LSUB : return "XCoreISD::LSUB";
case XCoreISD::MACCU : return "XCoreISD::MACCU";
case XCoreISD::MACCS : return "XCoreISD::MACCS";
case XCoreISD::BR_JT : return "XCoreISD::BR_JT";
case XCoreISD::BR_JT32 : return "XCoreISD::BR_JT32";
default : return NULL;
@ -541,12 +543,77 @@ LowerSTORE(SDValue Op, SelectionDAG &DAG)
return CallResult.second;
}
SDValue XCoreTargetLowering::
TryExpandADDSUBWithMul(SDNode *N, SelectionDAG &DAG)
{
SDValue Mul;
SDValue Other;
if (N->getOperand(0).getOpcode() == ISD::MUL) {
Mul = N->getOperand(0);
Other = N->getOperand(1);
} else if (N->getOperand(1).getOpcode() == ISD::MUL) {
Mul = N->getOperand(1);
Other = N->getOperand(0);
} else {
return SDValue();
}
DebugLoc dl = N->getDebugLoc();
SDValue LL, RL, AddendL, AddendH;
LL = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, MVT::i32,
Mul.getOperand(0), DAG.getConstant(0, MVT::i32));
RL = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, MVT::i32,
Mul.getOperand(1), DAG.getConstant(0, MVT::i32));
AddendL = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, MVT::i32,
Other, DAG.getConstant(0, MVT::i32));
AddendH = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, MVT::i32,
Other, DAG.getConstant(1, MVT::i32));
APInt HighMask = APInt::getHighBitsSet(64, 32);
unsigned LHSSB = DAG.ComputeNumSignBits(Mul.getOperand(0));
unsigned RHSSB = DAG.ComputeNumSignBits(Mul.getOperand(1));
if (DAG.MaskedValueIsZero(Mul.getOperand(0), HighMask) &&
DAG.MaskedValueIsZero(Mul.getOperand(1), HighMask)) {
// The inputs are both zero-extended.
SDValue Hi = DAG.getNode(XCoreISD::MACCU, dl,
DAG.getVTList(MVT::i32, MVT::i32), AddendH,
AddendL, LL, RL);
SDValue Lo(Hi.getNode(), 1);
return DAG.getNode(ISD::BUILD_PAIR, dl, MVT::i64, Lo, Hi);
}
if (LHSSB > 32 && RHSSB > 32) {
// The inputs are both sign-extended.
SDValue Hi = DAG.getNode(XCoreISD::MACCS, dl,
DAG.getVTList(MVT::i32, MVT::i32), AddendH,
AddendL, LL, RL);
SDValue Lo(Hi.getNode(), 1);
return DAG.getNode(ISD::BUILD_PAIR, dl, MVT::i64, Lo, Hi);
}
SDValue LH, RH;
LH = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, MVT::i32,
Mul.getOperand(0), DAG.getConstant(1, MVT::i32));
RH = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, MVT::i32,
Mul.getOperand(1), DAG.getConstant(1, MVT::i32));
SDValue Hi = DAG.getNode(XCoreISD::MACCU, dl,
DAG.getVTList(MVT::i32, MVT::i32), AddendH,
AddendL, LL, RL);
SDValue Lo(Hi.getNode(), 1);
RH = DAG.getNode(ISD::MUL, dl, MVT::i32, LL, RH);
LH = DAG.getNode(ISD::MUL, dl, MVT::i32, LH, RL);
Hi = DAG.getNode(ISD::ADD, dl, MVT::i32, Hi, RH);
Hi = DAG.getNode(ISD::ADD, dl, MVT::i32, Hi, LH);
return DAG.getNode(ISD::BUILD_PAIR, dl, MVT::i64, Lo, Hi);
}
SDValue XCoreTargetLowering::
ExpandADDSUB(SDNode *N, SelectionDAG &DAG)
{
assert(N->getValueType(0) == MVT::i64 &&
(N->getOpcode() == ISD::ADD || N->getOpcode() == ISD::SUB) &&
"Unknown operand to lower!");
SDValue Result = TryExpandADDSUBWithMul(N, DAG);
if (Result.getNode() != 0)
return Result;
DebugLoc dl = N->getDebugLoc();
// Extract components

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@ -54,6 +54,12 @@ namespace llvm {
// Corresponds to LSUB instruction
LSUB,
// Corresponds to MACCU instruction
MACCU,
// Corresponds to MACCS instruction
MACCS,
// Jumptable branch.
BR_JT,
@ -140,6 +146,7 @@ namespace llvm {
EVT VT) const;
// Expand specifics
SDValue TryExpandADDSUBWithMul(SDNode *Op, SelectionDAG &DAG);
SDValue ExpandADDSUB(SDNode *Op, SelectionDAG &DAG);
virtual SDValue PerformDAGCombine(SDNode *N, DAGCombinerInfo &DCI) const;

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@ -18,3 +18,27 @@ define i64 @sub64(i64 %a, i64 %b) {
; CHECK-NEXT: lsub r2, r0, r0, r2, r11
; CHECK-NEXT: lsub r2, r1, r1, r3, r2
; CHECK-NEXT: retsp 0
define i64 @maccu(i64 %a, i32 %b, i32 %c) {
entry:
%0 = zext i32 %b to i64
%1 = zext i32 %c to i64
%2 = mul i64 %1, %0
%3 = add i64 %2, %a
ret i64 %3
}
; CHECK: maccu:
; CHECK: maccu r1, r0, r3, r2
; CHECK-NEXT: retsp 0
define i64 @maccs(i64 %a, i32 %b, i32 %c) {
entry:
%0 = sext i32 %b to i64
%1 = sext i32 %c to i64
%2 = mul i64 %1, %0
%3 = add i64 %2, %a
ret i64 %3
}
; CHECK: maccs:
; CHECK: maccs r1, r0, r3, r2
; CHECK-NEXT: retsp 0