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Implement CodeGen/PowerPC/or-addressing-mode.ll, which is also PR668.

llvm-svn: 26450
This commit is contained in:
Chris Lattner 2006-03-01 07:14:48 +00:00
parent 66c4fffa4c
commit 317021b6c4

View File

@ -414,6 +414,10 @@ SDNode *PPCDAGToDAGISel::SelectBitfieldInsert(SDNode *N) {
/// a base register plus a signed 16-bit displacement [r+imm].
bool PPCDAGToDAGISel::SelectAddrImm(SDOperand N, SDOperand &Disp,
SDOperand &Base) {
// If this can be more profitably realized as r+r, fail.
if (SelectAddrIdx(N, Disp, Base))
return false;
if (N.getOpcode() == ISD::ADD) {
unsigned imm = 0;
if (isIntImmediate(N.getOperand(1), imm) && isInt16(imm)) {
@ -434,7 +438,23 @@ bool PPCDAGToDAGISel::SelectAddrImm(SDOperand N, SDOperand &Disp,
Base = N.getOperand(0);
return true; // [&g+r]
}
return false; // [r+r]
} else if (N.getOpcode() == ISD::OR) {
unsigned imm = 0;
if (isIntImmediate(N.getOperand(1), imm) && isInt16(imm)) {
// If this is an or of disjoint bitfields, we can codegen this as an add
// (for better address arithmetic) if the LHS and RHS of the OR are
// provably disjoint.
uint64_t LHSKnownZero, LHSKnownOne;
PPCLowering.ComputeMaskedBits(N.getOperand(0), ~0U,
LHSKnownZero, LHSKnownOne);
if ((LHSKnownZero|~imm) == ~0U) {
// If all of the bits are known zero on the LHS or RHS, the add won't
// carry.
Base = N.getOperand(0);
Disp = getI32Imm(imm & 0xFFFF);
return true;
}
}
}
Disp = getI32Imm(0);
if (FrameIndexSDNode *FI = dyn_cast<FrameIndexSDNode>(N))
@ -449,35 +469,56 @@ bool PPCDAGToDAGISel::SelectAddrImm(SDOperand N, SDOperand &Disp,
/// be represented by [r+imm], which are preferred.
bool PPCDAGToDAGISel::SelectAddrIdx(SDOperand N, SDOperand &Base,
SDOperand &Index) {
// Check to see if we can represent this as an [r+imm] address instead,
// which will fail if the address is more profitably represented as an
// [r+r] address.
if (SelectAddrImm(N, Base, Index))
return false;
unsigned imm = 0;
if (N.getOpcode() == ISD::ADD) {
if (isIntImmediate(N.getOperand(1), imm) && isInt16(imm))
return false; // r+i
if (N.getOperand(1).getOpcode() == PPCISD::Lo)
return false; // r+i
Base = N.getOperand(0);
Index = N.getOperand(1);
return true;
} else if (N.getOpcode() == ISD::OR) {
if (isIntImmediate(N.getOperand(1), imm) && isInt16(imm))
return false; // r+i can fold it if we can.
// If this is an or of disjoint bitfields, we can codegen this as an add
// (for better address arithmetic) if the LHS and RHS of the OR are provably
// disjoint.
uint64_t LHSKnownZero, LHSKnownOne;
uint64_t RHSKnownZero, RHSKnownOne;
PPCLowering.ComputeMaskedBits(N.getOperand(0), ~0U,
LHSKnownZero, LHSKnownOne);
if (LHSKnownZero) {
PPCLowering.ComputeMaskedBits(N.getOperand(1), ~0U,
RHSKnownZero, RHSKnownOne);
// If all of the bits are known zero on the LHS or RHS, the add won't
// carry.
if ((LHSKnownZero | RHSKnownZero) == ~0U) {
Base = N.getOperand(0);
Index = N.getOperand(1);
return true;
}
}
}
Base = CurDAG->getRegister(PPC::R0, MVT::i32);
Index = N;
return true;
return false;
}
/// SelectAddrIdxOnly - Given the specified addressed, force it to be
/// represented as an indexed [r+r] operation.
bool PPCDAGToDAGISel::SelectAddrIdxOnly(SDOperand N, SDOperand &Base,
SDOperand &Index) {
if (N.getOpcode() == ISD::ADD) {
Base = N.getOperand(0);
Index = N.getOperand(1);
return true;
// Check to see if we can easily represent this as an [r+r] address. This
// will fail if it thinks that the address is more profitably represented as
// reg+imm, e.g. where imm = 0.
if (!SelectAddrIdx(N, Base, Index)) {
// Nope, do it the hard way.
Base = CurDAG->getRegister(PPC::R0, MVT::i32);
Index = N;
}
Base = CurDAG->getRegister(PPC::R0, MVT::i32);
Index = N;
return true;
}