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Propagate debug loc info for Shifts.

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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@63424 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Bill Wendling 2009-01-30 21:37:17 +00:00
parent 317bd709bd
commit 8810337e36
1 changed files with 68 additions and 60 deletions
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128
lib/CodeGen/SelectionDAG/DAGCombiner.cpp
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@ -2430,13 +2430,12 @@ SDValue DAGCombiner::visitShiftByConstant(SDNode *N, unsigned Amt) {
// We require the RHS of the binop to be a constant as well.
ConstantSDNode *BinOpCst = dyn_cast<ConstantSDNode>(LHS->getOperand(1));
if (!BinOpCst) return SDValue();
// FIXME: disable this for unless the input to the binop is a shift by a
// constant. If it is not a shift, it pessimizes some common cases like:
// FIXME: disable this unless the input to the binop is a shift by a constant.
// If it is not a shift, it pessimizes some common cases like:
//
//void foo(int *X, int i) { X[i & 1235] = 1; }
//int bar(int *X, int i) { return X[i & 255]; }
// void foo(int *X, int i) { X[i & 1235] = 1; }
// int bar(int *X, int i) { return X[i & 255]; }
SDNode *BinOpLHSVal = LHS->getOperand(0).getNode();
if ((BinOpLHSVal->getOpcode() != ISD::SHL &&
BinOpLHSVal->getOpcode() != ISD::SRA &&
@ -2446,11 +2445,10 @@ SDValue DAGCombiner::visitShiftByConstant(SDNode *N, unsigned Amt) {
MVT VT = N->getValueType(0);
// If this is a signed shift right, and the high bit is modified
// by the logical operation, do not perform the transformation.
// The highBitSet boolean indicates the value of the high bit of
// the constant which would cause it to be modified for this
// operation.
// If this is a signed shift right, and the high bit is modified by the
// logical operation, do not perform the transformation. The highBitSet
// boolean indicates the value of the high bit of the constant which would
// cause it to be modified for this operation.
if (N->getOpcode() == ISD::SRA) {
bool BinOpRHSSignSet = BinOpCst->getAPIntValue().isNegative();
if (BinOpRHSSignSet != HighBitSet)
@ -2458,18 +2456,18 @@ SDValue DAGCombiner::visitShiftByConstant(SDNode *N, unsigned Amt) {
}
// Fold the constants, shifting the binop RHS by the shift amount.
SDValue NewRHS = DAG.getNode(N->getOpcode(), N->getValueType(0),
LHS->getOperand(1), N->getOperand(1));
SDValue NewRHS = DAG.getNode(N->getOpcode(), LHS->getOperand(1).getDebugLoc(),
N->getValueType(0),
LHS->getOperand(1), N->getOperand(1));
// Create the new shift.
SDValue NewShift = DAG.getNode(N->getOpcode(), VT, LHS->getOperand(0),
N->getOperand(1));
SDValue NewShift = DAG.getNode(N->getOpcode(), LHS->getOperand(0).getDebugLoc(),
VT, LHS->getOperand(0), N->getOperand(1));
// Create the new binop.
return DAG.getNode(LHS->getOpcode(), VT, NewShift, NewRHS);
return DAG.getNode(LHS->getOpcode(), N->getDebugLoc(), VT, NewShift, NewRHS);
}
SDValue DAGCombiner::visitSHL(SDNode *N) {
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
@ -2486,7 +2484,7 @@ SDValue DAGCombiner::visitSHL(SDNode *N) {
return N0;
// fold (shl x, c >= size(x)) -> undef
if (N1C && N1C->getZExtValue() >= OpSizeInBits)
return DAG.getNode(ISD::UNDEF, VT);
return DAG.getNode(ISD::UNDEF, N->getDebugLoc(), VT);
// fold (shl x, 0) -> x
if (N1C && N1C->isNullValue())
return N0;
@ -2505,7 +2503,7 @@ SDValue DAGCombiner::visitSHL(SDNode *N) {
SDValue N100 = N1.getOperand(0).getOperand(0);
uint64_t TruncC = TruncVT.getIntegerVTBitMask() &
N101C->getZExtValue();
return DAG.getNode(ISD::SHL, VT, N0,
return DAG.getNode(ISD::SHL, N->getDebugLoc(), VT, N0,
DAG.getNode(ISD::AND, TruncVT,
DAG.getNode(ISD::TRUNCATE, TruncVT, N100),
DAG.getConstant(TruncC, TruncVT)));
@ -2514,34 +2512,35 @@ SDValue DAGCombiner::visitSHL(SDNode *N) {
if (N1C && SimplifyDemandedBits(SDValue(N, 0)))
return SDValue(N, 0);
// fold (shl (shl x, c1), c2) -> 0 or (shl x, c1+c2)
// fold (shl (shl x, c1), c2) -> 0 or (shl x, (add c1, c2))
if (N1C && N0.getOpcode() == ISD::SHL &&
N0.getOperand(1).getOpcode() == ISD::Constant) {
uint64_t c1 = cast<ConstantSDNode>(N0.getOperand(1))->getZExtValue();
uint64_t c2 = N1C->getZExtValue();
if (c1 + c2 > OpSizeInBits)
return DAG.getConstant(0, VT);
return DAG.getNode(ISD::SHL, VT, N0.getOperand(0),
return DAG.getNode(ISD::SHL, N->getDebugLoc(), VT, N0.getOperand(0),
DAG.getConstant(c1 + c2, N1.getValueType()));
}
// fold (shl (srl x, c1), c2) -> (shl (and x, -1 << c1), c2-c1) or
// (srl (and x, -1 << c1), c1-c2)
// fold (shl (srl x, c1), c2) -> (shl (and x, (shl -1, c1)), (sub c2, c1)) or
// (srl (and x, (shl -1, c1)), (sub c1, c2))
if (N1C && N0.getOpcode() == ISD::SRL &&
N0.getOperand(1).getOpcode() == ISD::Constant) {
uint64_t c1 = cast<ConstantSDNode>(N0.getOperand(1))->getZExtValue();
uint64_t c2 = N1C->getZExtValue();
SDValue Mask = DAG.getNode(ISD::AND, VT, N0.getOperand(0),
DAG.getConstant(~0ULL << c1, VT));
SDValue Mask = DAG.getNode(ISD::AND, N0.getDebugLoc(), VT, N0.getOperand(0),
DAG.getConstant(~0ULL << c1, VT));
if (c2 > c1)
return DAG.getNode(ISD::SHL, VT, Mask,
return DAG.getNode(ISD::SHL, N->getDebugLoc(), VT, Mask,
DAG.getConstant(c2-c1, N1.getValueType()));
else
return DAG.getNode(ISD::SRL, VT, Mask,
return DAG.getNode(ISD::SRL, N->getDebugLoc(), VT, Mask,
DAG.getConstant(c1-c2, N1.getValueType()));
}
// fold (shl (sra x, c1), c1) -> (and x, -1 << c1)
// fold (shl (sra x, c1), c1) -> (and x, (shl -1, c1))
if (N1C && N0.getOpcode() == ISD::SRA && N1 == N0.getOperand(1))
return DAG.getNode(ISD::AND, VT, N0.getOperand(0),
return DAG.getNode(ISD::AND, N->getDebugLoc(), VT, N0.getOperand(0),
DAG.getConstant(~0ULL << N1C->getZExtValue(), VT));
return N1C ? visitShiftByConstant(N, N1C->getZExtValue()) : SDValue();
@ -2554,7 +2553,7 @@ SDValue DAGCombiner::visitSRA(SDNode *N) {
ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
MVT VT = N0.getValueType();
// fold (sra c1, c2) -> c1>>c2
// fold (sra c1, c2) -> (sra c1, c2)
if (N0C && N1C)
return DAG.FoldConstantArithmetic(ISD::SRA, VT, N0C, N1C);
// fold (sra 0, x) -> 0
@ -2563,9 +2562,9 @@ SDValue DAGCombiner::visitSRA(SDNode *N) {
// fold (sra -1, x) -> -1
if (N0C && N0C->isAllOnesValue())
return N0;
// fold (sra x, c >= size(x)) -> undef
// fold (sra x, (setge c, size(x))) -> undef
if (N1C && N1C->getZExtValue() >= VT.getSizeInBits())
return DAG.getNode(ISD::UNDEF, VT);
return DAG.getNode(ISD::UNDEF, N->getDebugLoc(), VT);
// fold (sra x, 0) -> x
if (N1C && N1C->isNullValue())
return N0;
@ -2575,22 +2574,22 @@ SDValue DAGCombiner::visitSRA(SDNode *N) {
unsigned LowBits = VT.getSizeInBits() - (unsigned)N1C->getZExtValue();
MVT EVT = MVT::getIntegerVT(LowBits);
if ((!LegalOperations || TLI.isOperationLegal(ISD::SIGN_EXTEND_INREG, EVT)))
return DAG.getNode(ISD::SIGN_EXTEND_INREG, VT, N0.getOperand(0),
DAG.getValueType(EVT));
return DAG.getNode(ISD::SIGN_EXTEND_INREG, N->getDebugLoc(), VT,
N0.getOperand(0), DAG.getValueType(EVT));
}
// fold (sra (sra x, c1), c2) -> (sra x, c1+c2)
// fold (sra (sra x, c1), c2) -> (sra x, (add c1, c2))
if (N1C && N0.getOpcode() == ISD::SRA) {
if (ConstantSDNode *C1 = dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
unsigned Sum = N1C->getZExtValue() + C1->getZExtValue();
if (Sum >= VT.getSizeInBits()) Sum = VT.getSizeInBits()-1;
return DAG.getNode(ISD::SRA, VT, N0.getOperand(0),
return DAG.getNode(ISD::SRA, N->getDebugLoc(), VT, N0.getOperand(0),
DAG.getConstant(Sum, N1C->getValueType(0)));
}
}
// fold sra (shl X, m), result_size - n
// -> (sign_extend (trunc (shl X, result_size - n - m))) for
// fold (sra (shl X, m), (sub result_size, n))
// -> (sign_extend (trunc (shl X, (sub (sub result_size, n), m)))) for
// result_size - n != m.
// If truncate is free for the target sext(shl) is likely to result in better
// code.
@ -2615,9 +2614,12 @@ SDValue DAGCombiner::visitSRA(SDNode *N) {
TLI.isTruncateFree(VT, TruncVT)) {
SDValue Amt = DAG.getConstant(ShiftAmt, TLI.getShiftAmountTy());
SDValue Shift = DAG.getNode(ISD::SRL, VT, N0.getOperand(0), Amt);
SDValue Trunc = DAG.getNode(ISD::TRUNCATE, TruncVT, Shift);
return DAG.getNode(ISD::SIGN_EXTEND, N->getValueType(0), Trunc);
SDValue Shift = DAG.getNode(ISD::SRL, N0.getDebugLoc(), VT,
N0.getOperand(0), Amt);
SDValue Trunc = DAG.getNode(ISD::TRUNCATE, N0.getDebugLoc(), TruncVT,
Shift);
return DAG.getNode(ISD::SIGN_EXTEND, N->getDebugLoc(),
N->getValueType(0), Trunc);
}
}
}
@ -2633,8 +2635,9 @@ SDValue DAGCombiner::visitSRA(SDNode *N) {
SDValue N100 = N1.getOperand(0).getOperand(0);
uint64_t TruncC = TruncVT.getIntegerVTBitMask() &
N101C->getZExtValue();
return DAG.getNode(ISD::SRA, VT, N0,
DAG.getNode(ISD::AND, TruncVT,
return DAG.getNode(ISD::SRA, N->getDebugLoc(), VT, N0,
DAG.getNode(ISD::AND, DebugLoc::getUnknownLoc(),
TruncVT,
DAG.getNode(ISD::TRUNCATE, TruncVT, N100),
DAG.getConstant(TruncC, TruncVT)));
}
@ -2647,7 +2650,7 @@ SDValue DAGCombiner::visitSRA(SDNode *N) {
// If the sign bit is known to be zero, switch this to a SRL.
if (DAG.SignBitIsZero(N0))
return DAG.getNode(ISD::SRL, VT, N0, N1);
return DAG.getNode(ISD::SRL, N->getDebugLoc(), VT, N0, N1);
return N1C ? visitShiftByConstant(N, N1C->getZExtValue()) : SDValue();
}
@ -2668,7 +2671,7 @@ SDValue DAGCombiner::visitSRL(SDNode *N) {
return N0;
// fold (srl x, c >= size(x)) -> undef
if (N1C && N1C->getZExtValue() >= OpSizeInBits)
return DAG.getNode(ISD::UNDEF, VT);
return DAG.getNode(ISD::UNDEF, N->getDebugLoc(), VT);
// fold (srl x, 0) -> x
if (N1C && N1C->isNullValue())
return N0;
@ -2677,14 +2680,14 @@ SDValue DAGCombiner::visitSRL(SDNode *N) {
APInt::getAllOnesValue(OpSizeInBits)))
return DAG.getConstant(0, VT);
// fold (srl (srl x, c1), c2) -> 0 or (srl x, c1+c2)
// fold (srl (srl x, c1), c2) -> 0 or (srl x, (add c1, c2))
if (N1C && N0.getOpcode() == ISD::SRL &&
N0.getOperand(1).getOpcode() == ISD::Constant) {
uint64_t c1 = cast<ConstantSDNode>(N0.getOperand(1))->getZExtValue();
uint64_t c2 = N1C->getZExtValue();
if (c1 + c2 > OpSizeInBits)
return DAG.getConstant(0, VT);
return DAG.getNode(ISD::SRL, VT, N0.getOperand(0),
return DAG.getNode(ISD::SRL, N->getDebugLoc(), VT, N0.getOperand(0),
DAG.getConstant(c1 + c2, N1.getValueType()));
}
@ -2693,18 +2696,19 @@ SDValue DAGCombiner::visitSRL(SDNode *N) {
// Shifting in all undef bits?
MVT SmallVT = N0.getOperand(0).getValueType();
if (N1C->getZExtValue() >= SmallVT.getSizeInBits())
return DAG.getNode(ISD::UNDEF, VT);
return DAG.getNode(ISD::UNDEF, N->getDebugLoc(), VT);
SDValue SmallShift = DAG.getNode(ISD::SRL, SmallVT, N0.getOperand(0), N1);
SDValue SmallShift = DAG.getNode(ISD::SRL, N0.getDebugLoc(), SmallVT,
N0.getOperand(0), N1);
AddToWorkList(SmallShift.getNode());
return DAG.getNode(ISD::ANY_EXTEND, VT, SmallShift);
return DAG.getNode(ISD::ANY_EXTEND, N->getDebugLoc(), VT, SmallShift);
}
// fold (srl (sra X, Y), 31) -> (srl X, 31). This srl only looks at the sign
// bit, which is unmodified by sra.
if (N1C && N1C->getZExtValue()+1 == VT.getSizeInBits()) {
if (N1C && N1C->getZExtValue() + 1 == VT.getSizeInBits()) {
if (N0.getOpcode() == ISD::SRA)
return DAG.getNode(ISD::SRL, VT, N0.getOperand(0), N1);
return DAG.getNode(ISD::SRL, N->getDebugLoc(), VT, N0.getOperand(0), N1);
}
// fold (srl (ctlz x), "5") -> x iff x has one bit set (the low bit).
@ -2724,19 +2728,22 @@ SDValue DAGCombiner::visitSRL(SDNode *N) {
if (UnknownBits == 0) return DAG.getConstant(1, VT);
// Otherwise, check to see if there is exactly one bit input to the ctlz.
if ((UnknownBits & (UnknownBits-1)) == 0) {
if ((UnknownBits & (UnknownBits - 1)) == 0) {
// Okay, we know that only that the single bit specified by UnknownBits
// could be set on input to the CTLZ node. If this bit is set, the SRL
// will return 0, if it is clear, it returns 1. Change the CTLZ/SRL pair
// to an SRL,XOR pair, which is likely to simplify more.
// could be set on input to the CTLZ node. If this bit is set, the SRL
// will return 0, if it is clear, it returns 1. Change the CTLZ/SRL pair
// to an SRL/XOR pair, which is likely to simplify more.
unsigned ShAmt = UnknownBits.countTrailingZeros();
SDValue Op = N0.getOperand(0);
if (ShAmt) {
Op = DAG.getNode(ISD::SRL, VT, Op,
Op = DAG.getNode(ISD::SRL, N0.getDebugLoc(), VT, Op,
DAG.getConstant(ShAmt, TLI.getShiftAmountTy()));
AddToWorkList(Op.getNode());
}
return DAG.getNode(ISD::XOR, VT, Op, DAG.getConstant(1, VT));
return DAG.getNode(ISD::XOR, N->getDebugLoc(), VT,
Op, DAG.getConstant(1, VT));
}
}
@ -2751,8 +2758,9 @@ SDValue DAGCombiner::visitSRL(SDNode *N) {
SDValue N100 = N1.getOperand(0).getOperand(0);
uint64_t TruncC = TruncVT.getIntegerVTBitMask() &
N101C->getZExtValue();
return DAG.getNode(ISD::SRL, VT, N0,
DAG.getNode(ISD::AND, TruncVT,
return DAG.getNode(ISD::SRL, N->getDebugLoc(), VT, N0,
DAG.getNode(ISD::AND, DebugLoc::getUnknownLoc(),
TruncVT,
DAG.getNode(ISD::TRUNCATE, TruncVT, N100),
DAG.getConstant(TruncC, TruncVT)));
}