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Diffstat (limited to 'llvm/lib/Target/RISCV/RISCVISelLowering.cpp')
-rw-r--r--llvm/lib/Target/RISCV/RISCVISelLowering.cpp127
1 files changed, 58 insertions, 69 deletions
diff --git a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
index e0cf739..b860562 100644
--- a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
+++ b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
@@ -9186,7 +9186,7 @@ static SDValue lowerSelectToBinOp(SDNode *N, SelectionDAG &DAG,
unsigned ShAmount = Log2_64(TrueM1);
if (Subtarget.hasShlAdd(ShAmount))
return DAG.getNode(RISCVISD::SHL_ADD, DL, VT, CondV,
- DAG.getConstant(ShAmount, DL, VT), CondV);
+ DAG.getTargetConstant(ShAmount, DL, VT), CondV);
}
}
// (select c, y, 0) -> -c & y
@@ -15463,7 +15463,7 @@ static SDValue transformAddShlImm(SDNode *N, SelectionDAG &DAG,
SDValue NS = (C0 < C1) ? N0->getOperand(0) : N1->getOperand(0);
SDValue NL = (C0 > C1) ? N0->getOperand(0) : N1->getOperand(0);
SDValue SHADD = DAG.getNode(RISCVISD::SHL_ADD, DL, VT, NL,
- DAG.getConstant(Diff, DL, VT), NS);
+ DAG.getTargetConstant(Diff, DL, VT), NS);
return DAG.getNode(ISD::SHL, DL, VT, SHADD, DAG.getConstant(Bits, DL, VT));
}
@@ -15501,7 +15501,7 @@ static SDValue combineShlAddIAddImpl(SDNode *N, SDValue AddI, SDValue Other,
int64_t AddConst = AddVal.getSExtValue();
SDValue SHADD = DAG.getNode(RISCVISD::SHL_ADD, DL, VT, SHLVal->getOperand(0),
- DAG.getConstant(ShlConst, DL, VT), Other);
+ DAG.getTargetConstant(ShlConst, DL, VT), Other);
return DAG.getNode(ISD::ADD, DL, VT, SHADD,
DAG.getSignedConstant(AddConst, DL, VT));
}
@@ -16495,6 +16495,35 @@ static SDValue expandMulToAddOrSubOfShl(SDNode *N, SelectionDAG &DAG,
return DAG.getNode(Op, DL, VT, Shift1, Shift2);
}
+static SDValue getShlAddShlAdd(SDNode *N, SelectionDAG &DAG, unsigned ShX,
+ unsigned ShY) {
+ SDLoc DL(N);
+ EVT VT = N->getValueType(0);
+ SDValue X = N->getOperand(0);
+ SDValue Mul359 = DAG.getNode(RISCVISD::SHL_ADD, DL, VT, X,
+ DAG.getTargetConstant(ShY, DL, VT), X);
+ return DAG.getNode(RISCVISD::SHL_ADD, DL, VT, Mul359,
+ DAG.getTargetConstant(ShX, DL, VT), Mul359);
+}
+
+static SDValue expandMulToShlAddShlAdd(SDNode *N, SelectionDAG &DAG,
+ uint64_t MulAmt) {
+ switch (MulAmt) {
+ case 5 * 3:
+ return getShlAddShlAdd(N, DAG, 2, 1);
+ case 9 * 3:
+ return getShlAddShlAdd(N, DAG, 3, 1);
+ case 5 * 5:
+ return getShlAddShlAdd(N, DAG, 2, 2);
+ case 9 * 5:
+ return getShlAddShlAdd(N, DAG, 3, 2);
+ case 9 * 9:
+ return getShlAddShlAdd(N, DAG, 3, 3);
+ default:
+ return SDValue();
+ }
+}
+
// Try to expand a scalar multiply to a faster sequence.
static SDValue expandMul(SDNode *N, SelectionDAG &DAG,
TargetLowering::DAGCombinerInfo &DCI,
@@ -16524,18 +16553,17 @@ static SDValue expandMul(SDNode *N, SelectionDAG &DAG,
if (Subtarget.hasVendorXqciac() && isInt<12>(CNode->getSExtValue()))
return SDValue();
- // WARNING: The code below is knowingly incorrect with regards to undef semantics.
- // We're adding additional uses of X here, and in principle, we should be freezing
- // X before doing so. However, adding freeze here causes real regressions, and no
- // other target properly freezes X in these cases either.
- SDValue X = N->getOperand(0);
-
+ // WARNING: The code below is knowingly incorrect with regards to undef
+ // semantics. We're adding additional uses of X here, and in principle, we
+ // should be freezing X before doing so. However, adding freeze here causes
+ // real regressions, and no other target properly freezes X in these cases
+ // either.
if (Subtarget.hasShlAdd(3)) {
+ SDValue X = N->getOperand(0);
int Shift;
if (int ShXAmount = isShifted359(MulAmt, Shift)) {
// 3/5/9 * 2^N -> shl (shXadd X, X), N
SDLoc DL(N);
- SDValue X = N->getOperand(0);
// Put the shift first if we can fold a zext into the shift forming
// a slli.uw.
if (X.getOpcode() == ISD::AND && isa<ConstantSDNode>(X.getOperand(1)) &&
@@ -16543,49 +16571,19 @@ static SDValue expandMul(SDNode *N, SelectionDAG &DAG,
SDValue Shl =
DAG.getNode(ISD::SHL, DL, VT, X, DAG.getConstant(Shift, DL, VT));
return DAG.getNode(RISCVISD::SHL_ADD, DL, VT, Shl,
- DAG.getConstant(ShXAmount, DL, VT), Shl);
+ DAG.getTargetConstant(ShXAmount, DL, VT), Shl);
}
// Otherwise, put the shl second so that it can fold with following
// instructions (e.g. sext or add).
SDValue Mul359 = DAG.getNode(RISCVISD::SHL_ADD, DL, VT, X,
- DAG.getConstant(ShXAmount, DL, VT), X);
+ DAG.getTargetConstant(ShXAmount, DL, VT), X);
return DAG.getNode(ISD::SHL, DL, VT, Mul359,
DAG.getConstant(Shift, DL, VT));
}
// 3/5/9 * 3/5/9 -> shXadd (shYadd X, X), (shYadd X, X)
- int ShX;
- int ShY;
- switch (MulAmt) {
- case 3 * 5:
- ShY = 1;
- ShX = 2;
- break;
- case 3 * 9:
- ShY = 1;
- ShX = 3;
- break;
- case 5 * 5:
- ShX = ShY = 2;
- break;
- case 5 * 9:
- ShY = 2;
- ShX = 3;
- break;
- case 9 * 9:
- ShX = ShY = 3;
- break;
- default:
- ShX = ShY = 0;
- break;
- }
- if (ShX) {
- SDLoc DL(N);
- SDValue Mul359 = DAG.getNode(RISCVISD::SHL_ADD, DL, VT, X,
- DAG.getConstant(ShY, DL, VT), X);
- return DAG.getNode(RISCVISD::SHL_ADD, DL, VT, Mul359,
- DAG.getConstant(ShX, DL, VT), Mul359);
- }
+ if (SDValue V = expandMulToShlAddShlAdd(N, DAG, MulAmt))
+ return V;
// If this is a power 2 + 2/4/8, we can use a shift followed by a single
// shXadd. First check if this a sum of two power of 2s because that's
@@ -16598,7 +16596,7 @@ static SDValue expandMul(SDNode *N, SelectionDAG &DAG,
SDValue Shift1 =
DAG.getNode(ISD::SHL, DL, VT, X, DAG.getConstant(ShiftAmt, DL, VT));
return DAG.getNode(RISCVISD::SHL_ADD, DL, VT, X,
- DAG.getConstant(ScaleShift, DL, VT), Shift1);
+ DAG.getTargetConstant(ScaleShift, DL, VT), Shift1);
}
}
@@ -16611,10 +16609,11 @@ static SDValue expandMul(SDNode *N, SelectionDAG &DAG,
assert(Shift != 0 && "MulAmt=4,6,10 handled before");
if (Shift <= 3) {
SDLoc DL(N);
- SDValue Mul359 = DAG.getNode(RISCVISD::SHL_ADD, DL, VT, X,
- DAG.getConstant(ShXAmount, DL, VT), X);
+ SDValue Mul359 =
+ DAG.getNode(RISCVISD::SHL_ADD, DL, VT, X,
+ DAG.getTargetConstant(ShXAmount, DL, VT), X);
return DAG.getNode(RISCVISD::SHL_ADD, DL, VT, Mul359,
- DAG.getConstant(Shift, DL, VT), X);
+ DAG.getTargetConstant(Shift, DL, VT), X);
}
}
@@ -16626,9 +16625,10 @@ static SDValue expandMul(SDNode *N, SelectionDAG &DAG,
SDLoc DL(N);
SDValue Shift1 =
DAG.getNode(ISD::SHL, DL, VT, X, DAG.getConstant(ShiftAmt, DL, VT));
- return DAG.getNode(ISD::ADD, DL, VT, Shift1,
- DAG.getNode(RISCVISD::SHL_ADD, DL, VT, X,
- DAG.getConstant(ScaleShift, DL, VT), X));
+ return DAG.getNode(
+ ISD::ADD, DL, VT, Shift1,
+ DAG.getNode(RISCVISD::SHL_ADD, DL, VT, X,
+ DAG.getTargetConstant(ScaleShift, DL, VT), X));
}
}
@@ -16643,28 +16643,17 @@ static SDValue expandMul(SDNode *N, SelectionDAG &DAG,
DAG.getNode(ISD::SHL, DL, VT, X, DAG.getConstant(ShAmt, DL, VT));
SDValue Mul359 =
DAG.getNode(RISCVISD::SHL_ADD, DL, VT, X,
- DAG.getConstant(Log2_64(Offset - 1), DL, VT), X);
+ DAG.getTargetConstant(Log2_64(Offset - 1), DL, VT), X);
return DAG.getNode(ISD::SUB, DL, VT, Shift1, Mul359);
}
}
- for (uint64_t Divisor : {3, 5, 9}) {
- if (MulAmt % Divisor != 0)
- continue;
- uint64_t MulAmt2 = MulAmt / Divisor;
- // 3/5/9 * 3/5/9 * 2^N - In particular, this covers multiples
- // of 25 which happen to be quite common.
- if (int ShBAmount = isShifted359(MulAmt2, Shift)) {
- SDLoc DL(N);
- SDValue Mul359A =
- DAG.getNode(RISCVISD::SHL_ADD, DL, VT, X,
- DAG.getConstant(Log2_64(Divisor - 1), DL, VT), X);
- SDValue Mul359B =
- DAG.getNode(RISCVISD::SHL_ADD, DL, VT, Mul359A,
- DAG.getConstant(ShBAmount, DL, VT), Mul359A);
- return DAG.getNode(ISD::SHL, DL, VT, Mul359B,
- DAG.getConstant(Shift, DL, VT));
- }
+ // 3/5/9 * 3/5/9 * 2^N - In particular, this covers multiples
+ // of 25 which happen to be quite common.
+ Shift = llvm::countr_zero(MulAmt);
+ if (SDValue V = expandMulToShlAddShlAdd(N, DAG, MulAmt >> Shift)) {
+ SDLoc DL(N);
+ return DAG.getNode(ISD::SHL, DL, VT, V, DAG.getConstant(Shift, DL, VT));
}
}
generated by cgit v1.1 at 2025-11-04 23:40:09 +0000