[RISCV] Remove unneeded check for ISD::VSCALE operand being a constant. NFC

ISD::VSCALE only allows constant operands.
This commit is contained in:
Craig Topper 2022-05-14 13:44:55 -07:00
parent 44ae09d75f
commit 5a19fbad83
1 changed files with 17 additions and 19 deletions

View File

@ -3097,26 +3097,24 @@ SDValue RISCVTargetLowering::LowerOperation(SDValue Op,
static_assert(RISCV::RVVBitsPerBlock == 64, "Unexpected bits per block!");
if (Subtarget.getMinVLen() < RISCV::RVVBitsPerBlock)
report_fatal_error("Support for VLEN==32 is incomplete.");
if (isa<ConstantSDNode>(Op.getOperand(0))) {
// We assume VLENB is a multiple of 8. We manually choose the best shift
// here because SimplifyDemandedBits isn't always able to simplify it.
uint64_t Val = Op.getConstantOperandVal(0);
if (isPowerOf2_64(Val)) {
uint64_t Log2 = Log2_64(Val);
if (Log2 < 3)
return DAG.getNode(ISD::SRL, DL, VT, VLENB,
DAG.getConstant(3 - Log2, DL, VT));
if (Log2 > 3)
return DAG.getNode(ISD::SHL, DL, VT, VLENB,
DAG.getConstant(Log2 - 3, DL, VT));
return VLENB;
}
// If the multiplier is a multiple of 8, scale it down to avoid needing
// to shift the VLENB value.
if ((Val % 8) == 0)
return DAG.getNode(ISD::MUL, DL, VT, VLENB,
DAG.getConstant(Val / 8, DL, VT));
// We assume VLENB is a multiple of 8. We manually choose the best shift
// here because SimplifyDemandedBits isn't always able to simplify it.
uint64_t Val = Op.getConstantOperandVal(0);
if (isPowerOf2_64(Val)) {
uint64_t Log2 = Log2_64(Val);
if (Log2 < 3)
return DAG.getNode(ISD::SRL, DL, VT, VLENB,
DAG.getConstant(3 - Log2, DL, VT));
if (Log2 > 3)
return DAG.getNode(ISD::SHL, DL, VT, VLENB,
DAG.getConstant(Log2 - 3, DL, VT));
return VLENB;
}
// If the multiplier is a multiple of 8, scale it down to avoid needing
// to shift the VLENB value.
if ((Val % 8) == 0)
return DAG.getNode(ISD::MUL, DL, VT, VLENB,
DAG.getConstant(Val / 8, DL, VT));
SDValue VScale = DAG.getNode(ISD::SRL, DL, VT, VLENB,
DAG.getConstant(3, DL, VT));