Patch by David Conrad:

"On ARMv6T2 this turns cttz into rbit, clz instead of the 4 instruction
 sequence it is now."




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93758 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Jim Grosbach 2010-01-18 19:58:49 +00:00
parent f9d5c5cf9f
commit 3482c8003a
5 changed files with 34 additions and 1 deletions

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@ -1680,6 +1680,12 @@ SDNode *ARMDAGToDAGISel::Select(SDNode *N) {
return CurDAG->getMachineNode(ARM::VMOVRRD, dl, MVT::i32, MVT::i32,
N->getOperand(0), getAL(CurDAG),
CurDAG->getRegister(0, MVT::i32));
case ARMISD::RBIT: {
EVT VT = N->getValueType(0);
SDValue Ops[] = { N->getOperand(0),
getAL(CurDAG), CurDAG->getRegister(0, MVT::i32) };
return CurDAG->getMachineNode(ARM::RBIT, dl, VT, Ops, 3);
}
case ISD::UMUL_LOHI: {
if (Subtarget->isThumb1Only())
break;

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@ -340,7 +340,7 @@ ARMTargetLowering::ARMTargetLowering(TargetMachine &TM)
// ARM does not have ROTL.
setOperationAction(ISD::ROTL, MVT::i32, Expand);
setOperationAction(ISD::CTTZ, MVT::i32, Expand);
setOperationAction(ISD::CTTZ, MVT::i32, Custom);
setOperationAction(ISD::CTPOP, MVT::i32, Expand);
if (!Subtarget->hasV5TOps() || Subtarget->isThumb1Only())
setOperationAction(ISD::CTLZ, MVT::i32, Expand);
@ -482,6 +482,8 @@ const char *ARMTargetLowering::getTargetNodeName(unsigned Opcode) const {
case ARMISD::CMOV: return "ARMISD::CMOV";
case ARMISD::CNEG: return "ARMISD::CNEG";
case ARMISD::RBIT: return "ARMISD::RBIT";
case ARMISD::FTOSI: return "ARMISD::FTOSI";
case ARMISD::FTOUI: return "ARMISD::FTOUI";
case ARMISD::SITOF: return "ARMISD::SITOF";
@ -2231,6 +2233,18 @@ SDValue ARMTargetLowering::LowerShiftLeftParts(SDValue Op, SelectionDAG &DAG) {
return DAG.getMergeValues(Ops, 2, dl);
}
static SDValue LowerCTTZ(SDNode *N, SelectionDAG &DAG,
const ARMSubtarget *ST) {
EVT VT = N->getValueType(0);
DebugLoc dl = N->getDebugLoc();
if (!ST->hasV6T2Ops())
return SDValue();
SDValue rbit = DAG.getNode(ARMISD::RBIT, dl, VT, N->getOperand(0));
return DAG.getNode(ISD::CTLZ, dl, VT, rbit);
}
static SDValue LowerShift(SDNode *N, SelectionDAG &DAG,
const ARMSubtarget *ST) {
EVT VT = N->getValueType(0);
@ -3016,6 +3030,7 @@ SDValue ARMTargetLowering::LowerOperation(SDValue Op, SelectionDAG &DAG) {
case ISD::SHL_PARTS: return LowerShiftLeftParts(Op, DAG);
case ISD::SRL_PARTS:
case ISD::SRA_PARTS: return LowerShiftRightParts(Op, DAG);
case ISD::CTTZ: return LowerCTTZ(Op.getNode(), DAG, Subtarget);
case ISD::VSETCC: return LowerVSETCC(Op, DAG);
case ISD::BUILD_VECTOR: return LowerBUILD_VECTOR(Op, DAG);
case ISD::VECTOR_SHUFFLE: return LowerVECTOR_SHUFFLE(Op, DAG);

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@ -53,6 +53,8 @@ namespace llvm {
CMOV, // ARM conditional move instructions.
CNEG, // ARM conditional negate instructions.
RBIT, // ARM bitreverse instruction
FTOSI, // FP to sint within a FP register.
FTOUI, // FP to uint within a FP register.
SITOF, // sint to FP within a FP register.

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@ -1455,6 +1455,13 @@ def CLZ : AMiscA1I<0b000010110, (outs GPR:$dst), (ins GPR:$src), IIC_iUNAr,
let Inst{19-16} = 0b1111;
}
def RBIT : AMiscA1I<0b01101111, (outs GPR:$dst), (ins GPR:$src), IIC_iUNAr,
"rbit", "\t$dst, $src", []>, Requires<[IsARM, HasV6T2]> {
let Inst{7-4} = 0b0011;
let Inst{11-8} = 0b1111;
let Inst{19-16} = 0b1111;
}
def REV : AMiscA1I<0b01101011, (outs GPR:$dst), (ins GPR:$src), IIC_iUNAr,
"rev", "\t$dst, $src",
[(set GPR:$dst, (bswap GPR:$src))]>, Requires<[IsARM, HasV6]> {

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@ -1540,6 +1540,9 @@ class T2I_misc<bits<2> op1, bits<2> op2, dag oops, dag iops, InstrItinClass itin
def t2CLZ : T2I_misc<0b11, 0b00, (outs GPR:$dst), (ins GPR:$src), IIC_iUNAr,
"clz", "\t$dst, $src", [(set GPR:$dst, (ctlz GPR:$src))]>;
def t2RBIT : T2I_misc<0b01, 0b10, (outs GPR:$dst), (ins GPR:$src), IIC_iUNAr,
"rbit", "\t$dst, $src", []>;
def t2REV : T2I_misc<0b01, 0b00, (outs GPR:$dst), (ins GPR:$src), IIC_iUNAr,
"rev", ".w\t$dst, $src", [(set GPR:$dst, (bswap GPR:$src))]>;