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[ARM] Use ADDCARRY / SUBCARRY 

This is a preparatory step for D34515.

This change:
 - makes nodes ISD::ADDCARRY and ISD::SUBCARRY legal for i32
 - lowering is done by first converting the boolean value into the carry flag
   using (_, C) ← (ARMISD::ADDC R, -1) and converted back to an integer value
   using (R, _) ← (ARMISD::ADDE 0, 0, C). An ARMISD::ADDE between the two
   operations does the actual addition.
 - for subtraction, given that ISD::SUBCARRY second result is actually a
   borrow, we need to invert the value of the second operand and result before
   and after using ARMISD::SUBE. We need to invert the carry result of
   ARMISD::SUBE to preserve the semantics.
 - given that the generic combiner may lower ISD::ADDCARRY and
   ISD::SUBCARRYinto ISD::UADDO and ISD::USUBO we need to update their lowering
   as well otherwise i64 operations now would require branches. This implies
   updating the corresponding test for unsigned.
 - add new combiner to remove the redundant conversions from/to carry flags
   to/from boolean values (ARMISD::ADDC (ARMISD::ADDE 0, 0, C), -1) → C
 - fixes PR34045
 - fixes PR34564

Differential Revision: https://reviews.llvm.org/D35192

llvm-svn: 313618
This commit is contained in:
Roger Ferrer Ibanez 2017-09-19 09:05:39 +00:00
parent 142516b456
commit 8d0180c955
5 changed files with 320 additions and 35 deletions
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184
llvm/lib/Target/ARM/ARMISelLowering.cpp
View File

@ -802,6 +802,9 @@ ARMTargetLowering::ARMTargetLowering(const TargetMachine &TM,
setOperationAction(ISD::SSUBO, MVT::i32, Custom); setOperationAction(ISD::SSUBO, MVT::i32, Custom);
setOperationAction(ISD::USUBO, MVT::i32, Custom); setOperationAction(ISD::USUBO, MVT::i32, Custom);
setOperationAction(ISD::ADDCARRY, MVT::i32, Custom);
setOperationAction(ISD::SUBCARRY, MVT::i32, Custom);
// i64 operation support. // i64 operation support.
setOperationAction(ISD::MUL, MVT::i64, Expand); setOperationAction(ISD::MUL, MVT::i64, Expand);
setOperationAction(ISD::MULHU, MVT::i32, Expand); setOperationAction(ISD::MULHU, MVT::i32, Expand);
@ -3953,7 +3956,7 @@ ARMTargetLowering::getARMXALUOOp(SDValue Op, SelectionDAG &DAG,
} }
SDValue SDValue
ARMTargetLowering::LowerXALUO(SDValue Op, SelectionDAG &DAG) const { ARMTargetLowering::LowerSignedALUO(SDValue Op, SelectionDAG &DAG) const {
// Let legalize expand this if it isn't a legal type yet. // Let legalize expand this if it isn't a legal type yet.
if (!DAG.getTargetLoweringInfo().isTypeLegal(Op.getValueType())) if (!DAG.getTargetLoweringInfo().isTypeLegal(Op.getValueType()))
return SDValue(); return SDValue();
@ -3975,6 +3978,66 @@ ARMTargetLowering::LowerXALUO(SDValue Op, SelectionDAG &DAG) const {
return DAG.getNode(ISD::MERGE_VALUES, dl, VTs, Value, Overflow); return DAG.getNode(ISD::MERGE_VALUES, dl, VTs, Value, Overflow);
} }
static SDValue ConvertBooleanCarryToCarryFlag(SDValue BoolCarry,
SelectionDAG &DAG) {
SDLoc DL(BoolCarry);
EVT CarryVT = BoolCarry.getValueType();
APInt NegOne = APInt::getAllOnesValue(CarryVT.getScalarSizeInBits());
// This converts the boolean value carry into the carry flag by doing
// ARMISD::ADDC Carry, ~0
return DAG.getNode(ARMISD::ADDC, DL, DAG.getVTList(CarryVT, MVT::i32),
BoolCarry, DAG.getConstant(NegOne, DL, CarryVT));
}
static SDValue ConvertCarryFlagToBooleanCarry(SDValue Flags, EVT VT,
SelectionDAG &DAG) {
SDLoc DL(Flags);
// Now convert the carry flag into a boolean carry. We do this
// using ARMISD:ADDE 0, 0, Carry
return DAG.getNode(ARMISD::ADDE, DL, DAG.getVTList(VT, MVT::i32),
DAG.getConstant(0, DL, MVT::i32),
DAG.getConstant(0, DL, MVT::i32), Flags);
}
SDValue ARMTargetLowering::LowerUnsignedALUO(SDValue Op,
SelectionDAG &DAG) const {
// Let legalize expand this if it isn't a legal type yet.
if (!DAG.getTargetLoweringInfo().isTypeLegal(Op.getValueType()))
return SDValue();
SDValue LHS = Op.getOperand(0);
SDValue RHS = Op.getOperand(1);
SDLoc dl(Op);
EVT VT = Op.getValueType();
SDVTList VTs = DAG.getVTList(VT, MVT::i32);
SDValue Value;
SDValue Overflow;
switch (Op.getOpcode()) {
default:
llvm_unreachable("Unknown overflow instruction!");
case ISD::UADDO:
Value = DAG.getNode(ARMISD::ADDC, dl, VTs, LHS, RHS);
// Convert the carry flag into a boolean value.
Overflow = ConvertCarryFlagToBooleanCarry(Value.getValue(1), VT, DAG);
break;
case ISD::USUBO: {
Value = DAG.getNode(ARMISD::SUBC, dl, VTs, LHS, RHS);
// Convert the carry flag into a boolean value.
Overflow = ConvertCarryFlagToBooleanCarry(Value.getValue(1), VT, DAG);
// ARMISD::SUBC returns 0 when we have to borrow, so make it an overflow
// value. So compute 1 - C.
Overflow = DAG.getNode(ISD::SUB, dl, MVT::i32,
DAG.getConstant(1, dl, MVT::i32), Overflow);
break;
}
}
return DAG.getNode(ISD::MERGE_VALUES, dl, VTs, Value, Overflow);
}
SDValue ARMTargetLowering::LowerSELECT(SDValue Op, SelectionDAG &DAG) const { SDValue ARMTargetLowering::LowerSELECT(SDValue Op, SelectionDAG &DAG) const {
SDValue Cond = Op.getOperand(0); SDValue Cond = Op.getOperand(0);
SDValue SelectTrue = Op.getOperand(1); SDValue SelectTrue = Op.getOperand(1);
@ -7380,6 +7443,53 @@ static SDValue LowerADDC_ADDE_SUBC_SUBE(SDValue Op, SelectionDAG &DAG) {
Op.getOperand(1), Op.getOperand(2)); Op.getOperand(1), Op.getOperand(2));
} }
static SDValue LowerADDSUBCARRY(SDValue Op, SelectionDAG &DAG) {
SDNode *N = Op.getNode();
EVT VT = N->getValueType(0);
SDVTList VTs = DAG.getVTList(VT, MVT::i32);
SDValue Carry = Op.getOperand(2);
EVT CarryVT = Carry.getValueType();
SDLoc DL(Op);
APInt NegOne = APInt::getAllOnesValue(CarryVT.getScalarSizeInBits());
SDValue Result;
if (Op.getOpcode() == ISD::ADDCARRY) {
// This converts the boolean value carry into the carry flag.
Carry = ConvertBooleanCarryToCarryFlag(Carry, DAG);
// Do the addition proper using the carry flag we wanted.
Result = DAG.getNode(ARMISD::ADDE, DL, VTs, Op.getOperand(0),
Op.getOperand(1), Carry.getValue(1));
// Now convert the carry flag into a boolean value.
Carry = ConvertCarryFlagToBooleanCarry(Result.getValue(1), VT, DAG);
} else {
// ARMISD::SUBE expects a carry not a borrow like ISD::SUBCARRY so we
// have to invert the carry first.
Carry = DAG.getNode(ISD::SUB, DL, MVT::i32,
DAG.getConstant(1, DL, MVT::i32), Carry);
// This converts the boolean value carry into the carry flag.
Carry = ConvertBooleanCarryToCarryFlag(Carry, DAG);
// Do the subtraction proper using the carry flag we wanted.
Result = DAG.getNode(ARMISD::SUBE, DL, VTs, Op.getOperand(0),
Op.getOperand(1), Carry.getValue(1));
// Now convert the carry flag into a boolean value.
Carry = ConvertCarryFlagToBooleanCarry(Result.getValue(1), VT, DAG);
// But the carry returned by ARMISD::SUBE is not a borrow as expected
// by ISD::SUBCARRY, so compute 1 - C.
Carry = DAG.getNode(ISD::SUB, DL, MVT::i32,
DAG.getConstant(1, DL, MVT::i32), Carry);
}
// Return both values.
return DAG.getNode(ISD::MERGE_VALUES, DL, N->getVTList(), Result, Carry);
}
SDValue ARMTargetLowering::LowerFSINCOS(SDValue Op, SelectionDAG &DAG) const { SDValue ARMTargetLowering::LowerFSINCOS(SDValue Op, SelectionDAG &DAG) const {
assert(Subtarget->isTargetDarwin()); assert(Subtarget->isTargetDarwin());
@ -7734,11 +7844,14 @@ SDValue ARMTargetLowering::LowerOperation(SDValue Op, SelectionDAG &DAG) const {
case ISD::ADDE: case ISD::ADDE:
case ISD::SUBC: case ISD::SUBC:
case ISD::SUBE: return LowerADDC_ADDE_SUBC_SUBE(Op, DAG); case ISD::SUBE: return LowerADDC_ADDE_SUBC_SUBE(Op, DAG);
case ISD::ADDCARRY:
case ISD::SUBCARRY: return LowerADDSUBCARRY(Op, DAG);
case ISD::SADDO: case ISD::SADDO:
case ISD::UADDO:
case ISD::SSUBO: case ISD::SSUBO:
return LowerSignedALUO(Op, DAG);
case ISD::UADDO:
case ISD::USUBO: case ISD::USUBO:
return LowerXALUO(Op, DAG); return LowerUnsignedALUO(Op, DAG);
case ISD::ATOMIC_LOAD: case ISD::ATOMIC_LOAD:
case ISD::ATOMIC_STORE: return LowerAtomicLoadStore(Op, DAG); case ISD::ATOMIC_STORE: return LowerAtomicLoadStore(Op, DAG);
case ISD::FSINCOS: return LowerFSINCOS(Op, DAG); case ISD::FSINCOS: return LowerFSINCOS(Op, DAG);
@ -9687,11 +9800,11 @@ static SDValue AddCombineTo64bitMLAL(SDNode *AddeNode,
// a S/UMLAL instruction. // a S/UMLAL instruction.
// UMUL_LOHI // UMUL_LOHI
// / :lo \ :hi // / :lo \ :hi
// / \ [no multiline comment] // V \ [no multiline comment]
// loAdd -> ADDE | // loAdd -> ADDC |
// \ :glue / // \ :carry /
// \ / // V V
// ADDC <- hiAdd // ADDE <- hiAdd
// //
assert(AddeNode->getOpcode() == ARMISD::ADDE && "Expect an ADDE"); assert(AddeNode->getOpcode() == ARMISD::ADDE && "Expect an ADDE");
@ -9699,7 +9812,7 @@ static SDValue AddCombineTo64bitMLAL(SDNode *AddeNode,
AddeNode->getOperand(2).getValueType() == MVT::i32 && AddeNode->getOperand(2).getValueType() == MVT::i32 &&
"ADDE node has the wrong inputs"); "ADDE node has the wrong inputs");
// Check that we have a glued ADDC node. // Check that we are chained to the right ADDC node.
SDNode* AddcNode = AddeNode->getOperand(2).getNode(); SDNode* AddcNode = AddeNode->getOperand(2).getNode();
if (AddcNode->getOpcode() != ARMISD::ADDC) if (AddcNode->getOpcode() != ARMISD::ADDC)
return SDValue(); return SDValue();
@ -9750,7 +9863,7 @@ static SDValue AddCombineTo64bitMLAL(SDNode *AddeNode,
SDValue* LoMul = nullptr; SDValue* LoMul = nullptr;
SDValue* LowAdd = nullptr; SDValue* LowAdd = nullptr;
// Ensure that ADDE is from high result of ISD::SMUL_LOHI. // Ensure that ADDE is from high result of ISD::xMUL_LOHI.
if ((AddeOp0 != MULOp.getValue(1)) && (AddeOp1 != MULOp.getValue(1))) if ((AddeOp0 != MULOp.getValue(1)) && (AddeOp1 != MULOp.getValue(1)))
return SDValue(); return SDValue();
@ -9775,6 +9888,12 @@ static SDValue AddCombineTo64bitMLAL(SDNode *AddeNode,
if (!LoMul) if (!LoMul)
return SDValue(); return SDValue();
// If HiAdd is the same node as ADDC or is a predecessor of ADDC the
// replacement below will create a cycle.
if (AddcNode == HiAdd->getNode() ||
AddcNode->isPredecessorOf(HiAdd->getNode()))
return SDValue();
// Create the merged node. // Create the merged node.
SelectionDAG &DAG = DCI.DAG; SelectionDAG &DAG = DCI.DAG;
@ -9877,8 +9996,22 @@ static SDValue PerformUMLALCombine(SDNode *N, SelectionDAG &DAG,
return SDValue(); return SDValue();
} }
static SDValue PerformAddcSubcCombine(SDNode *N, SelectionDAG &DAG, static SDValue PerformAddcSubcCombine(SDNode *N,
TargetLowering::DAGCombinerInfo &DCI,
const ARMSubtarget *Subtarget) { const ARMSubtarget *Subtarget) {
SelectionDAG &DAG(DCI.DAG);
if (N->getOpcode() == ARMISD::ADDC) {
// (ADDC (ADDE 0, 0, C), -1) -> C
SDValue LHS = N->getOperand(0);
SDValue RHS = N->getOperand(1);
if (LHS->getOpcode() == ARMISD::ADDE &&
isNullConstant(LHS->getOperand(0)) &&
isNullConstant(LHS->getOperand(1)) && isAllOnesConstant(RHS)) {
return DCI.CombineTo(N, SDValue(N, 0), LHS->getOperand(2));
}
}
if (Subtarget->isThumb1Only()) { if (Subtarget->isThumb1Only()) {
SDValue RHS = N->getOperand(1); SDValue RHS = N->getOperand(1);
if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(RHS)) { if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(RHS)) {
@ -11767,6 +11900,14 @@ static SDValue PerformExtendCombine(SDNode *N, SelectionDAG &DAG,
return SDValue(); return SDValue();
} }
static const APInt *isPowerOf2Constant(SDValue V) {
ConstantSDNode *C = dyn_cast<ConstantSDNode>(V);
if (!C)
return nullptr;
const APInt *CV = &C->getAPIntValue();
return CV->isPowerOf2() ? CV : nullptr;
}
SDValue ARMTargetLowering::PerformCMOVToBFICombine(SDNode *CMOV, SelectionDAG &DAG) const { SDValue ARMTargetLowering::PerformCMOVToBFICombine(SDNode *CMOV, SelectionDAG &DAG) const {
// If we have a CMOV, OR and AND combination such as: // If we have a CMOV, OR and AND combination such as:
// if (x & CN) // if (x & CN)
@ -11795,8 +11936,8 @@ SDValue ARMTargetLowering::PerformCMOVToBFICombine(SDNode *CMOV, SelectionDAG &D
SDValue And = CmpZ->getOperand(0); SDValue And = CmpZ->getOperand(0);
if (And->getOpcode() != ISD::AND) if (And->getOpcode() != ISD::AND)
return SDValue(); return SDValue();
ConstantSDNode *AndC = dyn_cast<ConstantSDNode>(And->getOperand(1)); const APInt *AndC = isPowerOf2Constant(And->getOperand(1));
if (!AndC || !AndC->getAPIntValue().isPowerOf2()) if (!AndC)
return SDValue(); return SDValue();
SDValue X = And->getOperand(0); SDValue X = And->getOperand(0);
@ -11836,7 +11977,7 @@ SDValue ARMTargetLowering::PerformCMOVToBFICombine(SDNode *CMOV, SelectionDAG &D
SDValue V = Y; SDValue V = Y;
SDLoc dl(X); SDLoc dl(X);
EVT VT = X.getValueType(); EVT VT = X.getValueType();
unsigned BitInX = AndC->getAPIntValue().logBase2(); unsigned BitInX = AndC->logBase2();
if (BitInX != 0) { if (BitInX != 0) {
// We must shift X first. // We must shift X first.
@ -11997,7 +12138,7 @@ SDValue ARMTargetLowering::PerformDAGCombine(SDNode *N,
case ISD::XOR: return PerformXORCombine(N, DCI, Subtarget); case ISD::XOR: return PerformXORCombine(N, DCI, Subtarget);
case ISD::AND: return PerformANDCombine(N, DCI, Subtarget); case ISD::AND: return PerformANDCombine(N, DCI, Subtarget);
case ARMISD::ADDC: case ARMISD::ADDC:
case ARMISD::SUBC: return PerformAddcSubcCombine(N, DCI.DAG, Subtarget); case ARMISD::SUBC: return PerformAddcSubcCombine(N, DCI, Subtarget);
case ARMISD::SUBE: return PerformAddeSubeCombine(N, DCI.DAG, Subtarget); case ARMISD::SUBE: return PerformAddeSubeCombine(N, DCI.DAG, Subtarget);
case ARMISD::BFI: return PerformBFICombine(N, DCI); case ARMISD::BFI: return PerformBFICombine(N, DCI);
case ARMISD::VMOVRRD: return PerformVMOVRRDCombine(N, DCI, Subtarget); case ARMISD::VMOVRRD: return PerformVMOVRRDCombine(N, DCI, Subtarget);
@ -12713,10 +12854,17 @@ void ARMTargetLowering::computeKnownBitsForTargetNode(const SDValue Op,
case ARMISD::ADDE: case ARMISD::ADDE:
case ARMISD::SUBC: case ARMISD::SUBC:
case ARMISD::SUBE: case ARMISD::SUBE:
// These nodes' second result is a boolean // Special cases when we convert a carry to a boolean.
if (Op.getResNo() == 0) if (Op.getResNo() == 0) {
break; SDValue LHS = Op.getOperand(0);
SDValue RHS = Op.getOperand(1);
// (ADDE 0, 0, C) will give us a single bit.
if (Op->getOpcode() == ARMISD::ADDE && isNullConstant(LHS) &&
isNullConstant(RHS)) {
Known.Zero |= APInt::getHighBitsSet(BitWidth, BitWidth - 1); Known.Zero |= APInt::getHighBitsSet(BitWidth, BitWidth - 1);
return;
}
}
break; break;
case ARMISD::CMOV: { case ARMISD::CMOV: {
// Bits are known zero/one if known on the LHS and RHS. // Bits are known zero/one if known on the LHS and RHS.

3
llvm/lib/Target/ARM/ARMISelLowering.h
View File

@ -626,7 +626,8 @@ class InstrItineraryData;
SDValue LowerGlobalTLSAddressWindows(SDValue Op, SelectionDAG &DAG) const; SDValue LowerGlobalTLSAddressWindows(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerGLOBAL_OFFSET_TABLE(SDValue Op, SelectionDAG &DAG) const; SDValue LowerGLOBAL_OFFSET_TABLE(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerBR_JT(SDValue Op, SelectionDAG &DAG) const; SDValue LowerBR_JT(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerXALUO(SDValue Op, SelectionDAG &DAG) const; SDValue LowerSignedALUO(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerUnsignedALUO(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerSELECT(SDValue Op, SelectionDAG &DAG) const; SDValue LowerSELECT(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerSELECT_CC(SDValue Op, SelectionDAG &DAG) const; SDValue LowerSELECT_CC(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerBR_CC(SDValue Op, SelectionDAG &DAG) const; SDValue LowerBR_CC(SDValue Op, SelectionDAG &DAG) const;

88
llvm/test/CodeGen/ARM/intrinsics-overflow.ll
View File

@ -1,4 +1,6 @@
; RUN: llc < %s -mtriple=arm-linux -mcpu=generic | FileCheck %s ; RUN: llc < %s -mtriple=arm-linux -mcpu=generic -verify-machineinstrs | FileCheck %s --check-prefix=CHECK --check-prefix=ARM
; RUN: llc < %s -mtriple=thumbv6m-eabi -verify-machineinstrs | FileCheck %s --check-prefix=CHECK --check-prefix=THUMBV6
; RUN: llc < %s -mtriple=thumbv7-eabi -verify-machineinstrs | FileCheck %s --check-prefix=CHECK --check-prefix=THUMBV7
define i32 @uadd_overflow(i32 %a, i32 %b) #0 { define i32 @uadd_overflow(i32 %a, i32 %b) #0 {
%sadd = tail call { i32, i1 } @llvm.uadd.with.overflow.i32(i32 %a, i32 %b) %sadd = tail call { i32, i1 } @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
@ -7,10 +9,19 @@ define i32 @uadd_overflow(i32 %a, i32 %b) #0 {
ret i32 %2 ret i32 %2
; CHECK-LABEL: uadd_overflow: ; CHECK-LABEL: uadd_overflow:
; CHECK: add r[[R2:[0-9]+]], r[[R0:[0-9]+]], r[[R1:[0-9]+]]
; CHECK: mov r[[R1]], #1 ; ARM: adds r[[R0:[0-9]+]], r[[R0]], r[[R1:[0-9]+]]
; CHECK: cmp r[[R2]], r[[R0]] ; ARM: mov r[[R2:[0-9]+]], #0
; CHECK: movhs r[[R1]], #0 ; ARM: adc r[[R0]], r[[R2]], #0
; THUMBV6: movs r[[R2:[0-9]+]], #0
; THUMBV6: adds r[[R0:[0-9]+]], r[[R0]], r[[R1:[0-9]+]]
; THUMBV6: adcs r[[R2]], r[[R2]]
; THUMBV6: mov r[[R0]], r[[R2]]
; THUMBV7: adds r[[R0:[0-9]+]], r[[R0]], r[[R1:[0-9]+]]
; THUMBV7: mov.w r[[R2:[0-9]+]], #0
; THUMBV7: adc r[[R0]], r[[R2]], #0
} }
@ -21,10 +32,26 @@ define i32 @sadd_overflow(i32 %a, i32 %b) #0 {
ret i32 %2 ret i32 %2
; CHECK-LABEL: sadd_overflow: ; CHECK-LABEL: sadd_overflow:
; CHECK: add r[[R2:[0-9]+]], r[[R0:[0-9]+]], r[[R1:[0-9]+]]
; CHECK: mov r[[R1]], #1 ; ARM: add r[[R2:[0-9]+]], r[[R0:[0-9]+]], r[[R1:[0-9]+]]
; CHECK: cmp r[[R2]], r[[R0]] ; ARM: mov r[[R1]], #1
; CHECK: movvc r[[R1]], #0 ; ARM: cmp r[[R2]], r[[R0]]
; ARM: movvc r[[R1]], #0
; THUMBV6: mov r[[R2:[0-9]+]], r[[R0:[0-9]+]]
; THUMBV6: adds r[[R3:[0-9]+]], r[[R2]], r[[R1:[0-9]+]]
; THUMBV6: movs r[[R0]], #0
; THUMBV6: movs r[[R1]], #1
; THUMBV6: cmp r[[R3]], r[[R2]]
; THUMBV6: bvc .L[[LABEL:.*]]
; THUMBV6: mov r[[R0]], r[[R1]]
; THUMBV6: .L[[LABEL]]:
; THUMBV7: movs r[[R1]], #1
; THUMBV7: cmp r[[R2]], r[[R0]]
; THUMBV7: it vc
; THUMBV7: movvc r[[R1]], #0
; THUMBV7: mov r[[R0]], r[[R1]]
} }
define i32 @usub_overflow(i32 %a, i32 %b) #0 { define i32 @usub_overflow(i32 %a, i32 %b) #0 {
@ -34,9 +61,26 @@ define i32 @usub_overflow(i32 %a, i32 %b) #0 {
ret i32 %2 ret i32 %2
; CHECK-LABEL: usub_overflow: ; CHECK-LABEL: usub_overflow:
; CHECK: mov r[[R2]], #1
; CHECK: cmp r[[R0]], r[[R1]] ; ARM: subs r[[R0:[0-9]+]], r[[R0]], r[[R1:[0-9]+]]
; CHECK: movhs r[[R2]], #0 ; ARM: mov r[[R2:[0-9]+]], #0
; ARM: adc r[[R0]], r[[R2]], #0
; ARM: rsb r[[R0]], r[[R0]], #1
; THUMBV6: movs r[[R2:[0-9]+]], #0
; THUMBV6: subs r[[R0:[0-9]+]], r[[R0]], r[[R1:[0-9]+]]
; THUMBV6: adcs r[[R2]], r[[R2]]
; THUMBV6: movs r[[R0]], #1
; THUMBV6: subs r[[R0]], r[[R0]], r[[R2]]
; THUMBV7: subs r[[R0:[0-9]+]], r[[R0]], r[[R1:[0-9]+]]
; THUMBV7: mov.w r[[R2:[0-9]+]], #0
; THUMBV7: adc r[[R0]], r[[R2]], #0
; THUMBV7: rsb.w r[[R0]], r[[R0]], #1
; We should know that the overflow is just 1 bit,
; no need to clear any other bit
; CHECK-NOT: and
} }
define i32 @ssub_overflow(i32 %a, i32 %b) #0 { define i32 @ssub_overflow(i32 %a, i32 %b) #0 {
@ -46,9 +90,23 @@ define i32 @ssub_overflow(i32 %a, i32 %b) #0 {
ret i32 %2 ret i32 %2
; CHECK-LABEL: ssub_overflow: ; CHECK-LABEL: ssub_overflow:
; CHECK: mov r[[R2]], #1
; CHECK: cmp r[[R0]], r[[R1]] ; ARM: mov r[[R2]], #1
; CHECK: movvc r[[R2]], #0 ; ARM: cmp r[[R0]], r[[R1]]
; ARM: movvc r[[R2]], #0
; THUMBV6: movs r[[R0]], #0
; THUMBV6: movs r[[R3:[0-9]+]], #1
; THUMBV6: cmp r[[R2]], r[[R1:[0-9]+]]
; THUMBV6: bvc .L[[LABEL:.*]]
; THUMBV6: mov r[[R0]], r[[R3]]
; THUMBV6: .L[[LABEL]]:
; THUMBV7: movs r[[R2:[0-9]+]], #1
; THUMBV7: cmp r[[R0:[0-9]+]], r[[R1:[0-9]+]]
; THUMBV7: it vc
; THUMBV7: movvc r[[R2]], #0
; THUMBV7: mov r[[R0]], r[[R2]]
} }
declare { i32, i1 } @llvm.uadd.with.overflow.i32(i32, i32) #1 declare { i32, i1 } @llvm.uadd.with.overflow.i32(i32, i32) #1

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llvm/test/CodeGen/ARM/pr34045-2.ll Normal file
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; RUN: llc < %s -mtriple thumbv7 | FileCheck %s
define hidden void @foo(i32* %ptr, i1 zeroext %long_blocks) {
entry:
; This test is actually checking that no cycle is introduced but at least we
; want to see one umull.
; CHECK: umull
%0 = load i32, i32* %ptr, align 4
%conv.i.i13.i = zext i32 %0 to i64
%mul.i.i14.i = mul nuw nsw i64 %conv.i.i13.i, 18782
%1 = load i32, i32* undef, align 4
%conv4.i.i16.i = zext i32 %1 to i64
%add5.i.i17.i = add nuw nsw i64 %mul.i.i14.i, %conv4.i.i16.i
%shr.i.i18.i = lshr i64 %add5.i.i17.i, 32
%add10.i.i20.i = add nuw nsw i64 %shr.i.i18.i, %add5.i.i17.i
%conv11.i.i21.i = trunc i64 %add10.i.i20.i to i32
%x.0.neg.i.i26.i = sub i32 -2, %conv11.i.i21.i
%sub.i.i27.i = add i32 %x.0.neg.i.i26.i, 0
store i32 %sub.i.i27.i, i32* %ptr, align 4
br label %while.body.i
while.body.i: ; preds = %while.body.i, %entry
br label %while.body.i
}

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; RUN: llc < %s -mtriple thumbv7 | FileCheck %s
; ModuleID = 'bugpoint-reduced-simplified.bc'
define hidden void @bn_mul_comba8(i32* nocapture %r, i32* nocapture readonly %a, i32* nocapture readonly %b) local_unnamed_addr {
entry:
; This test is actually checking that no cycle is introduced but at least we
; want to see a couple of umull and one umlal in the output
; CHECK: umull
; CHECK: umull
; CHECK: umlal
%0 = load i32, i32* %a, align 4
%conv = zext i32 %0 to i64
%1 = load i32, i32* %b, align 4
%conv2 = zext i32 %1 to i64
%mul = mul nuw i64 %conv2, %conv
%shr = lshr i64 %mul, 32
%2 = load i32, i32* %a, align 4
%conv13 = zext i32 %2 to i64
%3 = load i32, i32* undef, align 4
%conv15 = zext i32 %3 to i64
%mul16 = mul nuw i64 %conv15, %conv13
%add18 = add i64 %mul16, %shr
%shr20 = lshr i64 %add18, 32
%conv21 = trunc i64 %shr20 to i32
%4 = load i32, i32* undef, align 4
%conv34 = zext i32 %4 to i64
%5 = load i32, i32* %b, align 4
%conv36 = zext i32 %5 to i64
%mul37 = mul nuw i64 %conv36, %conv34
%conv38 = and i64 %add18, 4294967295
%add39 = add i64 %mul37, %conv38
%shr41 = lshr i64 %add39, 32
%conv42 = trunc i64 %shr41 to i32
%add43 = add i32 %conv42, %conv21
%cmp44 = icmp ult i32 %add43, %conv42
%c1.1 = zext i1 %cmp44 to i32
%add65 = add i32 0, %c1.1
%add86 = add i32 %add65, 0
%add107 = add i32 %add86, 0
%conv124 = zext i32 %add107 to i64
%add125 = add i64 0, %conv124
%conv145 = and i64 %add125, 4294967295
%add146 = add i64 %conv145, 0
%conv166 = and i64 %add146, 4294967295
%add167 = add i64 %conv166, 0
%conv187 = and i64 %add167, 4294967295
%add188 = add i64 %conv187, 0
%conv189 = trunc i64 %add188 to i32
%arrayidx200 = getelementptr inbounds i32, i32* %r, i32 3
store i32 %conv189, i32* %arrayidx200, align 4
ret void
}