Make the implicit inputs and outputs of target-independent
ADDC/ADDE use MVT::i1 (later, whatever it gets legalized to)
instead of MVT::Flag. Remove CARRY_FALSE in favor of 0; adjust
all target-independent code to use this format.
Most targets will still produce a Flag-setting target-dependent
version when selection is done. X86 is converted to use i32
instead, which means TableGen needs to produce different code
in xxxGenDAGISel.inc. This keys off the new supportsHasI1 bit
in xxxInstrInfo, currently set only for X86; in principle this
is temporary and should go away when all other targets have
been converted. All relevant X86 instruction patterns are
modified to represent setting and using EFLAGS explicitly. The
same can be done on other targets.
The immediate behavior change is that an ADC/ADD pair are no
longer tightly coupled in the X86 scheduler; they can be
separated by instructions that don't clobber the flags (MOV).
I will soon add some peephole optimizations based on using
other instructions that set the flags to feed into ADC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72707 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 4c1710d..e1554bf 100644
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -1085,8 +1085,7 @@
// If the flag result is dead, turn this into an ADD.
if (N->hasNUsesOfValue(0, 1))
return CombineTo(N, DAG.getNode(ISD::ADD, N->getDebugLoc(), VT, N1, N0),
- DAG.getNode(ISD::CARRY_FALSE,
- N->getDebugLoc(), MVT::Flag));
+ DAG.getConstant(0, N->getValueType(1)));
// canonicalize constant to RHS.
if (N0C && !N1C)
@@ -1094,10 +1093,9 @@
// fold (addc x, 0) -> x + no carry out
if (N1C && N1C->isNullValue())
- return CombineTo(N, N0, DAG.getNode(ISD::CARRY_FALSE,
- N->getDebugLoc(), MVT::Flag));
+ return CombineTo(N, N0, DAG.getConstant(0, N1.getValueType()));
- // fold (addc a, b) -> (or a, b), CARRY_FALSE iff a and b share no bits.
+ // fold (addc a, b) -> (or a, b), 0 iff a and b share no bits.
APInt LHSZero, LHSOne;
APInt RHSZero, RHSOne;
APInt Mask = APInt::getAllOnesValue(VT.getSizeInBits());
@@ -1111,8 +1109,7 @@
if ((RHSZero & (~LHSZero & Mask)) == (~LHSZero & Mask) ||
(LHSZero & (~RHSZero & Mask)) == (~RHSZero & Mask))
return CombineTo(N, DAG.getNode(ISD::OR, N->getDebugLoc(), VT, N0, N1),
- DAG.getNode(ISD::CARRY_FALSE,
- N->getDebugLoc(), MVT::Flag));
+ DAG.getConstant(0, N1.getValueType()));
}
return SDValue();
@@ -1131,8 +1128,9 @@
N1, N0, CarryIn);
// fold (adde x, y, false) -> (addc x, y)
- if (CarryIn.getOpcode() == ISD::CARRY_FALSE)
- return DAG.getNode(ISD::ADDC, N->getDebugLoc(), N->getVTList(), N1, N0);
+ if (ConstantSDNode *N2C = dyn_cast<ConstantSDNode>(CarryIn))
+ if (N2C->getAPIntValue()==0)
+ return DAG.getNode(ISD::ADDC, N->getDebugLoc(), N->getVTList(), N1, N0);
return SDValue();
}
diff --git a/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp b/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp
index eb9342c..a8d8b7d 100644
--- a/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp
+++ b/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp
@@ -98,6 +98,10 @@
case ISD::USUBO: Res = PromoteIntRes_UADDSUBO(N, ResNo); break;
case ISD::SMULO:
case ISD::UMULO: Res = PromoteIntRes_XMULO(N, ResNo); break;
+ case ISD::ADDC:
+ case ISD::SUBC: Res = PromoteIntRes_ADDSUBC(N, ResNo); break;
+ case ISD::ADDE:
+ case ISD::SUBE: Res = PromoteIntRes_ADDSUBE(N, ResNo); break;
case ISD::ATOMIC_LOAD_ADD:
case ISD::ATOMIC_LOAD_SUB:
@@ -121,6 +125,35 @@
SetPromotedInteger(SDValue(N, ResNo), Res);
}
+SDValue DAGTypeLegalizer::PromoteIntRes_ADDSUBC(SDNode *N, unsigned ResNo) {
+ // Only the carry bit result is expected to be promoted.
+ assert(ResNo == 1 && "Only carry bit result promotion currently supported!");
+ return PromoteIntRes_Overflow(N);
+}
+
+SDValue DAGTypeLegalizer::PromoteIntRes_ADDSUBE(SDNode *N, unsigned ResNo) {
+ // Only the carry bit result is expected to be promoted.
+ assert(ResNo == 1 && "Only carry bit result promotion currently supported!");
+ // This is a ternary operator, so clone a slightly modified
+ // PromoteIntRes_Overflow here (this is the only client).
+ if (ResNo == 1) {
+ // Simply change the return type of the boolean result.
+ MVT NVT = TLI.getTypeToTransformTo(N->getValueType(1));
+ MVT ValueVTs[] = { N->getValueType(0), NVT };
+ SDValue Ops[] = { N->getOperand(0), N->getOperand(1), N->getOperand(2) };
+ SDValue Res = DAG.getNode(N->getOpcode(), N->getDebugLoc(),
+ DAG.getVTList(ValueVTs, 2), Ops, 3);
+
+ // Modified the sum result - switch anything that used the old sum to use
+ // the new one.
+ ReplaceValueWith(SDValue(N, 0), Res);
+
+ return SDValue(Res.getNode(), 1);
+ }
+ assert(0 && "Do not know how to promote this operator!");
+ abort();
+}
+
SDValue DAGTypeLegalizer::PromoteIntRes_AssertSext(SDNode *N) {
// Sign-extend the new bits, and continue the assertion.
SDValue Op = SExtPromotedInteger(N->getOperand(0));
@@ -419,7 +452,7 @@
return Res;
}
-/// Promote the overflow flag of an overflowing arithmetic node.
+/// Promote the overflow or carry result of an overflowing arithmetic node.
SDValue DAGTypeLegalizer::PromoteIntRes_Overflow(SDNode *N) {
// Simply change the return type of the boolean result.
MVT NVT = TLI.getTypeToTransformTo(N->getValueType(1));
@@ -666,6 +699,8 @@
assert(0 && "Do not know how to promote this operator's operand!");
abort();
+ case ISD::ADDE:
+ case ISD::SUBE: Res = PromoteIntOp_ADDSUBE(N, OpNo); break;
case ISD::ANY_EXTEND: Res = PromoteIntOp_ANY_EXTEND(N); break;
case ISD::BIT_CONVERT: Res = PromoteIntOp_BIT_CONVERT(N); break;
case ISD::BR_CC: Res = PromoteIntOp_BR_CC(N, OpNo); break;
@@ -743,6 +778,13 @@
}
}
+SDValue DAGTypeLegalizer::PromoteIntOp_ADDSUBE(SDNode *N, unsigned OpNo) {
+ assert(OpNo == 2 && "Don't know how to promote this operand!");
+ return DAG.UpdateNodeOperands(SDValue(N, 0), N->getOperand(0),
+ N->getOperand(1),
+ GetPromotedInteger(N->getOperand(2)));
+}
+
SDValue DAGTypeLegalizer::PromoteIntOp_ANY_EXTEND(SDNode *N) {
SDValue Op = GetPromotedInteger(N->getOperand(0));
return DAG.getNode(ISD::ANY_EXTEND, N->getDebugLoc(), N->getValueType(0), Op);
@@ -1063,7 +1105,7 @@
TLI.isOperationLegalOrCustom(ISD::ADDC,
TLI.getTypeToExpandTo(NVT))) {
// Emit this X << 1 as X+X.
- SDVTList VTList = DAG.getVTList(NVT, MVT::Flag);
+ SDVTList VTList = DAG.getVTList(NVT, MVT::i1);
SDValue LoOps[2] = { InL, InL };
Lo = DAG.getNode(ISD::ADDC, dl, VTList, LoOps, 2);
SDValue HiOps[3] = { InH, InH, Lo.getValue(1) };
@@ -1299,7 +1341,7 @@
TLI.getTypeToExpandTo(NVT));
if (hasCarry) {
- SDVTList VTList = DAG.getVTList(NVT, MVT::Flag);
+ SDVTList VTList = DAG.getVTList(NVT, MVT::i1);
if (N->getOpcode() == ISD::ADD) {
Lo = DAG.getNode(ISD::ADDC, dl, VTList, LoOps, 2);
HiOps[2] = Lo.getValue(1);
@@ -1344,7 +1386,7 @@
DebugLoc dl = N->getDebugLoc();
GetExpandedInteger(N->getOperand(0), LHSL, LHSH);
GetExpandedInteger(N->getOperand(1), RHSL, RHSH);
- SDVTList VTList = DAG.getVTList(LHSL.getValueType(), MVT::Flag);
+ SDVTList VTList = DAG.getVTList(LHSL.getValueType(), MVT::i1);
SDValue LoOps[2] = { LHSL, RHSL };
SDValue HiOps[3] = { LHSH, RHSH };
@@ -1358,8 +1400,8 @@
Hi = DAG.getNode(ISD::SUBE, dl, VTList, HiOps, 3);
}
- // Legalized the flag result - switch anything that used the old flag to
- // use the new one.
+ // Legalized the second result (carry bit) - switch anything that used the
+ // result to use the new one.
ReplaceValueWith(SDValue(N, 1), Hi.getValue(1));
}
@@ -1370,7 +1412,7 @@
DebugLoc dl = N->getDebugLoc();
GetExpandedInteger(N->getOperand(0), LHSL, LHSH);
GetExpandedInteger(N->getOperand(1), RHSL, RHSH);
- SDVTList VTList = DAG.getVTList(LHSL.getValueType(), MVT::Flag);
+ SDVTList VTList = DAG.getVTList(LHSL.getValueType(), MVT::i1);
SDValue LoOps[3] = { LHSL, RHSL, N->getOperand(2) };
SDValue HiOps[3] = { LHSH, RHSH };
@@ -1378,8 +1420,8 @@
HiOps[2] = Lo.getValue(1);
Hi = DAG.getNode(N->getOpcode(), dl, VTList, HiOps, 3);
- // Legalized the flag result - switch anything that used the old flag to
- // use the new one.
+ // Legalized the second result (carry bit) - switch anything that used the
+ // result to use the new one.
ReplaceValueWith(SDValue(N, 1), Hi.getValue(1));
}
diff --git a/lib/CodeGen/SelectionDAG/LegalizeTypes.h b/lib/CodeGen/SelectionDAG/LegalizeTypes.h
index 75c8924..9488b49 100644
--- a/lib/CodeGen/SelectionDAG/LegalizeTypes.h
+++ b/lib/CodeGen/SelectionDAG/LegalizeTypes.h
@@ -242,6 +242,8 @@
// Integer Result Promotion.
void PromoteIntegerResult(SDNode *N, unsigned ResNo);
+ SDValue PromoteIntRes_ADDSUBC(SDNode *N, unsigned ResNo);
+ SDValue PromoteIntRes_ADDSUBE(SDNode *N, unsigned ResNo);
SDValue PromoteIntRes_AssertSext(SDNode *N);
SDValue PromoteIntRes_AssertZext(SDNode *N);
SDValue PromoteIntRes_Atomic1(AtomicSDNode *N);
@@ -278,6 +280,7 @@
// Integer Operand Promotion.
bool PromoteIntegerOperand(SDNode *N, unsigned OperandNo);
+ SDValue PromoteIntOp_ADDSUBE(SDNode *N, unsigned OpNo);
SDValue PromoteIntOp_ANY_EXTEND(SDNode *N);
SDValue PromoteIntOp_BIT_CONVERT(SDNode *N);
SDValue PromoteIntOp_BUILD_PAIR(SDNode *N);
diff --git a/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp b/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp
index 7aa15bc..e509372 100644
--- a/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp
+++ b/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp
@@ -268,6 +268,13 @@
unsigned N = Node->getNumOperands();
while (N && Node->getOperand(N - 1).getValueType() == MVT::Flag)
--N;
+ // Skip hard registers set as a side effect (i.e. not result 0).
+ while (N && Node->getOperand(N - 1).getOpcode() == ISD::CopyToReg &&
+ Node->getOperand(N-1).getResNo() != 0 &&
+ !TargetRegisterInfo::isVirtualRegister(
+ dyn_cast<RegisterSDNode>(Node->getOperand(N-1).getOperand(1))
+ ->getReg()))
+ --N;
if (N && Node->getOperand(N - 1).getValueType() == MVT::Other)
--N; // Ignore chain if it exists.
return N;
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index 195896e..279c5ca 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -5257,7 +5257,6 @@
case ISD::EXTRACT_SUBVECTOR: return "extract_subvector";
case ISD::SCALAR_TO_VECTOR: return "scalar_to_vector";
case ISD::VECTOR_SHUFFLE: return "vector_shuffle";
- case ISD::CARRY_FALSE: return "carry_false";
case ISD::ADDC: return "addc";
case ISD::ADDE: return "adde";
case ISD::SADDO: return "saddo";