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Revert "[ConstraintElimination] Add eq/ne facts to signed constraint system (llvm#121423)" (llvm#3144)
2 parents 133130d + d11f6b5 commit a74b2f2

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4 files changed

+13
-83
lines changed

4 files changed

+13
-83
lines changed

‎llvm/lib/Transforms/Scalar/ConstraintElimination.cpp‎

Lines changed: 7 additions & 30 deletions
Original file line numberDiff line numberDiff line change
@@ -313,8 +313,7 @@ class ConstraintInfo {
313313
/// New variables that need to be added to the system are collected in
314314
/// \p NewVariables.
315315
ConstraintTy getConstraint(CmpInst::Predicate Pred, Value *Op0, Value *Op1,
316-
SmallVectorImpl<Value *> &NewVariables,
317-
bool ForceSignedSystem = false) const;
316+
SmallVectorImpl<Value *> &NewVariables) const;
318317

319318
/// Turns a comparison of the form \p Op0 \p Pred \p Op1 into a vector of
320319
/// constraints using getConstraint. Returns an empty constraint if the result
@@ -331,14 +330,6 @@ class ConstraintInfo {
331330
void transferToOtherSystem(CmpInst::Predicate Pred, Value *A, Value *B,
332331
unsigned NumIn, unsigned NumOut,
333332
SmallVectorImpl<StackEntry> &DFSInStack);
334-
335-
private:
336-
/// Adds facts into constraint system. \p ForceSignedSystem can be set when
337-
/// the \p Pred is eq/ne, and signed constraint system is used when it's
338-
/// specified.
339-
void addFactImpl(CmpInst::Predicate Pred, Value *A, Value *B, unsigned NumIn,
340-
unsigned NumOut, SmallVectorImpl<StackEntry> &DFSInStack,
341-
bool ForceSignedSystem);
342333
};
343334

344335
/// Represents a (Coefficient * Variable) entry after IR decomposition.
@@ -645,12 +636,8 @@ static Decomposition decompose(Value *V,
645636

646637
ConstraintTy
647638
ConstraintInfo::getConstraint(CmpInst::Predicate Pred, Value *Op0, Value *Op1,
648-
SmallVectorImpl<Value *> &NewVariables,
649-
bool ForceSignedSystem) const {
639+
SmallVectorImpl<Value *> &NewVariables) const {
650640
assert(NewVariables.empty() && "NewVariables must be empty when passed in");
651-
assert((!ForceSignedSystem || CmpInst::isEquality(Pred)) &&
652-
"signed system can only be forced on eq/ne");
653-
654641
bool IsEq = false;
655642
bool IsNe = false;
656643

@@ -665,15 +652,15 @@ ConstraintInfo::getConstraint(CmpInst::Predicate Pred, Value *Op0, Value *Op1,
665652
break;
666653
}
667654
case CmpInst::ICMP_EQ:
668-
if (!ForceSignedSystem && match(Op1, m_Zero())) {
655+
if (match(Op1, m_Zero())) {
669656
Pred = CmpInst::ICMP_ULE;
670657
} else {
671658
IsEq = true;
672659
Pred = CmpInst::ICMP_ULE;
673660
}
674661
break;
675662
case CmpInst::ICMP_NE:
676-
if (!ForceSignedSystem && match(Op1, m_Zero())) {
663+
if (match(Op1, m_Zero())) {
677664
Pred = CmpInst::getSwappedPredicate(CmpInst::ICMP_UGT);
678665
std::swap(Op0, Op1);
679666
} else {
@@ -690,7 +677,7 @@ ConstraintInfo::getConstraint(CmpInst::Predicate Pred, Value *Op0, Value *Op1,
690677
return {};
691678

692679
SmallVector<ConditionTy, 4> Preconditions;
693-
bool IsSigned = ForceSignedSystem || CmpInst::isSigned(Pred);
680+
bool IsSigned = CmpInst::isSigned(Pred);
694681
auto &Value2Index = getValue2Index(IsSigned);
695682
auto ADec = decompose(Op0->stripPointerCastsSameRepresentation(),
696683
Preconditions, IsSigned, DL);
@@ -750,7 +737,7 @@ ConstraintInfo::getConstraint(CmpInst::Predicate Pred, Value *Op0, Value *Op1,
750737
int64_t OffsetSum;
751738
if (AddOverflow(Offset1, Offset2, OffsetSum))
752739
return {};
753-
if (Pred == CmpInst::ICMP_SLT || Pred == CmpInst::ICMP_ULT)
740+
if (Pred == (IsSigned ? CmpInst::ICMP_SLT : CmpInst::ICMP_ULT))
754741
if (AddOverflow(OffsetSum, int64_t(-1), OffsetSum))
755742
return {};
756743
R[0] = OffsetSum;
@@ -1593,20 +1580,10 @@ static bool checkOrAndOpImpliedByOther(
15931580
void ConstraintInfo::addFact(CmpInst::Predicate Pred, Value *A, Value *B,
15941581
unsigned NumIn, unsigned NumOut,
15951582
SmallVectorImpl<StackEntry> &DFSInStack) {
1596-
addFactImpl(Pred, A, B, NumIn, NumOut, DFSInStack, false);
1597-
// If the Pred is eq/ne, also add the fact to signed system.
1598-
if (CmpInst::isEquality(Pred))
1599-
addFactImpl(Pred, A, B, NumIn, NumOut, DFSInStack, true);
1600-
}
1601-
1602-
void ConstraintInfo::addFactImpl(CmpInst::Predicate Pred, Value *A, Value *B,
1603-
unsigned NumIn, unsigned NumOut,
1604-
SmallVectorImpl<StackEntry> &DFSInStack,
1605-
bool ForceSignedSystem) {
16061583
// If the constraint has a pre-condition, skip the constraint if it does not
16071584
// hold.
16081585
SmallVector<Value *> NewVariables;
1609-
auto R = getConstraint(Pred, A, B, NewVariables, ForceSignedSystem);
1586+
auto R = getConstraint(Pred, A, B, NewVariables);
16101587

16111588
// TODO: Support non-equality for facts as well.
16121589
if (!R.isValid(*this) || R.isNe())

‎llvm/test/Transforms/ConstraintElimination/eq.ll‎

Lines changed: 0 additions & 50 deletions
Original file line numberDiff line numberDiff line change
@@ -424,53 +424,3 @@ bc_equal:
424424
not_eq:
425425
ret i1 false
426426
}
427-
428-
define i1 @test_eq_for_signed_cmp(i32 noundef %v0, i32 noundef %v1, i32 noundef %v2) {
429-
; CHECK-LABEL: @test_eq_for_signed_cmp(
430-
; CHECK-NEXT: entry:
431-
; CHECK-NEXT: [[CMP:%.*]] = icmp eq i32 [[V2:%.*]], [[V0:%.*]]
432-
; CHECK-NEXT: [[CMP1:%.*]] = icmp sge i32 [[V0]], [[V1:%.*]]
433-
; CHECK-NEXT: [[AND0:%.*]] = and i1 [[CMP1]], [[CMP]]
434-
; CHECK-NEXT: [[CMP4:%.*]] = icmp sgt i32 [[V1]], [[V2]]
435-
; CHECK-NEXT: [[AND1:%.*]] = and i1 false, [[AND0]]
436-
; CHECK-NEXT: ret i1 [[AND1]]
437-
;
438-
entry:
439-
%cmp = icmp eq i32 %v2, %v0
440-
%cmp1 = icmp sge i32 %v0, %v1
441-
%and0 = and i1 %cmp1, %cmp
442-
%cmp4 = icmp sgt i32 %v1, %v2
443-
%and1 = and i1 %cmp4, %and0
444-
ret i1 %and1
445-
}
446-
447-
define i1 @test_eq_for_signed_cmp_with_decompsition(i32 noundef %v0, i32 noundef %v1, i32 noundef %v2, i32 noundef %addend0, i32 noundef %addend1) {
448-
; CHECK-LABEL: @test_eq_for_signed_cmp_with_decompsition(
449-
; CHECK-NEXT: entry:
450-
; CHECK-NEXT: [[V0ADD:%.*]] = add nsw i32 [[V0:%.*]], [[ADDEND0:%.*]]
451-
; CHECK-NEXT: [[V1ADD:%.*]] = add nsw i32 [[V1:%.*]], [[ADDEND1:%.*]]
452-
; CHECK-NEXT: [[CMP:%.*]] = icmp eq i32 [[V2:%.*]], [[V0ADD]]
453-
; CHECK-NEXT: [[CMP1:%.*]] = icmp sge i32 [[V0ADD]], [[V1ADD]]
454-
; CHECK-NEXT: [[CMP2:%.*]] = icmp sge i32 [[ADDEND0]], 0
455-
; CHECK-NEXT: [[CMP3:%.*]] = icmp slt i32 [[ADDEND0]], [[ADDEND1]]
456-
; CHECK-NEXT: [[AND0:%.*]] = and i1 [[CMP1]], [[CMP]]
457-
; CHECK-NEXT: [[AND1:%.*]] = and i1 [[AND0]], [[CMP2]]
458-
; CHECK-NEXT: [[AND2:%.*]] = and i1 [[AND1]], [[CMP3]]
459-
; CHECK-NEXT: [[CMP4:%.*]] = icmp sgt i32 [[V1]], [[V2]]
460-
; CHECK-NEXT: [[AND3:%.*]] = and i1 false, [[AND2]]
461-
; CHECK-NEXT: ret i1 [[AND3]]
462-
;
463-
entry:
464-
%v0add = add nsw i32 %v0, %addend0
465-
%v1add = add nsw i32 %v1, %addend1
466-
%cmp = icmp eq i32 %v2, %v0add
467-
%cmp1 = icmp sge i32 %v0add, %v1add
468-
%cmp2 = icmp sge i32 %addend0, 0
469-
%cmp3 = icmp slt i32 %addend0, %addend1
470-
%and0 = and i1 %cmp1, %cmp
471-
%and1 = and i1 %and0, %cmp2
472-
%and2 = and i1 %and1, %cmp3
473-
%cmp4 = icmp sgt i32 %v1, %v2
474-
%and3 = and i1 %cmp4, %and2
475-
ret i1 %and3
476-
}

‎llvm/test/Transforms/ConstraintElimination/ne.ll‎

Lines changed: 4 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -71,7 +71,8 @@ define i1 @test_ne_eq_0(i8 %a, i8 %b) {
7171
; CHECK-NEXT: [[RES_13:%.*]] = xor i1 [[RES_12]], false
7272
; CHECK-NEXT: [[RES_14:%.*]] = xor i1 [[RES_13]], false
7373
; CHECK-NEXT: [[RES_15:%.*]] = xor i1 [[RES_14]], false
74-
; CHECK-NEXT: [[RES_16:%.*]] = xor i1 [[RES_15]], false
74+
; CHECK-NEXT: [[C_12:%.*]] = icmp sgt i8 [[A]], 0
75+
; CHECK-NEXT: [[RES_16:%.*]] = xor i1 [[RES_15]], [[C_12]]
7576
; CHECK-NEXT: ret i1 [[RES_16]]
7677
;
7778
entry:
@@ -208,7 +209,8 @@ define i1 @test_ne_eq_1(i8 %a, i8 %b) {
208209
; CHECK-NEXT: [[RES_13:%.*]] = xor i1 [[RES_12]], true
209210
; CHECK-NEXT: [[RES_14:%.*]] = xor i1 [[RES_13]], true
210211
; CHECK-NEXT: [[RES_15:%.*]] = xor i1 [[RES_14]], false
211-
; CHECK-NEXT: [[RES_16:%.*]] = xor i1 [[RES_15]], true
212+
; CHECK-NEXT: [[C_12:%.*]] = icmp sgt i8 [[A]], 0
213+
; CHECK-NEXT: [[RES_16:%.*]] = xor i1 [[RES_15]], [[C_12]]
212214
; CHECK-NEXT: ret i1 [[RES_16]]
213215
;
214216
entry:

‎llvm/test/Transforms/ConstraintElimination/pr105785.ll‎

Lines changed: 2 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -15,7 +15,8 @@ define void @pr105785(ptr %p) {
1515
; CHECK-NEXT: [[CMP2:%.*]] = icmp ult i32 [[FOR_IND2]], 3
1616
; CHECK-NEXT: br i1 [[CMP2]], label %[[FOR_BODY3]], label %[[FOR_COND]]
1717
; CHECK: [[FOR_BODY3]]:
18-
; CHECK-NEXT: store i32 -1, ptr [[P]], align 4
18+
; CHECK-NEXT: [[SCMP:%.*]] = call i32 @llvm.scmp.i32.i32(i32 [[FOR_IND]], i32 1)
19+
; CHECK-NEXT: store i32 [[SCMP]], ptr [[P]], align 4
1920
; CHECK-NEXT: [[INC]] = add nuw nsw i32 [[FOR_IND2]], 1
2021
; CHECK-NEXT: br label %[[FOR_COND1]]
2122
; CHECK: [[FOR_END6]]:

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