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ValueTracking: Recognize fcmp ole/ugt with inf as a class test #79095

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merged 4 commits into from
Jan 23, 2024
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ValueTracking: Recognize fcmp ole/ugt with inf as a class test #79095

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bf92d79
ValueTracking: Recognize fcmp ole/ugt with inf as a class test
arsenm Jan 23, 2024
a6e7d38
Fix neginf
arsenm Jan 23, 2024
fb8bc7c
Fix unit test
arsenm Jan 23, 2024
2647890
Fix test update split
arsenm Jan 23, 2024
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18 changes: 16 additions & 2 deletions llvm/lib/Analysis/ValueTracking.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -4065,7 +4065,7 @@ llvm::fcmpToClassTest(FCmpInst::Predicate Pred, const Function &F, Value *LHS,
case FCmpInst::FCMP_ULE: // isnan(x) || x <= 0
return {LHS, fcNegative | fcPosZero | fcNan};
default:
break;
llvm_unreachable("all compare types are handled");
}

return {nullptr, fcAllFlags};
Expand Down Expand Up @@ -4184,8 +4184,22 @@ llvm::fcmpToClassTest(FCmpInst::Predicate Pred, const Function &F, Value *LHS,
Mask = fcNone;
break;
}
case FCmpInst::FCMP_OLE:
case FCmpInst::FCMP_UGT: {
if (ConstRHS->isNegative()) {
Mask = IsFabs ? fcNone : fcNegInf;
break;
}

// fcmp ole x, +inf -> fcmp ord x, x
// fcmp ole fabs(x), +inf -> fcmp ord x, x
// fcmp ole x, -inf -> fcmp oeq x, -inf
// fcmp ole fabs(x), -inf -> false
Mask = ~fcNan;
break;
}
default:
return {nullptr, fcAllFlags};
llvm_unreachable("all compare types are handled");
}
} else if (ConstRHS->isSmallestNormalized() && !ConstRHS->isNegative()) {
// Match pattern that's used in __builtin_isnormal.
Expand Down
28 changes: 14 additions & 14 deletions llvm/test/Transforms/Attributor/nofpclass-implied-by-fcmp.ll
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Expand Up @@ -2400,8 +2400,8 @@ define float @assume_oeq_smallest_normal_known_pos(float nofpclass(ninf nsub nno
;---------------------------------------------------------------------

define float @assume_ole_pinf(float %arg) {
; CHECK-LABEL: define float @assume_ole_pinf(
; CHECK-SAME: float returned [[ARG:%.*]]) #[[ATTR3]] {
; CHECK-LABEL: define nofpclass(nan) float @assume_ole_pinf(
; CHECK-SAME: float returned nofpclass(nan) [[ARG:%.*]]) #[[ATTR3]] {
; CHECK-NEXT: [[FCMP:%.*]] = fcmp ole float [[ARG]], 0x7FF0000000000000
; CHECK-NEXT: call void @llvm.assume(i1 noundef [[FCMP]]) #[[ATTR5]]
; CHECK-NEXT: ret float [[ARG]]
Expand All @@ -2412,8 +2412,8 @@ define float @assume_ole_pinf(float %arg) {
}

define float @assume_ole_ninf(float %arg) {
; CHECK-LABEL: define float @assume_ole_ninf(
; CHECK-SAME: float returned [[ARG:%.*]]) #[[ATTR3]] {
; CHECK-LABEL: define nofpclass(nan pinf zero sub norm) float @assume_ole_ninf(
; CHECK-SAME: float returned nofpclass(nan pinf zero sub norm) [[ARG:%.*]]) #[[ATTR3]] {
; CHECK-NEXT: [[FCMP:%.*]] = fcmp ole float [[ARG]], 0xFFF0000000000000
; CHECK-NEXT: call void @llvm.assume(i1 noundef [[FCMP]]) #[[ATTR5]]
; CHECK-NEXT: ret float [[ARG]]
Expand All @@ -2424,8 +2424,8 @@ define float @assume_ole_ninf(float %arg) {
}

define float @assume_ugt_pinf(float %arg) {
; CHECK-LABEL: define float @assume_ugt_pinf(
; CHECK-SAME: float returned [[ARG:%.*]]) #[[ATTR3]] {
; CHECK-LABEL: define nofpclass(inf zero sub norm) float @assume_ugt_pinf(
; CHECK-SAME: float returned nofpclass(inf zero sub norm) [[ARG:%.*]]) #[[ATTR3]] {
; CHECK-NEXT: [[FCMP:%.*]] = fcmp ugt float [[ARG]], 0x7FF0000000000000
; CHECK-NEXT: call void @llvm.assume(i1 noundef [[FCMP]]) #[[ATTR5]]
; CHECK-NEXT: ret float [[ARG]]
Expand All @@ -2436,8 +2436,8 @@ define float @assume_ugt_pinf(float %arg) {
}

define float @assume_ugt_ninf(float %arg) {
; CHECK-LABEL: define float @assume_ugt_ninf(
; CHECK-SAME: float returned [[ARG:%.*]]) #[[ATTR3]] {
; CHECK-LABEL: define nofpclass(ninf) float @assume_ugt_ninf(
; CHECK-SAME: float returned nofpclass(ninf) [[ARG:%.*]]) #[[ATTR3]] {
; CHECK-NEXT: [[FCMP:%.*]] = fcmp ugt float [[ARG]], 0xFFF0000000000000
; CHECK-NEXT: call void @llvm.assume(i1 noundef [[FCMP]]) #[[ATTR5]]
; CHECK-NEXT: ret float [[ARG]]
Expand All @@ -2448,8 +2448,8 @@ define float @assume_ugt_ninf(float %arg) {
}

define float @assume_fabs_ole_pinf(float %arg) {
; CHECK-LABEL: define nofpclass(ninf nzero nsub nnorm) float @assume_fabs_ole_pinf(
; CHECK-SAME: float returned nofpclass(ninf nzero nsub nnorm) [[ARG:%.*]]) #[[ATTR3]] {
; CHECK-LABEL: define nofpclass(nan ninf nzero nsub nnorm) float @assume_fabs_ole_pinf(
; CHECK-SAME: float returned nofpclass(nan ninf nzero nsub nnorm) [[ARG:%.*]]) #[[ATTR3]] {
; CHECK-NEXT: [[FABS:%.*]] = call float @llvm.fabs.f32(float [[ARG]]) #[[ATTR4]]
; CHECK-NEXT: [[FCMP:%.*]] = fcmp ole float [[FABS]], 0x7FF0000000000000
; CHECK-NEXT: call void @llvm.assume(i1 noundef [[FCMP]]) #[[ATTR5]]
Expand All @@ -2462,8 +2462,8 @@ define float @assume_fabs_ole_pinf(float %arg) {
}

define float @assume_fabs_ole_ninf(float %arg) {
; CHECK-LABEL: define nofpclass(ninf nzero nsub nnorm) float @assume_fabs_ole_ninf(
; CHECK-SAME: float returned nofpclass(ninf nzero nsub nnorm) [[ARG:%.*]]) #[[ATTR3]] {
; CHECK-LABEL: define nofpclass(all) float @assume_fabs_ole_ninf(
; CHECK-SAME: float returned nofpclass(all) [[ARG:%.*]]) #[[ATTR3]] {
; CHECK-NEXT: call void @llvm.assume(i1 noundef false) #[[ATTR5]]
; CHECK-NEXT: ret float [[ARG]]
;
Expand All @@ -2474,8 +2474,8 @@ define float @assume_fabs_ole_ninf(float %arg) {
}

define float @assume_fabs_ugt_pinf(float %arg) {
; CHECK-LABEL: define nofpclass(ninf nzero nsub nnorm) float @assume_fabs_ugt_pinf(
; CHECK-SAME: float returned nofpclass(ninf nzero nsub nnorm) [[ARG:%.*]]) #[[ATTR3]] {
; CHECK-LABEL: define nofpclass(inf zero sub norm) float @assume_fabs_ugt_pinf(
; CHECK-SAME: float returned nofpclass(inf zero sub norm) [[ARG:%.*]]) #[[ATTR3]] {
; CHECK-NEXT: [[FABS:%.*]] = call float @llvm.fabs.f32(float [[ARG]]) #[[ATTR4]]
; CHECK-NEXT: [[FCMP:%.*]] = fcmp ugt float [[FABS]], 0x7FF0000000000000
; CHECK-NEXT: call void @llvm.assume(i1 noundef [[FCMP]]) #[[ATTR5]]
Expand Down
5 changes: 1 addition & 4 deletions llvm/test/Transforms/InstCombine/and-fcmp.ll
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Expand Up @@ -4820,10 +4820,7 @@ define i1 @clang_builtin_isnormal_inf_check_olt(half %x) {

define i1 @clang_builtin_isnormal_inf_check_ole(half %x) {
; CHECK-LABEL: @clang_builtin_isnormal_inf_check_ole(
; CHECK-NEXT: [[FABS_X:%.*]] = call half @llvm.fabs.f16(half [[X:%.*]])
; CHECK-NEXT: [[ORD:%.*]] = fcmp ord half [[X]], 0xH0000
; CHECK-NEXT: [[CMP:%.*]] = fcmp ole half [[FABS_X]], 0xH7C00
; CHECK-NEXT: [[AND:%.*]] = and i1 [[ORD]], [[CMP]]
; CHECK-NEXT: [[AND:%.*]] = fcmp ord half [[X:%.*]], 0xH0000
; CHECK-NEXT: ret i1 [[AND]]
;
%fabs.x = call half @llvm.fabs.f16(half %x)
Expand Down
8 changes: 4 additions & 4 deletions llvm/unittests/Analysis/ValueTrackingTest.cpp
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Expand Up @@ -1945,14 +1945,14 @@ TEST_F(ComputeKnownFPClassTest, FCmpToClassTest_PInf) {
auto [OleVal, OleClass] =
fcmpToClassTest(CmpInst::FCMP_OLE, *A3->getFunction(), A3->getOperand(0),
A3->getOperand(1));
EXPECT_EQ(nullptr, OleVal);
EXPECT_EQ(fcAllFlags, OleClass);
EXPECT_EQ(A->getOperand(0), OleVal);
EXPECT_EQ(~fcNan, OleClass);

auto [UgtVal, UgtClass] =
fcmpToClassTest(CmpInst::FCMP_UGT, *A4->getFunction(), A4->getOperand(0),
A4->getOperand(1));
EXPECT_EQ(nullptr, UgtVal);
EXPECT_EQ(fcAllFlags, UgtClass);
EXPECT_EQ(A4->getOperand(0), UgtVal);
EXPECT_EQ(fcNan, UgtClass);
}

TEST_F(ComputeKnownFPClassTest, SqrtNszSignBit) {
Expand Down