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Revert "ValueTracking: Fix nan result handling for fmul"
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This reverts commit a632ca4.

Dependent commit to be reverted
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@aeubanks
aeubanks committed Jun 16, 2023
1 parent 95d3fd9 commit 464dcab
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Showing 4 changed files with 27 additions and 40 deletions.
41 changes: 17 additions & 24 deletions llvm/lib/Analysis/ValueTracking.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -4760,36 +4760,29 @@ void computeKnownFPClass(const Value *V, const APInt &DemandedElts,
if ((InterestedClasses & fcNan) != fcNan)
break;

// fcSubnormal is only needed in case of DAZ.
const FPClassTest NeedForNan = fcNan | fcInf | fcZero | fcSubnormal;

KnownFPClass KnownLHS, KnownRHS;
computeKnownFPClass(Op->getOperand(1), DemandedElts, NeedForNan, KnownRHS,
computeKnownFPClass(Op->getOperand(1), DemandedElts,
fcNan | fcInf | fcZero | fcSubnormal, KnownRHS,
Depth + 1, Q);
if (!KnownRHS.isKnownNeverNaN())
break;
if (KnownRHS.isKnownNeverNaN() &&
(KnownRHS.isKnownNeverInfinity() || KnownRHS.isKnownNeverZero())) {
computeKnownFPClass(Op->getOperand(0), DemandedElts,
fcNan | fcInf | fcZero, KnownLHS, Depth + 1, Q);
if (!KnownLHS.isKnownNeverNaN())
break;

computeKnownFPClass(Op->getOperand(0), DemandedElts, NeedForNan, KnownLHS,
Depth + 1, Q);
if (!KnownLHS.isKnownNeverNaN())
break;
const Function *F = cast<Instruction>(Op)->getFunction();

// If 0 * +/-inf produces NaN.
if (KnownLHS.isKnownNeverInfinity() && KnownRHS.isKnownNeverInfinity()) {
Known.knownNot(fcNan);
break;
// If neither side can be zero (or nan) fmul never produces NaN.
// TODO: Check operand combinations.
// e.g. fmul nofpclass(inf nan zero), nofpclass(nan) -> nofpclass(nan)
if ((KnownLHS.isKnownNeverInfinity() ||
(F && KnownLHS.isKnownNeverLogicalZero(*F, Op->getType()))) &&
(KnownRHS.isKnownNeverInfinity() ||
(F && KnownRHS.isKnownNeverLogicalZero(*F, Op->getType()))))
Known.knownNot(fcNan);
}

const Function *F = cast<Instruction>(Op)->getFunction();
if (!F)
break;

if ((KnownRHS.isKnownNeverInfinity() ||
KnownLHS.isKnownNeverLogicalZero(*F, Op->getType())) &&
(KnownLHS.isKnownNeverInfinity() ||
KnownRHS.isKnownNeverLogicalZero(*F, Op->getType())))
Known.knownNot(fcNan);

break;
}
case Instruction::FDiv:
Expand Down
12 changes: 6 additions & 6 deletions llvm/test/Transforms/Attributor/nofpclass-nan-fmul.ll
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Original file line number Diff line number Diff line change
Expand Up @@ -62,7 +62,7 @@ define float @ret_fmul_ieee_nonan_noinf__nonan_noinf(float nofpclass(nan inf) %a
}

define float @ret_fmul_ieee_nonan_nozero__nonan_noinf(float nofpclass(nan zero) %arg0, float nofpclass(nan inf) %arg1) #0 {
; CHECK-LABEL: define float @ret_fmul_ieee_nonan_nozero__nonan_noinf
; CHECK-LABEL: define nofpclass(nan) float @ret_fmul_ieee_nonan_nozero__nonan_noinf
; CHECK-SAME: (float nofpclass(nan zero) [[ARG0:%.*]], float nofpclass(nan inf) [[ARG1:%.*]]) #[[ATTR0]] {
; CHECK-NEXT: [[FMUL:%.*]] = fmul float [[ARG0]], [[ARG1]]
; CHECK-NEXT: ret float [[FMUL]]
Expand All @@ -72,7 +72,7 @@ define float @ret_fmul_ieee_nonan_nozero__nonan_noinf(float nofpclass(nan zero)
}

define float @ret_fmul_ieee_nonan_noinf__nonan_nozero(float nofpclass(nan inf) %arg0, float nofpclass(nan zero) %arg1) #0 {
; CHECK-LABEL: define float @ret_fmul_ieee_nonan_noinf__nonan_nozero
; CHECK-LABEL: define nofpclass(nan) float @ret_fmul_ieee_nonan_noinf__nonan_nozero
; CHECK-SAME: (float nofpclass(nan inf) [[ARG0:%.*]], float nofpclass(nan zero) [[ARG1:%.*]]) #[[ATTR0]] {
; CHECK-NEXT: [[FMUL:%.*]] = fmul float [[ARG0]], [[ARG1]]
; CHECK-NEXT: ret float [[FMUL]]
Expand Down Expand Up @@ -285,7 +285,7 @@ define float @ret_fmul_ieee_noinf_nonan__nozero(float nofpclass(inf nan) %arg0,
}

define float @ret_fmul_ieee_nozero_nonan__noinf_nonan(float nofpclass(zero nan) %arg0, float nofpclass(inf nan) %arg1) {
; CHECK-LABEL: define float @ret_fmul_ieee_nozero_nonan__noinf_nonan
; CHECK-LABEL: define nofpclass(nan) float @ret_fmul_ieee_nozero_nonan__noinf_nonan
; CHECK-SAME: (float nofpclass(nan zero) [[ARG0:%.*]], float nofpclass(nan inf) [[ARG1:%.*]]) #[[ATTR4]] {
; CHECK-NEXT: [[FMUL:%.*]] = fmul float [[ARG0]], [[ARG1]]
; CHECK-NEXT: ret float [[FMUL]]
Expand All @@ -295,7 +295,7 @@ define float @ret_fmul_ieee_nozero_nonan__noinf_nonan(float nofpclass(zero nan)
}

define float @ret_fmul_ieee_noinf_nonan__nozero_nonan(float nofpclass(inf nan) %arg0, float nofpclass(zero nan) %arg1) {
; CHECK-LABEL: define float @ret_fmul_ieee_noinf_nonan__nozero_nonan
; CHECK-LABEL: define nofpclass(nan) float @ret_fmul_ieee_noinf_nonan__nozero_nonan
; CHECK-SAME: (float nofpclass(nan inf) [[ARG0:%.*]], float nofpclass(nan zero) [[ARG1:%.*]]) #[[ATTR4]] {
; CHECK-NEXT: [[FMUL:%.*]] = fmul float [[ARG0]], [[ARG1]]
; CHECK-NEXT: ret float [[FMUL]]
Expand Down Expand Up @@ -345,7 +345,7 @@ define float @ret_fmul_ieee_nozero_nonan__nozero_nonan_noinf(float nofpclass(zer
}

define float @ret_fmul_ieee_nozero_nonan_noinf__nonan(float nofpclass(zero nan inf) %arg0, float nofpclass(nan) %arg1) {
; CHECK-LABEL: define nofpclass(nan) float @ret_fmul_ieee_nozero_nonan_noinf__nonan
; CHECK-LABEL: define float @ret_fmul_ieee_nozero_nonan_noinf__nonan
; CHECK-SAME: (float nofpclass(nan inf zero) [[ARG0:%.*]], float nofpclass(nan) [[ARG1:%.*]]) #[[ATTR4]] {
; CHECK-NEXT: [[FMUL:%.*]] = fmul float [[ARG0]], [[ARG1]]
; CHECK-NEXT: ret float [[FMUL]]
Expand All @@ -355,7 +355,7 @@ define float @ret_fmul_ieee_nozero_nonan_noinf__nonan(float nofpclass(zero nan i
}

define float @ret_fmul_ieee_nonan__nozero_nonan_noinf(float nofpclass(nan) %arg0, float nofpclass(zero nan inf) %arg1) {
; CHECK-LABEL: define nofpclass(nan) float @ret_fmul_ieee_nonan__nozero_nonan_noinf
; CHECK-LABEL: define float @ret_fmul_ieee_nonan__nozero_nonan_noinf
; CHECK-SAME: (float nofpclass(nan) [[ARG0:%.*]], float nofpclass(nan inf zero) [[ARG1:%.*]]) #[[ATTR4]] {
; CHECK-NEXT: [[FMUL:%.*]] = fmul float [[ARG0]], [[ARG1]]
; CHECK-NEXT: ret float [[FMUL]]
Expand Down
4 changes: 2 additions & 2 deletions llvm/test/Transforms/Inline/simplify-instruction-computeKnownFPClass-context.ll
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Original file line number Diff line number Diff line change
Expand Up @@ -60,9 +60,9 @@ define internal i1 @simplify_fcmp_ord_frem_callee(double %a, double %b) {
ret i1 %cmp
}

define i1 @simplify_fcmp_ord_fmul_caller(double nofpclass(zero nan inf) %i0, double nofpclass(zero nan inf) %i1) {
define i1 @simplify_fcmp_ord_fmul_caller(double nofpclass(zero nan) %i0, double nofpclass(zero nan) %i1) {
; CHECK-LABEL: define i1 @simplify_fcmp_ord_fmul_caller
; CHECK-SAME: (double nofpclass(nan inf zero) [[I0:%.*]], double nofpclass(nan inf zero) [[I1:%.*]]) {
; CHECK-SAME: (double nofpclass(nan zero) [[I0:%.*]], double nofpclass(nan zero) [[I1:%.*]]) {
; CHECK-NEXT: [[SUB_DOUBLE_SUB_I:%.*]] = fmul double [[I0]], [[I1]]
; CHECK-NEXT: ret i1 true
;
Expand Down
10 changes: 2 additions & 8 deletions llvm/test/Transforms/InstSimplify/known-never-nan.ll
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Original file line number Diff line number Diff line change
Expand Up @@ -559,10 +559,7 @@ unwind:
; This should not fold to false because fmul 0 * inf = nan
define i1 @issue63316(i64 %arg) {
; CHECK-LABEL: @issue63316(
; CHECK-NEXT: [[SITOFP:%.*]] = sitofp i64 [[ARG:%.*]] to float
; CHECK-NEXT: [[FMUL:%.*]] = fmul float [[SITOFP]], 0x7FF0000000000000
; CHECK-NEXT: [[FCMP:%.*]] = fcmp uno float [[FMUL]], 0.000000e+00
; CHECK-NEXT: ret i1 [[FCMP]]
; CHECK-NEXT: ret i1 false
;
%sitofp = sitofp i64 %arg to float
%fmul = fmul float %sitofp, 0x7FF0000000000000
Expand All @@ -572,10 +569,7 @@ define i1 @issue63316(i64 %arg) {

define i1 @issue63316_commute(i64 %arg) {
; CHECK-LABEL: @issue63316_commute(
; CHECK-NEXT: [[SITOFP:%.*]] = sitofp i64 [[ARG:%.*]] to float
; CHECK-NEXT: [[FMUL:%.*]] = fmul float 0x7FF0000000000000, [[SITOFP]]
; CHECK-NEXT: [[FCMP:%.*]] = fcmp uno float [[FMUL]], 0.000000e+00
; CHECK-NEXT: ret i1 [[FCMP]]
; CHECK-NEXT: ret i1 false
;
%sitofp = sitofp i64 %arg to float
%fmul = fmul float 0x7FF0000000000000, %sitofp
Expand Down

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