[llvm] a632ca4 - ValueTracking: Fix nan result handling for fmul
Matt Arsenault via llvm-commits
llvm-commits at lists.llvm.org
Thu Jun 15 06:35:19 PDT 2023
Author: Matt Arsenault
Date: 2023-06-15T09:35:12-04:00
New Revision: a632ca4b00279baf18e72a171ec0ce526e9d80aa
URL: https://github.com/llvm/llvm-project/commit/a632ca4b00279baf18e72a171ec0ce526e9d80aa
DIFF: https://github.com/llvm/llvm-project/commit/a632ca4b00279baf18e72a171ec0ce526e9d80aa.diff
LOG: ValueTracking: Fix nan result handling for fmul
This was mishandling maybe 0 * inf.
Fixes issue #63316
Added:
Modified:
llvm/lib/Analysis/ValueTracking.cpp
llvm/test/Transforms/Attributor/nofpclass-nan-fmul.ll
llvm/test/Transforms/Inline/simplify-instruction-computeKnownFPClass-context.ll
llvm/test/Transforms/InstSimplify/known-never-nan.ll
Removed:
################################################################################
diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp
index 5393be0e247b4..e4e1a2b4707dc 100644
--- a/llvm/lib/Analysis/ValueTracking.cpp
+++ b/llvm/lib/Analysis/ValueTracking.cpp
@@ -4760,29 +4760,36 @@ 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,
- fcNan | fcInf | fcZero | fcSubnormal, KnownRHS,
+ computeKnownFPClass(Op->getOperand(1), DemandedElts, NeedForNan, KnownRHS,
Depth + 1, Q);
- if (KnownRHS.isKnownNeverNaN() &&
- (KnownRHS.isKnownNeverInfinity() || KnownRHS.isKnownNeverZero())) {
- computeKnownFPClass(Op->getOperand(0), DemandedElts,
- fcNan | fcInf | fcZero, KnownLHS, Depth + 1, Q);
- if (!KnownLHS.isKnownNeverNaN())
- break;
+ if (!KnownRHS.isKnownNeverNaN())
+ break;
- const Function *F = cast<Instruction>(Op)->getFunction();
+ computeKnownFPClass(Op->getOperand(0), DemandedElts, NeedForNan, KnownLHS,
+ Depth + 1, Q);
+ if (!KnownLHS.isKnownNeverNaN())
+ 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);
+ // If 0 * +/-inf produces NaN.
+ if (KnownLHS.isKnownNeverInfinity() && KnownRHS.isKnownNeverInfinity()) {
+ Known.knownNot(fcNan);
+ break;
}
+ 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:
diff --git a/llvm/test/Transforms/Attributor/nofpclass-nan-fmul.ll b/llvm/test/Transforms/Attributor/nofpclass-nan-fmul.ll
index bb0179daefbda..fbf6c2e0981fb 100644
--- a/llvm/test/Transforms/Attributor/nofpclass-nan-fmul.ll
+++ b/llvm/test/Transforms/Attributor/nofpclass-nan-fmul.ll
@@ -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 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 zero) [[ARG0:%.*]], float nofpclass(nan inf) [[ARG1:%.*]]) #[[ATTR0]] {
; CHECK-NEXT: [[FMUL:%.*]] = fmul float [[ARG0]], [[ARG1]]
; CHECK-NEXT: ret float [[FMUL]]
@@ -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 nofpclass(nan) float @ret_fmul_ieee_nonan_noinf__nonan_nozero
+; CHECK-LABEL: define 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]]
@@ -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 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 zero) [[ARG0:%.*]], float nofpclass(nan inf) [[ARG1:%.*]]) #[[ATTR4]] {
; CHECK-NEXT: [[FMUL:%.*]] = fmul float [[ARG0]], [[ARG1]]
; CHECK-NEXT: ret float [[FMUL]]
@@ -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 nofpclass(nan) float @ret_fmul_ieee_noinf_nonan__nozero_nonan
+; CHECK-LABEL: define 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]]
@@ -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 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 inf zero) [[ARG0:%.*]], float nofpclass(nan) [[ARG1:%.*]]) #[[ATTR4]] {
; CHECK-NEXT: [[FMUL:%.*]] = fmul float [[ARG0]], [[ARG1]]
; CHECK-NEXT: ret float [[FMUL]]
@@ -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 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) [[ARG0:%.*]], float nofpclass(nan inf zero) [[ARG1:%.*]]) #[[ATTR4]] {
; CHECK-NEXT: [[FMUL:%.*]] = fmul float [[ARG0]], [[ARG1]]
; CHECK-NEXT: ret float [[FMUL]]
diff --git a/llvm/test/Transforms/Inline/simplify-instruction-computeKnownFPClass-context.ll b/llvm/test/Transforms/Inline/simplify-instruction-computeKnownFPClass-context.ll
index f0eb263bf0470..7e9f62158c2de 100644
--- a/llvm/test/Transforms/Inline/simplify-instruction-computeKnownFPClass-context.ll
+++ b/llvm/test/Transforms/Inline/simplify-instruction-computeKnownFPClass-context.ll
@@ -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) %i0, double nofpclass(zero nan) %i1) {
+define i1 @simplify_fcmp_ord_fmul_caller(double nofpclass(zero nan inf) %i0, double nofpclass(zero nan inf) %i1) {
; CHECK-LABEL: define i1 @simplify_fcmp_ord_fmul_caller
-; CHECK-SAME: (double nofpclass(nan zero) [[I0:%.*]], double nofpclass(nan zero) [[I1:%.*]]) {
+; CHECK-SAME: (double nofpclass(nan inf zero) [[I0:%.*]], double nofpclass(nan inf zero) [[I1:%.*]]) {
; CHECK-NEXT: [[SUB_DOUBLE_SUB_I:%.*]] = fmul double [[I0]], [[I1]]
; CHECK-NEXT: ret i1 true
;
diff --git a/llvm/test/Transforms/InstSimplify/known-never-nan.ll b/llvm/test/Transforms/InstSimplify/known-never-nan.ll
index 8583d9733d72d..49a48ae42d064 100644
--- a/llvm/test/Transforms/InstSimplify/known-never-nan.ll
+++ b/llvm/test/Transforms/InstSimplify/known-never-nan.ll
@@ -559,7 +559,10 @@ unwind:
; This should not fold to false because fmul 0 * inf = nan
define i1 @issue63316(i64 %arg) {
; CHECK-LABEL: @issue63316(
-; CHECK-NEXT: ret i1 false
+; 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]]
;
%sitofp = sitofp i64 %arg to float
%fmul = fmul float %sitofp, 0x7FF0000000000000
@@ -569,7 +572,10 @@ define i1 @issue63316(i64 %arg) {
define i1 @issue63316_commute(i64 %arg) {
; CHECK-LABEL: @issue63316_commute(
-; CHECK-NEXT: ret i1 false
+; 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]]
;
%sitofp = sitofp i64 %arg to float
%fmul = fmul float 0x7FF0000000000000, %sitofp
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