[llvm] r371735 - [ConstProp] allow folding for fma that produces NaN
Sanjay Patel via llvm-commits
llvm-commits at lists.llvm.org
Thu Sep 12 07:10:50 PDT 2019
Author: spatel
Date: Thu Sep 12 07:10:50 2019
New Revision: 371735
URL: http://llvm.org/viewvc/llvm-project?rev=371735&view=rev
Log:
[ConstProp] allow folding for fma that produces NaN
Folding for fma/fmuladd was added here:
rL202914
...and as seen in existing/unchanged tests, that works to propagate NaN
if it's already an input, but we should fold an fma() that creates NaN too.
>From IEEE-754-2008 7.2 "Invalid Operation", there are 2 clauses that apply
to fma, so I added tests for those patterns:
c) fusedMultiplyAdd: fusedMultiplyAdd(0, ∞, c) or fusedMultiplyAdd(∞, 0, c)
unless c is a quiet NaN; if c is a quiet NaN then it is implementation
defined whether the invalid operation exception is signaled
d) addition or subtraction or fusedMultiplyAdd: magnitude subtraction of
infinities, such as: addition(+∞, −∞)
Differential Revision: https://reviews.llvm.org/D67446
Modified:
llvm/trunk/include/llvm/ADT/APFloat.h
llvm/trunk/lib/Analysis/ConstantFolding.cpp
llvm/trunk/test/Transforms/ConstProp/fma.ll
Modified: llvm/trunk/include/llvm/ADT/APFloat.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/ADT/APFloat.h?rev=371735&r1=371734&r2=371735&view=diff
==============================================================================
--- llvm/trunk/include/llvm/ADT/APFloat.h (original)
+++ llvm/trunk/include/llvm/ADT/APFloat.h Thu Sep 12 07:10:50 2019
@@ -192,6 +192,11 @@ struct APFloatBase {
/// IEEE-754R 7: Default exception handling.
///
/// opUnderflow or opOverflow are always returned or-ed with opInexact.
+ ///
+ /// APFloat models this behavior specified by IEEE-754:
+ /// "For operations producing results in floating-point format, the default
+ /// result of an operation that signals the invalid operation exception
+ /// shall be a quiet NaN."
enum opStatus {
opOK = 0x00,
opInvalidOp = 0x01,
Modified: llvm/trunk/lib/Analysis/ConstantFolding.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/ConstantFolding.cpp?rev=371735&r1=371734&r2=371735&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/ConstantFolding.cpp (original)
+++ llvm/trunk/lib/Analysis/ConstantFolding.cpp Thu Sep 12 07:10:50 2019
@@ -2243,13 +2243,9 @@ static Constant *ConstantFoldScalarCall3
case Intrinsic::fma:
case Intrinsic::fmuladd: {
APFloat V = Op1->getValueAPF();
- APFloat::opStatus s = V.fusedMultiplyAdd(Op2->getValueAPF(),
- Op3->getValueAPF(),
- APFloat::rmNearestTiesToEven);
- if (s != APFloat::opInvalidOp)
- return ConstantFP::get(Ty->getContext(), V);
-
- return nullptr;
+ V.fusedMultiplyAdd(Op2->getValueAPF(), Op3->getValueAPF(),
+ APFloat::rmNearestTiesToEven);
+ return ConstantFP::get(Ty->getContext(), V);
}
}
}
Modified: llvm/trunk/test/Transforms/ConstProp/fma.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/ConstProp/fma.ll?rev=371735&r1=371734&r2=371735&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/ConstProp/fma.ll (original)
+++ llvm/trunk/test/Transforms/ConstProp/fma.ll Thu Sep 12 07:10:50 2019
@@ -129,8 +129,7 @@ define double @test_Inf_4() {
define double @inf_product_opposite_inf_addend_1() {
; CHECK-LABEL: @inf_product_opposite_inf_addend_1(
-; CHECK-NEXT: [[TMP1:%.*]] = call double @llvm.fma.f64(double 7.000000e+00, double 0xFFF0000000000000, double 0x7FF0000000000000)
-; CHECK-NEXT: ret double [[TMP1]]
+; CHECK-NEXT: ret double 0x7FF8000000000000
;
%1 = call double @llvm.fma.f64(double 7.0, double 0xFFF0000000000000, double 0x7FF0000000000000)
ret double %1
@@ -140,8 +139,7 @@ define double @inf_product_opposite_inf_
define double @inf_product_opposite_inf_addend_2() {
; CHECK-LABEL: @inf_product_opposite_inf_addend_2(
-; CHECK-NEXT: [[TMP1:%.*]] = call double @llvm.fma.f64(double 7.000000e+00, double 0x7FF0000000000000, double 0xFFF0000000000000)
-; CHECK-NEXT: ret double [[TMP1]]
+; CHECK-NEXT: ret double 0x7FF8000000000000
;
%1 = call double @llvm.fma.f64(double 7.0, double 0x7FF0000000000000, double 0xFFF0000000000000)
ret double %1
@@ -151,8 +149,7 @@ define double @inf_product_opposite_inf_
define double @inf_product_opposite_inf_addend_3() {
; CHECK-LABEL: @inf_product_opposite_inf_addend_3(
-; CHECK-NEXT: [[TMP1:%.*]] = call double @llvm.fma.f64(double 0xFFF0000000000000, double 4.200000e+01, double 0x7FF0000000000000)
-; CHECK-NEXT: ret double [[TMP1]]
+; CHECK-NEXT: ret double 0x7FF8000000000000
;
%1 = call double @llvm.fma.f64(double 0xFFF0000000000000, double 42.0, double 0x7FF0000000000000)
ret double %1
@@ -162,8 +159,7 @@ define double @inf_product_opposite_inf_
define double @inf_product_opposite_inf_addend_4() {
; CHECK-LABEL: @inf_product_opposite_inf_addend_4(
-; CHECK-NEXT: [[TMP1:%.*]] = call double @llvm.fma.f64(double 0x7FF0000000000000, double 4.200000e+01, double 0xFFF0000000000000)
-; CHECK-NEXT: ret double [[TMP1]]
+; CHECK-NEXT: ret double 0x7FF8000000000000
;
%1 = call double @llvm.fma.f64(double 0x7FF0000000000000, double 42.0, double 0xFFF0000000000000)
ret double %1
@@ -173,8 +169,7 @@ define double @inf_product_opposite_inf_
define double @inf_times_zero_1() {
; CHECK-LABEL: @inf_times_zero_1(
-; CHECK-NEXT: [[TMP1:%.*]] = call double @llvm.fma.f64(double 0.000000e+00, double 0xFFF0000000000000, double 4.200000e+01)
-; CHECK-NEXT: ret double [[TMP1]]
+; CHECK-NEXT: ret double 0x7FF8000000000000
;
%1 = call double @llvm.fma.f64(double 0.0, double 0xFFF0000000000000, double 42.0)
ret double %1
@@ -184,8 +179,7 @@ define double @inf_times_zero_1() {
define double @inf_times_zero_2() {
; CHECK-LABEL: @inf_times_zero_2(
-; CHECK-NEXT: [[TMP1:%.*]] = call double @llvm.fma.f64(double 0.000000e+00, double 0x7FF0000000000000, double 4.200000e+01)
-; CHECK-NEXT: ret double [[TMP1]]
+; CHECK-NEXT: ret double 0x7FF8000000000000
;
%1 = call double @llvm.fma.f64(double 0.0, double 0x7FF0000000000000, double 42.0)
ret double %1
@@ -195,8 +189,7 @@ define double @inf_times_zero_2() {
define double @inf_times_zero_3() {
; CHECK-LABEL: @inf_times_zero_3(
-; CHECK-NEXT: [[TMP1:%.*]] = call double @llvm.fma.f64(double 0xFFF0000000000000, double 0.000000e+00, double 4.200000e+01)
-; CHECK-NEXT: ret double [[TMP1]]
+; CHECK-NEXT: ret double 0x7FF8000000000000
;
%1 = call double @llvm.fma.f64(double 0xFFF0000000000000, double 0.0, double 42.0)
ret double %1
@@ -206,8 +199,7 @@ define double @inf_times_zero_3() {
define double @inf_times_zero_4() {
; CHECK-LABEL: @inf_times_zero_4(
-; CHECK-NEXT: [[TMP1:%.*]] = call double @llvm.fma.f64(double 0x7FF0000000000000, double 0.000000e+00, double 4.200000e+01)
-; CHECK-NEXT: ret double [[TMP1]]
+; CHECK-NEXT: ret double 0x7FF8000000000000
;
%1 = call double @llvm.fma.f64(double 0x7FF0000000000000, double 0.0, double 42.0)
ret double %1
@@ -217,8 +209,7 @@ define double @inf_times_zero_4() {
define double @inf_times_zero_5() {
; CHECK-LABEL: @inf_times_zero_5(
-; CHECK-NEXT: [[TMP1:%.*]] = call double @llvm.fma.f64(double -0.000000e+00, double 0xFFF0000000000000, double 4.200000e+01)
-; CHECK-NEXT: ret double [[TMP1]]
+; CHECK-NEXT: ret double 0x7FF8000000000000
;
%1 = call double @llvm.fma.f64(double -0.0, double 0xFFF0000000000000, double 42.0)
ret double %1
@@ -228,8 +219,7 @@ define double @inf_times_zero_5() {
define double @inf_times_zero_6() {
; CHECK-LABEL: @inf_times_zero_6(
-; CHECK-NEXT: [[TMP1:%.*]] = call double @llvm.fma.f64(double -0.000000e+00, double 0x7FF0000000000000, double 4.200000e+01)
-; CHECK-NEXT: ret double [[TMP1]]
+; CHECK-NEXT: ret double 0x7FF8000000000000
;
%1 = call double @llvm.fma.f64(double -0.0, double 0x7FF0000000000000, double 42.0)
ret double %1
@@ -239,8 +229,7 @@ define double @inf_times_zero_6() {
define double @inf_times_zero_7() {
; CHECK-LABEL: @inf_times_zero_7(
-; CHECK-NEXT: [[TMP1:%.*]] = call double @llvm.fma.f64(double 0xFFF0000000000000, double -0.000000e+00, double 4.200000e+01)
-; CHECK-NEXT: ret double [[TMP1]]
+; CHECK-NEXT: ret double 0x7FF8000000000000
;
%1 = call double @llvm.fma.f64(double 0xFFF0000000000000, double -0.0, double 42.0)
ret double %1
@@ -250,10 +239,8 @@ define double @inf_times_zero_7() {
define double @inf_times_zero_8() {
; CHECK-LABEL: @inf_times_zero_8(
-; CHECK-NEXT: [[TMP1:%.*]] = call double @llvm.fma.f64(double 0x7FF0000000000000, double -0.000000e+00, double 4.200000e+01)
-; CHECK-NEXT: ret double [[TMP1]]
+; CHECK-NEXT: ret double 0x7FF8000000000000
;
%1 = call double @llvm.fma.f64(double 0x7FF0000000000000, double -0.0, double 42.0)
ret double %1
}
-
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