[clang] [llvm] [ValueTracking] use KnownBits to compute fpclass from bitcast (PR #97762)

Alex MacLean via cfe-commits cfe-commits at lists.llvm.org
Thu Aug 29 21:39:28 PDT 2024


https://github.com/AlexMaclean updated https://github.com/llvm/llvm-project/pull/97762

>From 0477447f29b2889f92abf44cacd5e0f2c4e7f387 Mon Sep 17 00:00:00 2001
From: Alex MacLean <amaclean at nvidia.com>
Date: Mon, 1 Jul 2024 17:06:56 +0000
Subject: [PATCH 1/6] [ValueTracking] use KnownBits to compute fpclass from
 bitcast

---
 llvm/lib/Analysis/ValueTracking.cpp          |  30 ++++++
 llvm/test/Transforms/Attributor/nofpclass.ll | 104 +++++++++++++++++++
 2 files changed, 134 insertions(+)

diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp
index 173faa32a3878d..023303aa09e362 100644
--- a/llvm/lib/Analysis/ValueTracking.cpp
+++ b/llvm/lib/Analysis/ValueTracking.cpp
@@ -5921,6 +5921,36 @@ void computeKnownFPClass(const Value *V, const APInt &DemandedElts,
 
     break;
   }
+  case Instruction::BitCast: {
+    const Type *Ty = Op->getType();
+    const Value *Casted = Op->getOperand(0);
+    if (Ty->isVectorTy() || !Casted->getType()->isIntOrIntVectorTy())
+      break;
+
+    KnownBits Bits(Ty->getScalarSizeInBits());
+    computeKnownBits(Casted, Bits, Depth + 1, Q);
+
+    // Transfer information from the sign bit.
+    if (Bits.Zero.isSignBitSet())
+      Known.signBitMustBeZero();
+    else if (Bits.One.isSignBitSet())
+      Known.signBitMustBeOne();
+
+    if (Ty->isIEEE()) {
+      // IEEE floats are NaN when all bits of the exponent plus at least one of
+      // the fraction bits are 1. This means:
+      //   - If we assume unknown bits are 0 and the value is NaN, it will
+      //     always be NaN
+      //   - If we assume unknown bits are 1 and the value is not NaN, it can
+      //     never be NaN
+      if (APFloat(Ty->getFltSemantics(), Bits.One).isNaN())
+        Known.KnownFPClasses = fcNan;
+      else if (!APFloat(Ty->getFltSemantics(), ~Bits.Zero).isNaN())
+        Known.knownNot(fcNan);
+    }
+
+    break;
+  }
   default:
     break;
   }
diff --git a/llvm/test/Transforms/Attributor/nofpclass.ll b/llvm/test/Transforms/Attributor/nofpclass.ll
index 781ba636c3ab3c..c5d562a436b337 100644
--- a/llvm/test/Transforms/Attributor/nofpclass.ll
+++ b/llvm/test/Transforms/Attributor/nofpclass.ll
@@ -2690,6 +2690,110 @@ entry:
   ret double %abs
 }
 
+define float @bitcast_to_float_sign_0(i32 %arg) {
+; CHECK: Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(none)
+; CHECK-LABEL: define nofpclass(ninf nzero nsub nnorm) float @bitcast_to_float_sign_0
+; CHECK-SAME: (i32 [[ARG:%.*]]) #[[ATTR3]] {
+; CHECK-NEXT:    [[TMP1:%.*]] = lshr i32 [[ARG]], 1
+; CHECK-NEXT:    [[TMP2:%.*]] = bitcast i32 [[TMP1]] to float
+; CHECK-NEXT:    ret float [[TMP2]]
+;
+  %1 = lshr i32 %arg, 1
+  %2 = bitcast i32 %1 to float
+  ret float %2
+}
+
+define float @bitcast_to_float_nnan(i32 %arg) {
+; CHECK: Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(none)
+; CHECK-LABEL: define nofpclass(nan ninf nzero nsub nnorm) float @bitcast_to_float_nnan
+; CHECK-SAME: (i32 [[ARG:%.*]]) #[[ATTR3]] {
+; CHECK-NEXT:    [[TMP1:%.*]] = lshr i32 [[ARG]], 2
+; CHECK-NEXT:    [[TMP2:%.*]] = bitcast i32 [[TMP1]] to float
+; CHECK-NEXT:    ret float [[TMP2]]
+;
+  %1 = lshr i32 %arg, 2
+  %2 = bitcast i32 %1 to float
+  ret float %2
+}
+
+define float @bitcast_to_float_sign_1(i32 %arg) {
+; CHECK: Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(none)
+; CHECK-LABEL: define nofpclass(pinf pzero psub pnorm) float @bitcast_to_float_sign_1
+; CHECK-SAME: (i32 [[ARG:%.*]]) #[[ATTR3]] {
+; CHECK-NEXT:    [[TMP1:%.*]] = or i32 [[ARG]], -2147483648
+; CHECK-NEXT:    [[TMP2:%.*]] = bitcast i32 [[TMP1]] to float
+; CHECK-NEXT:    ret float [[TMP2]]
+;
+  %1 = or i32 %arg, -2147483648
+  %2 = bitcast i32 %1 to float
+  ret float %2
+}
+
+define float @bitcast_to_float_nan(i32 %arg) {
+; CHECK: Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(none)
+; CHECK-LABEL: define nofpclass(inf zero sub norm) float @bitcast_to_float_nan
+; CHECK-SAME: (i32 [[ARG:%.*]]) #[[ATTR3]] {
+; CHECK-NEXT:    [[TMP1:%.*]] = or i32 [[ARG]], 2139095041
+; CHECK-NEXT:    [[TMP2:%.*]] = bitcast i32 [[TMP1]] to float
+; CHECK-NEXT:    ret float [[TMP2]]
+;
+  %1 = or i32 %arg, 2139095041
+  %2 = bitcast i32 %1 to float
+  ret float %2
+}
+
+define double @bitcast_to_double_sign_0(i64 %arg) {
+; CHECK: Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(none)
+; CHECK-LABEL: define nofpclass(ninf nzero nsub nnorm) double @bitcast_to_double_sign_0
+; CHECK-SAME: (i64 [[ARG:%.*]]) #[[ATTR3]] {
+; CHECK-NEXT:    [[TMP1:%.*]] = lshr i64 [[ARG]], 1
+; CHECK-NEXT:    [[TMP2:%.*]] = bitcast i64 [[TMP1]] to double
+; CHECK-NEXT:    ret double [[TMP2]]
+;
+  %1 = lshr i64 %arg, 1
+  %2 = bitcast i64 %1 to double
+  ret double %2
+}
+
+define double @bitcast_to_double_nnan(i64 %arg) {
+; CHECK: Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(none)
+; CHECK-LABEL: define nofpclass(nan ninf nzero nsub nnorm) double @bitcast_to_double_nnan
+; CHECK-SAME: (i64 [[ARG:%.*]]) #[[ATTR3]] {
+; CHECK-NEXT:    [[TMP1:%.*]] = lshr i64 [[ARG]], 2
+; CHECK-NEXT:    [[TMP2:%.*]] = bitcast i64 [[TMP1]] to double
+; CHECK-NEXT:    ret double [[TMP2]]
+;
+  %1 = lshr i64 %arg, 2
+  %2 = bitcast i64 %1 to double
+  ret double %2
+}
+
+define double @bitcast_to_double_sign_1(i64 %arg) {
+; CHECK: Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(none)
+; CHECK-LABEL: define nofpclass(pinf pzero psub pnorm) double @bitcast_to_double_sign_1
+; CHECK-SAME: (i64 [[ARG:%.*]]) #[[ATTR3]] {
+; CHECK-NEXT:    [[TMP1:%.*]] = or i64 [[ARG]], -9223372036854775808
+; CHECK-NEXT:    [[TMP2:%.*]] = bitcast i64 [[TMP1]] to double
+; CHECK-NEXT:    ret double [[TMP2]]
+;
+  %1 = or i64 %arg, -9223372036854775808
+  %2 = bitcast i64 %1 to double
+  ret double %2
+}
+
+define double @bitcast_to_double_nan(i64 %arg) {
+; CHECK: Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(none)
+; CHECK-LABEL: define nofpclass(inf zero sub norm) double @bitcast_to_double_nan
+; CHECK-SAME: (i64 [[ARG:%.*]]) #[[ATTR3]] {
+; CHECK-NEXT:    [[TMP1:%.*]] = or i64 [[ARG]], -4503599627370495
+; CHECK-NEXT:    [[TMP2:%.*]] = bitcast i64 [[TMP1]] to double
+; CHECK-NEXT:    ret double [[TMP2]]
+;
+  %1 = or i64 %arg, -4503599627370495
+  %2 = bitcast i64 %1 to double
+  ret double %2
+}
+
 declare i64 @_Z13get_global_idj(i32 noundef)
 
 attributes #0 = { "denormal-fp-math"="preserve-sign,preserve-sign" }

>From 769cedb28a8a05d5689bb64a2d445536b2f8d8d6 Mon Sep 17 00:00:00 2001
From: Alex MacLean <alex at alex-maclean.com>
Date: Fri, 5 Jul 2024 09:01:33 -0700
Subject: [PATCH 2/6] Update llvm/lib/Analysis/ValueTracking.cpp

Co-authored-by: Yingwei Zheng <dtcxzyw at qq.com>
---
 llvm/lib/Analysis/ValueTracking.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp
index 023303aa09e362..824b9cb0a5333d 100644
--- a/llvm/lib/Analysis/ValueTracking.cpp
+++ b/llvm/lib/Analysis/ValueTracking.cpp
@@ -5931,7 +5931,7 @@ void computeKnownFPClass(const Value *V, const APInt &DemandedElts,
     computeKnownBits(Casted, Bits, Depth + 1, Q);
 
     // Transfer information from the sign bit.
-    if (Bits.Zero.isSignBitSet())
+    if (Bits.isNonNegative())
       Known.signBitMustBeZero();
     else if (Bits.One.isSignBitSet())
       Known.signBitMustBeOne();

>From 71aacaf73a99b438ad3d828048c06aa4da7a6e84 Mon Sep 17 00:00:00 2001
From: Alex MacLean <alex at alex-maclean.com>
Date: Fri, 5 Jul 2024 09:01:49 -0700
Subject: [PATCH 3/6] Update llvm/lib/Analysis/ValueTracking.cpp

Co-authored-by: Yingwei Zheng <dtcxzyw at qq.com>
---
 llvm/lib/Analysis/ValueTracking.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp
index 824b9cb0a5333d..121cebcebf9da6 100644
--- a/llvm/lib/Analysis/ValueTracking.cpp
+++ b/llvm/lib/Analysis/ValueTracking.cpp
@@ -5933,7 +5933,7 @@ void computeKnownFPClass(const Value *V, const APInt &DemandedElts,
     // Transfer information from the sign bit.
     if (Bits.isNonNegative())
       Known.signBitMustBeZero();
-    else if (Bits.One.isSignBitSet())
+    else if (Bits.isNegative())
       Known.signBitMustBeOne();
 
     if (Ty->isIEEE()) {

>From 0cf41b914189b021e0ae2d54177947afe5e7a71d Mon Sep 17 00:00:00 2001
From: Alex MacLean <amaclean at nvidia.com>
Date: Fri, 5 Jul 2024 17:12:22 +0000
Subject: [PATCH 4/6] address comments

---
 llvm/lib/Analysis/ValueTracking.cpp          |   9 +-
 llvm/test/Transforms/Attributor/nofpclass.ll | 149 +++++++++++++------
 2 files changed, 106 insertions(+), 52 deletions(-)

diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp
index 121cebcebf9da6..8ecaeef90b31b8 100644
--- a/llvm/lib/Analysis/ValueTracking.cpp
+++ b/llvm/lib/Analysis/ValueTracking.cpp
@@ -5922,13 +5922,14 @@ void computeKnownFPClass(const Value *V, const APInt &DemandedElts,
     break;
   }
   case Instruction::BitCast: {
-    const Type *Ty = Op->getType();
-    const Value *Casted = Op->getOperand(0);
-    if (Ty->isVectorTy() || !Casted->getType()->isIntOrIntVectorTy())
+    const Value *Src;
+    if (!match(Op, m_ElementWiseBitCast(m_Value(Src))) ||
+        !Src->getType()->isIntOrIntVectorTy())
       break;
 
+    const Type *Ty = Op->getType()->getScalarType();
     KnownBits Bits(Ty->getScalarSizeInBits());
-    computeKnownBits(Casted, Bits, Depth + 1, Q);
+    computeKnownBits(Src, DemandedElts, Bits, Depth + 1, Q);
 
     // Transfer information from the sign bit.
     if (Bits.isNonNegative())
diff --git a/llvm/test/Transforms/Attributor/nofpclass.ll b/llvm/test/Transforms/Attributor/nofpclass.ll
index c5d562a436b337..5ea688113eb19e 100644
--- a/llvm/test/Transforms/Attributor/nofpclass.ll
+++ b/llvm/test/Transforms/Attributor/nofpclass.ll
@@ -2694,104 +2694,157 @@ define float @bitcast_to_float_sign_0(i32 %arg) {
 ; CHECK: Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(none)
 ; CHECK-LABEL: define nofpclass(ninf nzero nsub nnorm) float @bitcast_to_float_sign_0
 ; CHECK-SAME: (i32 [[ARG:%.*]]) #[[ATTR3]] {
-; CHECK-NEXT:    [[TMP1:%.*]] = lshr i32 [[ARG]], 1
-; CHECK-NEXT:    [[TMP2:%.*]] = bitcast i32 [[TMP1]] to float
-; CHECK-NEXT:    ret float [[TMP2]]
+; CHECK-NEXT:    [[SHR:%.*]] = lshr i32 [[ARG]], 1
+; CHECK-NEXT:    [[CAST:%.*]] = bitcast i32 [[SHR]] to float
+; CHECK-NEXT:    ret float [[CAST]]
 ;
-  %1 = lshr i32 %arg, 1
-  %2 = bitcast i32 %1 to float
-  ret float %2
+  %shr = lshr i32 %arg, 1
+  %cast = bitcast i32 %shr to float
+  ret float %cast
 }
 
 define float @bitcast_to_float_nnan(i32 %arg) {
 ; CHECK: Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(none)
 ; CHECK-LABEL: define nofpclass(nan ninf nzero nsub nnorm) float @bitcast_to_float_nnan
 ; CHECK-SAME: (i32 [[ARG:%.*]]) #[[ATTR3]] {
-; CHECK-NEXT:    [[TMP1:%.*]] = lshr i32 [[ARG]], 2
-; CHECK-NEXT:    [[TMP2:%.*]] = bitcast i32 [[TMP1]] to float
-; CHECK-NEXT:    ret float [[TMP2]]
+; CHECK-NEXT:    [[SHR:%.*]] = lshr i32 [[ARG]], 2
+; CHECK-NEXT:    [[CAST:%.*]] = bitcast i32 [[SHR]] to float
+; CHECK-NEXT:    ret float [[CAST]]
 ;
-  %1 = lshr i32 %arg, 2
-  %2 = bitcast i32 %1 to float
-  ret float %2
+  %shr = lshr i32 %arg, 2
+  %cast = bitcast i32 %shr to float
+  ret float %cast
 }
 
 define float @bitcast_to_float_sign_1(i32 %arg) {
 ; CHECK: Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(none)
 ; CHECK-LABEL: define nofpclass(pinf pzero psub pnorm) float @bitcast_to_float_sign_1
 ; CHECK-SAME: (i32 [[ARG:%.*]]) #[[ATTR3]] {
-; CHECK-NEXT:    [[TMP1:%.*]] = or i32 [[ARG]], -2147483648
-; CHECK-NEXT:    [[TMP2:%.*]] = bitcast i32 [[TMP1]] to float
-; CHECK-NEXT:    ret float [[TMP2]]
+; CHECK-NEXT:    [[OR:%.*]] = or i32 [[ARG]], -2147483648
+; CHECK-NEXT:    [[CAST:%.*]] = bitcast i32 [[OR]] to float
+; CHECK-NEXT:    ret float [[CAST]]
 ;
-  %1 = or i32 %arg, -2147483648
-  %2 = bitcast i32 %1 to float
-  ret float %2
+  %or = or i32 %arg, -2147483648
+  %cast = bitcast i32 %or to float
+  ret float %cast
 }
 
 define float @bitcast_to_float_nan(i32 %arg) {
 ; CHECK: Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(none)
 ; CHECK-LABEL: define nofpclass(inf zero sub norm) float @bitcast_to_float_nan
 ; CHECK-SAME: (i32 [[ARG:%.*]]) #[[ATTR3]] {
-; CHECK-NEXT:    [[TMP1:%.*]] = or i32 [[ARG]], 2139095041
-; CHECK-NEXT:    [[TMP2:%.*]] = bitcast i32 [[TMP1]] to float
-; CHECK-NEXT:    ret float [[TMP2]]
+; CHECK-NEXT:    [[OR:%.*]] = or i32 [[ARG]], 2139095041
+; CHECK-NEXT:    [[CAST:%.*]] = bitcast i32 [[OR]] to float
+; CHECK-NEXT:    ret float [[CAST]]
 ;
-  %1 = or i32 %arg, 2139095041
-  %2 = bitcast i32 %1 to float
-  ret float %2
+  %or = or i32 %arg, 2139095041
+  %cast = bitcast i32 %or to float
+  ret float %cast
 }
 
 define double @bitcast_to_double_sign_0(i64 %arg) {
 ; CHECK: Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(none)
 ; CHECK-LABEL: define nofpclass(ninf nzero nsub nnorm) double @bitcast_to_double_sign_0
 ; CHECK-SAME: (i64 [[ARG:%.*]]) #[[ATTR3]] {
-; CHECK-NEXT:    [[TMP1:%.*]] = lshr i64 [[ARG]], 1
-; CHECK-NEXT:    [[TMP2:%.*]] = bitcast i64 [[TMP1]] to double
-; CHECK-NEXT:    ret double [[TMP2]]
+; CHECK-NEXT:    [[SHR:%.*]] = lshr i64 [[ARG]], 1
+; CHECK-NEXT:    [[CAST:%.*]] = bitcast i64 [[SHR]] to double
+; CHECK-NEXT:    ret double [[CAST]]
 ;
-  %1 = lshr i64 %arg, 1
-  %2 = bitcast i64 %1 to double
-  ret double %2
+  %shr = lshr i64 %arg, 1
+  %cast = bitcast i64 %shr to double
+  ret double %cast
 }
 
 define double @bitcast_to_double_nnan(i64 %arg) {
 ; CHECK: Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(none)
 ; CHECK-LABEL: define nofpclass(nan ninf nzero nsub nnorm) double @bitcast_to_double_nnan
 ; CHECK-SAME: (i64 [[ARG:%.*]]) #[[ATTR3]] {
-; CHECK-NEXT:    [[TMP1:%.*]] = lshr i64 [[ARG]], 2
-; CHECK-NEXT:    [[TMP2:%.*]] = bitcast i64 [[TMP1]] to double
-; CHECK-NEXT:    ret double [[TMP2]]
+; CHECK-NEXT:    [[SHR:%.*]] = lshr i64 [[ARG]], 2
+; CHECK-NEXT:    [[CAST:%.*]] = bitcast i64 [[SHR]] to double
+; CHECK-NEXT:    ret double [[CAST]]
 ;
-  %1 = lshr i64 %arg, 2
-  %2 = bitcast i64 %1 to double
-  ret double %2
+  %shr = lshr i64 %arg, 2
+  %cast = bitcast i64 %shr to double
+  ret double %cast
 }
 
 define double @bitcast_to_double_sign_1(i64 %arg) {
 ; CHECK: Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(none)
 ; CHECK-LABEL: define nofpclass(pinf pzero psub pnorm) double @bitcast_to_double_sign_1
 ; CHECK-SAME: (i64 [[ARG:%.*]]) #[[ATTR3]] {
-; CHECK-NEXT:    [[TMP1:%.*]] = or i64 [[ARG]], -9223372036854775808
-; CHECK-NEXT:    [[TMP2:%.*]] = bitcast i64 [[TMP1]] to double
-; CHECK-NEXT:    ret double [[TMP2]]
+; CHECK-NEXT:    [[OR:%.*]] = or i64 [[ARG]], -9223372036854775808
+; CHECK-NEXT:    [[CAST:%.*]] = bitcast i64 [[OR]] to double
+; CHECK-NEXT:    ret double [[CAST]]
 ;
-  %1 = or i64 %arg, -9223372036854775808
-  %2 = bitcast i64 %1 to double
-  ret double %2
+  %or = or i64 %arg, -9223372036854775808
+  %cast = bitcast i64 %or to double
+  ret double %cast
 }
 
 define double @bitcast_to_double_nan(i64 %arg) {
 ; CHECK: Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(none)
 ; CHECK-LABEL: define nofpclass(inf zero sub norm) double @bitcast_to_double_nan
 ; CHECK-SAME: (i64 [[ARG:%.*]]) #[[ATTR3]] {
-; CHECK-NEXT:    [[TMP1:%.*]] = or i64 [[ARG]], -4503599627370495
-; CHECK-NEXT:    [[TMP2:%.*]] = bitcast i64 [[TMP1]] to double
-; CHECK-NEXT:    ret double [[TMP2]]
+; CHECK-NEXT:    [[OR:%.*]] = or i64 [[ARG]], -4503599627370495
+; CHECK-NEXT:    [[CAST:%.*]] = bitcast i64 [[OR]] to double
+; CHECK-NEXT:    ret double [[CAST]]
 ;
-  %1 = or i64 %arg, -4503599627370495
-  %2 = bitcast i64 %1 to double
-  ret double %2
+  %or = or i64 %arg, -4503599627370495
+  %cast = bitcast i64 %or to double
+  ret double %cast
+}
+
+
+define <2 x float> @bitcast_to_float_vect_sign_0(<2 x i32> %arg) {
+; CHECK: Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(none)
+; CHECK-LABEL: define nofpclass(ninf nzero nsub nnorm) <2 x float> @bitcast_to_float_vect_sign_0
+; CHECK-SAME: (<2 x i32> [[ARG:%.*]]) #[[ATTR3]] {
+; CHECK-NEXT:    [[SHR:%.*]] = lshr <2 x i32> [[ARG]], <i32 1, i32 2>
+; CHECK-NEXT:    [[CAST:%.*]] = bitcast <2 x i32> [[SHR]] to <2 x float>
+; CHECK-NEXT:    ret <2 x float> [[CAST]]
+;
+  %shr = lshr <2 x i32> %arg, <i32 1, i32 2>
+  %cast = bitcast <2 x i32> %shr to <2 x float>
+  ret <2 x float> %cast
+}
+
+define <2 x float> @bitcast_to_float_vect_nnan(<2 x i32> %arg) {
+; CHECK: Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(none)
+; CHECK-LABEL: define nofpclass(nan ninf nzero nsub nnorm) <2 x float> @bitcast_to_float_vect_nnan
+; CHECK-SAME: (<2 x i32> [[ARG:%.*]]) #[[ATTR3]] {
+; CHECK-NEXT:    [[SHR:%.*]] = lshr <2 x i32> [[ARG]], <i32 4, i32 4>
+; CHECK-NEXT:    [[CAST:%.*]] = bitcast <2 x i32> [[SHR]] to <2 x float>
+; CHECK-NEXT:    ret <2 x float> [[CAST]]
+;
+  %shr = lshr <2 x i32> %arg, <i32 4, i32 4>
+  %cast = bitcast <2 x i32> %shr to <2 x float>
+  ret <2 x float> %cast
+}
+
+define <2 x float> @bitcast_to_float_vect_sign_1(<2 x i32> %arg) {
+; CHECK: Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(none)
+; CHECK-LABEL: define nofpclass(pinf pzero psub pnorm) <2 x float> @bitcast_to_float_vect_sign_1
+; CHECK-SAME: (<2 x i32> [[ARG:%.*]]) #[[ATTR3]] {
+; CHECK-NEXT:    [[OR:%.*]] = or <2 x i32> [[ARG]], <i32 -2147483648, i32 -2147483648>
+; CHECK-NEXT:    [[CAST:%.*]] = bitcast <2 x i32> [[OR]] to <2 x float>
+; CHECK-NEXT:    ret <2 x float> [[CAST]]
+;
+  %or = or <2 x i32> %arg, <i32 -2147483648, i32 -2147483648>
+  %cast = bitcast <2 x i32> %or to <2 x float>
+  ret <2 x float> %cast
+}
+
+define <2 x float> @bitcast_to_float_vect_nan(<2 x i32> %arg) {
+; CHECK: Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(none)
+; CHECK-LABEL: define nofpclass(inf zero sub norm) <2 x float> @bitcast_to_float_vect_nan
+; CHECK-SAME: (<2 x i32> [[ARG:%.*]]) #[[ATTR3]] {
+; CHECK-NEXT:    [[OR:%.*]] = or <2 x i32> [[ARG]], <i32 2139095041, i32 2139095041>
+; CHECK-NEXT:    [[CAST:%.*]] = bitcast <2 x i32> [[OR]] to <2 x float>
+; CHECK-NEXT:    ret <2 x float> [[CAST]]
+;
+  %or = or <2 x i32> %arg, <i32 2139095041, i32 2139095041>
+  %cast = bitcast <2 x i32> %or to <2 x float>
+  ret <2 x float> %cast
 }
 
 declare i64 @_Z13get_global_idj(i32 noundef)

>From 58ddb6aaa2b8b96fb476974a23427ad4557ccfeb Mon Sep 17 00:00:00 2001
From: Alex MacLean <amaclean at nvidia.com>
Date: Mon, 26 Aug 2024 17:47:46 +0000
Subject: [PATCH 5/6] address comments

---
 llvm/lib/Analysis/ValueTracking.cpp          |  26 ++++
 llvm/test/Transforms/Attributor/nofpclass.ll | 129 ++++++++++++++++++-
 2 files changed, 152 insertions(+), 3 deletions(-)

diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp
index 8ecaeef90b31b8..15e8716d256656 100644
--- a/llvm/lib/Analysis/ValueTracking.cpp
+++ b/llvm/lib/Analysis/ValueTracking.cpp
@@ -5948,6 +5948,32 @@ void computeKnownFPClass(const Value *V, const APInt &DemandedElts,
         Known.KnownFPClasses = fcNan;
       else if (!APFloat(Ty->getFltSemantics(), ~Bits.Zero).isNaN())
         Known.knownNot(fcNan);
+
+      // Build KnownBits representing Inf and check if it must be equal or
+      // unequal to this value.
+      auto InfKB = KnownBits::makeConstant(
+          APFloat::getInf(Ty->getFltSemantics(), false).bitcastToAPInt());
+      InfKB = InfKB.intersectWith(KnownBits::makeConstant(
+          APFloat::getInf(Ty->getFltSemantics(), true).bitcastToAPInt()));
+      if (const auto InfResult = KnownBits::eq(Bits, InfKB)) {
+        assert(!InfResult.value());
+        Known.knownNot(fcInf);
+      } else if (Bits == InfKB) {
+        Known.KnownFPClasses = fcInf;
+      }
+
+      // Build KnownBits representing Zero and check if it must be equal or
+      // unequal to this value.
+      auto ZeroKB = KnownBits::makeConstant(
+          APFloat::getZero(Ty->getFltSemantics(), false).bitcastToAPInt());
+      ZeroKB = ZeroKB.intersectWith(KnownBits::makeConstant(
+          APFloat::getZero(Ty->getFltSemantics(), true).bitcastToAPInt()));
+      if (const auto ZeroResult = KnownBits::eq(Bits, ZeroKB)) {
+        assert(!ZeroResult.value());
+        Known.knownNot(fcZero);
+      } else if (Bits == ZeroKB) {
+        Known.KnownFPClasses = fcZero;
+      }
     }
 
     break;
diff --git a/llvm/test/Transforms/Attributor/nofpclass.ll b/llvm/test/Transforms/Attributor/nofpclass.ll
index 5ea688113eb19e..2a6780b60211cf 100644
--- a/llvm/test/Transforms/Attributor/nofpclass.ll
+++ b/llvm/test/Transforms/Attributor/nofpclass.ll
@@ -2685,6 +2685,20 @@ define <vscale x 4 x float> @scalable_splat_zero() {
 ; See https://github.com/llvm/llvm-project/issues/78507
 
 define double @call_abs(double noundef %__x) {
+; TUNIT: Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(none)
+; TUNIT-LABEL: define noundef nofpclass(ninf nzero nsub nnorm) double @call_abs
+; TUNIT-SAME: (double noundef [[__X:%.*]]) #[[ATTR3]] {
+; TUNIT-NEXT:  entry:
+; TUNIT-NEXT:    [[ABS:%.*]] = tail call noundef nofpclass(ninf nzero nsub nnorm) double @llvm.fabs.f64(double noundef [[__X]]) #[[ATTR22]]
+; TUNIT-NEXT:    ret double [[ABS]]
+;
+; CGSCC: Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(none)
+; CGSCC-LABEL: define noundef nofpclass(ninf nzero nsub nnorm) double @call_abs
+; CGSCC-SAME: (double noundef [[__X:%.*]]) #[[ATTR3]] {
+; CGSCC-NEXT:  entry:
+; CGSCC-NEXT:    [[ABS:%.*]] = tail call noundef nofpclass(ninf nzero nsub nnorm) double @llvm.fabs.f64(double noundef [[__X]]) #[[ATTR19]]
+; CGSCC-NEXT:    ret double [[ABS]]
+;
 entry:
   %abs = tail call double @llvm.fabs.f64(double %__x)
   ret double %abs
@@ -2705,7 +2719,7 @@ define float @bitcast_to_float_sign_0(i32 %arg) {
 
 define float @bitcast_to_float_nnan(i32 %arg) {
 ; CHECK: Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(none)
-; CHECK-LABEL: define nofpclass(nan ninf nzero nsub nnorm) float @bitcast_to_float_nnan
+; CHECK-LABEL: define nofpclass(nan inf nzero nsub nnorm) float @bitcast_to_float_nnan
 ; CHECK-SAME: (i32 [[ARG:%.*]]) #[[ATTR3]] {
 ; CHECK-NEXT:    [[SHR:%.*]] = lshr i32 [[ARG]], 2
 ; CHECK-NEXT:    [[CAST:%.*]] = bitcast i32 [[SHR]] to float
@@ -2742,6 +2756,47 @@ define float @bitcast_to_float_nan(i32 %arg) {
   ret float %cast
 }
 
+define float @bitcast_to_float_zero(i32 %arg) {
+; CHECK: Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(none)
+; CHECK-LABEL: define nofpclass(nan inf sub norm) float @bitcast_to_float_zero
+; CHECK-SAME: (i32 [[ARG:%.*]]) #[[ATTR3]] {
+; CHECK-NEXT:    [[SHL:%.*]] = shl i32 [[ARG]], 31
+; CHECK-NEXT:    [[CAST:%.*]] = bitcast i32 [[SHL]] to float
+; CHECK-NEXT:    ret float [[CAST]]
+;
+  %shl = shl i32 %arg, 31
+  %cast = bitcast i32 %shl to float
+  ret float %cast
+}
+
+define float @bitcast_to_float_nzero(i32 %arg) {
+; CHECK: Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(none)
+; CHECK-LABEL: define nofpclass(zero) float @bitcast_to_float_nzero
+; CHECK-SAME: (i32 [[ARG:%.*]]) #[[ATTR3]] {
+; CHECK-NEXT:    [[OR:%.*]] = or i32 [[ARG]], 134217728
+; CHECK-NEXT:    [[CAST:%.*]] = bitcast i32 [[OR]] to float
+; CHECK-NEXT:    ret float [[CAST]]
+;
+  %or = or i32 %arg, 134217728
+  %cast = bitcast i32 %or to float
+  ret float %cast
+}
+
+define float @bitcast_to_float_inf(i32 %arg) {
+; CHECK: Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(none)
+; CHECK-LABEL: define nofpclass(nan zero sub norm) float @bitcast_to_float_inf
+; CHECK-SAME: (i32 [[ARG:%.*]]) #[[ATTR3]] {
+; CHECK-NEXT:    [[SHR:%.*]] = shl i32 [[ARG]], 31
+; CHECK-NEXT:    [[OR:%.*]] = or i32 [[SHR]], 2139095040
+; CHECK-NEXT:    [[CAST:%.*]] = bitcast i32 [[OR]] to float
+; CHECK-NEXT:    ret float [[CAST]]
+;
+  %shr = shl i32 %arg, 31
+  %or = or i32 %shr, 2139095040
+  %cast = bitcast i32 %or to float
+  ret float %cast
+}
+
 define double @bitcast_to_double_sign_0(i64 %arg) {
 ; CHECK: Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(none)
 ; CHECK-LABEL: define nofpclass(ninf nzero nsub nnorm) double @bitcast_to_double_sign_0
@@ -2757,7 +2812,7 @@ define double @bitcast_to_double_sign_0(i64 %arg) {
 
 define double @bitcast_to_double_nnan(i64 %arg) {
 ; CHECK: Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(none)
-; CHECK-LABEL: define nofpclass(nan ninf nzero nsub nnorm) double @bitcast_to_double_nnan
+; CHECK-LABEL: define nofpclass(nan inf nzero nsub nnorm) double @bitcast_to_double_nnan
 ; CHECK-SAME: (i64 [[ARG:%.*]]) #[[ATTR3]] {
 ; CHECK-NEXT:    [[SHR:%.*]] = lshr i64 [[ARG]], 2
 ; CHECK-NEXT:    [[CAST:%.*]] = bitcast i64 [[SHR]] to double
@@ -2795,6 +2850,48 @@ define double @bitcast_to_double_nan(i64 %arg) {
 }
 
 
+define double @bitcast_to_double_zero(i64 %arg) {
+; CHECK: Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(none)
+; CHECK-LABEL: define nofpclass(nan inf sub norm) double @bitcast_to_double_zero
+; CHECK-SAME: (i64 [[ARG:%.*]]) #[[ATTR3]] {
+; CHECK-NEXT:    [[SHL:%.*]] = shl i64 [[ARG]], 63
+; CHECK-NEXT:    [[CAST:%.*]] = bitcast i64 [[SHL]] to double
+; CHECK-NEXT:    ret double [[CAST]]
+;
+  %shl = shl i64 %arg, 63
+  %cast = bitcast i64 %shl to double
+  ret double %cast
+}
+
+define double @bitcast_to_double_nzero(i64 %arg) {
+; CHECK: Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(none)
+; CHECK-LABEL: define nofpclass(zero) double @bitcast_to_double_nzero
+; CHECK-SAME: (i64 [[ARG:%.*]]) #[[ATTR3]] {
+; CHECK-NEXT:    [[OR:%.*]] = or i64 [[ARG]], 1152921504606846976
+; CHECK-NEXT:    [[CAST:%.*]] = bitcast i64 [[OR]] to double
+; CHECK-NEXT:    ret double [[CAST]]
+;
+  %or = or i64 %arg, 1152921504606846976
+  %cast = bitcast i64 %or to double
+  ret double %cast
+}
+
+define double @bitcast_to_double_inf(i64 %arg) {
+; CHECK: Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(none)
+; CHECK-LABEL: define nofpclass(nan zero sub norm) double @bitcast_to_double_inf
+; CHECK-SAME: (i64 [[ARG:%.*]]) #[[ATTR3]] {
+; CHECK-NEXT:    [[SHR:%.*]] = shl i64 [[ARG]], 63
+; CHECK-NEXT:    [[OR:%.*]] = or i64 [[SHR]], 9218868437227405312
+; CHECK-NEXT:    [[CAST:%.*]] = bitcast i64 [[OR]] to double
+; CHECK-NEXT:    ret double [[CAST]]
+;
+  %shr = shl i64 %arg, 63
+  %or = or i64 %shr, 9218868437227405312
+  %cast = bitcast i64 %or to double
+  ret double %cast
+}
+
+
 define <2 x float> @bitcast_to_float_vect_sign_0(<2 x i32> %arg) {
 ; CHECK: Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(none)
 ; CHECK-LABEL: define nofpclass(ninf nzero nsub nnorm) <2 x float> @bitcast_to_float_vect_sign_0
@@ -2810,7 +2907,7 @@ define <2 x float> @bitcast_to_float_vect_sign_0(<2 x i32> %arg) {
 
 define <2 x float> @bitcast_to_float_vect_nnan(<2 x i32> %arg) {
 ; CHECK: Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(none)
-; CHECK-LABEL: define nofpclass(nan ninf nzero nsub nnorm) <2 x float> @bitcast_to_float_vect_nnan
+; CHECK-LABEL: define nofpclass(nan inf nzero nsub nnorm) <2 x float> @bitcast_to_float_vect_nnan
 ; CHECK-SAME: (<2 x i32> [[ARG:%.*]]) #[[ATTR3]] {
 ; CHECK-NEXT:    [[SHR:%.*]] = lshr <2 x i32> [[ARG]], <i32 4, i32 4>
 ; CHECK-NEXT:    [[CAST:%.*]] = bitcast <2 x i32> [[SHR]] to <2 x float>
@@ -2847,6 +2944,32 @@ define <2 x float> @bitcast_to_float_vect_nan(<2 x i32> %arg) {
   ret <2 x float> %cast
 }
 
+define <2 x float> @bitcast_to_float_vect_conservative_1(<2 x i32> %arg) {
+; CHECK: Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(none)
+; CHECK-LABEL: define <2 x float> @bitcast_to_float_vect_conservative_1
+; CHECK-SAME: (<2 x i32> [[ARG:%.*]]) #[[ATTR3]] {
+; CHECK-NEXT:    [[OR:%.*]] = or <2 x i32> [[ARG]], <i32 -2147483648, i32 0>
+; CHECK-NEXT:    [[CAST:%.*]] = bitcast <2 x i32> [[OR]] to <2 x float>
+; CHECK-NEXT:    ret <2 x float> [[CAST]]
+;
+  %or = or <2 x i32> %arg, <i32 -2147483648, i32 0>
+  %cast = bitcast <2 x i32> %or to <2 x float>
+  ret <2 x float> %cast
+}
+
+define <2 x float> @bitcast_to_float_vect_conservative_2(<2 x i32> %arg) {
+; CHECK: Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(none)
+; CHECK-LABEL: define <2 x float> @bitcast_to_float_vect_conservative_2
+; CHECK-SAME: (<2 x i32> [[ARG:%.*]]) #[[ATTR3]] {
+; CHECK-NEXT:    [[OR:%.*]] = or <2 x i32> [[ARG]], <i32 0, i32 2139095041>
+; CHECK-NEXT:    [[CAST:%.*]] = bitcast <2 x i32> [[OR]] to <2 x float>
+; CHECK-NEXT:    ret <2 x float> [[CAST]]
+;
+  %or = or <2 x i32> %arg, <i32 0, i32 2139095041>
+  %cast = bitcast <2 x i32> %or to <2 x float>
+  ret <2 x float> %cast
+}
+
 declare i64 @_Z13get_global_idj(i32 noundef)
 
 attributes #0 = { "denormal-fp-math"="preserve-sign,preserve-sign" }

>From a3fb277404581ab6b17a0502644d07a8cfe3d818 Mon Sep 17 00:00:00 2001
From: Alex MacLean <amaclean at nvidia.com>
Date: Tue, 27 Aug 2024 19:28:51 +0000
Subject: [PATCH 6/6] address comments

---
 clang/test/Headers/__clang_hip_math.hip | 571 ++++++++++++++++--------
 llvm/lib/Analysis/ValueTracking.cpp     |  10 +-
 2 files changed, 388 insertions(+), 193 deletions(-)

diff --git a/clang/test/Headers/__clang_hip_math.hip b/clang/test/Headers/__clang_hip_math.hip
index 6ee10976f12079..9d202e0d046822 100644
--- a/clang/test/Headers/__clang_hip_math.hip
+++ b/clang/test/Headers/__clang_hip_math.hip
@@ -2361,198 +2361,395 @@ extern "C" __device__ double test_modf(double x, double* y) {
   return modf(x, y);
 }
 
-// CHECK-LABEL: @test_nanf(
-// CHECK-NEXT:  entry:
-// CHECK-NEXT:    [[TMP0:%.*]] = load i8, ptr [[TAG:%.*]], align 1, !tbaa [[TBAA4]]
-// CHECK-NEXT:    [[CMP_I_I:%.*]] = icmp eq i8 [[TMP0]], 48
-// CHECK-NEXT:    br i1 [[CMP_I_I]], label [[IF_THEN_I_I:%.*]], label [[WHILE_COND_I14_I_I:%.*]]
-// CHECK:       if.then.i.i:
-// CHECK-NEXT:    [[INCDEC_PTR_I_I:%.*]] = getelementptr inbounds i8, ptr [[TAG]], i64 1
-// CHECK-NEXT:    [[TMP1:%.*]] = load i8, ptr [[INCDEC_PTR_I_I]], align 1, !tbaa [[TBAA4]]
-// CHECK-NEXT:    switch i8 [[TMP1]], label [[WHILE_COND_I_I_I:%.*]] [
-// CHECK-NEXT:      i8 120, label [[WHILE_COND_I30_I_I_PREHEADER:%.*]]
-// CHECK-NEXT:      i8 88, label [[WHILE_COND_I30_I_I_PREHEADER]]
-// CHECK-NEXT:    ]
-// CHECK:       while.cond.i30.i.i.preheader:
-// CHECK-NEXT:    br label [[WHILE_COND_I30_I_I:%.*]]
-// CHECK:       while.cond.i30.i.i:
-// CHECK-NEXT:    [[__TAGP_ADDR_0_I31_I_I:%.*]] = phi ptr [ [[__TAGP_ADDR_1_I37_I_I:%.*]], [[CLEANUP_I36_I_I:%.*]] ], [ [[INCDEC_PTR_I_I]], [[WHILE_COND_I30_I_I_PREHEADER]] ]
-// CHECK-NEXT:    [[__R_0_I32_I_I:%.*]] = phi i64 [ [[__R_2_I_I_I:%.*]], [[CLEANUP_I36_I_I]] ], [ 0, [[WHILE_COND_I30_I_I_PREHEADER]] ]
-// CHECK-NEXT:    [[TMP2:%.*]] = load i8, ptr [[__TAGP_ADDR_0_I31_I_I]], align 1, !tbaa [[TBAA4]]
-// CHECK-NEXT:    [[CMP_NOT_I33_I_I:%.*]] = icmp eq i8 [[TMP2]], 0
-// CHECK-NEXT:    br i1 [[CMP_NOT_I33_I_I]], label [[_ZL4NANFPKC_EXIT:%.*]], label [[WHILE_BODY_I34_I_I:%.*]]
-// CHECK:       while.body.i34.i.i:
-// CHECK-NEXT:    [[TMP3:%.*]] = add i8 [[TMP2]], -48
-// CHECK-NEXT:    [[OR_COND_I35_I_I:%.*]] = icmp ult i8 [[TMP3]], 10
-// CHECK-NEXT:    br i1 [[OR_COND_I35_I_I]], label [[IF_END31_I_I_I:%.*]], label [[IF_ELSE_I_I_I:%.*]]
-// CHECK:       if.else.i.i.i:
-// CHECK-NEXT:    [[TMP4:%.*]] = add i8 [[TMP2]], -97
-// CHECK-NEXT:    [[OR_COND33_I_I_I:%.*]] = icmp ult i8 [[TMP4]], 6
-// CHECK-NEXT:    br i1 [[OR_COND33_I_I_I]], label [[IF_END31_I_I_I]], label [[IF_ELSE17_I_I_I:%.*]]
-// CHECK:       if.else17.i.i.i:
-// CHECK-NEXT:    [[TMP5:%.*]] = add i8 [[TMP2]], -65
-// CHECK-NEXT:    [[OR_COND34_I_I_I:%.*]] = icmp ult i8 [[TMP5]], 6
-// CHECK-NEXT:    br i1 [[OR_COND34_I_I_I]], label [[IF_END31_I_I_I]], label [[CLEANUP_I36_I_I]]
-// CHECK:       if.end31.i.i.i:
-// CHECK-NEXT:    [[DOTSINK:%.*]] = phi i64 [ -48, [[WHILE_BODY_I34_I_I]] ], [ -87, [[IF_ELSE_I_I_I]] ], [ -55, [[IF_ELSE17_I_I_I]] ]
-// CHECK-NEXT:    [[MUL24_I_I_I:%.*]] = shl i64 [[__R_0_I32_I_I]], 4
-// CHECK-NEXT:    [[CONV25_I_I_I:%.*]] = zext nneg i8 [[TMP2]] to i64
-// CHECK-NEXT:    [[ADD26_I_I_I:%.*]] = add i64 [[MUL24_I_I_I]], [[DOTSINK]]
-// CHECK-NEXT:    [[ADD28_I_I_I:%.*]] = add i64 [[ADD26_I_I_I]], [[CONV25_I_I_I]]
-// CHECK-NEXT:    [[INCDEC_PTR_I40_I_I:%.*]] = getelementptr inbounds i8, ptr [[__TAGP_ADDR_0_I31_I_I]], i64 1
-// CHECK-NEXT:    br label [[CLEANUP_I36_I_I]]
-// CHECK:       cleanup.i36.i.i:
-// CHECK-NEXT:    [[__TAGP_ADDR_1_I37_I_I]] = phi ptr [ [[INCDEC_PTR_I40_I_I]], [[IF_END31_I_I_I]] ], [ [[__TAGP_ADDR_0_I31_I_I]], [[IF_ELSE17_I_I_I]] ]
-// CHECK-NEXT:    [[__R_2_I_I_I]] = phi i64 [ [[ADD28_I_I_I]], [[IF_END31_I_I_I]] ], [ [[__R_0_I32_I_I]], [[IF_ELSE17_I_I_I]] ]
-// CHECK-NEXT:    [[COND_I_I_I:%.*]] = phi i1 [ true, [[IF_END31_I_I_I]] ], [ false, [[IF_ELSE17_I_I_I]] ]
-// CHECK-NEXT:    br i1 [[COND_I_I_I]], label [[WHILE_COND_I30_I_I]], label [[_ZL4NANFPKC_EXIT]], !llvm.loop [[LOOP11]]
-// CHECK:       while.cond.i.i.i:
-// CHECK-NEXT:    [[__TAGP_ADDR_0_I_I_I:%.*]] = phi ptr [ [[__TAGP_ADDR_1_I_I_I:%.*]], [[CLEANUP_I_I_I:%.*]] ], [ [[INCDEC_PTR_I_I]], [[IF_THEN_I_I]] ]
-// CHECK-NEXT:    [[__R_0_I_I_I:%.*]] = phi i64 [ [[__R_1_I_I_I:%.*]], [[CLEANUP_I_I_I]] ], [ 0, [[IF_THEN_I_I]] ]
-// CHECK-NEXT:    [[TMP6:%.*]] = load i8, ptr [[__TAGP_ADDR_0_I_I_I]], align 1, !tbaa [[TBAA4]]
-// CHECK-NEXT:    [[CMP_NOT_I_I_I:%.*]] = icmp eq i8 [[TMP6]], 0
-// CHECK-NEXT:    br i1 [[CMP_NOT_I_I_I]], label [[_ZL4NANFPKC_EXIT]], label [[WHILE_BODY_I_I_I:%.*]]
-// CHECK:       while.body.i.i.i:
-// CHECK-NEXT:    [[TMP7:%.*]] = and i8 [[TMP6]], -8
-// CHECK-NEXT:    [[OR_COND_I_I_I:%.*]] = icmp eq i8 [[TMP7]], 48
-// CHECK-NEXT:    br i1 [[OR_COND_I_I_I]], label [[IF_THEN_I_I_I:%.*]], label [[CLEANUP_I_I_I]]
-// CHECK:       if.then.i.i.i:
-// CHECK-NEXT:    [[MUL_I_I_I:%.*]] = shl i64 [[__R_0_I_I_I]], 3
-// CHECK-NEXT:    [[CONV5_I_I_I:%.*]] = zext nneg i8 [[TMP6]] to i64
-// CHECK-NEXT:    [[ADD_I_I_I:%.*]] = add i64 [[MUL_I_I_I]], -48
-// CHECK-NEXT:    [[SUB_I_I_I:%.*]] = add i64 [[ADD_I_I_I]], [[CONV5_I_I_I]]
-// CHECK-NEXT:    [[INCDEC_PTR_I_I_I:%.*]] = getelementptr inbounds i8, ptr [[__TAGP_ADDR_0_I_I_I]], i64 1
-// CHECK-NEXT:    br label [[CLEANUP_I_I_I]]
-// CHECK:       cleanup.i.i.i:
-// CHECK-NEXT:    [[__TAGP_ADDR_1_I_I_I]] = phi ptr [ [[INCDEC_PTR_I_I_I]], [[IF_THEN_I_I_I]] ], [ [[__TAGP_ADDR_0_I_I_I]], [[WHILE_BODY_I_I_I]] ]
-// CHECK-NEXT:    [[__R_1_I_I_I]] = phi i64 [ [[SUB_I_I_I]], [[IF_THEN_I_I_I]] ], [ [[__R_0_I_I_I]], [[WHILE_BODY_I_I_I]] ]
-// CHECK-NEXT:    br i1 [[OR_COND_I_I_I]], label [[WHILE_COND_I_I_I]], label [[_ZL4NANFPKC_EXIT]], !llvm.loop [[LOOP7]]
-// CHECK:       while.cond.i14.i.i:
-// CHECK-NEXT:    [[__TAGP_ADDR_0_I15_I_I:%.*]] = phi ptr [ [[__TAGP_ADDR_1_I21_I_I:%.*]], [[CLEANUP_I20_I_I:%.*]] ], [ [[TAG]], [[ENTRY:%.*]] ]
-// CHECK-NEXT:    [[__R_0_I16_I_I:%.*]] = phi i64 [ [[__R_1_I22_I_I:%.*]], [[CLEANUP_I20_I_I]] ], [ 0, [[ENTRY]] ]
-// CHECK-NEXT:    [[TMP8:%.*]] = load i8, ptr [[__TAGP_ADDR_0_I15_I_I]], align 1, !tbaa [[TBAA4]]
-// CHECK-NEXT:    [[CMP_NOT_I17_I_I:%.*]] = icmp eq i8 [[TMP8]], 0
-// CHECK-NEXT:    br i1 [[CMP_NOT_I17_I_I]], label [[_ZL4NANFPKC_EXIT]], label [[WHILE_BODY_I18_I_I:%.*]]
-// CHECK:       while.body.i18.i.i:
-// CHECK-NEXT:    [[TMP9:%.*]] = add i8 [[TMP8]], -48
-// CHECK-NEXT:    [[OR_COND_I19_I_I:%.*]] = icmp ult i8 [[TMP9]], 10
-// CHECK-NEXT:    br i1 [[OR_COND_I19_I_I]], label [[IF_THEN_I24_I_I:%.*]], label [[CLEANUP_I20_I_I]]
-// CHECK:       if.then.i24.i.i:
-// CHECK-NEXT:    [[MUL_I25_I_I:%.*]] = mul i64 [[__R_0_I16_I_I]], 10
-// CHECK-NEXT:    [[CONV5_I26_I_I:%.*]] = zext nneg i8 [[TMP8]] to i64
-// CHECK-NEXT:    [[ADD_I27_I_I:%.*]] = add i64 [[MUL_I25_I_I]], -48
-// CHECK-NEXT:    [[SUB_I28_I_I:%.*]] = add i64 [[ADD_I27_I_I]], [[CONV5_I26_I_I]]
-// CHECK-NEXT:    [[INCDEC_PTR_I29_I_I:%.*]] = getelementptr inbounds i8, ptr [[__TAGP_ADDR_0_I15_I_I]], i64 1
-// CHECK-NEXT:    br label [[CLEANUP_I20_I_I]]
-// CHECK:       cleanup.i20.i.i:
-// CHECK-NEXT:    [[__TAGP_ADDR_1_I21_I_I]] = phi ptr [ [[INCDEC_PTR_I29_I_I]], [[IF_THEN_I24_I_I]] ], [ [[__TAGP_ADDR_0_I15_I_I]], [[WHILE_BODY_I18_I_I]] ]
-// CHECK-NEXT:    [[__R_1_I22_I_I]] = phi i64 [ [[SUB_I28_I_I]], [[IF_THEN_I24_I_I]] ], [ [[__R_0_I16_I_I]], [[WHILE_BODY_I18_I_I]] ]
-// CHECK-NEXT:    br i1 [[OR_COND_I19_I_I]], label [[WHILE_COND_I14_I_I]], label [[_ZL4NANFPKC_EXIT]], !llvm.loop [[LOOP10]]
-// CHECK:       _ZL4nanfPKc.exit:
-// CHECK-NEXT:    [[RETVAL_0_I_I:%.*]] = phi i64 [ 0, [[CLEANUP_I_I_I]] ], [ [[__R_0_I_I_I]], [[WHILE_COND_I_I_I]] ], [ 0, [[CLEANUP_I36_I_I]] ], [ [[__R_0_I32_I_I]], [[WHILE_COND_I30_I_I]] ], [ 0, [[CLEANUP_I20_I_I]] ], [ [[__R_0_I16_I_I]], [[WHILE_COND_I14_I_I]] ]
-// CHECK-NEXT:    [[CONV_I:%.*]] = trunc i64 [[RETVAL_0_I_I]] to i32
-// CHECK-NEXT:    [[BF_VALUE_I:%.*]] = and i32 [[CONV_I]], 4194303
-// CHECK-NEXT:    [[BF_SET9_I:%.*]] = or disjoint i32 [[BF_VALUE_I]], 2143289344
-// CHECK-NEXT:    [[TMP10:%.*]] = bitcast i32 [[BF_SET9_I]] to float
-// CHECK-NEXT:    ret float [[TMP10]]
+// DEFAULT-LABEL: @test_nanf(
+// DEFAULT-NEXT:  entry:
+// DEFAULT-NEXT:    [[TMP0:%.*]] = load i8, ptr [[TAG:%.*]], align 1, !tbaa [[TBAA4]]
+// DEFAULT-NEXT:    [[CMP_I_I:%.*]] = icmp eq i8 [[TMP0]], 48
+// DEFAULT-NEXT:    br i1 [[CMP_I_I]], label [[IF_THEN_I_I:%.*]], label [[WHILE_COND_I14_I_I:%.*]]
+// DEFAULT:       if.then.i.i:
+// DEFAULT-NEXT:    [[INCDEC_PTR_I_I:%.*]] = getelementptr inbounds i8, ptr [[TAG]], i64 1
+// DEFAULT-NEXT:    [[TMP1:%.*]] = load i8, ptr [[INCDEC_PTR_I_I]], align 1, !tbaa [[TBAA4]]
+// DEFAULT-NEXT:    switch i8 [[TMP1]], label [[WHILE_COND_I_I_I:%.*]] [
+// DEFAULT-NEXT:      i8 120, label [[WHILE_COND_I30_I_I_PREHEADER:%.*]]
+// DEFAULT-NEXT:      i8 88, label [[WHILE_COND_I30_I_I_PREHEADER]]
+// DEFAULT-NEXT:    ]
+// DEFAULT:       while.cond.i30.i.i.preheader:
+// DEFAULT-NEXT:    br label [[WHILE_COND_I30_I_I:%.*]]
+// DEFAULT:       while.cond.i30.i.i:
+// DEFAULT-NEXT:    [[__TAGP_ADDR_0_I31_I_I:%.*]] = phi ptr [ [[__TAGP_ADDR_1_I37_I_I:%.*]], [[CLEANUP_I36_I_I:%.*]] ], [ [[INCDEC_PTR_I_I]], [[WHILE_COND_I30_I_I_PREHEADER]] ]
+// DEFAULT-NEXT:    [[__R_0_I32_I_I:%.*]] = phi i64 [ [[__R_2_I_I_I:%.*]], [[CLEANUP_I36_I_I]] ], [ 0, [[WHILE_COND_I30_I_I_PREHEADER]] ]
+// DEFAULT-NEXT:    [[TMP2:%.*]] = load i8, ptr [[__TAGP_ADDR_0_I31_I_I]], align 1, !tbaa [[TBAA4]]
+// DEFAULT-NEXT:    [[CMP_NOT_I33_I_I:%.*]] = icmp eq i8 [[TMP2]], 0
+// DEFAULT-NEXT:    br i1 [[CMP_NOT_I33_I_I]], label [[_ZL4NANFPKC_EXIT:%.*]], label [[WHILE_BODY_I34_I_I:%.*]]
+// DEFAULT:       while.body.i34.i.i:
+// DEFAULT-NEXT:    [[TMP3:%.*]] = add i8 [[TMP2]], -48
+// DEFAULT-NEXT:    [[OR_COND_I35_I_I:%.*]] = icmp ult i8 [[TMP3]], 10
+// DEFAULT-NEXT:    br i1 [[OR_COND_I35_I_I]], label [[IF_END31_I_I_I:%.*]], label [[IF_ELSE_I_I_I:%.*]]
+// DEFAULT:       if.else.i.i.i:
+// DEFAULT-NEXT:    [[TMP4:%.*]] = add i8 [[TMP2]], -97
+// DEFAULT-NEXT:    [[OR_COND33_I_I_I:%.*]] = icmp ult i8 [[TMP4]], 6
+// DEFAULT-NEXT:    br i1 [[OR_COND33_I_I_I]], label [[IF_END31_I_I_I]], label [[IF_ELSE17_I_I_I:%.*]]
+// DEFAULT:       if.else17.i.i.i:
+// DEFAULT-NEXT:    [[TMP5:%.*]] = add i8 [[TMP2]], -65
+// DEFAULT-NEXT:    [[OR_COND34_I_I_I:%.*]] = icmp ult i8 [[TMP5]], 6
+// DEFAULT-NEXT:    br i1 [[OR_COND34_I_I_I]], label [[IF_END31_I_I_I]], label [[CLEANUP_I36_I_I]]
+// DEFAULT:       if.end31.i.i.i:
+// DEFAULT-NEXT:    [[DOTSINK:%.*]] = phi i64 [ -48, [[WHILE_BODY_I34_I_I]] ], [ -87, [[IF_ELSE_I_I_I]] ], [ -55, [[IF_ELSE17_I_I_I]] ]
+// DEFAULT-NEXT:    [[MUL24_I_I_I:%.*]] = shl i64 [[__R_0_I32_I_I]], 4
+// DEFAULT-NEXT:    [[CONV25_I_I_I:%.*]] = zext nneg i8 [[TMP2]] to i64
+// DEFAULT-NEXT:    [[ADD26_I_I_I:%.*]] = add i64 [[MUL24_I_I_I]], [[DOTSINK]]
+// DEFAULT-NEXT:    [[ADD28_I_I_I:%.*]] = add i64 [[ADD26_I_I_I]], [[CONV25_I_I_I]]
+// DEFAULT-NEXT:    [[INCDEC_PTR_I40_I_I:%.*]] = getelementptr inbounds i8, ptr [[__TAGP_ADDR_0_I31_I_I]], i64 1
+// DEFAULT-NEXT:    br label [[CLEANUP_I36_I_I]]
+// DEFAULT:       cleanup.i36.i.i:
+// DEFAULT-NEXT:    [[__TAGP_ADDR_1_I37_I_I]] = phi ptr [ [[INCDEC_PTR_I40_I_I]], [[IF_END31_I_I_I]] ], [ [[__TAGP_ADDR_0_I31_I_I]], [[IF_ELSE17_I_I_I]] ]
+// DEFAULT-NEXT:    [[__R_2_I_I_I]] = phi i64 [ [[ADD28_I_I_I]], [[IF_END31_I_I_I]] ], [ [[__R_0_I32_I_I]], [[IF_ELSE17_I_I_I]] ]
+// DEFAULT-NEXT:    [[COND_I_I_I:%.*]] = phi i1 [ true, [[IF_END31_I_I_I]] ], [ false, [[IF_ELSE17_I_I_I]] ]
+// DEFAULT-NEXT:    br i1 [[COND_I_I_I]], label [[WHILE_COND_I30_I_I]], label [[_ZL4NANFPKC_EXIT]], !llvm.loop [[LOOP11]]
+// DEFAULT:       while.cond.i.i.i:
+// DEFAULT-NEXT:    [[__TAGP_ADDR_0_I_I_I:%.*]] = phi ptr [ [[__TAGP_ADDR_1_I_I_I:%.*]], [[CLEANUP_I_I_I:%.*]] ], [ [[INCDEC_PTR_I_I]], [[IF_THEN_I_I]] ]
+// DEFAULT-NEXT:    [[__R_0_I_I_I:%.*]] = phi i64 [ [[__R_1_I_I_I:%.*]], [[CLEANUP_I_I_I]] ], [ 0, [[IF_THEN_I_I]] ]
+// DEFAULT-NEXT:    [[TMP6:%.*]] = load i8, ptr [[__TAGP_ADDR_0_I_I_I]], align 1, !tbaa [[TBAA4]]
+// DEFAULT-NEXT:    [[CMP_NOT_I_I_I:%.*]] = icmp eq i8 [[TMP6]], 0
+// DEFAULT-NEXT:    br i1 [[CMP_NOT_I_I_I]], label [[_ZL4NANFPKC_EXIT]], label [[WHILE_BODY_I_I_I:%.*]]
+// DEFAULT:       while.body.i.i.i:
+// DEFAULT-NEXT:    [[TMP7:%.*]] = and i8 [[TMP6]], -8
+// DEFAULT-NEXT:    [[OR_COND_I_I_I:%.*]] = icmp eq i8 [[TMP7]], 48
+// DEFAULT-NEXT:    br i1 [[OR_COND_I_I_I]], label [[IF_THEN_I_I_I:%.*]], label [[CLEANUP_I_I_I]]
+// DEFAULT:       if.then.i.i.i:
+// DEFAULT-NEXT:    [[MUL_I_I_I:%.*]] = shl i64 [[__R_0_I_I_I]], 3
+// DEFAULT-NEXT:    [[CONV5_I_I_I:%.*]] = zext nneg i8 [[TMP6]] to i64
+// DEFAULT-NEXT:    [[ADD_I_I_I:%.*]] = add i64 [[MUL_I_I_I]], -48
+// DEFAULT-NEXT:    [[SUB_I_I_I:%.*]] = add i64 [[ADD_I_I_I]], [[CONV5_I_I_I]]
+// DEFAULT-NEXT:    [[INCDEC_PTR_I_I_I:%.*]] = getelementptr inbounds i8, ptr [[__TAGP_ADDR_0_I_I_I]], i64 1
+// DEFAULT-NEXT:    br label [[CLEANUP_I_I_I]]
+// DEFAULT:       cleanup.i.i.i:
+// DEFAULT-NEXT:    [[__TAGP_ADDR_1_I_I_I]] = phi ptr [ [[INCDEC_PTR_I_I_I]], [[IF_THEN_I_I_I]] ], [ [[__TAGP_ADDR_0_I_I_I]], [[WHILE_BODY_I_I_I]] ]
+// DEFAULT-NEXT:    [[__R_1_I_I_I]] = phi i64 [ [[SUB_I_I_I]], [[IF_THEN_I_I_I]] ], [ [[__R_0_I_I_I]], [[WHILE_BODY_I_I_I]] ]
+// DEFAULT-NEXT:    br i1 [[OR_COND_I_I_I]], label [[WHILE_COND_I_I_I]], label [[_ZL4NANFPKC_EXIT]], !llvm.loop [[LOOP7]]
+// DEFAULT:       while.cond.i14.i.i:
+// DEFAULT-NEXT:    [[__TAGP_ADDR_0_I15_I_I:%.*]] = phi ptr [ [[__TAGP_ADDR_1_I21_I_I:%.*]], [[CLEANUP_I20_I_I:%.*]] ], [ [[TAG]], [[ENTRY:%.*]] ]
+// DEFAULT-NEXT:    [[__R_0_I16_I_I:%.*]] = phi i64 [ [[__R_1_I22_I_I:%.*]], [[CLEANUP_I20_I_I]] ], [ 0, [[ENTRY]] ]
+// DEFAULT-NEXT:    [[TMP8:%.*]] = load i8, ptr [[__TAGP_ADDR_0_I15_I_I]], align 1, !tbaa [[TBAA4]]
+// DEFAULT-NEXT:    [[CMP_NOT_I17_I_I:%.*]] = icmp eq i8 [[TMP8]], 0
+// DEFAULT-NEXT:    br i1 [[CMP_NOT_I17_I_I]], label [[_ZL4NANFPKC_EXIT]], label [[WHILE_BODY_I18_I_I:%.*]]
+// DEFAULT:       while.body.i18.i.i:
+// DEFAULT-NEXT:    [[TMP9:%.*]] = add i8 [[TMP8]], -48
+// DEFAULT-NEXT:    [[OR_COND_I19_I_I:%.*]] = icmp ult i8 [[TMP9]], 10
+// DEFAULT-NEXT:    br i1 [[OR_COND_I19_I_I]], label [[IF_THEN_I24_I_I:%.*]], label [[CLEANUP_I20_I_I]]
+// DEFAULT:       if.then.i24.i.i:
+// DEFAULT-NEXT:    [[MUL_I25_I_I:%.*]] = mul i64 [[__R_0_I16_I_I]], 10
+// DEFAULT-NEXT:    [[CONV5_I26_I_I:%.*]] = zext nneg i8 [[TMP8]] to i64
+// DEFAULT-NEXT:    [[ADD_I27_I_I:%.*]] = add i64 [[MUL_I25_I_I]], -48
+// DEFAULT-NEXT:    [[SUB_I28_I_I:%.*]] = add i64 [[ADD_I27_I_I]], [[CONV5_I26_I_I]]
+// DEFAULT-NEXT:    [[INCDEC_PTR_I29_I_I:%.*]] = getelementptr inbounds i8, ptr [[__TAGP_ADDR_0_I15_I_I]], i64 1
+// DEFAULT-NEXT:    br label [[CLEANUP_I20_I_I]]
+// DEFAULT:       cleanup.i20.i.i:
+// DEFAULT-NEXT:    [[__TAGP_ADDR_1_I21_I_I]] = phi ptr [ [[INCDEC_PTR_I29_I_I]], [[IF_THEN_I24_I_I]] ], [ [[__TAGP_ADDR_0_I15_I_I]], [[WHILE_BODY_I18_I_I]] ]
+// DEFAULT-NEXT:    [[__R_1_I22_I_I]] = phi i64 [ [[SUB_I28_I_I]], [[IF_THEN_I24_I_I]] ], [ [[__R_0_I16_I_I]], [[WHILE_BODY_I18_I_I]] ]
+// DEFAULT-NEXT:    br i1 [[OR_COND_I19_I_I]], label [[WHILE_COND_I14_I_I]], label [[_ZL4NANFPKC_EXIT]], !llvm.loop [[LOOP10]]
+// DEFAULT:       _ZL4nanfPKc.exit:
+// DEFAULT-NEXT:    [[RETVAL_0_I_I:%.*]] = phi i64 [ 0, [[CLEANUP_I_I_I]] ], [ [[__R_0_I_I_I]], [[WHILE_COND_I_I_I]] ], [ 0, [[CLEANUP_I36_I_I]] ], [ [[__R_0_I32_I_I]], [[WHILE_COND_I30_I_I]] ], [ 0, [[CLEANUP_I20_I_I]] ], [ [[__R_0_I16_I_I]], [[WHILE_COND_I14_I_I]] ]
+// DEFAULT-NEXT:    [[CONV_I:%.*]] = trunc i64 [[RETVAL_0_I_I]] to i32
+// DEFAULT-NEXT:    [[BF_VALUE_I:%.*]] = and i32 [[CONV_I]], 4194303
+// DEFAULT-NEXT:    [[BF_SET9_I:%.*]] = or disjoint i32 [[BF_VALUE_I]], 2143289344
+// DEFAULT-NEXT:    [[TMP10:%.*]] = bitcast i32 [[BF_SET9_I]] to float
+// DEFAULT-NEXT:    ret float [[TMP10]]
+//
+// FINITEONLY-LABEL: @test_nanf(
+// FINITEONLY-NEXT:  entry:
+// FINITEONLY-NEXT:    ret float poison
+//
+// APPROX-LABEL: @test_nanf(
+// APPROX-NEXT:  entry:
+// APPROX-NEXT:    [[TMP0:%.*]] = load i8, ptr [[TAG:%.*]], align 1, !tbaa [[TBAA4]]
+// APPROX-NEXT:    [[CMP_I_I:%.*]] = icmp eq i8 [[TMP0]], 48
+// APPROX-NEXT:    br i1 [[CMP_I_I]], label [[IF_THEN_I_I:%.*]], label [[WHILE_COND_I14_I_I:%.*]]
+// APPROX:       if.then.i.i:
+// APPROX-NEXT:    [[INCDEC_PTR_I_I:%.*]] = getelementptr inbounds i8, ptr [[TAG]], i64 1
+// APPROX-NEXT:    [[TMP1:%.*]] = load i8, ptr [[INCDEC_PTR_I_I]], align 1, !tbaa [[TBAA4]]
+// APPROX-NEXT:    switch i8 [[TMP1]], label [[WHILE_COND_I_I_I:%.*]] [
+// APPROX-NEXT:      i8 120, label [[WHILE_COND_I30_I_I_PREHEADER:%.*]]
+// APPROX-NEXT:      i8 88, label [[WHILE_COND_I30_I_I_PREHEADER]]
+// APPROX-NEXT:    ]
+// APPROX:       while.cond.i30.i.i.preheader:
+// APPROX-NEXT:    br label [[WHILE_COND_I30_I_I:%.*]]
+// APPROX:       while.cond.i30.i.i:
+// APPROX-NEXT:    [[__TAGP_ADDR_0_I31_I_I:%.*]] = phi ptr [ [[__TAGP_ADDR_1_I37_I_I:%.*]], [[CLEANUP_I36_I_I:%.*]] ], [ [[INCDEC_PTR_I_I]], [[WHILE_COND_I30_I_I_PREHEADER]] ]
+// APPROX-NEXT:    [[__R_0_I32_I_I:%.*]] = phi i64 [ [[__R_2_I_I_I:%.*]], [[CLEANUP_I36_I_I]] ], [ 0, [[WHILE_COND_I30_I_I_PREHEADER]] ]
+// APPROX-NEXT:    [[TMP2:%.*]] = load i8, ptr [[__TAGP_ADDR_0_I31_I_I]], align 1, !tbaa [[TBAA4]]
+// APPROX-NEXT:    [[CMP_NOT_I33_I_I:%.*]] = icmp eq i8 [[TMP2]], 0
+// APPROX-NEXT:    br i1 [[CMP_NOT_I33_I_I]], label [[_ZL4NANFPKC_EXIT:%.*]], label [[WHILE_BODY_I34_I_I:%.*]]
+// APPROX:       while.body.i34.i.i:
+// APPROX-NEXT:    [[TMP3:%.*]] = add i8 [[TMP2]], -48
+// APPROX-NEXT:    [[OR_COND_I35_I_I:%.*]] = icmp ult i8 [[TMP3]], 10
+// APPROX-NEXT:    br i1 [[OR_COND_I35_I_I]], label [[IF_END31_I_I_I:%.*]], label [[IF_ELSE_I_I_I:%.*]]
+// APPROX:       if.else.i.i.i:
+// APPROX-NEXT:    [[TMP4:%.*]] = add i8 [[TMP2]], -97
+// APPROX-NEXT:    [[OR_COND33_I_I_I:%.*]] = icmp ult i8 [[TMP4]], 6
+// APPROX-NEXT:    br i1 [[OR_COND33_I_I_I]], label [[IF_END31_I_I_I]], label [[IF_ELSE17_I_I_I:%.*]]
+// APPROX:       if.else17.i.i.i:
+// APPROX-NEXT:    [[TMP5:%.*]] = add i8 [[TMP2]], -65
+// APPROX-NEXT:    [[OR_COND34_I_I_I:%.*]] = icmp ult i8 [[TMP5]], 6
+// APPROX-NEXT:    br i1 [[OR_COND34_I_I_I]], label [[IF_END31_I_I_I]], label [[CLEANUP_I36_I_I]]
+// APPROX:       if.end31.i.i.i:
+// APPROX-NEXT:    [[DOTSINK:%.*]] = phi i64 [ -48, [[WHILE_BODY_I34_I_I]] ], [ -87, [[IF_ELSE_I_I_I]] ], [ -55, [[IF_ELSE17_I_I_I]] ]
+// APPROX-NEXT:    [[MUL24_I_I_I:%.*]] = shl i64 [[__R_0_I32_I_I]], 4
+// APPROX-NEXT:    [[CONV25_I_I_I:%.*]] = zext nneg i8 [[TMP2]] to i64
+// APPROX-NEXT:    [[ADD26_I_I_I:%.*]] = add i64 [[MUL24_I_I_I]], [[DOTSINK]]
+// APPROX-NEXT:    [[ADD28_I_I_I:%.*]] = add i64 [[ADD26_I_I_I]], [[CONV25_I_I_I]]
+// APPROX-NEXT:    [[INCDEC_PTR_I40_I_I:%.*]] = getelementptr inbounds i8, ptr [[__TAGP_ADDR_0_I31_I_I]], i64 1
+// APPROX-NEXT:    br label [[CLEANUP_I36_I_I]]
+// APPROX:       cleanup.i36.i.i:
+// APPROX-NEXT:    [[__TAGP_ADDR_1_I37_I_I]] = phi ptr [ [[INCDEC_PTR_I40_I_I]], [[IF_END31_I_I_I]] ], [ [[__TAGP_ADDR_0_I31_I_I]], [[IF_ELSE17_I_I_I]] ]
+// APPROX-NEXT:    [[__R_2_I_I_I]] = phi i64 [ [[ADD28_I_I_I]], [[IF_END31_I_I_I]] ], [ [[__R_0_I32_I_I]], [[IF_ELSE17_I_I_I]] ]
+// APPROX-NEXT:    [[COND_I_I_I:%.*]] = phi i1 [ true, [[IF_END31_I_I_I]] ], [ false, [[IF_ELSE17_I_I_I]] ]
+// APPROX-NEXT:    br i1 [[COND_I_I_I]], label [[WHILE_COND_I30_I_I]], label [[_ZL4NANFPKC_EXIT]], !llvm.loop [[LOOP11]]
+// APPROX:       while.cond.i.i.i:
+// APPROX-NEXT:    [[__TAGP_ADDR_0_I_I_I:%.*]] = phi ptr [ [[__TAGP_ADDR_1_I_I_I:%.*]], [[CLEANUP_I_I_I:%.*]] ], [ [[INCDEC_PTR_I_I]], [[IF_THEN_I_I]] ]
+// APPROX-NEXT:    [[__R_0_I_I_I:%.*]] = phi i64 [ [[__R_1_I_I_I:%.*]], [[CLEANUP_I_I_I]] ], [ 0, [[IF_THEN_I_I]] ]
+// APPROX-NEXT:    [[TMP6:%.*]] = load i8, ptr [[__TAGP_ADDR_0_I_I_I]], align 1, !tbaa [[TBAA4]]
+// APPROX-NEXT:    [[CMP_NOT_I_I_I:%.*]] = icmp eq i8 [[TMP6]], 0
+// APPROX-NEXT:    br i1 [[CMP_NOT_I_I_I]], label [[_ZL4NANFPKC_EXIT]], label [[WHILE_BODY_I_I_I:%.*]]
+// APPROX:       while.body.i.i.i:
+// APPROX-NEXT:    [[TMP7:%.*]] = and i8 [[TMP6]], -8
+// APPROX-NEXT:    [[OR_COND_I_I_I:%.*]] = icmp eq i8 [[TMP7]], 48
+// APPROX-NEXT:    br i1 [[OR_COND_I_I_I]], label [[IF_THEN_I_I_I:%.*]], label [[CLEANUP_I_I_I]]
+// APPROX:       if.then.i.i.i:
+// APPROX-NEXT:    [[MUL_I_I_I:%.*]] = shl i64 [[__R_0_I_I_I]], 3
+// APPROX-NEXT:    [[CONV5_I_I_I:%.*]] = zext nneg i8 [[TMP6]] to i64
+// APPROX-NEXT:    [[ADD_I_I_I:%.*]] = add i64 [[MUL_I_I_I]], -48
+// APPROX-NEXT:    [[SUB_I_I_I:%.*]] = add i64 [[ADD_I_I_I]], [[CONV5_I_I_I]]
+// APPROX-NEXT:    [[INCDEC_PTR_I_I_I:%.*]] = getelementptr inbounds i8, ptr [[__TAGP_ADDR_0_I_I_I]], i64 1
+// APPROX-NEXT:    br label [[CLEANUP_I_I_I]]
+// APPROX:       cleanup.i.i.i:
+// APPROX-NEXT:    [[__TAGP_ADDR_1_I_I_I]] = phi ptr [ [[INCDEC_PTR_I_I_I]], [[IF_THEN_I_I_I]] ], [ [[__TAGP_ADDR_0_I_I_I]], [[WHILE_BODY_I_I_I]] ]
+// APPROX-NEXT:    [[__R_1_I_I_I]] = phi i64 [ [[SUB_I_I_I]], [[IF_THEN_I_I_I]] ], [ [[__R_0_I_I_I]], [[WHILE_BODY_I_I_I]] ]
+// APPROX-NEXT:    br i1 [[OR_COND_I_I_I]], label [[WHILE_COND_I_I_I]], label [[_ZL4NANFPKC_EXIT]], !llvm.loop [[LOOP7]]
+// APPROX:       while.cond.i14.i.i:
+// APPROX-NEXT:    [[__TAGP_ADDR_0_I15_I_I:%.*]] = phi ptr [ [[__TAGP_ADDR_1_I21_I_I:%.*]], [[CLEANUP_I20_I_I:%.*]] ], [ [[TAG]], [[ENTRY:%.*]] ]
+// APPROX-NEXT:    [[__R_0_I16_I_I:%.*]] = phi i64 [ [[__R_1_I22_I_I:%.*]], [[CLEANUP_I20_I_I]] ], [ 0, [[ENTRY]] ]
+// APPROX-NEXT:    [[TMP8:%.*]] = load i8, ptr [[__TAGP_ADDR_0_I15_I_I]], align 1, !tbaa [[TBAA4]]
+// APPROX-NEXT:    [[CMP_NOT_I17_I_I:%.*]] = icmp eq i8 [[TMP8]], 0
+// APPROX-NEXT:    br i1 [[CMP_NOT_I17_I_I]], label [[_ZL4NANFPKC_EXIT]], label [[WHILE_BODY_I18_I_I:%.*]]
+// APPROX:       while.body.i18.i.i:
+// APPROX-NEXT:    [[TMP9:%.*]] = add i8 [[TMP8]], -48
+// APPROX-NEXT:    [[OR_COND_I19_I_I:%.*]] = icmp ult i8 [[TMP9]], 10
+// APPROX-NEXT:    br i1 [[OR_COND_I19_I_I]], label [[IF_THEN_I24_I_I:%.*]], label [[CLEANUP_I20_I_I]]
+// APPROX:       if.then.i24.i.i:
+// APPROX-NEXT:    [[MUL_I25_I_I:%.*]] = mul i64 [[__R_0_I16_I_I]], 10
+// APPROX-NEXT:    [[CONV5_I26_I_I:%.*]] = zext nneg i8 [[TMP8]] to i64
+// APPROX-NEXT:    [[ADD_I27_I_I:%.*]] = add i64 [[MUL_I25_I_I]], -48
+// APPROX-NEXT:    [[SUB_I28_I_I:%.*]] = add i64 [[ADD_I27_I_I]], [[CONV5_I26_I_I]]
+// APPROX-NEXT:    [[INCDEC_PTR_I29_I_I:%.*]] = getelementptr inbounds i8, ptr [[__TAGP_ADDR_0_I15_I_I]], i64 1
+// APPROX-NEXT:    br label [[CLEANUP_I20_I_I]]
+// APPROX:       cleanup.i20.i.i:
+// APPROX-NEXT:    [[__TAGP_ADDR_1_I21_I_I]] = phi ptr [ [[INCDEC_PTR_I29_I_I]], [[IF_THEN_I24_I_I]] ], [ [[__TAGP_ADDR_0_I15_I_I]], [[WHILE_BODY_I18_I_I]] ]
+// APPROX-NEXT:    [[__R_1_I22_I_I]] = phi i64 [ [[SUB_I28_I_I]], [[IF_THEN_I24_I_I]] ], [ [[__R_0_I16_I_I]], [[WHILE_BODY_I18_I_I]] ]
+// APPROX-NEXT:    br i1 [[OR_COND_I19_I_I]], label [[WHILE_COND_I14_I_I]], label [[_ZL4NANFPKC_EXIT]], !llvm.loop [[LOOP10]]
+// APPROX:       _ZL4nanfPKc.exit:
+// APPROX-NEXT:    [[RETVAL_0_I_I:%.*]] = phi i64 [ 0, [[CLEANUP_I_I_I]] ], [ [[__R_0_I_I_I]], [[WHILE_COND_I_I_I]] ], [ 0, [[CLEANUP_I36_I_I]] ], [ [[__R_0_I32_I_I]], [[WHILE_COND_I30_I_I]] ], [ 0, [[CLEANUP_I20_I_I]] ], [ [[__R_0_I16_I_I]], [[WHILE_COND_I14_I_I]] ]
+// APPROX-NEXT:    [[CONV_I:%.*]] = trunc i64 [[RETVAL_0_I_I]] to i32
+// APPROX-NEXT:    [[BF_VALUE_I:%.*]] = and i32 [[CONV_I]], 4194303
+// APPROX-NEXT:    [[BF_SET9_I:%.*]] = or disjoint i32 [[BF_VALUE_I]], 2143289344
+// APPROX-NEXT:    [[TMP10:%.*]] = bitcast i32 [[BF_SET9_I]] to float
+// APPROX-NEXT:    ret float [[TMP10]]
 //
 extern "C" __device__ float test_nanf(const char *tag) {
   return nanf(tag);
 }
 
-// CHECK-LABEL: @test_nan(
-// CHECK-NEXT:  entry:
-// CHECK-NEXT:    [[TMP0:%.*]] = load i8, ptr [[TAG:%.*]], align 1, !tbaa [[TBAA4]]
-// CHECK-NEXT:    [[CMP_I_I:%.*]] = icmp eq i8 [[TMP0]], 48
-// CHECK-NEXT:    br i1 [[CMP_I_I]], label [[IF_THEN_I_I:%.*]], label [[WHILE_COND_I14_I_I:%.*]]
-// CHECK:       if.then.i.i:
-// CHECK-NEXT:    [[INCDEC_PTR_I_I:%.*]] = getelementptr inbounds i8, ptr [[TAG]], i64 1
-// CHECK-NEXT:    [[TMP1:%.*]] = load i8, ptr [[INCDEC_PTR_I_I]], align 1, !tbaa [[TBAA4]]
-// CHECK-NEXT:    switch i8 [[TMP1]], label [[WHILE_COND_I_I_I:%.*]] [
-// CHECK-NEXT:      i8 120, label [[WHILE_COND_I30_I_I_PREHEADER:%.*]]
-// CHECK-NEXT:      i8 88, label [[WHILE_COND_I30_I_I_PREHEADER]]
-// CHECK-NEXT:    ]
-// CHECK:       while.cond.i30.i.i.preheader:
-// CHECK-NEXT:    br label [[WHILE_COND_I30_I_I:%.*]]
-// CHECK:       while.cond.i30.i.i:
-// CHECK-NEXT:    [[__TAGP_ADDR_0_I31_I_I:%.*]] = phi ptr [ [[__TAGP_ADDR_1_I37_I_I:%.*]], [[CLEANUP_I36_I_I:%.*]] ], [ [[INCDEC_PTR_I_I]], [[WHILE_COND_I30_I_I_PREHEADER]] ]
-// CHECK-NEXT:    [[__R_0_I32_I_I:%.*]] = phi i64 [ [[__R_2_I_I_I:%.*]], [[CLEANUP_I36_I_I]] ], [ 0, [[WHILE_COND_I30_I_I_PREHEADER]] ]
-// CHECK-NEXT:    [[TMP2:%.*]] = load i8, ptr [[__TAGP_ADDR_0_I31_I_I]], align 1, !tbaa [[TBAA4]]
-// CHECK-NEXT:    [[CMP_NOT_I33_I_I:%.*]] = icmp eq i8 [[TMP2]], 0
-// CHECK-NEXT:    br i1 [[CMP_NOT_I33_I_I]], label [[_ZL3NANPKC_EXIT:%.*]], label [[WHILE_BODY_I34_I_I:%.*]]
-// CHECK:       while.body.i34.i.i:
-// CHECK-NEXT:    [[TMP3:%.*]] = add i8 [[TMP2]], -48
-// CHECK-NEXT:    [[OR_COND_I35_I_I:%.*]] = icmp ult i8 [[TMP3]], 10
-// CHECK-NEXT:    br i1 [[OR_COND_I35_I_I]], label [[IF_END31_I_I_I:%.*]], label [[IF_ELSE_I_I_I:%.*]]
-// CHECK:       if.else.i.i.i:
-// CHECK-NEXT:    [[TMP4:%.*]] = add i8 [[TMP2]], -97
-// CHECK-NEXT:    [[OR_COND33_I_I_I:%.*]] = icmp ult i8 [[TMP4]], 6
-// CHECK-NEXT:    br i1 [[OR_COND33_I_I_I]], label [[IF_END31_I_I_I]], label [[IF_ELSE17_I_I_I:%.*]]
-// CHECK:       if.else17.i.i.i:
-// CHECK-NEXT:    [[TMP5:%.*]] = add i8 [[TMP2]], -65
-// CHECK-NEXT:    [[OR_COND34_I_I_I:%.*]] = icmp ult i8 [[TMP5]], 6
-// CHECK-NEXT:    br i1 [[OR_COND34_I_I_I]], label [[IF_END31_I_I_I]], label [[CLEANUP_I36_I_I]]
-// CHECK:       if.end31.i.i.i:
-// CHECK-NEXT:    [[DOTSINK:%.*]] = phi i64 [ -48, [[WHILE_BODY_I34_I_I]] ], [ -87, [[IF_ELSE_I_I_I]] ], [ -55, [[IF_ELSE17_I_I_I]] ]
-// CHECK-NEXT:    [[MUL24_I_I_I:%.*]] = shl i64 [[__R_0_I32_I_I]], 4
-// CHECK-NEXT:    [[CONV25_I_I_I:%.*]] = zext nneg i8 [[TMP2]] to i64
-// CHECK-NEXT:    [[ADD26_I_I_I:%.*]] = add i64 [[MUL24_I_I_I]], [[DOTSINK]]
-// CHECK-NEXT:    [[ADD28_I_I_I:%.*]] = add i64 [[ADD26_I_I_I]], [[CONV25_I_I_I]]
-// CHECK-NEXT:    [[INCDEC_PTR_I40_I_I:%.*]] = getelementptr inbounds i8, ptr [[__TAGP_ADDR_0_I31_I_I]], i64 1
-// CHECK-NEXT:    br label [[CLEANUP_I36_I_I]]
-// CHECK:       cleanup.i36.i.i:
-// CHECK-NEXT:    [[__TAGP_ADDR_1_I37_I_I]] = phi ptr [ [[INCDEC_PTR_I40_I_I]], [[IF_END31_I_I_I]] ], [ [[__TAGP_ADDR_0_I31_I_I]], [[IF_ELSE17_I_I_I]] ]
-// CHECK-NEXT:    [[__R_2_I_I_I]] = phi i64 [ [[ADD28_I_I_I]], [[IF_END31_I_I_I]] ], [ [[__R_0_I32_I_I]], [[IF_ELSE17_I_I_I]] ]
-// CHECK-NEXT:    [[COND_I_I_I:%.*]] = phi i1 [ true, [[IF_END31_I_I_I]] ], [ false, [[IF_ELSE17_I_I_I]] ]
-// CHECK-NEXT:    br i1 [[COND_I_I_I]], label [[WHILE_COND_I30_I_I]], label [[_ZL3NANPKC_EXIT]], !llvm.loop [[LOOP11]]
-// CHECK:       while.cond.i.i.i:
-// CHECK-NEXT:    [[__TAGP_ADDR_0_I_I_I:%.*]] = phi ptr [ [[__TAGP_ADDR_1_I_I_I:%.*]], [[CLEANUP_I_I_I:%.*]] ], [ [[INCDEC_PTR_I_I]], [[IF_THEN_I_I]] ]
-// CHECK-NEXT:    [[__R_0_I_I_I:%.*]] = phi i64 [ [[__R_1_I_I_I:%.*]], [[CLEANUP_I_I_I]] ], [ 0, [[IF_THEN_I_I]] ]
-// CHECK-NEXT:    [[TMP6:%.*]] = load i8, ptr [[__TAGP_ADDR_0_I_I_I]], align 1, !tbaa [[TBAA4]]
-// CHECK-NEXT:    [[CMP_NOT_I_I_I:%.*]] = icmp eq i8 [[TMP6]], 0
-// CHECK-NEXT:    br i1 [[CMP_NOT_I_I_I]], label [[_ZL3NANPKC_EXIT]], label [[WHILE_BODY_I_I_I:%.*]]
-// CHECK:       while.body.i.i.i:
-// CHECK-NEXT:    [[TMP7:%.*]] = and i8 [[TMP6]], -8
-// CHECK-NEXT:    [[OR_COND_I_I_I:%.*]] = icmp eq i8 [[TMP7]], 48
-// CHECK-NEXT:    br i1 [[OR_COND_I_I_I]], label [[IF_THEN_I_I_I:%.*]], label [[CLEANUP_I_I_I]]
-// CHECK:       if.then.i.i.i:
-// CHECK-NEXT:    [[MUL_I_I_I:%.*]] = shl i64 [[__R_0_I_I_I]], 3
-// CHECK-NEXT:    [[CONV5_I_I_I:%.*]] = zext nneg i8 [[TMP6]] to i64
-// CHECK-NEXT:    [[ADD_I_I_I:%.*]] = add i64 [[MUL_I_I_I]], -48
-// CHECK-NEXT:    [[SUB_I_I_I:%.*]] = add i64 [[ADD_I_I_I]], [[CONV5_I_I_I]]
-// CHECK-NEXT:    [[INCDEC_PTR_I_I_I:%.*]] = getelementptr inbounds i8, ptr [[__TAGP_ADDR_0_I_I_I]], i64 1
-// CHECK-NEXT:    br label [[CLEANUP_I_I_I]]
-// CHECK:       cleanup.i.i.i:
-// CHECK-NEXT:    [[__TAGP_ADDR_1_I_I_I]] = phi ptr [ [[INCDEC_PTR_I_I_I]], [[IF_THEN_I_I_I]] ], [ [[__TAGP_ADDR_0_I_I_I]], [[WHILE_BODY_I_I_I]] ]
-// CHECK-NEXT:    [[__R_1_I_I_I]] = phi i64 [ [[SUB_I_I_I]], [[IF_THEN_I_I_I]] ], [ [[__R_0_I_I_I]], [[WHILE_BODY_I_I_I]] ]
-// CHECK-NEXT:    br i1 [[OR_COND_I_I_I]], label [[WHILE_COND_I_I_I]], label [[_ZL3NANPKC_EXIT]], !llvm.loop [[LOOP7]]
-// CHECK:       while.cond.i14.i.i:
-// CHECK-NEXT:    [[__TAGP_ADDR_0_I15_I_I:%.*]] = phi ptr [ [[__TAGP_ADDR_1_I21_I_I:%.*]], [[CLEANUP_I20_I_I:%.*]] ], [ [[TAG]], [[ENTRY:%.*]] ]
-// CHECK-NEXT:    [[__R_0_I16_I_I:%.*]] = phi i64 [ [[__R_1_I22_I_I:%.*]], [[CLEANUP_I20_I_I]] ], [ 0, [[ENTRY]] ]
-// CHECK-NEXT:    [[TMP8:%.*]] = load i8, ptr [[__TAGP_ADDR_0_I15_I_I]], align 1, !tbaa [[TBAA4]]
-// CHECK-NEXT:    [[CMP_NOT_I17_I_I:%.*]] = icmp eq i8 [[TMP8]], 0
-// CHECK-NEXT:    br i1 [[CMP_NOT_I17_I_I]], label [[_ZL3NANPKC_EXIT]], label [[WHILE_BODY_I18_I_I:%.*]]
-// CHECK:       while.body.i18.i.i:
-// CHECK-NEXT:    [[TMP9:%.*]] = add i8 [[TMP8]], -48
-// CHECK-NEXT:    [[OR_COND_I19_I_I:%.*]] = icmp ult i8 [[TMP9]], 10
-// CHECK-NEXT:    br i1 [[OR_COND_I19_I_I]], label [[IF_THEN_I24_I_I:%.*]], label [[CLEANUP_I20_I_I]]
-// CHECK:       if.then.i24.i.i:
-// CHECK-NEXT:    [[MUL_I25_I_I:%.*]] = mul i64 [[__R_0_I16_I_I]], 10
-// CHECK-NEXT:    [[CONV5_I26_I_I:%.*]] = zext nneg i8 [[TMP8]] to i64
-// CHECK-NEXT:    [[ADD_I27_I_I:%.*]] = add i64 [[MUL_I25_I_I]], -48
-// CHECK-NEXT:    [[SUB_I28_I_I:%.*]] = add i64 [[ADD_I27_I_I]], [[CONV5_I26_I_I]]
-// CHECK-NEXT:    [[INCDEC_PTR_I29_I_I:%.*]] = getelementptr inbounds i8, ptr [[__TAGP_ADDR_0_I15_I_I]], i64 1
-// CHECK-NEXT:    br label [[CLEANUP_I20_I_I]]
-// CHECK:       cleanup.i20.i.i:
-// CHECK-NEXT:    [[__TAGP_ADDR_1_I21_I_I]] = phi ptr [ [[INCDEC_PTR_I29_I_I]], [[IF_THEN_I24_I_I]] ], [ [[__TAGP_ADDR_0_I15_I_I]], [[WHILE_BODY_I18_I_I]] ]
-// CHECK-NEXT:    [[__R_1_I22_I_I]] = phi i64 [ [[SUB_I28_I_I]], [[IF_THEN_I24_I_I]] ], [ [[__R_0_I16_I_I]], [[WHILE_BODY_I18_I_I]] ]
-// CHECK-NEXT:    br i1 [[OR_COND_I19_I_I]], label [[WHILE_COND_I14_I_I]], label [[_ZL3NANPKC_EXIT]], !llvm.loop [[LOOP10]]
-// CHECK:       _ZL3nanPKc.exit:
-// CHECK-NEXT:    [[RETVAL_0_I_I:%.*]] = phi i64 [ 0, [[CLEANUP_I_I_I]] ], [ [[__R_0_I_I_I]], [[WHILE_COND_I_I_I]] ], [ 0, [[CLEANUP_I36_I_I]] ], [ [[__R_0_I32_I_I]], [[WHILE_COND_I30_I_I]] ], [ 0, [[CLEANUP_I20_I_I]] ], [ [[__R_0_I16_I_I]], [[WHILE_COND_I14_I_I]] ]
-// CHECK-NEXT:    [[BF_VALUE_I:%.*]] = and i64 [[RETVAL_0_I_I]], 2251799813685247
-// CHECK-NEXT:    [[BF_SET9_I:%.*]] = or disjoint i64 [[BF_VALUE_I]], 9221120237041090560
-// CHECK-NEXT:    [[TMP10:%.*]] = bitcast i64 [[BF_SET9_I]] to double
-// CHECK-NEXT:    ret double [[TMP10]]
+// DEFAULT-LABEL: @test_nan(
+// DEFAULT-NEXT:  entry:
+// DEFAULT-NEXT:    [[TMP0:%.*]] = load i8, ptr [[TAG:%.*]], align 1, !tbaa [[TBAA4]]
+// DEFAULT-NEXT:    [[CMP_I_I:%.*]] = icmp eq i8 [[TMP0]], 48
+// DEFAULT-NEXT:    br i1 [[CMP_I_I]], label [[IF_THEN_I_I:%.*]], label [[WHILE_COND_I14_I_I:%.*]]
+// DEFAULT:       if.then.i.i:
+// DEFAULT-NEXT:    [[INCDEC_PTR_I_I:%.*]] = getelementptr inbounds i8, ptr [[TAG]], i64 1
+// DEFAULT-NEXT:    [[TMP1:%.*]] = load i8, ptr [[INCDEC_PTR_I_I]], align 1, !tbaa [[TBAA4]]
+// DEFAULT-NEXT:    switch i8 [[TMP1]], label [[WHILE_COND_I_I_I:%.*]] [
+// DEFAULT-NEXT:      i8 120, label [[WHILE_COND_I30_I_I_PREHEADER:%.*]]
+// DEFAULT-NEXT:      i8 88, label [[WHILE_COND_I30_I_I_PREHEADER]]
+// DEFAULT-NEXT:    ]
+// DEFAULT:       while.cond.i30.i.i.preheader:
+// DEFAULT-NEXT:    br label [[WHILE_COND_I30_I_I:%.*]]
+// DEFAULT:       while.cond.i30.i.i:
+// DEFAULT-NEXT:    [[__TAGP_ADDR_0_I31_I_I:%.*]] = phi ptr [ [[__TAGP_ADDR_1_I37_I_I:%.*]], [[CLEANUP_I36_I_I:%.*]] ], [ [[INCDEC_PTR_I_I]], [[WHILE_COND_I30_I_I_PREHEADER]] ]
+// DEFAULT-NEXT:    [[__R_0_I32_I_I:%.*]] = phi i64 [ [[__R_2_I_I_I:%.*]], [[CLEANUP_I36_I_I]] ], [ 0, [[WHILE_COND_I30_I_I_PREHEADER]] ]
+// DEFAULT-NEXT:    [[TMP2:%.*]] = load i8, ptr [[__TAGP_ADDR_0_I31_I_I]], align 1, !tbaa [[TBAA4]]
+// DEFAULT-NEXT:    [[CMP_NOT_I33_I_I:%.*]] = icmp eq i8 [[TMP2]], 0
+// DEFAULT-NEXT:    br i1 [[CMP_NOT_I33_I_I]], label [[_ZL3NANPKC_EXIT:%.*]], label [[WHILE_BODY_I34_I_I:%.*]]
+// DEFAULT:       while.body.i34.i.i:
+// DEFAULT-NEXT:    [[TMP3:%.*]] = add i8 [[TMP2]], -48
+// DEFAULT-NEXT:    [[OR_COND_I35_I_I:%.*]] = icmp ult i8 [[TMP3]], 10
+// DEFAULT-NEXT:    br i1 [[OR_COND_I35_I_I]], label [[IF_END31_I_I_I:%.*]], label [[IF_ELSE_I_I_I:%.*]]
+// DEFAULT:       if.else.i.i.i:
+// DEFAULT-NEXT:    [[TMP4:%.*]] = add i8 [[TMP2]], -97
+// DEFAULT-NEXT:    [[OR_COND33_I_I_I:%.*]] = icmp ult i8 [[TMP4]], 6
+// DEFAULT-NEXT:    br i1 [[OR_COND33_I_I_I]], label [[IF_END31_I_I_I]], label [[IF_ELSE17_I_I_I:%.*]]
+// DEFAULT:       if.else17.i.i.i:
+// DEFAULT-NEXT:    [[TMP5:%.*]] = add i8 [[TMP2]], -65
+// DEFAULT-NEXT:    [[OR_COND34_I_I_I:%.*]] = icmp ult i8 [[TMP5]], 6
+// DEFAULT-NEXT:    br i1 [[OR_COND34_I_I_I]], label [[IF_END31_I_I_I]], label [[CLEANUP_I36_I_I]]
+// DEFAULT:       if.end31.i.i.i:
+// DEFAULT-NEXT:    [[DOTSINK:%.*]] = phi i64 [ -48, [[WHILE_BODY_I34_I_I]] ], [ -87, [[IF_ELSE_I_I_I]] ], [ -55, [[IF_ELSE17_I_I_I]] ]
+// DEFAULT-NEXT:    [[MUL24_I_I_I:%.*]] = shl i64 [[__R_0_I32_I_I]], 4
+// DEFAULT-NEXT:    [[CONV25_I_I_I:%.*]] = zext nneg i8 [[TMP2]] to i64
+// DEFAULT-NEXT:    [[ADD26_I_I_I:%.*]] = add i64 [[MUL24_I_I_I]], [[DOTSINK]]
+// DEFAULT-NEXT:    [[ADD28_I_I_I:%.*]] = add i64 [[ADD26_I_I_I]], [[CONV25_I_I_I]]
+// DEFAULT-NEXT:    [[INCDEC_PTR_I40_I_I:%.*]] = getelementptr inbounds i8, ptr [[__TAGP_ADDR_0_I31_I_I]], i64 1
+// DEFAULT-NEXT:    br label [[CLEANUP_I36_I_I]]
+// DEFAULT:       cleanup.i36.i.i:
+// DEFAULT-NEXT:    [[__TAGP_ADDR_1_I37_I_I]] = phi ptr [ [[INCDEC_PTR_I40_I_I]], [[IF_END31_I_I_I]] ], [ [[__TAGP_ADDR_0_I31_I_I]], [[IF_ELSE17_I_I_I]] ]
+// DEFAULT-NEXT:    [[__R_2_I_I_I]] = phi i64 [ [[ADD28_I_I_I]], [[IF_END31_I_I_I]] ], [ [[__R_0_I32_I_I]], [[IF_ELSE17_I_I_I]] ]
+// DEFAULT-NEXT:    [[COND_I_I_I:%.*]] = phi i1 [ true, [[IF_END31_I_I_I]] ], [ false, [[IF_ELSE17_I_I_I]] ]
+// DEFAULT-NEXT:    br i1 [[COND_I_I_I]], label [[WHILE_COND_I30_I_I]], label [[_ZL3NANPKC_EXIT]], !llvm.loop [[LOOP11]]
+// DEFAULT:       while.cond.i.i.i:
+// DEFAULT-NEXT:    [[__TAGP_ADDR_0_I_I_I:%.*]] = phi ptr [ [[__TAGP_ADDR_1_I_I_I:%.*]], [[CLEANUP_I_I_I:%.*]] ], [ [[INCDEC_PTR_I_I]], [[IF_THEN_I_I]] ]
+// DEFAULT-NEXT:    [[__R_0_I_I_I:%.*]] = phi i64 [ [[__R_1_I_I_I:%.*]], [[CLEANUP_I_I_I]] ], [ 0, [[IF_THEN_I_I]] ]
+// DEFAULT-NEXT:    [[TMP6:%.*]] = load i8, ptr [[__TAGP_ADDR_0_I_I_I]], align 1, !tbaa [[TBAA4]]
+// DEFAULT-NEXT:    [[CMP_NOT_I_I_I:%.*]] = icmp eq i8 [[TMP6]], 0
+// DEFAULT-NEXT:    br i1 [[CMP_NOT_I_I_I]], label [[_ZL3NANPKC_EXIT]], label [[WHILE_BODY_I_I_I:%.*]]
+// DEFAULT:       while.body.i.i.i:
+// DEFAULT-NEXT:    [[TMP7:%.*]] = and i8 [[TMP6]], -8
+// DEFAULT-NEXT:    [[OR_COND_I_I_I:%.*]] = icmp eq i8 [[TMP7]], 48
+// DEFAULT-NEXT:    br i1 [[OR_COND_I_I_I]], label [[IF_THEN_I_I_I:%.*]], label [[CLEANUP_I_I_I]]
+// DEFAULT:       if.then.i.i.i:
+// DEFAULT-NEXT:    [[MUL_I_I_I:%.*]] = shl i64 [[__R_0_I_I_I]], 3
+// DEFAULT-NEXT:    [[CONV5_I_I_I:%.*]] = zext nneg i8 [[TMP6]] to i64
+// DEFAULT-NEXT:    [[ADD_I_I_I:%.*]] = add i64 [[MUL_I_I_I]], -48
+// DEFAULT-NEXT:    [[SUB_I_I_I:%.*]] = add i64 [[ADD_I_I_I]], [[CONV5_I_I_I]]
+// DEFAULT-NEXT:    [[INCDEC_PTR_I_I_I:%.*]] = getelementptr inbounds i8, ptr [[__TAGP_ADDR_0_I_I_I]], i64 1
+// DEFAULT-NEXT:    br label [[CLEANUP_I_I_I]]
+// DEFAULT:       cleanup.i.i.i:
+// DEFAULT-NEXT:    [[__TAGP_ADDR_1_I_I_I]] = phi ptr [ [[INCDEC_PTR_I_I_I]], [[IF_THEN_I_I_I]] ], [ [[__TAGP_ADDR_0_I_I_I]], [[WHILE_BODY_I_I_I]] ]
+// DEFAULT-NEXT:    [[__R_1_I_I_I]] = phi i64 [ [[SUB_I_I_I]], [[IF_THEN_I_I_I]] ], [ [[__R_0_I_I_I]], [[WHILE_BODY_I_I_I]] ]
+// DEFAULT-NEXT:    br i1 [[OR_COND_I_I_I]], label [[WHILE_COND_I_I_I]], label [[_ZL3NANPKC_EXIT]], !llvm.loop [[LOOP7]]
+// DEFAULT:       while.cond.i14.i.i:
+// DEFAULT-NEXT:    [[__TAGP_ADDR_0_I15_I_I:%.*]] = phi ptr [ [[__TAGP_ADDR_1_I21_I_I:%.*]], [[CLEANUP_I20_I_I:%.*]] ], [ [[TAG]], [[ENTRY:%.*]] ]
+// DEFAULT-NEXT:    [[__R_0_I16_I_I:%.*]] = phi i64 [ [[__R_1_I22_I_I:%.*]], [[CLEANUP_I20_I_I]] ], [ 0, [[ENTRY]] ]
+// DEFAULT-NEXT:    [[TMP8:%.*]] = load i8, ptr [[__TAGP_ADDR_0_I15_I_I]], align 1, !tbaa [[TBAA4]]
+// DEFAULT-NEXT:    [[CMP_NOT_I17_I_I:%.*]] = icmp eq i8 [[TMP8]], 0
+// DEFAULT-NEXT:    br i1 [[CMP_NOT_I17_I_I]], label [[_ZL3NANPKC_EXIT]], label [[WHILE_BODY_I18_I_I:%.*]]
+// DEFAULT:       while.body.i18.i.i:
+// DEFAULT-NEXT:    [[TMP9:%.*]] = add i8 [[TMP8]], -48
+// DEFAULT-NEXT:    [[OR_COND_I19_I_I:%.*]] = icmp ult i8 [[TMP9]], 10
+// DEFAULT-NEXT:    br i1 [[OR_COND_I19_I_I]], label [[IF_THEN_I24_I_I:%.*]], label [[CLEANUP_I20_I_I]]
+// DEFAULT:       if.then.i24.i.i:
+// DEFAULT-NEXT:    [[MUL_I25_I_I:%.*]] = mul i64 [[__R_0_I16_I_I]], 10
+// DEFAULT-NEXT:    [[CONV5_I26_I_I:%.*]] = zext nneg i8 [[TMP8]] to i64
+// DEFAULT-NEXT:    [[ADD_I27_I_I:%.*]] = add i64 [[MUL_I25_I_I]], -48
+// DEFAULT-NEXT:    [[SUB_I28_I_I:%.*]] = add i64 [[ADD_I27_I_I]], [[CONV5_I26_I_I]]
+// DEFAULT-NEXT:    [[INCDEC_PTR_I29_I_I:%.*]] = getelementptr inbounds i8, ptr [[__TAGP_ADDR_0_I15_I_I]], i64 1
+// DEFAULT-NEXT:    br label [[CLEANUP_I20_I_I]]
+// DEFAULT:       cleanup.i20.i.i:
+// DEFAULT-NEXT:    [[__TAGP_ADDR_1_I21_I_I]] = phi ptr [ [[INCDEC_PTR_I29_I_I]], [[IF_THEN_I24_I_I]] ], [ [[__TAGP_ADDR_0_I15_I_I]], [[WHILE_BODY_I18_I_I]] ]
+// DEFAULT-NEXT:    [[__R_1_I22_I_I]] = phi i64 [ [[SUB_I28_I_I]], [[IF_THEN_I24_I_I]] ], [ [[__R_0_I16_I_I]], [[WHILE_BODY_I18_I_I]] ]
+// DEFAULT-NEXT:    br i1 [[OR_COND_I19_I_I]], label [[WHILE_COND_I14_I_I]], label [[_ZL3NANPKC_EXIT]], !llvm.loop [[LOOP10]]
+// DEFAULT:       _ZL3nanPKc.exit:
+// DEFAULT-NEXT:    [[RETVAL_0_I_I:%.*]] = phi i64 [ 0, [[CLEANUP_I_I_I]] ], [ [[__R_0_I_I_I]], [[WHILE_COND_I_I_I]] ], [ 0, [[CLEANUP_I36_I_I]] ], [ [[__R_0_I32_I_I]], [[WHILE_COND_I30_I_I]] ], [ 0, [[CLEANUP_I20_I_I]] ], [ [[__R_0_I16_I_I]], [[WHILE_COND_I14_I_I]] ]
+// DEFAULT-NEXT:    [[BF_VALUE_I:%.*]] = and i64 [[RETVAL_0_I_I]], 2251799813685247
+// DEFAULT-NEXT:    [[BF_SET9_I:%.*]] = or disjoint i64 [[BF_VALUE_I]], 9221120237041090560
+// DEFAULT-NEXT:    [[TMP10:%.*]] = bitcast i64 [[BF_SET9_I]] to double
+// DEFAULT-NEXT:    ret double [[TMP10]]
+//
+// FINITEONLY-LABEL: @test_nan(
+// FINITEONLY-NEXT:  entry:
+// FINITEONLY-NEXT:    ret double poison
+//
+// APPROX-LABEL: @test_nan(
+// APPROX-NEXT:  entry:
+// APPROX-NEXT:    [[TMP0:%.*]] = load i8, ptr [[TAG:%.*]], align 1, !tbaa [[TBAA4]]
+// APPROX-NEXT:    [[CMP_I_I:%.*]] = icmp eq i8 [[TMP0]], 48
+// APPROX-NEXT:    br i1 [[CMP_I_I]], label [[IF_THEN_I_I:%.*]], label [[WHILE_COND_I14_I_I:%.*]]
+// APPROX:       if.then.i.i:
+// APPROX-NEXT:    [[INCDEC_PTR_I_I:%.*]] = getelementptr inbounds i8, ptr [[TAG]], i64 1
+// APPROX-NEXT:    [[TMP1:%.*]] = load i8, ptr [[INCDEC_PTR_I_I]], align 1, !tbaa [[TBAA4]]
+// APPROX-NEXT:    switch i8 [[TMP1]], label [[WHILE_COND_I_I_I:%.*]] [
+// APPROX-NEXT:      i8 120, label [[WHILE_COND_I30_I_I_PREHEADER:%.*]]
+// APPROX-NEXT:      i8 88, label [[WHILE_COND_I30_I_I_PREHEADER]]
+// APPROX-NEXT:    ]
+// APPROX:       while.cond.i30.i.i.preheader:
+// APPROX-NEXT:    br label [[WHILE_COND_I30_I_I:%.*]]
+// APPROX:       while.cond.i30.i.i:
+// APPROX-NEXT:    [[__TAGP_ADDR_0_I31_I_I:%.*]] = phi ptr [ [[__TAGP_ADDR_1_I37_I_I:%.*]], [[CLEANUP_I36_I_I:%.*]] ], [ [[INCDEC_PTR_I_I]], [[WHILE_COND_I30_I_I_PREHEADER]] ]
+// APPROX-NEXT:    [[__R_0_I32_I_I:%.*]] = phi i64 [ [[__R_2_I_I_I:%.*]], [[CLEANUP_I36_I_I]] ], [ 0, [[WHILE_COND_I30_I_I_PREHEADER]] ]
+// APPROX-NEXT:    [[TMP2:%.*]] = load i8, ptr [[__TAGP_ADDR_0_I31_I_I]], align 1, !tbaa [[TBAA4]]
+// APPROX-NEXT:    [[CMP_NOT_I33_I_I:%.*]] = icmp eq i8 [[TMP2]], 0
+// APPROX-NEXT:    br i1 [[CMP_NOT_I33_I_I]], label [[_ZL3NANPKC_EXIT:%.*]], label [[WHILE_BODY_I34_I_I:%.*]]
+// APPROX:       while.body.i34.i.i:
+// APPROX-NEXT:    [[TMP3:%.*]] = add i8 [[TMP2]], -48
+// APPROX-NEXT:    [[OR_COND_I35_I_I:%.*]] = icmp ult i8 [[TMP3]], 10
+// APPROX-NEXT:    br i1 [[OR_COND_I35_I_I]], label [[IF_END31_I_I_I:%.*]], label [[IF_ELSE_I_I_I:%.*]]
+// APPROX:       if.else.i.i.i:
+// APPROX-NEXT:    [[TMP4:%.*]] = add i8 [[TMP2]], -97
+// APPROX-NEXT:    [[OR_COND33_I_I_I:%.*]] = icmp ult i8 [[TMP4]], 6
+// APPROX-NEXT:    br i1 [[OR_COND33_I_I_I]], label [[IF_END31_I_I_I]], label [[IF_ELSE17_I_I_I:%.*]]
+// APPROX:       if.else17.i.i.i:
+// APPROX-NEXT:    [[TMP5:%.*]] = add i8 [[TMP2]], -65
+// APPROX-NEXT:    [[OR_COND34_I_I_I:%.*]] = icmp ult i8 [[TMP5]], 6
+// APPROX-NEXT:    br i1 [[OR_COND34_I_I_I]], label [[IF_END31_I_I_I]], label [[CLEANUP_I36_I_I]]
+// APPROX:       if.end31.i.i.i:
+// APPROX-NEXT:    [[DOTSINK:%.*]] = phi i64 [ -48, [[WHILE_BODY_I34_I_I]] ], [ -87, [[IF_ELSE_I_I_I]] ], [ -55, [[IF_ELSE17_I_I_I]] ]
+// APPROX-NEXT:    [[MUL24_I_I_I:%.*]] = shl i64 [[__R_0_I32_I_I]], 4
+// APPROX-NEXT:    [[CONV25_I_I_I:%.*]] = zext nneg i8 [[TMP2]] to i64
+// APPROX-NEXT:    [[ADD26_I_I_I:%.*]] = add i64 [[MUL24_I_I_I]], [[DOTSINK]]
+// APPROX-NEXT:    [[ADD28_I_I_I:%.*]] = add i64 [[ADD26_I_I_I]], [[CONV25_I_I_I]]
+// APPROX-NEXT:    [[INCDEC_PTR_I40_I_I:%.*]] = getelementptr inbounds i8, ptr [[__TAGP_ADDR_0_I31_I_I]], i64 1
+// APPROX-NEXT:    br label [[CLEANUP_I36_I_I]]
+// APPROX:       cleanup.i36.i.i:
+// APPROX-NEXT:    [[__TAGP_ADDR_1_I37_I_I]] = phi ptr [ [[INCDEC_PTR_I40_I_I]], [[IF_END31_I_I_I]] ], [ [[__TAGP_ADDR_0_I31_I_I]], [[IF_ELSE17_I_I_I]] ]
+// APPROX-NEXT:    [[__R_2_I_I_I]] = phi i64 [ [[ADD28_I_I_I]], [[IF_END31_I_I_I]] ], [ [[__R_0_I32_I_I]], [[IF_ELSE17_I_I_I]] ]
+// APPROX-NEXT:    [[COND_I_I_I:%.*]] = phi i1 [ true, [[IF_END31_I_I_I]] ], [ false, [[IF_ELSE17_I_I_I]] ]
+// APPROX-NEXT:    br i1 [[COND_I_I_I]], label [[WHILE_COND_I30_I_I]], label [[_ZL3NANPKC_EXIT]], !llvm.loop [[LOOP11]]
+// APPROX:       while.cond.i.i.i:
+// APPROX-NEXT:    [[__TAGP_ADDR_0_I_I_I:%.*]] = phi ptr [ [[__TAGP_ADDR_1_I_I_I:%.*]], [[CLEANUP_I_I_I:%.*]] ], [ [[INCDEC_PTR_I_I]], [[IF_THEN_I_I]] ]
+// APPROX-NEXT:    [[__R_0_I_I_I:%.*]] = phi i64 [ [[__R_1_I_I_I:%.*]], [[CLEANUP_I_I_I]] ], [ 0, [[IF_THEN_I_I]] ]
+// APPROX-NEXT:    [[TMP6:%.*]] = load i8, ptr [[__TAGP_ADDR_0_I_I_I]], align 1, !tbaa [[TBAA4]]
+// APPROX-NEXT:    [[CMP_NOT_I_I_I:%.*]] = icmp eq i8 [[TMP6]], 0
+// APPROX-NEXT:    br i1 [[CMP_NOT_I_I_I]], label [[_ZL3NANPKC_EXIT]], label [[WHILE_BODY_I_I_I:%.*]]
+// APPROX:       while.body.i.i.i:
+// APPROX-NEXT:    [[TMP7:%.*]] = and i8 [[TMP6]], -8
+// APPROX-NEXT:    [[OR_COND_I_I_I:%.*]] = icmp eq i8 [[TMP7]], 48
+// APPROX-NEXT:    br i1 [[OR_COND_I_I_I]], label [[IF_THEN_I_I_I:%.*]], label [[CLEANUP_I_I_I]]
+// APPROX:       if.then.i.i.i:
+// APPROX-NEXT:    [[MUL_I_I_I:%.*]] = shl i64 [[__R_0_I_I_I]], 3
+// APPROX-NEXT:    [[CONV5_I_I_I:%.*]] = zext nneg i8 [[TMP6]] to i64
+// APPROX-NEXT:    [[ADD_I_I_I:%.*]] = add i64 [[MUL_I_I_I]], -48
+// APPROX-NEXT:    [[SUB_I_I_I:%.*]] = add i64 [[ADD_I_I_I]], [[CONV5_I_I_I]]
+// APPROX-NEXT:    [[INCDEC_PTR_I_I_I:%.*]] = getelementptr inbounds i8, ptr [[__TAGP_ADDR_0_I_I_I]], i64 1
+// APPROX-NEXT:    br label [[CLEANUP_I_I_I]]
+// APPROX:       cleanup.i.i.i:
+// APPROX-NEXT:    [[__TAGP_ADDR_1_I_I_I]] = phi ptr [ [[INCDEC_PTR_I_I_I]], [[IF_THEN_I_I_I]] ], [ [[__TAGP_ADDR_0_I_I_I]], [[WHILE_BODY_I_I_I]] ]
+// APPROX-NEXT:    [[__R_1_I_I_I]] = phi i64 [ [[SUB_I_I_I]], [[IF_THEN_I_I_I]] ], [ [[__R_0_I_I_I]], [[WHILE_BODY_I_I_I]] ]
+// APPROX-NEXT:    br i1 [[OR_COND_I_I_I]], label [[WHILE_COND_I_I_I]], label [[_ZL3NANPKC_EXIT]], !llvm.loop [[LOOP7]]
+// APPROX:       while.cond.i14.i.i:
+// APPROX-NEXT:    [[__TAGP_ADDR_0_I15_I_I:%.*]] = phi ptr [ [[__TAGP_ADDR_1_I21_I_I:%.*]], [[CLEANUP_I20_I_I:%.*]] ], [ [[TAG]], [[ENTRY:%.*]] ]
+// APPROX-NEXT:    [[__R_0_I16_I_I:%.*]] = phi i64 [ [[__R_1_I22_I_I:%.*]], [[CLEANUP_I20_I_I]] ], [ 0, [[ENTRY]] ]
+// APPROX-NEXT:    [[TMP8:%.*]] = load i8, ptr [[__TAGP_ADDR_0_I15_I_I]], align 1, !tbaa [[TBAA4]]
+// APPROX-NEXT:    [[CMP_NOT_I17_I_I:%.*]] = icmp eq i8 [[TMP8]], 0
+// APPROX-NEXT:    br i1 [[CMP_NOT_I17_I_I]], label [[_ZL3NANPKC_EXIT]], label [[WHILE_BODY_I18_I_I:%.*]]
+// APPROX:       while.body.i18.i.i:
+// APPROX-NEXT:    [[TMP9:%.*]] = add i8 [[TMP8]], -48
+// APPROX-NEXT:    [[OR_COND_I19_I_I:%.*]] = icmp ult i8 [[TMP9]], 10
+// APPROX-NEXT:    br i1 [[OR_COND_I19_I_I]], label [[IF_THEN_I24_I_I:%.*]], label [[CLEANUP_I20_I_I]]
+// APPROX:       if.then.i24.i.i:
+// APPROX-NEXT:    [[MUL_I25_I_I:%.*]] = mul i64 [[__R_0_I16_I_I]], 10
+// APPROX-NEXT:    [[CONV5_I26_I_I:%.*]] = zext nneg i8 [[TMP8]] to i64
+// APPROX-NEXT:    [[ADD_I27_I_I:%.*]] = add i64 [[MUL_I25_I_I]], -48
+// APPROX-NEXT:    [[SUB_I28_I_I:%.*]] = add i64 [[ADD_I27_I_I]], [[CONV5_I26_I_I]]
+// APPROX-NEXT:    [[INCDEC_PTR_I29_I_I:%.*]] = getelementptr inbounds i8, ptr [[__TAGP_ADDR_0_I15_I_I]], i64 1
+// APPROX-NEXT:    br label [[CLEANUP_I20_I_I]]
+// APPROX:       cleanup.i20.i.i:
+// APPROX-NEXT:    [[__TAGP_ADDR_1_I21_I_I]] = phi ptr [ [[INCDEC_PTR_I29_I_I]], [[IF_THEN_I24_I_I]] ], [ [[__TAGP_ADDR_0_I15_I_I]], [[WHILE_BODY_I18_I_I]] ]
+// APPROX-NEXT:    [[__R_1_I22_I_I]] = phi i64 [ [[SUB_I28_I_I]], [[IF_THEN_I24_I_I]] ], [ [[__R_0_I16_I_I]], [[WHILE_BODY_I18_I_I]] ]
+// APPROX-NEXT:    br i1 [[OR_COND_I19_I_I]], label [[WHILE_COND_I14_I_I]], label [[_ZL3NANPKC_EXIT]], !llvm.loop [[LOOP10]]
+// APPROX:       _ZL3nanPKc.exit:
+// APPROX-NEXT:    [[RETVAL_0_I_I:%.*]] = phi i64 [ 0, [[CLEANUP_I_I_I]] ], [ [[__R_0_I_I_I]], [[WHILE_COND_I_I_I]] ], [ 0, [[CLEANUP_I36_I_I]] ], [ [[__R_0_I32_I_I]], [[WHILE_COND_I30_I_I]] ], [ 0, [[CLEANUP_I20_I_I]] ], [ [[__R_0_I16_I_I]], [[WHILE_COND_I14_I_I]] ]
+// APPROX-NEXT:    [[BF_VALUE_I:%.*]] = and i64 [[RETVAL_0_I_I]], 2251799813685247
+// APPROX-NEXT:    [[BF_SET9_I:%.*]] = or disjoint i64 [[BF_VALUE_I]], 9221120237041090560
+// APPROX-NEXT:    [[TMP10:%.*]] = bitcast i64 [[BF_SET9_I]] to double
+// APPROX-NEXT:    ret double [[TMP10]]
 //
 extern "C" __device__ double test_nan(const char *tag) {
   return nan(tag);
diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp
index 15e8716d256656..533fe62fb8cdd6 100644
--- a/llvm/lib/Analysis/ValueTracking.cpp
+++ b/llvm/lib/Analysis/ValueTracking.cpp
@@ -5952,9 +5952,8 @@ void computeKnownFPClass(const Value *V, const APInt &DemandedElts,
       // Build KnownBits representing Inf and check if it must be equal or
       // unequal to this value.
       auto InfKB = KnownBits::makeConstant(
-          APFloat::getInf(Ty->getFltSemantics(), false).bitcastToAPInt());
-      InfKB = InfKB.intersectWith(KnownBits::makeConstant(
-          APFloat::getInf(Ty->getFltSemantics(), true).bitcastToAPInt()));
+          APFloat::getInf(Ty->getFltSemantics()).bitcastToAPInt());
+      InfKB.Zero.clearSignBit();
       if (const auto InfResult = KnownBits::eq(Bits, InfKB)) {
         assert(!InfResult.value());
         Known.knownNot(fcInf);
@@ -5965,9 +5964,8 @@ void computeKnownFPClass(const Value *V, const APInt &DemandedElts,
       // Build KnownBits representing Zero and check if it must be equal or
       // unequal to this value.
       auto ZeroKB = KnownBits::makeConstant(
-          APFloat::getZero(Ty->getFltSemantics(), false).bitcastToAPInt());
-      ZeroKB = ZeroKB.intersectWith(KnownBits::makeConstant(
-          APFloat::getZero(Ty->getFltSemantics(), true).bitcastToAPInt()));
+          APFloat::getZero(Ty->getFltSemantics()).bitcastToAPInt());
+      ZeroKB.Zero.clearSignBit();
       if (const auto ZeroResult = KnownBits::eq(Bits, ZeroKB)) {
         assert(!ZeroResult.value());
         Known.knownNot(fcZero);



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