Index: llvm/include/llvm/Analysis/ValueTracking.h
===================================================================
--- llvm/include/llvm/Analysis/ValueTracking.h
+++ llvm/include/llvm/Analysis/ValueTracking.h
@@ -249,6 +249,11 @@
     return (KnownFPClasses & fcInf) == fcNone;
   }
 
+  /// Return true if it's known this can never be +infinity.
+  bool isKnownNeverPosInfinity() const {
+    return (KnownFPClasses & fcPosInf) == fcNone;
+  }
+
   /// Return true if it's known this can never be a zero.
   bool isKnownNeverZero() const {
     return (KnownFPClasses & fcZero) == fcNone;
Index: llvm/lib/Analysis/ValueTracking.cpp
===================================================================
--- llvm/lib/Analysis/ValueTracking.cpp
+++ llvm/lib/Analysis/ValueTracking.cpp
@@ -4432,6 +4432,36 @@
         Known.copysign(KnownSign);
         break;
       }
+      case Intrinsic::sqrt: {
+        KnownFPClass KnownSrc;
+        computeKnownFPClass(II->getArgOperand(0), DemandedElts,
+                            InterestedClasses, KnownSrc, Depth + 1, Q, TLI);
+
+        if (KnownSrc.isKnownNeverPosInfinity())
+          Known.knownNot(fcPosInf);
+
+        if (KnownSrc.isKnownNeverNaN() &&
+            (InterestedClasses & fcNan) != fcNone &&
+            cannotBeOrderedLessThanZeroImpl(II->getArgOperand(0), TLI, false,
+                                            Depth + 1))
+          Known.knownNot(fcNan);
+
+        // Any negative value besides -0 returns a nan.
+        if (KnownSrc.isKnownNeverNaN() && KnownSrc.SignBit &&
+            !*KnownSrc.SignBit) {
+          Known.knownNot(fcNan);
+          Known.SignBit = false;
+        }
+
+        // The only negative value that can be returned is -0 for -0 inputs.
+        Known.knownNot(fcNegInf | fcNegSubnormal | fcNegNormal);
+        if ((KnownSrc.KnownFPClasses & fcNegZero) == fcNone) {
+          Known.knownNot(fcNegZero);
+          Known.SignBit = false;
+        }
+
+        break;
+      }
       case Intrinsic::sin:
       case Intrinsic::cos: {
         // Return NaN on infinite inputs.
Index: llvm/test/Transforms/Attributor/nofpclass-sqrt.ll
===================================================================
--- /dev/null
+++ llvm/test/Transforms/Attributor/nofpclass-sqrt.ll
@@ -4,9 +4,9 @@
 declare float @llvm.sqrt.f32(float)
 
 define float @ret_sqrt(float %arg0) {
-; CHECK-LABEL: define float @ret_sqrt
+; CHECK-LABEL: define nofpclass(ninf nsub nnorm) float @ret_sqrt
 ; CHECK-SAME: (float [[ARG0:%.*]]) #[[ATTR1:[0-9]+]] {
-; CHECK-NEXT:    [[CALL:%.*]] = call float @llvm.sqrt.f32(float [[ARG0]]) #[[ATTR2:[0-9]+]]
+; CHECK-NEXT:    [[CALL:%.*]] = call nofpclass(ninf nsub nnorm) float @llvm.sqrt.f32(float [[ARG0]]) #[[ATTR2:[0-9]+]]
 ; CHECK-NEXT:    ret float [[CALL]]
 ;
   %call = call float @llvm.sqrt.f32(float %arg0)
@@ -14,9 +14,9 @@
 }
 
 define float @ret_sqrt_noinf(float nofpclass(inf) %arg0) {
-; CHECK-LABEL: define float @ret_sqrt_noinf
+; CHECK-LABEL: define nofpclass(inf nsub nnorm) float @ret_sqrt_noinf
 ; CHECK-SAME: (float nofpclass(inf) [[ARG0:%.*]]) #[[ATTR1]] {
-; CHECK-NEXT:    [[CALL:%.*]] = call float @llvm.sqrt.f32(float [[ARG0]]) #[[ATTR2]]
+; CHECK-NEXT:    [[CALL:%.*]] = call nofpclass(inf nsub nnorm) float @llvm.sqrt.f32(float [[ARG0]]) #[[ATTR2]]
 ; CHECK-NEXT:    ret float [[CALL]]
 ;
   %call = call float @llvm.sqrt.f32(float %arg0)
@@ -24,9 +24,9 @@
 }
 
 define float @ret_sqrt_nopinf(float nofpclass(pinf) %arg0) {
-; CHECK-LABEL: define float @ret_sqrt_nopinf
+; CHECK-LABEL: define nofpclass(inf nsub nnorm) float @ret_sqrt_nopinf
 ; CHECK-SAME: (float nofpclass(pinf) [[ARG0:%.*]]) #[[ATTR1]] {
-; CHECK-NEXT:    [[CALL:%.*]] = call float @llvm.sqrt.f32(float [[ARG0]]) #[[ATTR2]]
+; CHECK-NEXT:    [[CALL:%.*]] = call nofpclass(inf nsub nnorm) float @llvm.sqrt.f32(float [[ARG0]]) #[[ATTR2]]
 ; CHECK-NEXT:    ret float [[CALL]]
 ;
   %call = call float @llvm.sqrt.f32(float %arg0)
@@ -34,9 +34,9 @@
 }
 
 define float @ret_sqrt_noninf(float nofpclass(ninf) %arg0) {
-; CHECK-LABEL: define float @ret_sqrt_noninf
+; CHECK-LABEL: define nofpclass(ninf nsub nnorm) float @ret_sqrt_noninf
 ; CHECK-SAME: (float nofpclass(ninf) [[ARG0:%.*]]) #[[ATTR1]] {
-; CHECK-NEXT:    [[CALL:%.*]] = call float @llvm.sqrt.f32(float [[ARG0]]) #[[ATTR2]]
+; CHECK-NEXT:    [[CALL:%.*]] = call nofpclass(ninf nsub nnorm) float @llvm.sqrt.f32(float [[ARG0]]) #[[ATTR2]]
 ; CHECK-NEXT:    ret float [[CALL]]
 ;
   %call = call float @llvm.sqrt.f32(float %arg0)
@@ -44,9 +44,9 @@
 }
 
 define float @ret_sqrt_nonan(float nofpclass(nan) %arg0) {
-; CHECK-LABEL: define float @ret_sqrt_nonan
+; CHECK-LABEL: define nofpclass(ninf nsub nnorm) float @ret_sqrt_nonan
 ; CHECK-SAME: (float nofpclass(nan) [[ARG0:%.*]]) #[[ATTR1]] {
-; CHECK-NEXT:    [[CALL:%.*]] = call float @llvm.sqrt.f32(float [[ARG0]]) #[[ATTR2]]
+; CHECK-NEXT:    [[CALL:%.*]] = call nofpclass(ninf nsub nnorm) float @llvm.sqrt.f32(float [[ARG0]]) #[[ATTR2]]
 ; CHECK-NEXT:    ret float [[CALL]]
 ;
   %call = call float @llvm.sqrt.f32(float %arg0)
@@ -54,9 +54,9 @@
 }
 
 define float @ret_sqrt_nonan_noinf(float nofpclass(nan inf) %arg0) {
-; CHECK-LABEL: define float @ret_sqrt_nonan_noinf
+; CHECK-LABEL: define nofpclass(inf nsub nnorm) float @ret_sqrt_nonan_noinf
 ; CHECK-SAME: (float nofpclass(nan inf) [[ARG0:%.*]]) #[[ATTR1]] {
-; CHECK-NEXT:    [[CALL:%.*]] = call float @llvm.sqrt.f32(float [[ARG0]]) #[[ATTR2]]
+; CHECK-NEXT:    [[CALL:%.*]] = call nofpclass(inf nsub nnorm) float @llvm.sqrt.f32(float [[ARG0]]) #[[ATTR2]]
 ; CHECK-NEXT:    ret float [[CALL]]
 ;
   %call = call float @llvm.sqrt.f32(float %arg0)
@@ -64,9 +64,9 @@
 }
 
 define float @ret_sqrt_nonan_noinf_nozero(float nofpclass(nan inf zero) %arg0) {
-; CHECK-LABEL: define float @ret_sqrt_nonan_noinf_nozero
+; CHECK-LABEL: define nofpclass(inf nzero nsub nnorm) float @ret_sqrt_nonan_noinf_nozero
 ; CHECK-SAME: (float nofpclass(nan inf zero) [[ARG0:%.*]]) #[[ATTR1]] {
-; CHECK-NEXT:    [[CALL:%.*]] = call float @llvm.sqrt.f32(float [[ARG0]]) #[[ATTR2]]
+; CHECK-NEXT:    [[CALL:%.*]] = call nofpclass(inf nzero nsub nnorm) float @llvm.sqrt.f32(float [[ARG0]]) #[[ATTR2]]
 ; CHECK-NEXT:    ret float [[CALL]]
 ;
   %call = call float @llvm.sqrt.f32(float %arg0)
@@ -74,9 +74,9 @@
 }
 
 define float @ret_sqrt_noinf_nozero(float nofpclass(inf zero) %arg0) {
-; CHECK-LABEL: define float @ret_sqrt_noinf_nozero
+; CHECK-LABEL: define nofpclass(inf nzero nsub nnorm) float @ret_sqrt_noinf_nozero
 ; CHECK-SAME: (float nofpclass(inf zero) [[ARG0:%.*]]) #[[ATTR1]] {
-; CHECK-NEXT:    [[CALL:%.*]] = call float @llvm.sqrt.f32(float [[ARG0]]) #[[ATTR2]]
+; CHECK-NEXT:    [[CALL:%.*]] = call nofpclass(inf nzero nsub nnorm) float @llvm.sqrt.f32(float [[ARG0]]) #[[ATTR2]]
 ; CHECK-NEXT:    ret float [[CALL]]
 ;
   %call = call float @llvm.sqrt.f32(float %arg0)
@@ -84,9 +84,9 @@
 }
 
 define float @ret_sqrt_noinf_nonegzero(float nofpclass(inf nzero) %arg0) {
-; CHECK-LABEL: define float @ret_sqrt_noinf_nonegzero
+; CHECK-LABEL: define nofpclass(inf nzero nsub nnorm) float @ret_sqrt_noinf_nonegzero
 ; CHECK-SAME: (float nofpclass(inf nzero) [[ARG0:%.*]]) #[[ATTR1]] {
-; CHECK-NEXT:    [[CALL:%.*]] = call float @llvm.sqrt.f32(float [[ARG0]]) #[[ATTR2]]
+; CHECK-NEXT:    [[CALL:%.*]] = call nofpclass(inf nzero nsub nnorm) float @llvm.sqrt.f32(float [[ARG0]]) #[[ATTR2]]
 ; CHECK-NEXT:    ret float [[CALL]]
 ;
   %call = call float @llvm.sqrt.f32(float %arg0)
@@ -94,10 +94,10 @@
 }
 
 define float @ret_sqrt_positive_source(i32 %arg) {
-; CHECK-LABEL: define float @ret_sqrt_positive_source
+; CHECK-LABEL: define nofpclass(nan inf nzero nsub nnorm) float @ret_sqrt_positive_source
 ; CHECK-SAME: (i32 [[ARG:%.*]]) #[[ATTR1]] {
 ; CHECK-NEXT:    [[UITOFP:%.*]] = uitofp i32 [[ARG]] to float
-; CHECK-NEXT:    [[CALL:%.*]] = call float @llvm.sqrt.f32(float [[UITOFP]]) #[[ATTR2]]
+; CHECK-NEXT:    [[CALL:%.*]] = call nofpclass(nan inf nzero nsub nnorm) float @llvm.sqrt.f32(float [[UITOFP]]) #[[ATTR2]]
 ; CHECK-NEXT:    ret float [[CALL]]
 ;
   %uitofp = uitofp i32 %arg to float
@@ -107,10 +107,10 @@
 
 ; Could produce a nan because we don't know if the multiply is negative.
 define float @ret_sqrt_unknown_sign(float nofpclass(nan) %arg0, float nofpclass(nan) %arg1) {
-; CHECK-LABEL: define float @ret_sqrt_unknown_sign
+; CHECK-LABEL: define nofpclass(ninf nsub nnorm) float @ret_sqrt_unknown_sign
 ; CHECK-SAME: (float nofpclass(nan) [[ARG0:%.*]], float nofpclass(nan) [[ARG1:%.*]]) #[[ATTR1]] {
 ; CHECK-NEXT:    [[UNKNOWN_SIGN_NOT_NAN:%.*]] = fmul nnan float [[ARG0]], [[ARG1]]
-; CHECK-NEXT:    [[CALL:%.*]] = call float @llvm.sqrt.f32(float [[UNKNOWN_SIGN_NOT_NAN]]) #[[ATTR2]]
+; CHECK-NEXT:    [[CALL:%.*]] = call nofpclass(ninf nsub nnorm) float @llvm.sqrt.f32(float [[UNKNOWN_SIGN_NOT_NAN]]) #[[ATTR2]]
 ; CHECK-NEXT:    ret float [[CALL]]
 ;
   %unknown.sign.not.nan = fmul nnan float %arg0, %arg1