diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp
index 5ae8574ebe13..0458d284eb40 100644
--- a/llvm/lib/Analysis/ValueTracking.cpp
+++ b/llvm/lib/Analysis/ValueTracking.cpp
@@ -2000,8 +2000,11 @@ bool llvm::CannotBeNegativeZero(const Value *V, unsigned Depth) {
   if (const ConstantFP *CFP = dyn_cast<ConstantFP>(V))
     return !CFP->getValueAPF().isNegZero();
 
+  // FIXME: Magic number! At the least, this should be given a name because it's
+  // used similarly in CannotBeOrderedLessThanZero(). A better fix may be to
+  // expose it as a parameter, so it can be used for testing / experimenting.
   if (Depth == 6)
-    return 1;  // Limit search depth.
+    return false;  // Limit search depth.
 
   const Operator *I = dyn_cast<Operator>(V);
   if (!I) return false;
@@ -2048,6 +2051,9 @@ bool llvm::CannotBeOrderedLessThanZero(const Value *V, unsigned Depth) {
   if (const ConstantFP *CFP = dyn_cast<ConstantFP>(V))
     return !CFP->getValueAPF().isNegative() || CFP->getValueAPF().isZero();
 
+  // FIXME: Magic number! At the least, this should be given a name because it's
+  // used similarly in CannotBeNegativeZero(). A better fix may be to
+  // expose it as a parameter, so it can be used for testing / experimenting.
   if (Depth == 6)
     return false;  // Limit search depth.
 
diff --git a/llvm/test/Transforms/InstSimplify/floating-point-arithmetic.ll b/llvm/test/Transforms/InstSimplify/floating-point-arithmetic.ll
index 8177440472cb..b0957a817739 100644
--- a/llvm/test/Transforms/InstSimplify/floating-point-arithmetic.ll
+++ b/llvm/test/Transforms/InstSimplify/floating-point-arithmetic.ll
@@ -33,3 +33,29 @@ define double @fmul_X_1(double %a) {
   ; CHECK: ret double %a
   ret double %b
 }
+
+; We can't optimize away the fadd in this test because the input
+; value to the function and subsequently to the fadd may be -0.0. 
+; In that one special case, the result of the fadd should be +0.0
+; rather than the first parameter of the fadd.
+
+; Fragile test warning: We need 6 sqrt calls to trigger the bug 
+; because the internal logic has a magic recursion limit of 6. 
+; This is presented without any explanation or ability to customize.
+
+declare float @sqrtf(float)
+
+define float @PR22688(float %x) {
+  %1 = call float @sqrtf(float %x)
+  %2 = call float @sqrtf(float %1)
+  %3 = call float @sqrtf(float %2)
+  %4 = call float @sqrtf(float %3)
+  %5 = call float @sqrtf(float %4)
+  %6 = call float @sqrtf(float %5)
+  %7 = fadd float %6, 0.0
+  ret float %7
+
+; CHECK-LABEL: @PR22688(
+; CHECK: fadd float %6, 0.0
+}
+