[llvm] [ValueTracking] Compute knownbits from known fp classes (PR #86409)

[Matt Arsenault via llvm-commits]

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@@ -1121,6 +1121,40 @@ static void computeKnownBitsFromOperator(const Operator *I,
       break;
     }
 
+    Value *V;
+    // Handle bitcast from floating point to integer.
+    if (match(const_cast<Operator *>(I), m_ElementWiseBitCast(m_Value(V))) &&
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arsenm wrote:

Shouldn't need const cast if V is const? 

https://github.com/llvm/llvm-project/pull/86409