[llvm] [llubi] Initial support for floating-point numbers (PR #188453)

[Yingwei Zheng via llvm-commits]

================
@@ -108,6 +209,28 @@ class InstExecutor : public InstVisitor<InstExecutor, void>,
     });
   }
 
+  void visitFPUnOp(Instruction &I,
+                   function_ref<APFloat(const APFloat &)> ScalarFn) {
+    FastMathFlags FMF = cast<FPMathOperator>(I).getFastMathFlags();
+
+    visitUnOp(I, [&](const AnyValue &Operand) -> AnyValue {
+      if (Operand.isPoison())
+        return AnyValue::poison();
+
+      // We don't flush denormals here since the only floating-point unary
+      // operation is fneg. And fneg is specified as a bitwise operation which
+      // only flips the sign bit of the input.
+
+      AnyValue ValidatedOperand = handleFMFFlags(Operand, FMF, true);
+      if (ValidatedOperand.isPoison())
+        return ValidatedOperand;
+
+      APFloat Result = ScalarFn(ValidatedOperand.asFloat());
+
+      return handleFMFFlags(Result, FMF, false);
----------------
dtcxzyw wrote:

```suggestion
      return handleFMFFlags(Result, FMF,  /*IsInput=*/false);
```

https://github.com/llvm/llvm-project/pull/188453