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

[Yingwei Zheng via llvm-commits]

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@@ -794,6 +996,77 @@ class InstExecutor : public InstVisitor<InstExecutor, void> {
     });
   }
 
+  void visitFPExtInst(FPExtInst &FPExt) { visitFPConvInst(FPExt); }
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dtcxzyw wrote:

> NaN values follow the usual [NaN behaviors](https://llvm.org/docs/LangRef.html#floatnan), except that _if_ a NaN payload is propagated from the input (“Quieting NaN propagation” or “Unchanged NaN propagation” cases), then it is copied to the high order bits of the resulting payload, and the remaining low order bits are zero.

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