[clang] [clang][bytecode] Allocate IntegralAP and Floating types using an allocator (PR #144246)

[Aaron Ballman via cfe-commits]

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@@ -17,63 +17,80 @@
 #include "clang/AST/APValue.h"
 #include "llvm/ADT/APFloat.h"
 
+// XXX This is just a debugging help. Setting this to 1 will heap-allocate ALL
+// floating values.
+#define ALLOCATE_ALL 0
+
 namespace clang {
 namespace interp {
 
 using APFloat = llvm::APFloat;
 using APSInt = llvm::APSInt;
+using APInt = llvm::APInt;
 
+/// If a Floating is constructed from Memory, it DOES NOT OWN THAT MEMORY.
+/// It will NOT copy the memory (unless, of course, copy() is called) an it
+/// won't alllocate anything. The allocation should happen via InterpState or
+/// Program.
 class Floating final {
 private:
-  // The underlying value storage.
-  APFloat F;
+  union {
+    uint64_t Val = 0;
+    uint64_t *Memory;
+  };
+  llvm::APFloatBase::Semantics Semantics =
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AaronBallman wrote:

Why is the default `half`?

https://github.com/llvm/llvm-project/pull/144246