[llvm] Extend MemoryEffects to Support Target-Specific Memory Locations (PR #148650)

[Paul Walker via llvm-commits]

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@@ -56,6 +56,11 @@ enum class ModRefInfo : uint8_t {
 /// Debug print ModRefInfo.
 LLVM_ABI raw_ostream &operator<<(raw_ostream &OS, ModRefInfo MR);
 
+enum class InaccessibleTargetMemLocation {
+  TargetMem0 = 3,
+  TargetMem1 = 4,
+};
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paulwalker-arm wrote:

Is there a good reason to separate these from `IRMemLocation`? Parts of the patch is forced to use `>ErrnoMem` because there's no enum value to directly compare. Having all the locations in `IRMemLocation` removes this problem along with a bunch on unnecessary casting.

When doing this perhaps it's worth adding `FirstTargetMem = TargetMem0` and `LastTargetMem = TargetMem1` then using this for range checking, that way it'll be easy to add more TargetMem locations in the future.

https://github.com/llvm/llvm-project/pull/148650