[llvm] [RFC][Draft] Extend MemoryEffects to Support Target-Specific Memory L… (PR #148650)

[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 {
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CarolineConcatto wrote:

Hi @antoniofrighetto 
I will try to follow your suggestion in a next iteration. I am not sure I fully understand the consequences of implementing this way.

For instance: I am not sure I can have only one Kind.

For instance, something like this:
def int_aarch64_get_fpmr_set_za   : DefaultAttrsIntrinsic<[], [llvm_i64_ty], [IntrInaccessibleReadMemOnly<AArch64_FPMR>, IntrInaccessibleWriteMemOnly<AArch64_ZA>]>;

I imagine that the ModRefInfo for  TargetSpecificMem  will be 11, that is ModRef.
But how Kind will work in the case above? Do you have an idea?  Because we need to set one to just write and another to just read.
I can only think about another TargetMemoryLocation and another vector like Data, but only used when TargetSpecificMem !=NoModRef 


I would also have to see how this will work in BasicAliasAnalysis.cpp/getModRefInfo and  BitcodeReader.cpp(parseAttributeGroupBlock)

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