[llvm] [InferAddressSpaces] Handle unconverted ptrmask (PR #140802)

[Robert Imschweiler via llvm-commits]

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@@ -495,6 +495,13 @@ class TargetTransformInfo {
 
   LLVM_ABI bool isNoopAddrSpaceCast(unsigned FromAS, unsigned ToAS) const;
 
+  LLVM_ABI std::pair<KnownBits, KnownBits>
+  computeKnownBitsAddrSpaceCast(unsigned FromAS, unsigned ToAS,
+                                const Value &PtrOp) const;
+
+  LLVM_ABI KnownBits computeKnownBitsAddrSpaceCast(
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ro-i wrote:

at least in general. For amdgpu, this assumption has already been in the original code, so ig I can add an override for computeKnownBitsAddrSpaceCast in AMDGPUTargetTransformInfo

https://github.com/llvm/llvm-project/pull/140802