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

[Shilei Tian 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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shiltian wrote:

> The addrspacecast.

Then I'd just leave the cast between two address spaces part into TTI, which makes sense, and then leave no default implementation. Even for us, with GAS, AS5->AS0 is not zero extension.

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