[llvm] [NVPTX] instcombine known pointer AS checks. (PR #112964)

[Artem Belevich via llvm-commits]

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@@ -6365,6 +6367,32 @@ static Value *simplifyUnaryIntrinsic(Function *F, Value *Op0,
 
     break;
   }
+  case Intrinsic::nvvm_isspacep_global:
+  case Intrinsic::nvvm_isspacep_local:
+  case Intrinsic::nvvm_isspacep_shared:
+  case Intrinsic::nvvm_isspacep_const: {
+    auto *Ty = F->getReturnType();
+    unsigned AS = Op0->getType()->getPointerAddressSpace();
+    if (AS == NVPTXAS::ADDRESS_SPACE_GENERIC) {
+      if (auto *ASC = dyn_cast<AddrSpaceCastInst>(Op0))
+        AS = ASC->getSrcAddressSpace();
+      else if (auto *ASCO = dyn_cast<AddrSpaceCastOperator>(Op0))
+        AS = ASCO->getOperand(0)->getType()->getPointerAddressSpace();
+    }
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Artem-B wrote:

Ooh. This is convenient. Thanks for pointing it out. 

Coincidentally, the current tests in the patch didn't actually test handling of ASC instruction, as instcombine collapsed ASC(constant) into an ASC operator before we've got to handle the intrinsics. I'll update the code and the tests.

https://github.com/llvm/llvm-project/pull/112964