[llvm] [llvm][SelectionDAG] Relax llvm.ptrmask's size check on arm64_32 (PR #94125)

[Nikita Popov via llvm-commits]

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@@ -7842,9 +7842,19 @@ void SelectionDAGBuilder::visitIntrinsicCall(const CallInst &I,
     SDValue Ptr = getValue(I.getOperand(0));
     SDValue Mask = getValue(I.getOperand(1));
 
-    EVT PtrVT = Ptr.getValueType();
-    assert(PtrVT == Mask.getValueType() &&
-           "Pointers with different index type are not supported by SDAG");
+    // On arm64_32, pointers are 32 bits when stored in memory, but
+    // zero-extended to 64 bits when in registers.  Thus the mask is 32 bits to
+    // match the index type, but the pointer is 64 bits, so the the mask must be
+    // zero-extended up to 64 bits to match the pointer.
+    EVT PtrVT =
+        TLI.getValueType(DAG.getDataLayout(), I.getOperand(0)->getType());
+    EVT MemVT =
+        TLI.getMemValueType(DAG.getDataLayout(), I.getOperand(0)->getType());
+    assert(PtrVT == Ptr.getValueType());
+    assert(MemVT == Mask.getValueType());
+    if (MemVT != PtrVT)
+      Mask = DAG.getPtrExtOrTrunc(Mask, sdl, PtrVT);
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nikic wrote:

Hm actually, this doesn't look quite right. This would not have the right result if PtrExt does a SignExt.

https://github.com/llvm/llvm-project/pull/94125