Fix Memory64Lowering table.copy size wrapping for mixed tables (#8319)

`visitTableCopy` wrapped `curr->size` using only the dest table's type,
but the wasm spec (and `child-typer.h`) defines the size type as i64
only when **both** source and dest tables are 64-bit. When copying
between a 64-bit and a 32-bit table, the size is i32, but wrapping
checks only the dest table — causing an assertion failure
(`assert(ptr->type == Type::i64)`) when dest is 64-bit but source is
32-bit.

**Fix:** Check both tables before wrapping the size operand, matching
the type logic in `child-typer.h`.

Author: sumleo

src/passes/Memory64Lowering.cpp

@@ -278,7 +278,12 @@ struct Memory64Lowering : public WalkerPass<PostWalker<Memory64Lowering>> {
   void visitTableCopy(TableCopy* curr) {
     wrapTableAddress64(curr->dest, curr->destTable);
     wrapTableAddress64(curr->source, curr->sourceTable);
-    wrapTableAddress64(curr->size, curr->destTable);
+    // The size type is i64 only when both tables are 64-bit.
+    auto& module = *getModule();
+    if (module.getTable(curr->destTable)->is64() &&
+        module.getTable(curr->sourceTable)->is64()) {
+      wrapAddress64(curr->size, curr->destTable, true);
+    }
   }
 
   void visitTableInit(TableInit* curr) {

test/lit/passes/memory64-lowering-table-copy.wast

@@ -0,0 +1,63 @@
+;; NOTE: Assertions have been generated by update_lit_checks.py --all-items and should not be edited.
+
+;; RUN: foreach %s %t wasm-opt --memory64-lowering --enable-memory64 --enable-reference-types --enable-bulk-memory -S -o - | filecheck %s
+
+;; Test that table.copy with mixed 32/64-bit tables correctly handles the
+;; size operand type.
+(module
+  ;; CHECK:      (type $0 (func))
+
+  ;; CHECK:      (table $t64 10 funcref)
+  (table $t64 i64 10 funcref)
+  ;; CHECK:      (table $t32 10 funcref)
+  (table $t32 10 funcref)
+
+  ;; CHECK:      (func $table-copy-mixed-64-to-32
+  ;; CHECK-NEXT:  (table.copy $t32 $t64
+  ;; CHECK-NEXT:   (i32.const 0)
+  ;; CHECK-NEXT:   (i32.wrap_i64
+  ;; CHECK-NEXT:    (i64.const 0)
+  ;; CHECK-NEXT:   )
+  ;; CHECK-NEXT:   (i32.const 5)
+  ;; CHECK-NEXT:  )
+  ;; CHECK-NEXT: )
+  (func $table-copy-mixed-64-to-32
+    ;; Copy from 64-bit table to 32-bit table. The size is i32 because not
+    ;; both tables are 64-bit, so no wrapping of size should occur.
+    (table.copy $t32 $t64 (i32.const 0) (i64.const 0) (i32.const 5))
+  )
+
+  ;; CHECK:      (func $table-copy-mixed-32-to-64
+  ;; CHECK-NEXT:  (table.copy $t64 $t32
+  ;; CHECK-NEXT:   (i32.wrap_i64
+  ;; CHECK-NEXT:    (i64.const 0)
+  ;; CHECK-NEXT:   )
+  ;; CHECK-NEXT:   (i32.const 0)
+  ;; CHECK-NEXT:   (i32.const 5)
+  ;; CHECK-NEXT:  )
+  ;; CHECK-NEXT: )
+  (func $table-copy-mixed-32-to-64
+    ;; Copy from 32-bit table to 64-bit table. The size is i32 because not
+    ;; both tables are 64-bit, so no wrapping of size should occur.
+    (table.copy $t64 $t32 (i64.const 0) (i32.const 0) (i32.const 5))
+  )
+
+  ;; CHECK:      (func $table-copy-both-64
+  ;; CHECK-NEXT:  (table.copy $t64 $t64
+  ;; CHECK-NEXT:   (i32.wrap_i64
+  ;; CHECK-NEXT:    (i64.const 0)
+  ;; CHECK-NEXT:   )
+  ;; CHECK-NEXT:   (i32.wrap_i64
+  ;; CHECK-NEXT:    (i64.const 5)
+  ;; CHECK-NEXT:   )
+  ;; CHECK-NEXT:   (i32.wrap_i64
+  ;; CHECK-NEXT:    (i64.const 3)
+  ;; CHECK-NEXT:   )
+  ;; CHECK-NEXT:  )
+  ;; CHECK-NEXT: )
+  (func $table-copy-both-64
+    ;; Copy between same 64-bit table. All operands including size are i64
+    ;; and should be wrapped.
+    (table.copy $t64 $t64 (i64.const 0) (i64.const 5) (i64.const 3))
+  )
+)