Merge pull request #13284 from wateret/fix-13281

[RyuJIT/arm32] Fix Regression

src/jit/gentree.h

@@ -4012,7 +4012,16 @@ struct GenTreeMultiRegOp : public GenTreeOp
     var_types GetRegType(unsigned index)
     {
         assert(index < 2);
-        var_types result = TYP_INT; // XXX
+        // The type of register is usually the same as GenTree type
+        // since most of time GenTreeMultiRegOp uses only a single reg (when gtOtherReg is REG_NA).
+        // The special case is when we have TYP_LONG here, which was `TYP_DOUBLE` originally
+        // (copied to int regs for argument push on armel). Then we need to separate them into int for each index.
+        var_types result = TypeGet();
+        if (result == TYP_LONG)
+        {
+            assert(gtOtherReg != REG_NA);
+            result = TYP_INT;
+        }
         return result;
     }
 

src/jit/regset.cpp

@@ -1552,7 +1552,7 @@ void RegSet::rsSpillTree(regNumber reg, GenTreePtr tree, unsigned regIdx /* =0 *
     else if (tree->OperIsMultiRegOp())
     {
         multiReg = tree->AsMultiRegOp();
-        treeType = multiReg->GetRegType(regIdx); // XXX check
+        treeType = multiReg->GetRegType(regIdx);
     }
 #endif // _TARGET_ARM_
     else