// Promote i8/i16 arguments to i32.
CCIfType<[i8, i16], CCPromoteToType<i32>>,
- // Integer/FP values are always stored in stack slots that are 8 bytes in size
- // and 8-byte aligned.
- CCIfType<[i32, i64, f32, f64], CCAssignToStack<8, 8>>
+ // Only the first integer argument is passed in register.
+ CCIfType<[i32], CCAssignToReg<[EAX]>>,
+ CCIfType<[i64], CCAssignToReg<[RAX]>>,
+
+ // The remaining integer arguments are passed on the stack. 32bit integer and
+ // floating-point arguments are aligned to 4 byte and stored in 4 byte slots.
+ // 64bit integer and floating-point arguments are aligned to 8 byte and stored
+ // in 8 byte stack slots.
+ CCIfType<[i32, f32], CCAssignToStack<4, 4>>,
+ CCIfType<[i64, f64], CCAssignToStack<8, 8>>
]>;
// No explicit register is specified for the AnyReg calling convention. The