CodeGeneration.CGenState.CGenPopLong C# (CSharp) Method

        public void CGenPopLong(Int32 saved_size, Reg dst) {
            if (this.StackSize == saved_size) {
                POPL(dst);
                this.StackSize -= 4;
            } else {
                MOVL(-saved_size, Reg.EBP, dst);
            }
        }

        // %eax = left, %ebx = right, stack unchanged
        private void CGenPrepareIntegralOperands(CGenState state) {
            // 1. Load Left to EAX.
            // 
            // regs:
            // %eax = Left
            // 
            // stack:
            // +-----+
            // | ... | <- %esp
            // +-----+
            // 
            if (this.Left.CGenValue(state) != Reg.EAX) {
                throw new InvalidOperationException();
            }

            // 2. Push Left to stack.
            // 
            // regs:
            // %eax = Left
            // 
            // stack:
            // +-----+
            // | ... |
            // +-----+
            // | Left | <- %esp has decreased by 4
            // +-----+
            // 
            Int32 stack_size = state.CGenPushLong(Reg.EAX);

            // 3. Load Right to EAX.
            // 
            // regs:
            // %eax = Right
            // 
            // stack:
            // +-----+
            // | ... |
            // +-----+
            // | Left | <- %esp
            // +-----+
            // 
            if (this.Right.CGenValue(state) != Reg.EAX) {
                throw new InvalidOperationException();
            }

            // 4. Move Right into EBX. Pop Left from stack, into EAX.
            // 
            // regs:
            // %eax = Left
            // %ebx = Right
            // 
            // stack:
            // +-----+
            // | ... | <- %esp has moved back.
            // +-----+
            // 
            state.MOVL(Reg.EAX, Reg.EBX);
            state.CGenPopLong(stack_size, Reg.EAX);
        }