MIPS＆QUOT;拉＆QUOT;伪instruciton [英] MIPS "la" pseudo instruciton

问题描述

在MIPS中，拉指令转换成雷和 ORI 。然而，MARS模拟器似乎并没有做到这一点的。当我转储以下机床code：

In MIPS, the la instruction translates into lui and ori. However, MARS Simulator does not seem to do that at all. When I dump the following machine code:

.text
    la $a0, array
    la $a1, array_size
    lw $a1, 0($a1)

.data
    array: .word 0:10
    array_size: .word 10
    message: .asciiz "The sum of numbers in array is: "

我得到：

00100000000001000010000000000000
00100000000001010010000000101000
10001100101001010000000000000000

这是显而易见的。据倾销拉为一条指令。什么是MARS办？我怎样才能使它间preT 拉为雷和 ORI ？

Which is obviously. It is dumping la as one instruction. What does MARS do? How can I make it interpret la as lui and ori?

感谢您，

推荐答案

这里发生的事情是，你的汇编作为汇编这些拉取值 ADDI $＆LT; D​​EST＆gt;中$ 0＆LT; VALUE＆GT; 。两个指令序列时，才需要的量不能重新在一个16位立即psented $ P $值;您正在使用这里的值看起来像为0x2000 和 0x2028 ，使其适合在一个单一的指令。

What's happening here is that your assembler is compiling these las as addi $<dest>, $0, <value>. The two-instruction sequence is only required for values which can't be represented in a 16-bit immediate; the values you're using here look like 0x2000 and 0x2028, so they fit in a single instruction.

我怎样才能使它间preT 拉为雷和 ORI ？

How can I make it interpret la as lui and ori?

负载更大的常量。 ：）您的汇编程序还可能有一个选项，以强制使用全序列的，即使它是不必要的。

Load bigger constants. :) Your assembler might also have an option to force the use of the full sequence even when it's unnecessary.

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