MIPS“la”伪指令
在 MIPS 中，la 指令转换为 lui 和 ori。然而，MARS Simulator 似乎根本没有这样做。当我转储以下机器代码时：
.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
这显然是。它将 la 转储为一条指令。火星有什么作用？如何让它将 la 解释为 lui 和 ori？
谢谢你，
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: "
I get:
00100000000001000010000000000000
00100000000001010010000000101000
10001100101001010000000000000000
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?
Thank you,
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这里发生的情况是，您的汇编器正在将这些
la编译为addi $, $0, 。仅当无法用 16 位立即数表示的值时才需要两指令序列；您在此处使用的值类似于0x2000和0x2028，因此它们适合单个指令。加载更大的常数。
:)您的汇编程序还可能有一个选项来强制使用完整序列，即使这是不必要的。What's happening here is that your assembler is compiling these
las asaddi $<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 like0x2000and0x2028, so they fit in a single instruction.Load bigger constants.
:)Your assembler might also have an option to force the use of the full sequence even when it's unnecessary.