不懂汇编，只能在线求助解读

freshow 2014-04-03 11:38:50

请教各位大神以下2段汇编代码是什么意思？关键不同点是什么？谢谢



	.syntax unified

	.arch armv7-a

	.eabi_attribute 27, 3

	.eabi_attribute 28, 1

	.fpu neon

	.eabi_attribute 20, 1

	.eabi_attribute 21, 1

	.eabi_attribute 23, 3

	.eabi_attribute 24, 1

	.eabi_attribute 25, 1

	.eabi_attribute 26, 2

	.eabi_attribute 30, 6

	.eabi_attribute 34, 1

	.eabi_attribute 18, 4

	.thumb

	.file	"multiCheck.c"

	.text

	.align	2

	.global	main

	.thumb

	.thumb_func

	.type	main, %function

main:

	@ args = 0, pretend = 0, frame = 8

	@ frame_needed = 1, uses_anonymous_args = 0

	@ link register save eliminated.

	push	{r7}

	sub	sp, sp, #12

	add	r7, sp, #0

	movs	r3, #2

	str	r3, [r7, #4]

	ldr	r3, [r7, #4]

	lsls	r3, r3, #3

	str	r3, [r7, #4]

	movs	r3, #2

	str	r3, [r7, #0]

	ldr	r3, [r7, #0]

	lsls	r3, r3, #3

	str	r3, [r7, #0]

	movs	r3, #0

	mov	r0, r3

	add	r7, r7, #12

	mov	sp, r7

	pop	{r7}

	bx	lr

	.size	main, .-main

	.ident	"GCC: (Linaro GCC 4.7-2013.09) 4.7.4 20130903 (prerelease)"

	.section	.note.GNU-stack,"",%progbits



	.syntax unified

	.arch armv7-a

	.eabi_attribute 27, 3

	.eabi_attribute 28, 1

	.fpu neon

	.eabi_attribute 20, 1

	.eabi_attribute 21, 1

	.eabi_attribute 23, 3

	.eabi_attribute 24, 1

	.eabi_attribute 25, 1

	.eabi_attribute 26, 2

	.eabi_attribute 30, 1

	.eabi_attribute 34, 1

	.eabi_attribute 18, 4

	.thumb

	.file	"multiCheck.c"

	.text

	.align	2

	.global	main

	.thumb

	.thumb_func

	.type	main, %function

main:

	@ args = 0, pretend = 0, frame = 0

	@ frame_needed = 0, uses_anonymous_args = 0

	@ link register save eliminated.

	movs	r0, #0

	bx	lr

	.size	main, .-main

	.ident	"GCC: (Linaro GCC 4.7-2013.09) 4.7.4 20130903 (prerelease)"

	.section	.note.GNU-stack,"",%progbits