请问循环左/右移的汇编语句应该怎么写呢？

[mstlq]

如题^_^
体力不支，没心思去google，只好懒一回^_^

另外，求下面代码的汇编版本，谢谢^_^

void Udadress(UINT *adress,size_t len, UINT newValue, size_t ex)
{
    assert(ex<8 && len>0);
    for (size_t pos=0; pos<len-1; ++pos)
    {
        adress[pos] = (adress[pos]<<ex) | (adress[pos+1] >> (32-ex));
    }
    adress[len-1] = (adress[len-1]<<ex) | ((0x01<<len) -1) & (newValue);
    return ;
}

[FancyMouse]

x86 asm: ror/rol

[mstlq]

[Quote=引用 5 楼 whg01 的回复:]
http://hi.baidu.com/shawpinlee/blog/item/1cf5f8fb3efb5c214f4aea9b.html
楼主想用的是SHL和SHR吧？
[/Quote]
其实是想要下面四个的例子……
ROL
ROR
RCL
RCR

[老邓]

关于汇编，编译器可以生成汇编代码。详见：http://www.qpsoft.com/blog/asm-c-cpp-cl-fa-compiler/

[baihacker]

ROR Rotate bits right

operands bytes 8088 186 286 386 486 Pentium
reg, 1 2 2 2 2 3 3 1 PU
mem, 1 2+d(0,2) 23+EA 15 7 7 4 3 PU
reg, cl 2 8+4n 5+n 5+n 3 3 4 NP
mem, cl 2+d(0,2) 28+EA+4n 17+n 8+n 7 4 4 NP
reg, imm 3 - 5+n 5+n 3 2 1 PU
mem, imm 3+d(0,2) - 17+n 8+n 7 4 3 PU*

* = not pairable if there is a displacement and immediate

Example: ror eax, 16


ROL Rotate bits left

operands bytes 8088 186 286 386 486 Pentium
reg, 1 2 2 2 2 3 3 1 PU
mem, 1 2+d(0,2) 23+EA 15 7 7 4 3 PU
reg, cl 2 8+4n 5+n 5+n 3 3 4 NP
mem, cl 2+d(0,2) 28+EA+4n 17+n 8+n 7 4 4 NP
reg, imm 3 - 5+n 5+n 3 2 1 PU
mem, imm 3+d(0,2) - 17+n 8+n 7 4 3 PU*

* = not pairable if there is a displacement and immediate

Example: rol eax, 16


RCL Rotate bits left with CF

operands bytes 8088 186 286 386 486 Pentium
reg, 1 2 2 2 2 9 3 1 PU
mem, 1 2+d(0,2) 23+EA 15 7 10 4 3 PU
reg, cl 2 8+4n 5+n 5+n 9 8-30 7-24 NP
mem, cl 2+d(0,2) 28+EA+4n 17+n 8+n 10 9-31 9-26 NP
reg, imm 3 - 5+n 5+n 9 8-30 8-25 NP
mem, imm 3+d(0,2) - 17+n 8+n 10 9-31 10-27 NP

Example: rcl eax, 16


RCR Rotate bits right with CF

operands bytes 8088 186 286 386 486 Pentium
reg, 1 2 2 2 2 9 3 1 PU
mem, 1 2+d(0,2) 23+EA 15 7 10 4 3 PU
reg, cl 2 8+4n 5+n 5+n 9 8-30 7-24 NP
mem, cl 2+d(0,2) 28+EA+4n 17+n 8+n 10 9-31 9-26 NP
reg, imm 3 - 5+n 5+n 9 8-30 8-25 NP
mem, imm 3+d(0,2) - 17+n 8+n 10 9-31 10-27 NP

Example: rcr eax, 16









Legend:
General
acc = AL, AX or EAX unless specified otherwise
reg = any general register
r8 = any 8-bit register
r16 = any general purpose 16-bit register
r32 = any general purpose 32-bit register
imm = immediate data
imm8 = 8-bit immediate data
imm16 = 16-bit immediate data
mem = memory address
mem8 = address of 8-bit data item
mem16 = address of 16-bit data item
mem32 = address of 32-bit data item
mem48 = address of 48-bit data item
dest = 16/32-bit destination
short = 8-bit destination

Integer instruction timings:
n - generally refers to a number of repeated counts
m - in a jump or call;
286: bytes in next instruction
386/486: number of components
(each byte of opcode) + 1 (if immed data) + 1 (if displacement)
EA = cycles to calculate the Effective Address
8088/8086:
base = 5 BP+DI or BX+SI = 7 BP+DI+disp or BX+SI+disp = 11
index = 5 BX+DI or BP+SI = 8 BX+DI+disp or BP+SI+disp = 12
disp = 6 segment override = +2
286 - 486:
base+index+disp = +1 all others, no penalty

instruction length:

The byte count includes the opcode length and length of any required
displacement or immediate data. If the displacement is optional, it
is shown as d() with the possible lengths in parentheses. If the
immediate data is optional, it is shown as i() with the possible
lengths in parentheses.

pairing categories for Pentium:

NP = not pairable
UV = pairable in the U pipe or V pipe
PU = pairable in the U pipe only
PV = pairable in the V pipe only
(end of legend)

[loveour]

标记一下...
对汇编还真是有一个反复的认识...最开始觉得，这才是编程，厉害；然后觉得没什么用，反正用不到，再然后发现还是离不开，而且有助于很多问题的理解...

[z569362161]

我是来接点分的

[whg01]

http://hi.baidu.com/shawpinlee/blog/item/1cf5f8fb3efb5c214f4aea9b.html
楼主想用的是SHL和SHR吧？

[mLee79]

偶觉得这个定向到汇编版的宝宝或者数据结构版出没的gxqcn写这个比较放心....

[mstlq]

请问现在的csdn是不是取消“问专家”功能了 >_<?

[老邓]

[Quote=引用 10 楼 mstlq 的回复:]
请问现在的csdn是不是取消“问专家”功能了 >_ <?
[/Quote]
取消了半年左右了...

[jernymy]

#define UINT unsigned int
#define size_t int

void Udadress(UINT *adress, size_t len, UINT newValue, size_t ex)
{
    assert(ex<8 && len>0);
    for (size_t pos=0; pos<len-1; ++pos)
    {
        adress[pos] = (adress[pos]<<ex) | (adress[pos+1] >> (32-ex));
    }
    adress[len-1] = (adress[len-1]<<ex) | ((0x01<<len) -1) & (newValue);
    return ;
}



	.file	"new.c"
	.text
.globl _Udadress
	.def	_Udadress;	.scl	2;	.type	32;	.endef
_Udadress:
	pushl	%ebp
	movl	%esp, %ebp
	pushl	%edi
	pushl	%esi
	pushl	%ebx
	subl	$12, %esp
	movl	$0, -20(%ebp)
	cmpl	$7, 20(%ebp)
	jg	L2
	cmpl	$0, 12(%ebp)
	jle	L2
	movl	$1, -20(%ebp)
L2:
	movl	-20(%ebp), %eax
	movl	%eax, (%esp)
	call	_assert
	movl	$0, -16(%ebp)
L3:
	movl	12(%ebp), %eax
	decl	%eax
	cmpl	%eax, -16(%ebp)
	jl	L6
	jmp	L4
L6:
	movl	-16(%ebp), %eax
	leal	0(,%eax,4), %esi
	movl	8(%ebp), %edi
	movl	-16(%ebp), %eax
	leal	0(,%eax,4), %edx
	movl	8(%ebp), %eax
	movzbl	20(%ebp), %ecx
	movl	(%eax,%edx), %eax
	movl	%eax, %ebx
	sall	%cl, %ebx
	movl	-16(%ebp), %eax
	sall	$2, %eax
	addl	8(%ebp), %eax
	leal	4(%eax), %edx
	movl	$32, %eax
	movl	%eax, %ecx
	subl	20(%ebp), %ecx
	movl	(%edx), %eax
	shrl	%cl, %eax
	orl	%ebx, %eax
	movl	%eax, (%edi,%esi)
	leal	-16(%ebp), %eax
	incl	(%eax)
	jmp	L3
L4:
	movl	12(%ebp), %eax
	sall	$2, %eax
	addl	8(%ebp), %eax
	leal	-4(%eax), %ebx
	movl	12(%ebp), %eax
	sall	$2, %eax
	addl	8(%ebp), %eax
	subl	$4, %eax
	movzbl	20(%ebp), %ecx
	movl	(%eax), %eax
	movl	%eax, %edx
	sall	%cl, %edx
	movl	$1, %eax
	movzbl	12(%ebp), %ecx
	sall	%cl, %eax
	decl	%eax
	andl	16(%ebp), %eax
	orl	%edx, %eax
	movl	%eax, (%ebx)
	addl	$12, %esp
	popl	%ebx
	popl	%esi
	popl	%edi
	popl	%ebp
	ret
	.def	_assert;	.scl	2;	.type	32;	.endef

[jernymy]

使用的是mingw 自带的gcc编译的汇编

[苍蝇①号]

在AT &T的汇编中相应的左右移指令：
sall k,D
shll k,D
sarl k,D
shrl k,D