All Questions
183
questions
12
votes
2
answers
4k
views
GNU as .macro directive expansion
Is there a way to have GNU as only expand .macro directives in a .S file, producing another .S file without them? Similiar to what gcc -E does with C code.
Note this is about the assembler .macro ...
- 2,230
7
votes
1
answer
2k
views
Weird Macros (TASM)
Consider the following macros:
pixelFast MACRO
; This macro draws a pixel, assuming the coordinates are already loaded in cx&dx and the color is in al.
xor bh, bh
mov ah, 0ch
int ...
- 137
7
votes
0
answers
721
views
Eclipse CDT macro awareness in assembler files
Currently I am using Eclipse (3.5.x and 3.7.x) with the CDT plugin for several projects that contain besides .c and .h files also .S files with x86 (or IA64) assembler code.
The problem is, that in ...
- 401
6
votes
2
answers
10k
views
Assembly language: macros vs procedures
I'm new to assembly language and this question came across to my mind: Which is better solution for structuring my code, macros or procedures?
While code included in a macro is just copied to the ...
- 367
6
votes
1
answer
6k
views
Issues using a local label in a macro in MASM
I'm to write a macro that takes E,NE,A,B... as a parameter and a single command i.e mov eax,ebx which would execute if the condition set by a preceding cmp operation is true.
An example call would ...
- 123
5
votes
1
answer
3k
views
For-loop macro/preprocessor for assembly files in GCC
I am fairly certain I have seen this in code before, but I am unable to find any references on how to do it. I do expect this to be compiler or assembler specific.
I want to define an function ...
- 4,737
5
votes
2
answers
6k
views
GCC ARM Assembly Preprocessor Macro
I am trying to use an assembly(ARM) macro for fixed-point multiplication:
#define MULT(a,b) __asm__ __volatile__ ( \
"SMULL r2, r3, %0, %1\n\t" \
"ADD r2, r2, #0x8000\n\t" \
...
- 489
5
votes
1
answer
5k
views
Referencing operands/parameters in GNU assembler macros
I am currently trying to understand the concept of macros in the assembly language, specifically in GNU assembler, AT&T syntax for IA-32 (x86). The slides from my university say the following:
# ...
- 6,652
5
votes
3
answers
16k
views
How to create a GNU GAS macro that expands to an expression like "(x+y*240)*2"?
I'm building a program for ARM Linux using GAS, but I want to do some macros to make my development some more smart. Then I want to know:
How could I do a macro for this: (x+y*240)*2, were x and y ...
- 29.2k
4
votes
3
answers
10k
views
struct or class in assembly
I need something like struct or class in c++
For example I need a class with an array and two attribute (size and len) and some function like append and remove .
How can I implement this in assembly ...
- 5,903
4
votes
3
answers
4k
views
Call a C preprocessor macro multiple times (through a variable)
I'd like to clean up my assembly code and povide a way to call "NOP" multiple times through a macro:
#define NOP() asm(" nop")
#define NOP_N( N ) \
NOP(); \
NOP(); \
.... call NOP() N ...
- 13.2k
4
votes
2
answers
10k
views
Macros in x86 assembly coding
Can somebody please explain how to use macros in x86 assembly coding
- 43
4
votes
1
answer
182
views
How do I write a macro to repeat something up to a specific address?
The .org directive advances the location counter to a specified offset, and fills the extra bytes with a specified value.
.org 123, 1 @ Pads 1s until we reach address 123.
I want to write a macro to ...
- 24.7k
4
votes
1
answer
1k
views
How do you compare variable types in assembly?
This might be a bit of a stupid syntax question, but is there a way you can make conditional jumps based on variable type? I'm trying to write a macro (for a class) that can take a byte, word, or ...
- 109
4
votes
3
answers
361
views
Unable to understand following macro [duplicate]
I found below macro when i am going through kernel source code and I am unable to understand what it is doing.
#define barrer() __asm__ __volatile__("":::"memory")
Please some one clarify this.
- 3,990
4
votes
1
answer
411
views
GNU Assembler GAS check if macro paramater is register
I want handle in case if macro argument (parameter) is a register.
I expect I have similiar code like this but I'm sure it doesn't work due to lack my knowledge of directive syntax.
.macro myMacro ...
- 223
3
votes
3
answers
2k
views
asm block in c++ as a macro
I would like to write a macro which converts everything to void* even the member functions.
Here is the code:
#define toVoidStar(xx,yy)\
__asm push ecx; \
__asm mov ecx, yy; \
__asm mov [...
- 1,493
3
votes
1
answer
369
views
Breaking long macro argument list in GNU assembler for AArch64
I'm writing assembly code targeting ARMv8 (AArch64) in GNU assembler. Not sure if it matters, but I'm coding directly in my ARMv8 target (a Raspberry Pi board) running Linux.
I have a macro with a ...
- 2,568
3
votes
2
answers
1k
views
x86 assembly: Using #define'd constants as arguments in calls to to #define's macros
I'm working on manually constructing an IDT table in x86 assembly. I have the following macros defined using the C preprocessor in my .S file:
// sets up an entry in the idt for a trap type
#define ...
- 1,945
3
votes
1
answer
402
views
macro vs equ in nasm
I'm having trouble understanding the difference between the two, the following example really had me puzzled:
section .data
msg: db "Thank you"
var: dd 0x31323334
len equ msg-4
section ....
- 377
3
votes
1
answer
62
views
How to replace the value of symbol in x86 assembly using gnu asembler macro? Compose register names like xmm0 from xmm(i)
.macro macro_name
.set i, 0
.rept 8
movss (i * 4)(%rsi), %xmm(i)
set i , i + 1
.endr
.endm
I wrote this macro to load 8 single precession floating point numbers into xmm registers to ...
- 418
3
votes
1
answer
7k
views
What is the effect of the assembler directive `.global`
When I run my code in MARS it doesn't need any .global directive and i know that MARS doesn't use that directive.
Now when i ported my code to a particular assembler (MCB32) which runs from the ...
user7583029
3
votes
1
answer
569
views
Calling a table of function using repeat blocks or macros in GNU assembly
If I wanted to generate code that looks like this:
CALL FUNC0
CALL FUNC1
CALL FUNC2
CALL FUNC3
CALL FUNC4
CALL FUNC5
...
CALL FUNC19
How can I use a repeat block generate such code, using something ...
- 227
3
votes
1
answer
1k
views
Macro printing a value stored in a byte. Assembly masm
Assembly, masm
Hey, I wrote macro which prints the 1 byte value stored in dane1 segment.
I divide the value by 16, then i push reminder to stack until value==0. Then I pop reminders convert them to ...
- 207
3
votes
1
answer
1k
views
MOV into a register specified by macro argument
I'm trying to execute a mov operation in a macro in AVR assembly. I want to specify the target by a numeric argument to a macro. I am using the Atmel Studio assembler.
I'm trying to do something like ...
- 6,996
3
votes
1
answer
725
views
error: junk `bswapl eax movl %eax' after register
I define a MACRO in GAS source code. But it is not compiled by gcc.
The following is my defined MACRO.
#define MSGSCHEDULE0(index) \
movl (index*4)(%rsi) ,%eax \
bswapl eax \
movl %...
- 191
3
votes
1
answer
76
views
Tasm macros default value
In turbo assembler i have a macro
subs macro x,y
mov ax,x
sub ax,y
endm
how can I give to y a default value, equal to 1, so I can write
subs bx
and ax becomes equal to bx - 1?
- 749
3
votes
1
answer
986
views
how to expand TASM macros
Is there a way to expand macros with Borland's TASM ?
I'd like to transform a TASM compatible .ASM file to see all his macros expanded.
Couldn't find any options to do that.
- 3,015
3
votes
1
answer
1k
views
.weak assembler macro for MinGW GCC / C alternative
I have a modular C-Project with some different libraries/objects, which are only linked to the release if some conditions are met. This project is build with GCC 3.4.4 for PowerPC.
So all over my ...
- 3,845
3
votes
0
answers
102
views
Passing a subset of a macro's arguments to another macro in NASM
I've been experimenting with macros in NASM recently, and despite reading the documentation, I still don't know if there is a way to pass a subset of a macro's arguments to another macro; and if there ...
- 76
3
votes
0
answers
1k
views
Macros vs subroutines in assembly
Statement: A subroutine cannot always be used to replace a macro in an assembly language program.
Is the above statement true or false?
My book has given false as an answer. But I cannot think of ...
- 265
3
votes
0
answers
2k
views
How to use labels in Nasm macros
I am experimenting in Nasm assembly out of pure interest. I was wondering how I would go about using labels in a macro function. I have tried my code below and this gives me redefining label errors, I ...
user5464295
3
votes
0
answers
132
views
How to loop inside of a MACRO in x86 Assembly [duplicate]
I have a MACRO written like this:
putspaces MACRO numspaces
push ecx ;pushes ecx reg onto stack for use
mov ecx, numspaces ;move the integer param numspaces into ecx for ...
- 1,986
2
votes
1
answer
3k
views
How do i define macros in NASM x86
I'm trying to implement couple of macros for x86 project.
I just moved from MARS mips assembly so dont judge my incompetence.
I think I'm doing everything as in this guide https://www.tutorialspoint....
2
votes
4
answers
2k
views
macro vs procedure in assembly
I'm learning now how to use macros in assembly language.
I know that macros are faster than procedures because there's no costly jumps, only copying the lines.
But I don't understand why macros take ...
- 490
2
votes
1
answer
320
views
Is there a point in using %assign over %define?
It seems to me that the %define directive to define a single-line macro is just the %assign directive with additional features like an ability to get parameters. If that's the case, what's the point ...
- 73
2
votes
1
answer
72
views
Is it possible to to use the outer macro parameter is used by inner macro?
data segment
str db "hello$"
str2 db "world$"
data ends
adds macro a,b
lea si,a
lea di,b
endm
subs macro x,y
adds x,y
endm
code segment
assume cs:...
2
votes
2
answers
101
views
What is this code trying to do?
I'm trying to understand how the following code is working:
#define M32toX128(x128,m32) __asm__ \
("movddup %1, %0\n\t" \
"movsldup %0, %0" ...
- 7,642
2
votes
1
answer
251
views
Trouble with MIPS macros in SPIM
I'm struggling to get a macro to work in my lab code. This is how I wrote it:
.macro print_char($arg)
li $v0, 11
add $a0, $zero, $arg
syscall
.end_macro
I don't think it should matter ...
- 204
2
votes
1
answer
3k
views
Understanding NASM Macro
I've come around this macro in a assembly source file and I just can't figure out how it's working.
So first I come around this function (hevc_deblock.h):
cglobal hevc_v_loop_filter_chroma_8, 3, 5, ...
- 1,727
2
votes
1
answer
2k
views
Expression in GCC ARM assembly macro
I'm in need of macros with many registers involved, like :
.macro load128bytes
vld1.8 {d0, d1, d2, d3}, [r0]!
vld1.8 {d4, d5, d6, d7}, [r0]!
vld1.8 {d8, d9, d10, d11}, [r0]!
vld1.8 {d12, d13, ...
- 6,275
2
votes
1
answer
698
views
MASM: .IF with signed numbers comparison
I have:
mov ecx, r
.if ecx < 0
mov cl, 0
.elseif ecx > 255
mov cl, 255
.endif
mov [eax + 2], cl
r is signed integer. I want it to cap it within byte limit.
...
- 29.3k
2
votes
1
answer
721
views
How can I concatenate a label not in a macro definition? (in GAS assembler)
I want to do this:
i=0
.rept 3
add rcx,[a?(i*2+1)]
i=i+1
.endr
It should output this:
add rcx,[a1]
add rcx,[a3]
add rcx,[a5]
I can't find any solution to this problem. I don't want it to ...
- 139
2
votes
1
answer
632
views
Concatenate in macro assembler
I want use in my code something like that:
.data?
my_macro_var db MAX_PATH DUP (?)
.code
mov esi, offset my_macro_var
my_macro esi, "hello and bye"
For that i create this macro but i get few ...
- 411
2
votes
1
answer
610
views
Nasm: Macros not expanded as operands to instructions
I wrote a small bit of assembly for nasm like this:
%macro register 1
%if %1 = 0
rax
%elif %1 = 1
rbx
%elif %1 = 2
rcx
%endif
%endmacro
add register(1), ...
- 1,480
2
votes
1
answer
5k
views
passing values in MIPS macros
I've been studying MIPS as an introduction to assembly, and recently started playing with macros. What I want to be able to do is pass a value generated by another macro, or just any value in any ...
- 31
2
votes
1
answer
168
views
How do I force a constant C-expression evaluation for use as a constant in a .S file?
A header file I'm including from /usr/include/**/asm (rudely?) uses simple C expressions to express an offset from a base value, i.e.:
#define __NR_exit (__NR_SYSCALL_BASE+ 1)
...
- 70.5k
2
votes
1
answer
768
views
How to reverse an array is assembly?
I'm trying to write a simple program that reverses an array. It almost works, well it works for the first half of the array anyway. The term in the middle is always "0" and then it returns to the ...
- 109
2
votes
1
answer
88
views
Assembly macro check argument
Well, a new strange problem occurred within assembly (especially tasm)
CheckInfo MACRO arr:REQ, length:REQ, arr_type := <l>
mov bx, arr
mov cl, length
mov si, 1
IF arr_type eq &...
- 880
2
votes
1
answer
664
views
Average in assembly 8086 (macro error)
The code below computes the average of 20 user entered numbers. It works fine when I disable ShowMsg msg2 (make it a comment), but when its enabled, I get this error :
INT 21h, AH=09h -
address: ...
- 313