How to define a macro function

In C language, you can define macros using the #DEFINE pre-processing command.

It will do text replacement before compiling.

Here is a documentation chapter explaining ARM Inline Assembly: ARM® Compiler armcc User Guide

Here is documentation about C preprocessor and #DEFINE: C preprocessor - Wikipedia, the free encyclopedia

#DEFINE push_x1_x12 \
    __asm {                 \
    push x1,x2              \
    push x3,x4              \              
    push x5,x6              \
    push x7,x8              \
    push x9,x10             \
    push x11,x12            \
    }

thanks,

1、I used ARMV8 that platforms is: ARM DS-5 Documentation > ARM Compiler 6 (64-bit platforms only) > armclang Reference Guide

     not armcc but armclang

2、how to expand in C language?like this:

void test_tt(void)

{

      push_x1_x12;

}

3、If I want to define a macro with parameters, how to deal with it ?

Replace:

.macro cpus_tst_get_opcode, _reg0

lsl \_reg0,\_reg0,#4

lsr \_reg0,\_reg0,#24

.endm

albanrampon

2. Yes. The #define is identical to replacing the text.

3. You use parameters like for a function:

#define RADTODEG(x) ((x) * 57.29578)

and in your code

y = RADTODEG(25);

will do:

y = (25) * 57.29578;

sorry,

//    define:

//-------------------------------------

#define  push_x1_x12     \

    __asm {                 \ 

     push x1,x2              \ 

     push x3,x4              \               

     push x5,x6              \ 

     push x7,x8              \ 

     push x9,x10             \ 

     push x11,x12            \ 

}

//     call

//----------------------------------------

void test_tt(void)

{

push_x1_x12;

}

ARM Compiler 6  Compilation error

javascript:liveAction('org.eclipse.help.ui', 'org.eclipse.help.ui.internal.ShowInTocAction', '2_4')

Oups, can you try the following?

#DEFINE push_x1_x12 __asm("push x1,x2", "push x1,x2", "push x3,x4", "push x5,x6", "push x7,x8", "push x9,x10", "push x11,x12")

6.4 Inline assembly language syntax with the __asm keyword in C and C++

The link just above also shows how to add parameters: you need to put them outside of the " " starting with #.

There are several ways of declaring assembly instructions. One at a time, or a list. And for the list, the way I explained previously with curly brackets "{}" or like strings in round brackets "()".

I am not sure why the curly brackets didn't work. It may depend on the compiler.

As i can see, the chinese climat make you more productive Alban

Macros tend to make things difficult to debug, so if you can I would try to use a normal function and get the compiler to inline it. I try to avoid macros whenever possible; modern compilers are good enough that you can generally avoid them without a performance penalty.

HTH,
Pete

albanrampon  @Peter Harris

hi all,  

    I need to do some big test cases with macros.    

    read armclang's embedded assembly document.    and i can define macros in c ,and expand in c function .

    Now,I want to expand macros in other macros,the code as following:

//define

#define cpus_tst_code_lsl(_reg0,ret)  asm("adr  %[input_i],#4\n\t"      \

            "mov %[input_i],%[input_i]\n\t"    \

            "ldr %[input_i],[%[input_i]]\n\t"    \

            "lsl %[input_i],%[input_i],#36\n\t"  \

            "lsr %[input_i],%[input_i],#56\n\t"  \

            "cmp %[input_i],#0x80\n\t"    \

            "b.eq  lable1\n\t"      \

            "mov %[result],#0x1\n\t"      \

            "b lable2\n\t"        \

            "lable1:mov %[result],#0x0\n\t"    \

            "lable2:\n\t"        \

            : [result] "=r"  (ret)      \

            : [input_i] "r"  (_reg0)      \

          )

//expand

#define test_cpus_l1_code_base(ret)    asm("mov x5,#16\n\t"        \

                "mov x6,x4\n\t"        \

                "mov x8,#20\n\t"        \

               "cpus_tst_code_lsl x5,%[result] \n\t"    \                                   

                ........

              : [result] "=r"  (ret)      \

              :            \

              )

ARM Complier 6Complier  error:

    error: invalid instruction

<inline asm>:4:2: note: instantiated into assembly here

        cpus_tst_code_lsl x5,x1

        ^

As described in the suggested by albanrampon to link section 6.4 Inline assembly language syntax with the __asm keyword in C and C++, the correct syntax is:

//   define:
//-------------------------------------
#define  push_x1_x12  \
__asm {                 \
    "push x1,x2   \n"   \
    "push x3,x4   \n"   \
    "push x5,x6   \n"   \
    "push x7,x8   \n"   \
    "push x9,x10  \n"   \
    "push x11,x12 \n"   \
}

//call
//----------------------------------------
void test_tt(void)
{
push_x1_x12;
}

See lacked the quotes involving the mnemonics and the line break.

Sure. The #define does text replacement only. It does not do any evaluation of your string to then go to look for other things.