#190 Is it possible to have inline assembler to load constant created by define?

[Deqing Sun]

Hi,

I tried to create some constant in C with #define such as

#define TL0_RECV_START_VALUE 0

And load it into registers. But it seem SDCC can not replace the text with value. How can I do that. Now I put the value into an SFR in C and have the inline assembler to read it back. It seems in efficient.

[Benedikt Freisen]

I don't know whether there is any way to use C preprocessor macros in combination with the old inline assembly syntax, but it should be possible with the C-compliant syntax that uses string constants:

#define MY_MACRO "0"
__asm__(
    "mov a,1 \n"
    "add a," MY_MACRO "\n"
    "add b,a \n"
)

Add some preprocessor stringification magic if you want to work with a literal 0.

[Deqing Sun]

Thank!

#define TL0_RECV_START_VALUE 64
#define STR_INDIR(x) #x
#define STR(x) STR_INDIR(x)
"    mov r6,#" STR(TL0_RECV_START_VALUE) "    \n"

got compiled to

mov r6,#64 

Awesome!