I am attempting to mix some C and assembly language and I am having a bear of a time. I am experienced with C, somewhat with assembly, but I haven't used them on the same project before.
At the moment, I am attempting to compile the simplest possible project, which is a Q1.15 fixed-point multiplication. I don't actually care about the code output, I just needed something to compile so that I could build off of it.
myq15.h:
#ifndef _Q15_MATH
#define _Q15_MATH
#include <stdint.h>
typedef int16_t q15_t;
extern q15_t q15_mul(q15_t multiplicand, q15_t multiplier);
q15_t q15_add(q15_t addend, q15_t adder);
#endif
myq15.c
#include "myq15.h"
q15_t q15_add(q15_t addend, q15_t adder){
int32_t result = (uint32_t)addend + (uint32_t)adder;
if(result > 32767) result = 32767;
else if(result < -32768) result = -32768;
return (q15_t)result;
}
myq15.s:
.include "xc.inc"
.text
.global _q15_mul
_q15_mul:
; w3:w2 = w1 * w0
mul.ss w0, w1, w2
; w0 = (w3:w2) >> 15
rlc w2, w2
rlc w3, w3
; w0 = w3
mov w3, w0
return
.end
My 'main' file simply calls a q15_add() and q15_mul() instance.
On compile, The linker states:
build/default/production/_ext/608098890/myq15.o(.text+0x0): In function `_q15_mul':
: multiple definition of `_q15_mul'
Again, I am trying to figure out how to mix the assembly and C file for other purposes, but if I can't get this simple program to work, I'm hopeless!
Thanks,
It's a bad idea to name your files the same, the toolchain might confuse them, given that both myq15.c and myq15.s compile to myq15.o by default.