Question about FlexGUI/FastSpin _ Cordic Issue _

Reinhard · 2019-12-03 16:48

I try to write a cordic example in C with FlexGui (running with wine under Linux)
I want use the _rotxy - Function.
But i get a compiler error : error: unknown identifier _rotxy used in function call
Maybe not implemented yet ?

Then i make a quick and row workaround with own function and inline asm.
The list file and a test with spinsim looks good, i get the expected values.

But how can i use the functions with FastSpin ?
thank's for help
Reinhard

ersmith · 2019-12-03 17:13

Yes, unfortunately _rotxy isn't implemented yet in fastspin's C libraries. It looks like your work-around is working though?

I'll try to get some of those missing propeller2.h functions implemented before the next release.

Thanks,
Eric

Reinhard · 2019-12-03 17:21

Yes, I thought it was not implemented yet.
It is a very helpful tool.
The communication about structs I find a good solution.

Thank's
Reinhard

Reinhard · 2019-12-03 22:38

works also with fastspin

void my_rotxy (cartesian_t * input, cartesian_t * output, uint32_t angle)
{
int32_t x = input->x;
int32_t y = input->y;
__asm {
	setq	y		
	qrotate	x,angle		
	getqx	x		
	getqy	y		
};	
output->x = x;
output->y = y;
}

function call example is

cartesian_t rectangle;
cartesian_t rot;
.
.
.
rectangle.x = 100;
rectangle.y = 100;
my_rotxy(&rectangle,&rot,0x40000000); 
.
.

Reinhard · 2019-12-05 10:28

the inline assembler works very well.

//Example:  Multiplication of 2 complex numbers
//input:  z1 = real1,imag1
//        z2 = real2,imag2
//calc:   z3 = z1 * z2
//output: real3,imag3
//
//testcase: z2 = conj(z1)
//expected: z3 is pure real. imag3 = 0. 
//
//
//how to compile
//wine ../../fastspin/fastspin.exe  -I ../../fastspin/include -l -2b --code=cog cplx_mult_c.c
 
#include <propeller2.h>

void cplx_mult (int32_t real1,   int32_t imag1,
		          int32_t real2,   int32_t imag2,
			  int32_t * real3, int32_t * imag3)
{
int32_t _abs1;
int32_t _arg1;
int32_t _abs2;
int32_t _arg2;
int32_t _abs3;
int32_t _arg3;
int32_t result_lo = 0;
int32_t result_hi = 0;
__asm {
	qvector	real1,imag1		//z1 to polar	
	getqx	_abs1
	getqy	_arg1
	qvector	real2,imag2		//z2 to polar	
	getqx	_abs2
	getqy	_arg2
	qmul	_abs1,_abs2		//multiply the abs
	getqx	result_lo
	getqy	result_hi
	mov	_abs3,result_lo
	add	_arg1,_arg2			//add the phase	
	mov	_arg3,_arg1
	qrotate	_abs3,_arg3		//z3 to cartesian
	getqx	result_lo
	getqy	result_hi	
};	
*real3 = result_lo;
*imag3 = result_hi;
}

void main(void)
{
int32_t r1 = 100;
int32_t i1 = 100;
int32_t r2 = 100;
int32_t i2 = -100;
int32_t r;
int32_t i;

cplx_mult (r1,i1,r2,i2,&r,&i);//ok
cplx_mult (100,100,100,-100,&r,&i);//ok
}

Question about FlexGUI/FastSpin _ Cordic Issue _

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