option explicit
option default none
dim integer a
dim float b
'
zerotimer()
a=gettimer() 'measure how long the clock takes to zero and read
'
zerotimer()
b=atan2(1.5.1.6)
? gettimer()-a," usec" 'print the time taken to execute the function
'
end


CSub zerotimer 'zero the tick clock
00000000
00001021 40824800 03E00008 00000000
End CSub
'
CFunction gettimer 'get the number of microseconds since the tick clock was zeroed
00000000
40044800 3C029D00 8C420000 3C03001E 34638480 8C450000 00A3001B 006001F4
00001812 0083001B 006001F4 00001821 03E00008 00001012
End CFunction

FUNCTION atan2(y as float,x as float) as float
IF x > 0 THEN
atan2 = ATN(y/x)
ELSEIF y >= 0 AND x < 0 THEN
atan2 = PI + ATN(y/x)
ELSEIF y < 0 AND x < 0 THEN
atan2 = ATN(y/x) - PI
ELSEIF y > 0 AND x = 0 THEN
atan2 = PI / 2
ELSEIF y < 0 AND x = 0 THEN
atan2 = PI / -2
ENDIF
IF atan2 < 0 THEN
atan2 = atan2 + 2 * PI
ENDIF
END FUNCTION

void zerotimer(void){
unsigned int current_ticks = 0;
asm volatile("mtc0 %0, $9": "+r"(current_ticks)); //set the current number of ticks to 0
}
long long gettimer(void){
unsigned int current_ticks;
asm volatile("mfc0 %0, $9" : "=r"(current_ticks));//get the time in ticks since zeroed
unsigned int tick_rate;
tick_rate = CurrentCpuSpeed /2000000; //get the number of clock ticks per usecond
return current_ticks/tick_rate;
}