Mikroelektronika MIKROE-724 データシート

162

mikoBasic PRO for dsPIC30/33 and PIC24

MikroElektronika

0x0102        0x320001          BRA Z        L__SSA_Test2

L__SSA_Test6:

;Example.mbas,31 ::                 nop

0x0104        0x000000          NOP

Without SSA enabled, sub procedure 

SSA_Test

 this example is consisted of 5 asm instructions :

;Example.mbas,29 ::                 if (y+k) then

0x0102        0x97B8CE          MOV        [W14-8], W1

0x0104        0x57006A          SUB        W14, #10, W0

0x0106        0x408010          ADD        W1, [W0], W0

0x0108        0x320001          BRA Z        L__SSA_Test2

L__SSA_Test6:

;Example.mbas,31 ::                 nop

0x010A        0x000000          NOP

Proper Coding Recommendations

To get the maximum out of the SSA, user should regard the following rules during the coding process:

 

- Routines should not contain too many parameters (not more than 4 words). 

 

- Don’t change the value of the parameter in the function body (it is better to use a new local variable). 

 

- If the 

function1

 parameters are passed as 

function2

 parameters, then parameter order should remain  

 

  the same: 

 

sub procedure f2(dim a as integer, dim b as integer)

 

sub procedure f1(dim x as integer, dim y as integer)

  

   

f2(x,y) ‘ x->a and y->b (1 to 1 and 2 to 2) is far more efficient than:

   

f2(y,x) ‘ y->a and x->b (1 to 2 and 2 to 1)

 

 

- Large amount of nested loops and complex structures as its members should be avoided. 

 

- When writing a code in assembly, keep in mind that there are registers reserved exclusively for routine  

 

  parameters. 

 

- Using 

goto

 and 

label

 statements in nested loops should be avoided. 

 

- Obtaining address of the local variable with the global pointer and using it to alter the variable’s address  

 

  should be avoided. 

Note: 

 

- 

mcl 

files compiled with or without SSA enabled are fully compatible and can be used and mixed without  

 

  any restrictions, except pointers to functions. 

 

- Functions, functions declarations and pointers that may point to these functions must be compiled with the  

 

  same option, either SSA enabled or disabled. If this is not the case, compiler will report an error.