/***********************************************************************************************************************
PicoMite MMBasic

Operators.c

<COPYRIGHT HOLDERS>  Geoff Graham, Peter Mather
Copyright (c) 2021, <COPYRIGHT HOLDERS> All rights reserved. 
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2.	Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer
    in the documentation and/or other materials provided with the distribution.
3.	The name MMBasic be used when referring to the interpreter in any documentation and promotional material and the original copyright message be displayed 
    on the console at startup (additional copyright messages may be added).
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    by the <copyright holder>.
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************************************************************************************************************************/
/**
* @file Operators.c
* @author Geoff Graham, Peter Mather
* @brief Source for standard MMBasic operators
*/
/**
 * @cond
 * The following section will be excluded from the documentation.
 */

#include "MMBasic_Includes.h"
#include "Hardware_Includes.h"
#include <errno.h>



/********************************************************************************************************************************************
 basic operators
 each function is responsible for decoding a basic operator
 all function names are in the form op_xxxx() so, if you want to search for the function responsible for the AND operator look for op_and

 There are 5 globals used by these finctions:

 farg1, farg2   These are the floating point arguments to the operator.  farg1 is the left argument

 sarg1, sarg2   These are the string pointers to the arguments for a the string operator.  sarg1 is the left argument

 fret           Is the return value for a basic operator that returns a float value

 iret           Is the return value for a basic operator that returns an integer

 sret           Is the return value for a basic operator that returns a string

 targ           Is the type of the arguments.  normally this is set by the caller and is not changed by the function

 ********************************************************************************************************************************************/




void  __not_in_flash_func(op_invalid)(void) {
	error("Syntax error");
}
/*  @endcond */

void  __not_in_flash_func(op_exp)(void) {
    long long int  i;
    if(targ & T_NBR){
        fret = (MMFLOAT)pow(farg1, farg2);
        if(fret==INFINITY) error("Overflow");
    }
    else {
        if(iarg2 < 0) {
            targ = T_NBR;
            fret = (MMFLOAT)pow((MMFLOAT)iarg1, (MMFLOAT)iarg2);
        } else
            for(iret = i = 1; i <= iarg2; i++) iret *= iarg1;
    }
}


void  __not_in_flash_func(op_mul)(void) {
    if(targ & T_NBR){
        fret = farg1 * farg2;
        if(fret==INFINITY) error("Overflow");
    }
    else
        iret = iarg1 * iarg2;
}


// division will always return a float even if given integer arguments
void  __not_in_flash_func(op_div)(void) {
    if(farg2 == 0) error("Divide by zero");
    fret = farg1 / farg2;
    if(fret==INFINITY) error("Overflow");
    targ = T_NBR;
}


void  __not_in_flash_func(op_divint)(void) {
    if(iarg2 == 0) error("Divide by zero");
    iret = iarg1 / iarg2;
}


void  __not_in_flash_func(op_add)(void) {
	if(targ & T_NBR){
		fret = farg1 + farg2;
        if(fret==INFINITY) error("Overflow");
    }
	else if(targ & T_INT)
		iret = iarg1 + iarg2;
    else {
		if(*sarg1 + *sarg2 > MAXSTRLEN) error("String too long");
		sret = GetTempMemory(STRINGSIZE);								// this will last for the life of the command
		Mstrcpy(sret, sarg1);
		Mstrcat(sret, sarg2);
	}
}

void  __not_in_flash_func(op_subtract)(void) {
	if(targ & T_NBR)
		fret = farg1 - farg2;
	else
		iret = iarg1 - iarg2;
}


void  __not_in_flash_func(op_mod)(void) {
    if(iarg2 == 0) error("Divide by zero");
    iret = iarg1 % iarg2;
}


/* 
 * @cond
 * The following section will be excluded from the documentation.
 */

static inline long long int (compare)(void) {
    long long int  r;
    MMFLOAT f;
    if(targ & T_NBR) {
		f = farg1 - farg2;
        if(f > 0)
            r = 1;
        else if(f < 0)
            r = -1;
        else
            r = 0;
    }
	else
        if(targ & T_INT)
            r = iarg1 - iarg2;
        else
            r = Mstrcmp(sarg1, sarg2);
     targ = T_INT;									// always return an float, even if the args are string
     return r;
}
/*  @endcond */

void  __not_in_flash_func(op_ne)(void) {
    if(targ & T_INT)
        iret = iarg1 != iarg2;
    else
        iret = (compare() != 0);
}



void  __not_in_flash_func(op_gte)(void) {
    iret = (compare() >= 0);
}


void  __not_in_flash_func(op_lte)(void) {
    iret = (compare() <= 0);
}


void  __not_in_flash_func(op_lt)(void) {
    iret = (compare() < 0);
}


void  __not_in_flash_func(op_gt)(void) {
    iret = (compare() > 0);
}


void  __not_in_flash_func(op_equal)(void) {
    if(targ & T_INT)
        iret = iarg1 == iarg2;
    else
        iret = (compare() == 0);
}


void  __not_in_flash_func(op_shiftleft)(void) {
    iret = (long long int )((unsigned long long int )iarg1 << (long long int )iarg2);
}


void  __not_in_flash_func(op_shiftright)(void) {
    iret = (long long int )((unsigned long long int )iarg1 >> (long long int )iarg2);
}


void  __not_in_flash_func(op_and)(void) {
    iret = (long long int )((unsigned long long int )iarg1 & (unsigned long long int )iarg2);
}


void  __not_in_flash_func(op_or)(void) {
    iret = (long long int )((unsigned long long int )iarg1 | (unsigned long long int )iarg2);
}


void  __not_in_flash_func(op_xor)(void) {
    iret = (long long int )((unsigned long long int )iarg1 ^ (unsigned long long int )iarg2);
}



void  __not_in_flash_func(op_not)(void){
	// don't do anything, just a place holder
	error("Syntax error");
}

void  __not_in_flash_func(op_inv)(void){
	// don't do anything, just a place holder
	error("Syntax error");
}