10 times faster int to string implementation
@@ -54,53 +54,33 @@ static int16_t sin0_90_table[] = {
*/
char * lv_math_num_to_str(int32_t num, char * buf)
{
- char * buf_ori = buf;
if (num == 0) {
buf[0] = '0';
buf[1] = '\0';
return buf;
- } else if(num < 0) {
- (*buf) = '-';
- buf++;
- num = LV_MATH_ABS(num);
}
- uint32_t output = 0;
- int8_t i;
-
- for(i = 31; i >= 0; i--) {
- if((output & 0xF) >= 5)
- output += 3;
- if(((output & 0xF0) >> 4) >= 5)
- output += (3 << 4);
- if(((output & 0xF00) >> 8) >= 5)
- output += (3 << 8);
- if(((output & 0xF000) >> 12) >= 5)
- output += (3 << 12);
- if(((output & 0xF0000) >> 16) >= 5)
- output += (3 << 16);
- if(((output & 0xF00000) >> 20) >= 5)
- output += (3 << 20);
- if(((output & 0xF000000) >> 24) >= 5)
- output += (3 << 24);
- if(((output & 0xF0000000) >> 28) >= 5)
- output += (3 << 28);
- output = (output << 1) | ((num >> i) & 1);
+ int8_t digitCount = 0;
+ int8_t i = 0;
+ if (num < 0) {
+ buf[digitCount++] = '-';
+ num = abs(num);
+ ++i;
}
-
- uint8_t digit;
- bool leading_zero_ready = false;
- for(i = 28; i >= 0; i -= 4) {
- digit = ((output >> i) & 0xF) + '0';
- if(digit == '0' && leading_zero_ready == false) continue;
-
- leading_zero_ready = true;
- (*buf) = digit;
- buf++;
+ while (num) {
+ char digit = num % 10;
+ buf[digitCount++] = digit + 48;
+ num /= 10;
}
-
- (*buf) = '\0';
-
- return buf_ori;
+ buf[digitCount] = '\0';
+ digitCount--;
+ while (digitCount > i) {
+ char temp = buf[i];
+ buf[i] = buf[digitCount];
+ buf[digitCount] = temp;
+ digitCount--;
+ i++;
+ }
+ return buf;
}
/**
