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[/] [forwardcom/] [libraries/] [print_hexadecimal_light.as] - Rev 145
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/*************************** print_hexadecimal_light.as **********************
* Author: Agner Fog
* date created: 2021-05-16
* Last modified: 2021-05-16
* Version: 1.11
* Project: ForwardCom library libc_light.li
* Description: puts: print a string to stdout. Does not append linefeed
* This version is for CPUs with limited capabilities
* C declaration: void print_hexadecimal(uint64_t h);
*
* Copyright 2021 GNU General Public License http://www.gnu.org/licenses
******************************************************************************/
code section execute align = 4 // code section
// Print a hexadecimal number to stdout
_print_hexadecimal function public reguse=3,0
// save r2-r3
int64 sp -= 2*8
int64 [sp] = r2
int64 [sp+8] = r3
int64 r1 = bitscan(r0, 1) // find number of bits
uint32 r1 >>= 2
uint32 r1++ // number of digits to print
if (int r1 > 8) { // must use 64 bits
int r2 = 16 - r1 // number of digits to skip
int r2 <<= 2 // number of bits to skip
uint64 r0 <<= r2 // remove leading zeroes
for (int ; r1 > 0; r1--) { // loop r1 times
uint64 r0 = rotate(r0, 4) // get digit into low position
int r2 = r0 & 0xF // get digit
int r2 += '0' // convert to ASCII
int r3 = r2 > '9' // digit is A - F
int r2 = r3 ? r2 + 7 : r2 // add 7 to get letter
int8 output(r2, r2, 10); // output digit
}
}
else { // use 32 bits. CPU may not support 64 bits
int r2 = 8 - r1 // number of digits to skip
int r2 <<= 2 // number of bits to skip
uint32 r0 <<= r2 // remove leading zeroes
for (int ; r1 > 0; r1--) { // loop r1 times
uint32 r0 = rotate(r0, 4) // get digit into low position
int r2 = r0 & 0xF // get digit
int r2 += '0' // convert to ASCII
int r3 = r2 > '9' // digit is A - F
int r2 = r3 ? r2 + 7 : r2 // add 7 to get letter
int8 output(r2, r2, 10); // output digit
}
}
// restore r2-r3
int64 r2 = [sp]
int64 r3 = [sp+8]
int64 sp += 2*8
return
_print_hexadecimal end
code end
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