Hello,
When I use bitwise operation to get the high/low byte of a 16bit int:
=========================================
IAP_ADDRH = (unsigned int)src >>8;
IAP_ADDRL = (unsigned int)src & 0x00FF;
=========================================
SDCC gives me the following asm code:
=========================================
488 ; eeprom.c:21: IAP_ADDRH = (unsigned int)src >> 8;^M
489 mov ar0,r5
490 mov ar1,r6
491 mov _IAP_ADDRH,r1
492 ; eeprom.c:22: IAP_ADDRL = (unsigned int)src & 0x00FF;^M
493 mov r1,#0x00
494 mov _IAP_ADDRL,r0
=========================================
I think there are many useless asm code. This is the second version:
=========================================
2 39 IAP_ADDRH = *((unsigned char *)&dest);
2 40 IAP_ADDRL = *((unsigned char *)&dest + 1);
=========================================
which gives better asm code:
=========================================
555 ; eeprom.c:39: IAP_ADDRH = *((unsigned char *)&dest);^M
556 mov _IAP_ADDRH,_memcpy_toeep_dest_1_1
557 ; eeprom.c:40: IAP_ADDRL = *((unsigned char *)&dest + 1);^M
558 mov _IAP_ADDRL,(_memcpy_toeep_dest_1_1 + 0x0001)
=========================================
But the C code is ugly. Is there a better way? Thanks in advance.
--
Cheers,
Grissiom
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