| ??? 06/08/11 07:22 Modified: 06/08/11 07:27 Read: times |
#182534 - Compiler variations?? |
I've moved somewhat ahead with my 89S52 based clock using 2x16 LCD & DS1307.
Now that time setting part is in progress, I've found something which I want to share & get myself corrected if there is something wrong with code itself. I've inserted .LST file parts where anomalies were observed. ...==========================================================================
1 ;--------------------------------------------------------
2 ; File Created by SDCC : free open source ANSI-C Compiler
3 ; Version 3.0.0 #6037 (Oct 31 2010) (MINGW32)
==========================================================================
[1]
2442 ; Test9.c:461: if(up_pressed)
0ABE 30 85 99 2443 jnb _P0_5,00144$
2444 ; Test9.c:463: if(dn_pressed)
0AC1 A2 86 2445 mov c,_P0_6
2446 ; Test9.c:467: dn2: if (dn_pressed)
0AC3 2447 00157$:
0AC3 20 86 63 2448 jb _P0_6,00169$
| || || || || || ||
[2]
2502 ; Test9.c:483: if(up_pressed)
0B20 20 85 03 2503 jb _P0_5,00303$
0B23 02s0Ar5A 2504 ljmp 00144$
0B26 2505 00303$:
2506 ; Test9.c:485: if(dn_pressed)
0B26 30 86 9A 2507 jnb _P0_6,00157$
| || || || || || ||
[3]
2686 ; Test9.c:540: if(up_pressed)
0C68 30 85 91 2687 jnb _P0_5,00175$
2688 ; Test9.c:542: if(dn_pressed)
0C6B A2 86 2689 mov c,_P0_6
2690 ; Test9.c:546: dn3: if (dn_pressed)
0C6D 2691 00188$:
0C6D 20 86 6B 2692 jb _P0_6,00200$
| || || || || || ||
In part[2] if(dn_pressed) gives jnb P0.6 ; which is as expected whereas in part [1] & [3] if(dn_pressed) is giving mov c, P0.6 ; which is not expected. Same code is used at all the three places. Can somebody help & point out the problem here. Sandy |
| Topic | Author | Date |
| Compiler variations?? | 01/01/70 00:00 | |
| Fundamental philosophy of High-Level Languges (HLL) | 01/01/70 00:00 | |
| C code | 01/01/70 00:00 | |
| and so what | 01/01/70 00:00 | |
| Stop wondering about the compiler output | 01/01/70 00:00 | |
| Very nice to learn this important matter | 01/01/70 00:00 | |
| Exactly what you wrote | 01/01/70 00:00 | |
| volatile sbit may be the problem | 01/01/70 00:00 | |
| read up on (not) volatile | 01/01/70 00:00 | |
| Look at my profile | 01/01/70 00:00 | |
| Not offence intended | 01/01/70 00:00 | |
| defining P0_6 so that compiler doesn't treat it as volatile | 01/01/70 00:00 | |
| Skip the goto - almost always exists beautiful rewrites | 01/01/70 00:00 | |
| Goto really is a bastard code construct | 01/01/70 00:00 | |
| and therefore ... | 01/01/70 00:00 | |
Will come back with modified code | 01/01/70 00:00 | |
| Wonderful as always! | 01/01/70 00:00 |