| ??? 03/19/07 06:47 Read: times |
#135244 - Optimise & kill code Responding to: ???'s previous message |
When I started using the IAR 8051 compiler, I'd crank up the optimisation and my code would stop! So I'd just turn the optimisation off. Over the years I've become a lot wiser especially with the use of the 'volatile' keyword and now I can turn up the optimisation and my code still works. Whilst the code size for most of my apps isn't an issue (as long as it fits in the flash!) I noted when I got the latest version of the IAR compiler than on full optimisation the code shrank by half. Whilst still not quite as good as assembler (the original app was in assembler as the cpu I used only had 8k flash, when the new cpu came out, it had 62k flash, so I rewrote the code in 'c') the assembler app was around 6K, the 'c' version weighs in around 9k with full optimisation. |
| Topic | Author | Date |
| akkkk! stupid compilers, something to watch | 01/01/70 00:00 | |
| ehm, isn't it the user? | 01/01/70 00:00 | |
| Well it might be phooey;- but its pretty common | 01/01/70 00:00 | |
| have you considered using a timer, perhaps... :-) | 01/01/70 00:00 | |
| yep but... | 01/01/70 00:00 | |
| Sorry - not this time, Jez | 01/01/70 00:00 | |
| if it is THAT short... | 01/01/70 00:00 | |
| Maybe not... | 01/01/70 00:00 | |
| Beware. | 01/01/70 00:00 | |
| Well, any compiler with half a brain does that. | 01/01/70 00:00 | |
| volatile | 01/01/70 00:00 | |
| use util/delay.h and read the lib documents | 01/01/70 00:00 | |
| optimization = lost control | 01/01/70 00:00 | |
| well that is the first mistake | 01/01/70 00:00 | |
| First mistake is using a HLL | 01/01/70 00:00 | |
| Optimise & kill code | 01/01/70 00:00 | |
| optimizers and NASA | 01/01/70 00:00 | |
| There are many levels in Keil | 01/01/70 00:00 | |
not always a good idea | 01/01/70 00:00 |