| ??? 03/16/07 08:28 Read: times Msg Score: +1 +1 Good Answer/Helpful |
#135084 - Well, any compiler with half a brain does that. Responding to: ???'s previous message |
for the avr only to discover that if you have an empty loop for timing and the loop can be shown to be finite and it has no other effects then gcc will remove the loop,<p>
That's called "Optimization". There are some ways around it. If you can control the optimization level via #pragmas, you can just disable any optimizations for the loop. Alternatively, you can use intrinsic _nop_() functions, or twiddle a volatile variable. Or use inline assembly. Or write the delay function in assembly. |
| 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 |