| ??? 05/07/08 09:15 Read: times |
#154528 - Compiler smarter than coder Responding to: ???'s previous message |
The assumption that (a << 3) is more efficient than a * 3 is only true for some processors. This means that some optimisations made by a programmer may be detrimental in some circumstances. The optimisations made by the compiler should however always be correct, as long as the programmer states his intention clearly. In the past, compilers optimisation wasn't terribly good, but this is an area where progress is continuous. |
| Topic | Author | Date |
| "Real C" vs '51 C | 01/01/70 00:00 | |
| there is nothing wrong except... | 01/01/70 00:00 | |
| if you are not , why are you even here | 01/01/70 00:00 | |
| *(buffer+8+index)? | 01/01/70 00:00 | |
| none of the above | 01/01/70 00:00 | |
| OK then how? | 01/01/70 00:00 | |
| like this | 01/01/70 00:00 | |
| but it's basically the same... | 01/01/70 00:00 | |
| YCMV | 01/01/70 00:00 | |
| No | 01/01/70 00:00 | |
| assumptions | 01/01/70 00:00 | |
| Re: assumptions | 01/01/70 00:00 | |
| I took a \'known\' example | 01/01/70 00:00 | |
| Compiler-independent efficient C | 01/01/70 00:00 | |
| a clarification and an example | 01/01/70 00:00 | |
| Two kinds of "efficiency" | 01/01/70 00:00 | |
| Compiler smarter than coder | 01/01/70 00:00 | |
| Getting the least out of your compiler | 01/01/70 00:00 | |
| Real C is inherently reentrant | 01/01/70 00:00 | |
which, even when possible, often is ill advised | 01/01/70 00:00 |