| ??? 09/11/12 09:26 Read: times |
#188306 - no defined bit order Responding to: ???'s previous message |
Per Westermark said:
Next thing - you show sample code with union + C bit fields. But note that bit fields is a C construct to store multiple small state information fields more compactly into a larger integer. The C language do not have bit variables, and the bit field construct is intended to make the C source code look like it accesses normal struct member fields while the compiler performs logical and/or/not operations to set/clear bits within the containing byte.
[...] The C bit fields are always stored side-by-side (with optional high or low padding) in a container integer of an appropriate size. True, but also note: C-standard said:
The order of allocation of bit-fields within a unit (high-order to low-order or low-order to high-order) is implementation-defined. This means that the compiler gets to choose which order it uses (globally, not case-by-case) and another compiler can make a different choice. |
| Topic | Author | Date |
| Different variable bit merge into single variable? | 01/01/70 00:00 | |
| Of course | 01/01/70 00:00 | |
| its bit addressable.... | 01/01/70 00:00 | |
| No | 01/01/70 00:00 | |
| just want to check... | 01/01/70 00:00 | |
| What was missing in the answers you have already received? | 01/01/70 00:00 | |
| no defined bit order | 01/01/70 00:00 | |
| Just use C expression | 01/01/70 00:00 | |
| what is wrong with IE? | 01/01/70 00:00 | |
| Right!!!!!!!!!! | 01/01/70 00:00 | |
gobbledygook | 01/01/70 00:00 |