| … | |
… | |
| 53 | C<uint32_t>, then the corresponding function works only with that type. If |
53 | C<uint32_t>, then the corresponding function works only with that type. If |
| 54 | only a generic name is used (C<expr>, C<cond>, C<value> and so on), then |
54 | only a generic name is used (C<expr>, C<cond>, C<value> and so on), then |
| 55 | the corresponding function relies on C to implement the correct types, and |
55 | the corresponding function relies on C to implement the correct types, and |
| 56 | is usually implemented as a macro. Specifically, a "bool" in this manual |
56 | is usually implemented as a macro. Specifically, a "bool" in this manual |
| 57 | refers to any kind of boolean value, not a specific type. |
57 | refers to any kind of boolean value, not a specific type. |
|
|
58 | |
|
|
59 | =head2 TYPES / TYPE SUPPORT |
|
|
60 | |
|
|
61 | ecb.h makes sure that the following types are defined (in the expected way): |
|
|
62 | |
|
|
63 | int8_t uint8_t int16_t uint16_t |
|
|
64 | int32_t uint32_t int64_t uint64_t |
|
|
65 | intptr_t uintptr_t |
|
|
66 | |
|
|
67 | The macro C<ECB_PTRSIZE> is defined to the size of a pointer on this |
|
|
68 | platform (currently C<4> or C<8>). |
| 58 | |
69 | |
| 59 | =head2 GCC ATTRIBUTES |
70 | =head2 GCC ATTRIBUTES |
| 60 | |
71 | |
| 61 | A major part of libecb deals with GCC attributes. These are additional |
72 | A major part of libecb deals with GCC attributes. These are additional |
| 62 | attributes that you can assign to functions, variables and sometimes even |
73 | attributes that you can assign to functions, variables and sometimes even |
| … | |
… | |
| 425 | For example: |
436 | For example: |
| 426 | |
437 | |
| 427 | ecb_ctz32 (3) = 0 |
438 | ecb_ctz32 (3) = 0 |
| 428 | ecb_ctz32 (6) = 1 |
439 | ecb_ctz32 (6) = 1 |
| 429 | |
440 | |
|
|
441 | =item bool ecb_is_pot32 (uint32_t x) |
|
|
442 | |
|
|
443 | =item bool ecb_is_pot64 (uint32_t x) |
|
|
444 | |
|
|
445 | Return true iff C<x> is a power of two or C<x == 0>. |
|
|
446 | |
|
|
447 | For smaller types then C<uint32_t> you can safely use C<ecb_is_pot32>. |
|
|
448 | |
| 430 | =item int ecb_ld32 (uint32_t x) |
449 | =item int ecb_ld32 (uint32_t x) |
| 431 | |
450 | |
| 432 | =item int ecb_ld64 (uint64_t x) |
451 | =item int ecb_ld64 (uint64_t x) |
| 433 | |
452 | |
| 434 | Returns the index of the most significant bit set in C<x>, or the number |
453 | Returns the index of the most significant bit set in C<x>, or the number |
| … | |
… | |
| 454 | |
473 | |
| 455 | For example: |
474 | For example: |
| 456 | |
475 | |
| 457 | ecb_popcount32 (7) = 3 |
476 | ecb_popcount32 (7) = 3 |
| 458 | ecb_popcount32 (255) = 8 |
477 | ecb_popcount32 (255) = 8 |
|
|
478 | |
|
|
479 | =item uint8_t ecb_bitrev8 (uint8_t x) |
|
|
480 | |
|
|
481 | =item uint16_t ecb_bitrev16 (uint16_t x) |
|
|
482 | |
|
|
483 | =item uint32_t ecb_bitrev32 (uint32_t x) |
|
|
484 | |
|
|
485 | Reverses the bits in x, i.e. the MSB becomes the LSB, MSB-1 becomes LSB+1 |
|
|
486 | and so on. |
|
|
487 | |
|
|
488 | Example: |
|
|
489 | |
|
|
490 | ecb_bitrev8 (0xa7) = 0xea |
|
|
491 | ecb_bitrev32 (0xffcc4411) = 0x882233ff |
| 459 | |
492 | |
| 460 | =item uint32_t ecb_bswap16 (uint32_t x) |
493 | =item uint32_t ecb_bswap16 (uint32_t x) |
| 461 | |
494 | |
| 462 | =item uint32_t ecb_bswap32 (uint32_t x) |
495 | =item uint32_t ecb_bswap32 (uint32_t x) |
| 463 | |
496 | |
