Alexandre Lision | 744f742 | 2013-09-25 11:39:37 -0400 | [diff] [blame] | 1 | /* Copyright (c) 2003-2008 Timothy B. Terriberry |
| 2 | Copyright (c) 2008 Xiph.Org Foundation */ |
| 3 | /* |
| 4 | Redistribution and use in source and binary forms, with or without |
| 5 | modification, are permitted provided that the following conditions |
| 6 | are met: |
| 7 | |
| 8 | - Redistributions of source code must retain the above copyright |
| 9 | notice, this list of conditions and the following disclaimer. |
| 10 | |
| 11 | - Redistributions in binary form must reproduce the above copyright |
| 12 | notice, this list of conditions and the following disclaimer in the |
| 13 | documentation and/or other materials provided with the distribution. |
| 14 | |
| 15 | THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 16 | ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 17 | LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| 18 | A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER |
| 19 | OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
| 20 | EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
| 21 | PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR |
| 22 | PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF |
| 23 | LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING |
| 24 | NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS |
| 25 | SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 26 | */ |
| 27 | |
| 28 | /*Some common macros for potential platform-specific optimization.*/ |
| 29 | #include "opus_types.h" |
| 30 | #include <math.h> |
| 31 | #include <limits.h> |
| 32 | #include "arch.h" |
| 33 | #if !defined(_ecintrin_H) |
| 34 | # define _ecintrin_H (1) |
| 35 | |
Alexandre Lision | 8538238 | 2014-01-27 15:54:16 -0500 | [diff] [blame] | 36 | /*Some specific platforms may have optimized intrinsic or OPUS_INLINE assembly |
Alexandre Lision | 744f742 | 2013-09-25 11:39:37 -0400 | [diff] [blame] | 37 | versions of these functions which can substantially improve performance. |
| 38 | We define macros for them to allow easy incorporation of these non-ANSI |
| 39 | features.*/ |
| 40 | |
| 41 | /*Modern gcc (4.x) can compile the naive versions of min and max with cmov if |
| 42 | given an appropriate architecture, but the branchless bit-twiddling versions |
| 43 | are just as fast, and do not require any special target architecture. |
| 44 | Earlier gcc versions (3.x) compiled both code to the same assembly |
| 45 | instructions, because of the way they represented ((_b)>(_a)) internally.*/ |
| 46 | # define EC_MINI(_a,_b) ((_a)+(((_b)-(_a))&-((_b)<(_a)))) |
| 47 | |
| 48 | /*Count leading zeros. |
| 49 | This macro should only be used for implementing ec_ilog(), if it is defined. |
| 50 | All other code should use EC_ILOG() instead.*/ |
| 51 | #if defined(_MSC_VER) && (_MSC_VER >= 1400) |
| 52 | # include <intrin.h> |
| 53 | /*In _DEBUG mode this is not an intrinsic by default.*/ |
| 54 | # pragma intrinsic(_BitScanReverse) |
| 55 | |
| 56 | static __inline int ec_bsr(unsigned long _x){ |
| 57 | unsigned long ret; |
| 58 | _BitScanReverse(&ret,_x); |
| 59 | return (int)ret; |
| 60 | } |
| 61 | # define EC_CLZ0 (1) |
| 62 | # define EC_CLZ(_x) (-ec_bsr(_x)) |
| 63 | #elif defined(ENABLE_TI_DSPLIB) |
| 64 | # include "dsplib.h" |
| 65 | # define EC_CLZ0 (31) |
| 66 | # define EC_CLZ(_x) (_lnorm(_x)) |
| 67 | #elif __GNUC_PREREQ(3,4) |
| 68 | # if INT_MAX>=2147483647 |
| 69 | # define EC_CLZ0 ((int)sizeof(unsigned)*CHAR_BIT) |
| 70 | # define EC_CLZ(_x) (__builtin_clz(_x)) |
| 71 | # elif LONG_MAX>=2147483647L |
| 72 | # define EC_CLZ0 ((int)sizeof(unsigned long)*CHAR_BIT) |
| 73 | # define EC_CLZ(_x) (__builtin_clzl(_x)) |
| 74 | # endif |
| 75 | #endif |
| 76 | |
| 77 | #if defined(EC_CLZ) |
| 78 | /*Note that __builtin_clz is not defined when _x==0, according to the gcc |
| 79 | documentation (and that of the BSR instruction that implements it on x86). |
| 80 | The majority of the time we can never pass it zero. |
| 81 | When we need to, it can be special cased.*/ |
| 82 | # define EC_ILOG(_x) (EC_CLZ0-EC_CLZ(_x)) |
| 83 | #else |
| 84 | int ec_ilog(opus_uint32 _v); |
| 85 | # define EC_ILOG(_x) (ec_ilog(_x)) |
| 86 | #endif |
| 87 | #endif |