digit@google.com | eec9dbc | 2012-05-30 13:54:41 +0000 | [diff] [blame] | 1 | |
| 2 | /* |
| 3 | * Copyright 2012 The Android Open Source Project |
| 4 | * |
| 5 | * Use of this source code is governed by a BSD-style license that can be |
| 6 | * found in the LICENSE file. |
| 7 | */ |
| 8 | |
| 9 | #ifndef SkUtilsArm_DEFINED |
| 10 | #define SkUtilsArm_DEFINED |
| 11 | |
| 12 | #include "SkUtils.h" |
| 13 | |
| 14 | // Define SK_ARM_NEON_MODE to one of the following values |
| 15 | // corresponding respectively to: |
| 16 | // - No ARM Neon support at all (not targetting ARMv7-A, or don't have NEON) |
| 17 | // - Full ARM Neon support (i.e. assume the CPU always supports it) |
| 18 | // - Optional ARM Neon support (i.e. probe CPU at runtime) |
| 19 | // |
| 20 | #define SK_ARM_NEON_MODE_NONE 0 |
| 21 | #define SK_ARM_NEON_MODE_ALWAYS 1 |
| 22 | #define SK_ARM_NEON_MODE_DYNAMIC 2 |
| 23 | |
| 24 | #if defined(__arm__) && defined(__ARM_HAVE_OPTIONAL_NEON_SUPPORT) |
| 25 | # define SK_ARM_NEON_MODE SK_ARM_NEON_MODE_DYNAMIC |
| 26 | #elif defined(__arm__) && defined(__ARM_HAVE_NEON) |
| 27 | # define SK_ARM_NEON_MODE SK_ARM_NEON_MODE_ALWAYS |
| 28 | #else |
| 29 | # define SK_ARM_NEON_MODE SK_ARM_NEON_MODE_NONE |
| 30 | #endif |
| 31 | |
| 32 | // Convenience test macros, always defined as 0 or 1 |
| 33 | #define SK_ARM_NEON_IS_NONE (SK_ARM_NEON_MODE == SK_ARM_NEON_MODE_NONE) |
| 34 | #define SK_ARM_NEON_IS_ALWAYS (SK_ARM_NEON_MODE == SK_ARM_NEON_MODE_ALWAYS) |
| 35 | #define SK_ARM_NEON_IS_DYNAMIC (SK_ARM_NEON_MODE == SK_ARM_NEON_MODE_DYNAMIC) |
| 36 | |
| 37 | // The sk_cpu_arm_has_neon() function returns true iff the target device |
| 38 | // is ARMv7-A and supports Neon instructions. In DYNAMIC mode, this actually |
| 39 | // probes the CPU at runtime (and caches the result). |
| 40 | |
| 41 | #if SK_ARM_NEON_IS_NONE |
| 42 | static bool sk_cpu_arm_has_neon(void) { |
| 43 | return false; |
| 44 | } |
| 45 | #elif SK_ARM_NEON_IS_ALWAYS |
| 46 | static bool sk_cpu_arm_has_neon(void) { |
| 47 | return true; |
| 48 | } |
| 49 | #else // SK_ARM_NEON_IS_DYNAMIC |
digit@google.com | 157d944 | 2012-08-06 14:53:32 +0000 | [diff] [blame] | 50 | |
| 51 | extern bool sk_cpu_arm_has_neon(void) SK_PURE_FUNC; |
| 52 | #endif |
| 53 | |
| 54 | // Use SK_ARM_NEON_WRAP(symbol) to map 'symbol' to a NEON-specific symbol |
| 55 | // when applicable. This will transform 'symbol' differently depending on |
| 56 | // the current NEON configuration, i.e.: |
| 57 | // |
| 58 | // NONE -> 'symbol' |
| 59 | // ALWAYS -> 'symbol_neon' |
| 60 | // DYNAMIC -> 'symbol' or 'symbol_neon' depending on runtime check. |
| 61 | // |
| 62 | // The goal is to simplify user code, for example: |
| 63 | // |
| 64 | // return SK_ARM_NEON_WRAP(do_something)(params); |
| 65 | // |
| 66 | // Replaces the equivalent: |
| 67 | // |
| 68 | // #if SK_ARM_NEON_IS_NONE |
| 69 | // return do_something(params); |
| 70 | // #elif SK_ARM_NEON_IS_ALWAYS |
| 71 | // return do_something_neon(params); |
| 72 | // #elif SK_ARM_NEON_IS_DYNAMIC |
| 73 | // if (sk_cpu_arm_has_neon()) |
| 74 | // return do_something_neon(params); |
| 75 | // else |
| 76 | // return do_something(params); |
| 77 | // #endif |
| 78 | // |
| 79 | #if SK_ARM_NEON_IS_NONE |
| 80 | # define SK_ARM_NEON_WRAP(x) (x) |
| 81 | #elif SK_ARM_NEON_IS_ALWAYS |
| 82 | # define SK_ARM_NEON_WRAP(x) (x ## _neon) |
| 83 | #elif SK_ARM_NEON_IS_DYNAMIC |
| 84 | # define SK_ARM_NEON_WRAP(x) (sk_cpu_arm_has_neon() ? x ## _neon : x) |
digit@google.com | eec9dbc | 2012-05-30 13:54:41 +0000 | [diff] [blame] | 85 | #endif |
| 86 | |
| 87 | #endif // SkUtilsArm_DEFINED |