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(SK_ARM_HAS_OPTIONAL_NEON) 25 # define SK_ARM_NEON_MODE SK_ARM_NEON_MODE_DYNAMIC 26 #elif defined(SK_ARM_HAS_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 inline bool sk_cpu_arm_has_neon(void) { 43 return false; 44 } 45 #elif SK_ARM_NEON_IS_ALWAYS 46 static inline bool sk_cpu_arm_has_neon(void) { 47 return true; 48 } 49 #else // SK_ARM_NEON_IS_DYNAMIC 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) 85 #endif 86 87 #endif // SkUtilsArm_DEFINED 88
