| |
| /* |
| * Copyright 2012 The Android Open Source Project |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #ifndef SkUtilsArm_DEFINED |
| #define SkUtilsArm_DEFINED |
| |
| #include "SkUtils.h" |
| |
| // Define SK_ARM_NEON_MODE to one of the following values |
| // corresponding respectively to: |
| // - No ARM Neon support at all (not targetting ARMv7-A, or don't have NEON) |
| // - Full ARM Neon support (i.e. assume the CPU always supports it) |
| // - Optional ARM Neon support (i.e. probe CPU at runtime) |
| // |
| #define SK_ARM_NEON_MODE_NONE 0 |
| #define SK_ARM_NEON_MODE_ALWAYS 1 |
| #define SK_ARM_NEON_MODE_DYNAMIC 2 |
| |
| #if defined(SK_CPU_ARM) && defined(__ARM_HAVE_OPTIONAL_NEON_SUPPORT) |
| # define SK_ARM_NEON_MODE SK_ARM_NEON_MODE_DYNAMIC |
| #elif defined(SK_CPU_ARM) && defined(__ARM_HAVE_NEON) |
| # define SK_ARM_NEON_MODE SK_ARM_NEON_MODE_ALWAYS |
| #else |
| # define SK_ARM_NEON_MODE SK_ARM_NEON_MODE_NONE |
| #endif |
| |
| // Convenience test macros, always defined as 0 or 1 |
| #define SK_ARM_NEON_IS_NONE (SK_ARM_NEON_MODE == SK_ARM_NEON_MODE_NONE) |
| #define SK_ARM_NEON_IS_ALWAYS (SK_ARM_NEON_MODE == SK_ARM_NEON_MODE_ALWAYS) |
| #define SK_ARM_NEON_IS_DYNAMIC (SK_ARM_NEON_MODE == SK_ARM_NEON_MODE_DYNAMIC) |
| |
| // The sk_cpu_arm_has_neon() function returns true iff the target device |
| // is ARMv7-A and supports Neon instructions. In DYNAMIC mode, this actually |
| // probes the CPU at runtime (and caches the result). |
| |
| #if SK_ARM_NEON_IS_NONE |
| static bool sk_cpu_arm_has_neon(void) { |
| return false; |
| } |
| #elif SK_ARM_NEON_IS_ALWAYS |
| static bool sk_cpu_arm_has_neon(void) { |
| return true; |
| } |
| #else // SK_ARM_NEON_IS_DYNAMIC |
| |
| extern bool sk_cpu_arm_has_neon(void) SK_PURE_FUNC; |
| #endif |
| |
| // Use SK_ARM_NEON_WRAP(symbol) to map 'symbol' to a NEON-specific symbol |
| // when applicable. This will transform 'symbol' differently depending on |
| // the current NEON configuration, i.e.: |
| // |
| // NONE -> 'symbol' |
| // ALWAYS -> 'symbol_neon' |
| // DYNAMIC -> 'symbol' or 'symbol_neon' depending on runtime check. |
| // |
| // The goal is to simplify user code, for example: |
| // |
| // return SK_ARM_NEON_WRAP(do_something)(params); |
| // |
| // Replaces the equivalent: |
| // |
| // #if SK_ARM_NEON_IS_NONE |
| // return do_something(params); |
| // #elif SK_ARM_NEON_IS_ALWAYS |
| // return do_something_neon(params); |
| // #elif SK_ARM_NEON_IS_DYNAMIC |
| // if (sk_cpu_arm_has_neon()) |
| // return do_something_neon(params); |
| // else |
| // return do_something(params); |
| // #endif |
| // |
| #if SK_ARM_NEON_IS_NONE |
| # define SK_ARM_NEON_WRAP(x) (x) |
| #elif SK_ARM_NEON_IS_ALWAYS |
| # define SK_ARM_NEON_WRAP(x) (x ## _neon) |
| #elif SK_ARM_NEON_IS_DYNAMIC |
| # define SK_ARM_NEON_WRAP(x) (sk_cpu_arm_has_neon() ? x ## _neon : x) |
| #endif |
| |
| #endif // SkUtilsArm_DEFINED |
