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