gfx/skia/trunk/src/core/SkUtilsArm.h@6474c204b198
gfx/skia/trunk/src/core/SkUtilsArm.h
Wed, 31 Dec 2014 06:09:35 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Wed, 31 Dec 2014 06:09:35 +0100
- changeset 0
- 6474c204b198
- permissions
- -rw-r--r--
Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.
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 */
9 #ifndef SkUtilsArm_DEFINED
10 #define SkUtilsArm_DEFINED
12 #include "SkUtils.h"
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
24 #if defined(SK_CPU_ARM) && defined(__ARM_HAVE_OPTIONAL_NEON_SUPPORT)
25 # define SK_ARM_NEON_MODE SK_ARM_NEON_MODE_DYNAMIC
26 #elif defined(SK_CPU_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
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)
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).
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
51 extern bool sk_cpu_arm_has_neon(void) SK_PURE_FUNC;
52 #endif
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
87 #endif // SkUtilsArm_DEFINED
