1 /* 2 * Copyright (C) 2010 The Android Open Source Project 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * * Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * * Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in 12 * the documentation and/or other materials provided with the 13 * distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 #ifndef CPU_FEATURES_H 29 #define CPU_FEATURES_H 30 31 #include <sys/cdefs.h> 32 #include <stdint.h> 33 34 __BEGIN_DECLS 35 36 typedef enum { 37 ANDROID_CPU_FAMILY_UNKNOWN = 0, 38 ANDROID_CPU_FAMILY_ARM, 39 ANDROID_CPU_FAMILY_X86, 40 ANDROID_CPU_FAMILY_MIPS, 41 42 ANDROID_CPU_FAMILY_MAX /* do not remove */ 43 44 } AndroidCpuFamily; 45 46 /* Return family of the device's CPU */ 47 extern AndroidCpuFamily android_getCpuFamily(void); 48 49 /* The list of feature flags for ARM CPUs that can be recognized by the 50 * library. Value details are: 51 * 52 * VFPv2: 53 * CPU supports the VFPv2 instruction set. Many, but not all, ARMv6 CPUs 54 * support these instructions. VFPv2 is a subset of VFPv3 so this will 55 * be set whenever VFPv3 is set too. 56 * 57 * ARMv7: 58 * CPU supports the ARMv7-A basic instruction set. 59 * This feature is mandated by the 'armeabi-v7a' ABI. 60 * 61 * VFPv3: 62 * CPU supports the VFPv3-D16 instruction set, providing hardware FPU 63 * support for single and double precision floating point registers. 64 * Note that only 16 FPU registers are available by default, unless 65 * the D32 bit is set too. This feature is also mandated by the 66 * 'armeabi-v7a' ABI. 67 * 68 * VFP_D32: 69 * CPU VFP optional extension that provides 32 FPU registers, 70 * instead of 16. Note that ARM mandates this feature is the 'NEON' 71 * feature is implemented by the CPU. 72 * 73 * NEON: 74 * CPU FPU supports "ARM Advanced SIMD" instructions, also known as 75 * NEON. Note that this mandates the VFP_D32 feature as well, per the 76 * ARM Architecture specification. 77 * 78 * VFP_FP16: 79 * Half-width floating precision VFP extension. If set, the CPU 80 * supports instructions to perform floating-point operations on 81 * 16-bit registers. This is part of the VFPv4 specification, but 82 * not mandated by any Android ABI. 83 * 84 * VFP_FMA: 85 * Fused multiply-accumulate VFP instructions extension. Also part of 86 * the VFPv4 specification, but not mandated by any Android ABI. 87 * 88 * NEON_FMA: 89 * Fused multiply-accumulate NEON instructions extension. Optional 90 * extension from the VFPv4 specification, but not mandated by any 91 * Android ABI. 92 * 93 * IDIV_ARM: 94 * Integer division available in ARM mode. Only available 95 * on recent CPUs (e.g. Cortex-A15). 96 * 97 * IDIV_THUMB2: 98 * Integer division available in Thumb-2 mode. Only available 99 * on recent CPUs (e.g. Cortex-A15). 100 * 101 * iWMMXt: 102 * Optional extension that adds MMX registers and operations to an 103 * ARM CPU. This is only available on a few XScale-based CPU designs 104 * sold by Marvell. Pretty rare in practice. 105 * 106 * If you want to tell the compiler to generate code that targets one of 107 * the feature set above, you should probably use one of the following 108 * flags (for more details, see technical note at the end of this file): 109 * 110 * -mfpu=vfp 111 * -mfpu=vfpv2 112 * These are equivalent and tell GCC to use VFPv2 instructions for 113 * floating-point operations. Use this if you want your code to 114 * run on *some* ARMv6 devices, and any ARMv7-A device supported 115 * by Android. 116 * 117 * Generated code requires VFPv2 feature. 118 * 119 * -mfpu=vfpv3-d16 120 * Tell GCC to use VFPv3 instructions (using only 16 FPU registers). 121 * This should be generic code that runs on any CPU that supports the 122 * 'armeabi-v7a' Android ABI. Note that no ARMv6 CPU supports this. 123 * 124 * Generated code requires VFPv3 feature. 125 * 126 * -mfpu=vfpv3 127 * Tell GCC to use VFPv3 instructions with 32 FPU registers. 128 * Generated code requires VFPv3|VFP_D32 features. 129 * 130 * -mfpu=neon 131 * Tell GCC to use VFPv3 instructions with 32 FPU registers, and 132 * also support NEON intrinsics (see <arm_neon.h>). 133 * Generated code requires VFPv3|VFP_D32|NEON features. 134 * 135 * -mfpu=vfpv4-d16 136 * Generated code requires VFPv3|VFP_FP16|VFP_FMA features. 137 * 138 * -mfpu=vfpv4 139 * Generated code requires VFPv3|VFP_FP16|VFP_FMA|VFP_D32 features. 140 * 141 * -mfpu=neon-vfpv4 142 * Generated code requires VFPv3|VFP_FP16|VFP_FMA|VFP_D32|NEON|NEON_FMA 143 * features. 144 * 145 * -mcpu=cortex-a7 146 * -mcpu=cortex-a15 147 * Generated code requires VFPv3|VFP_FP16|VFP_FMA|VFP_D32| 148 * NEON|NEON_FMA|IDIV_ARM|IDIV_THUMB2 149 * This flag implies -mfpu=neon-vfpv4. 150 * 151 * -mcpu=iwmmxt 152 * Allows the use of iWMMXt instrinsics with GCC. 153 */ 154 enum { 155 ANDROID_CPU_ARM_FEATURE_ARMv7 = (1 << 0), 156 ANDROID_CPU_ARM_FEATURE_VFPv3 = (1 << 1), 157 ANDROID_CPU_ARM_FEATURE_NEON = (1 << 2), 158 ANDROID_CPU_ARM_FEATURE_LDREX_STREX = (1 << 3), 159 ANDROID_CPU_ARM_FEATURE_VFPv2 = (1 << 4), 160 ANDROID_CPU_ARM_FEATURE_VFP_D32 = (1 << 5), 161 ANDROID_CPU_ARM_FEATURE_VFP_FP16 = (1 << 6), 162 ANDROID_CPU_ARM_FEATURE_VFP_FMA = (1 << 7), 163 ANDROID_CPU_ARM_FEATURE_NEON_FMA = (1 << 8), 164 ANDROID_CPU_ARM_FEATURE_IDIV_ARM = (1 << 9), 165 ANDROID_CPU_ARM_FEATURE_IDIV_THUMB2 = (1 << 10), 166 ANDROID_CPU_ARM_FEATURE_iWMMXt = (1 << 11), 167 }; 168 169 enum { 170 ANDROID_CPU_X86_FEATURE_SSSE3 = (1 << 0), 171 ANDROID_CPU_X86_FEATURE_POPCNT = (1 << 1), 172 ANDROID_CPU_X86_FEATURE_MOVBE = (1 << 2), 173 }; 174 175 extern uint64_t android_getCpuFeatures(void); 176 177 /* Return the number of CPU cores detected on this device. */ 178 extern int android_getCpuCount(void); 179 180 /* The following is used to force the CPU count and features 181 * mask in sandboxed processes. Under 4.1 and higher, these processes 182 * cannot access /proc, which is the only way to get information from 183 * the kernel about the current hardware (at least on ARM). 184 * 185 * It _must_ be called only once, and before any android_getCpuXXX 186 * function, any other case will fail. 187 * 188 * This function return 1 on success, and 0 on failure. 189 */ 190 extern int android_setCpu(int cpu_count, 191 uint64_t cpu_features); 192 193 #ifdef __arm__ 194 /* Retrieve the ARM 32-bit CPUID value from the kernel. 195 * Note that this cannot work on sandboxed processes under 4.1 and 196 * higher, unless you called android_setCpuArm() before. 197 */ 198 extern uint32_t android_getCpuIdArm(void); 199 200 /* An ARM-specific variant of android_setCpu() that also allows you 201 * to set the ARM CPUID field. 202 */ 203 extern int android_setCpuArm(int cpu_count, 204 uint64_t cpu_features, 205 uint32_t cpu_id); 206 #endif 207 208 __END_DECLS 209 210 #endif /* CPU_FEATURES_H */ 211
