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/*
* Copyright (C) 2010 The Android Open Source Project
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef CPU_FEATURES_H
#define CPU_FEATURES_H
#include <sys/cdefs.h>
#include <stdint.h>
__BEGIN_DECLS
typedef enum {
ANDROID_CPU_FAMILY_UNKNOWN = 0,
ANDROID_CPU_FAMILY_ARM,
ANDROID_CPU_FAMILY_X86,
ANDROID_CPU_FAMILY_MIPS,
ANDROID_CPU_FAMILY_MAX /* do not remove */
} AndroidCpuFamily;
/* Return family of the device's CPU */
extern AndroidCpuFamily android_getCpuFamily(void);
/* The list of feature flags for ARM CPUs that can be recognized by the
* library. Value details are:
*
* VFPv2:
* CPU supports the VFPv2 instruction set. Many, but not all, ARMv6 CPUs
* support these instructions. VFPv2 is a subset of VFPv3 so this will
* be set whenever VFPv3 is set too.
*
* ARMv7:
* CPU supports the ARMv7-A basic instruction set.
* This feature is mandated by the 'armeabi-v7a' ABI.
*
* VFPv3:
* CPU supports the VFPv3-D16 instruction set, providing hardware FPU
* support for single and double precision floating point registers.
* Note that only 16 FPU registers are available by default, unless
* the D32 bit is set too. This feature is also mandated by the
* 'armeabi-v7a' ABI.
*
* VFP_D32:
* CPU VFP optional extension that provides 32 FPU registers,
* instead of 16. Note that ARM mandates this feature is the 'NEON'
* feature is implemented by the CPU.
*
* NEON:
* CPU FPU supports "ARM Advanced SIMD" instructions, also known as
* NEON. Note that this mandates the VFP_D32 feature as well, per the
* ARM Architecture specification.
*
* VFP_FP16:
* Half-width floating precision VFP extension. If set, the CPU
* supports instructions to perform floating-point operations on
* 16-bit registers. This is part of the VFPv4 specification, but
* not mandated by any Android ABI.
*
* VFP_FMA:
* Fused multiply-accumulate VFP instructions extension. Also part of
* the VFPv4 specification, but not mandated by any Android ABI.
*
* NEON_FMA:
* Fused multiply-accumulate NEON instructions extension. Optional
* extension from the VFPv4 specification, but not mandated by any
* Android ABI.
*
* IDIV_ARM:
* Integer division available in ARM mode. Only available
* on recent CPUs (e.g. Cortex-A15).
*
* IDIV_THUMB2:
* Integer division available in Thumb-2 mode. Only available
* on recent CPUs (e.g. Cortex-A15).
*
* iWMMXt:
* Optional extension that adds MMX registers and operations to an
* ARM CPU. This is only available on a few XScale-based CPU designs
* sold by Marvell. Pretty rare in practice.
*
* If you want to tell the compiler to generate code that targets one of
* the feature set above, you should probably use one of the following
* flags (for more details, see technical note at the end of this file):
*
* -mfpu=vfp
* -mfpu=vfpv2
* These are equivalent and tell GCC to use VFPv2 instructions for
* floating-point operations. Use this if you want your code to
* run on *some* ARMv6 devices, and any ARMv7-A device supported
* by Android.
*
* Generated code requires VFPv2 feature.
*
* -mfpu=vfpv3-d16
* Tell GCC to use VFPv3 instructions (using only 16 FPU registers).
* This should be generic code that runs on any CPU that supports the
* 'armeabi-v7a' Android ABI. Note that no ARMv6 CPU supports this.
*
* Generated code requires VFPv3 feature.
*
* -mfpu=vfpv3
* Tell GCC to use VFPv3 instructions with 32 FPU registers.
* Generated code requires VFPv3|VFP_D32 features.
*
* -mfpu=neon
* Tell GCC to use VFPv3 instructions with 32 FPU registers, and
* also support NEON intrinsics (see <arm_neon.h>).
* Generated code requires VFPv3|VFP_D32|NEON features.
*
* -mfpu=vfpv4-d16
* Generated code requires VFPv3|VFP_FP16|VFP_FMA features.
*
* -mfpu=vfpv4
* Generated code requires VFPv3|VFP_FP16|VFP_FMA|VFP_D32 features.
*
* -mfpu=neon-vfpv4
* Generated code requires VFPv3|VFP_FP16|VFP_FMA|VFP_D32|NEON|NEON_FMA
* features.
*
* -mcpu=cortex-a7
* -mcpu=cortex-a15
* Generated code requires VFPv3|VFP_FP16|VFP_FMA|VFP_D32|
* NEON|NEON_FMA|IDIV_ARM|IDIV_THUMB2
* This flag implies -mfpu=neon-vfpv4.
*
* -mcpu=iwmmxt
* Allows the use of iWMMXt instrinsics with GCC.
*/
enum {
ANDROID_CPU_ARM_FEATURE_ARMv7 = (1 << 0),
ANDROID_CPU_ARM_FEATURE_VFPv3 = (1 << 1),
ANDROID_CPU_ARM_FEATURE_NEON = (1 << 2),
ANDROID_CPU_ARM_FEATURE_LDREX_STREX = (1 << 3),
ANDROID_CPU_ARM_FEATURE_VFPv2 = (1 << 4),
ANDROID_CPU_ARM_FEATURE_VFP_D32 = (1 << 5),
ANDROID_CPU_ARM_FEATURE_VFP_FP16 = (1 << 6),
ANDROID_CPU_ARM_FEATURE_VFP_FMA = (1 << 7),
ANDROID_CPU_ARM_FEATURE_NEON_FMA = (1 << 8),
ANDROID_CPU_ARM_FEATURE_IDIV_ARM = (1 << 9),
ANDROID_CPU_ARM_FEATURE_IDIV_THUMB2 = (1 << 10),
ANDROID_CPU_ARM_FEATURE_iWMMXt = (1 << 11),
};
enum {
ANDROID_CPU_X86_FEATURE_SSSE3 = (1 << 0),
ANDROID_CPU_X86_FEATURE_POPCNT = (1 << 1),
ANDROID_CPU_X86_FEATURE_MOVBE = (1 << 2),
};
extern uint64_t android_getCpuFeatures(void);
/* Return the number of CPU cores detected on this device. */
extern int android_getCpuCount(void);
/* The following is used to force the CPU count and features
* mask in sandboxed processes. Under 4.1 and higher, these processes
* cannot access /proc, which is the only way to get information from
* the kernel about the current hardware (at least on ARM).
*
* It _must_ be called only once, and before any android_getCpuXXX
* function, any other case will fail.
*
* This function return 1 on success, and 0 on failure.
*/
extern int android_setCpu(int cpu_count,
uint64_t cpu_features);
__END_DECLS
#endif /* CPU_FEATURES_H */
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