--- /dev/null
+/*
+ * 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.
+ */
+
+/* ChangeLog for this library:
+ *
+ * NDK r8d: Add android_setCpu().
+ *
+ * NDK r8c: Add new ARM CPU features: VFPv2, VFP_D32, VFP_FP16,
+ * VFP_FMA, NEON_FMA, IDIV_ARM, IDIV_THUMB2 and iWMMXt.
+ *
+ * Rewrite the code to parse /proc/self/auxv instead of
+ * the "Features" field in /proc/cpuinfo.
+ *
+ * Dynamically allocate the buffer that hold the content
+ * of /proc/cpuinfo to deal with newer hardware.
+ *
+ * NDK r7c: Fix CPU count computation. The old method only reported the
+ * number of _active_ CPUs when the library was initialized,
+ * which could be less than the real total.
+ *
+ * NDK r5: Handle buggy kernels which report a CPU Architecture number of 7
+ * for an ARMv6 CPU (see below).
+ *
+ * Handle kernels that only report 'neon', and not 'vfpv3'
+ * (VFPv3 is mandated by the ARM architecture is Neon is implemented)
+ *
+ * Handle kernels that only report 'vfpv3d16', and not 'vfpv3'
+ *
+ * Fix x86 compilation. Report ANDROID_CPU_FAMILY_X86 in
+ * android_getCpuFamily().
+ *
+ * NDK r4: Initial release
+ */
+#include <sys/system_properties.h>
+#ifdef __arm__
+#include <machine/cpu-features.h>
+#endif
+#include <pthread.h>
+#include "cpu-features.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <errno.h>
+
+static pthread_once_t g_once;
+static int g_inited;
+static AndroidCpuFamily g_cpuFamily;
+static uint64_t g_cpuFeatures;
+static int g_cpuCount;
+
+static const int android_cpufeatures_debug = 0;
+
+#ifdef __arm__
+# define DEFAULT_CPU_FAMILY ANDROID_CPU_FAMILY_ARM
+#elif defined __i386__
+# define DEFAULT_CPU_FAMILY ANDROID_CPU_FAMILY_X86
+#else
+# define DEFAULT_CPU_FAMILY ANDROID_CPU_FAMILY_UNKNOWN
+#endif
+
+#define D(...) \
+ do { \
+ if (android_cpufeatures_debug) { \
+ printf(__VA_ARGS__); fflush(stdout); \
+ } \
+ } while (0)
+
+#ifdef __i386__
+static __inline__ void x86_cpuid(int func, int values[4])
+{
+ int a, b, c, d;
+ /* We need to preserve ebx since we're compiling PIC code */
+ /* this means we can't use "=b" for the second output register */
+ __asm__ __volatile__ ( \
+ "push %%ebx\n"
+ "cpuid\n" \
+ "mov %%ebx, %1\n"
+ "pop %%ebx\n"
+ : "=a" (a), "=r" (b), "=c" (c), "=d" (d) \
+ : "a" (func) \
+ );
+ values[0] = a;
+ values[1] = b;
+ values[2] = c;
+ values[3] = d;
+}
+#endif
+
+/* Get the size of a file by reading it until the end. This is needed
+ * because files under /proc do not always return a valid size when
+ * using fseek(0, SEEK_END) + ftell(). Nor can they be mmap()-ed.
+ */
+static int
+get_file_size(const char* pathname)
+{
+ int fd, ret, result = 0;
+ char buffer[256];
+
+ fd = open(pathname, O_RDONLY);
+ if (fd < 0) {
+ D("Can't open %s: %s\n", pathname, strerror(errno));
+ return -1;
+ }
+
+ for (;;) {
+ int ret = read(fd, buffer, sizeof buffer);
+ if (ret < 0) {
+ if (errno == EINTR)
+ continue;
+ D("Error while reading %s: %s\n", pathname, strerror(errno));
+ break;
+ }
+ if (ret == 0)
+ break;
+
+ result += ret;
+ }
+ close(fd);
+ return result;
+}
+
+/* Read the content of /proc/cpuinfo into a user-provided buffer.
+ * Return the length of the data, or -1 on error. Does *not*
+ * zero-terminate the content. Will not read more
+ * than 'buffsize' bytes.
+ */
+static int
+read_file(const char* pathname, char* buffer, size_t buffsize)
+{
+ int fd, count;
+
+ fd = open(pathname, O_RDONLY);
+ if (fd < 0) {
+ D("Could not open %s: %s\n", pathname, strerror(errno));
+ return -1;
+ }
+ count = 0;
+ while (count < (int)buffsize) {
+ int ret = read(fd, buffer + count, buffsize - count);
+ if (ret < 0) {
+ if (errno == EINTR)
+ continue;
+ D("Error while reading from %s: %s\n", pathname, strerror(errno));
+ if (count == 0)
+ count = -1;
+ break;
+ }
+ if (ret == 0)
+ break;
+ count += ret;
+ }
+ close(fd);
+ return count;
+}
+
+/* Extract the content of a the first occurence of a given field in
+ * the content of /proc/cpuinfo and return it as a heap-allocated
+ * string that must be freed by the caller.
+ *
+ * Return NULL if not found
+ */
+static char*
+extract_cpuinfo_field(const char* buffer, int buflen, const char* field)
+{
+ int fieldlen = strlen(field);
+ const char* bufend = buffer + buflen;
+ char* result = NULL;
+ int len, ignore;
+ const char *p, *q;
+
+ /* Look for first field occurence, and ensures it starts the line. */
+ p = buffer;
+ bufend = buffer + buflen;
+ for (;;) {
+ p = memmem(p, bufend-p, field, fieldlen);
+ if (p == NULL)
+ goto EXIT;
+
+ if (p == buffer || p[-1] == '\n')
+ break;
+
+ p += fieldlen;
+ }
+
+ /* Skip to the first column followed by a space */
+ p += fieldlen;
+ p = memchr(p, ':', bufend-p);
+ if (p == NULL || p[1] != ' ')
+ goto EXIT;
+
+ /* Find the end of the line */
+ p += 2;
+ q = memchr(p, '\n', bufend-p);
+ if (q == NULL)
+ q = bufend;
+
+ /* Copy the line into a heap-allocated buffer */
+ len = q-p;
+ result = malloc(len+1);
+ if (result == NULL)
+ goto EXIT;
+
+ memcpy(result, p, len);
+ result[len] = '\0';
+
+EXIT:
+ return result;
+}
+
+/* Like strlen(), but for constant string literals */
+#define STRLEN_CONST(x) ((sizeof(x)-1)
+
+
+/* Checks that a space-separated list of items contains one given 'item'.
+ * Returns 1 if found, 0 otherwise.
+ */
+static int
+has_list_item(const char* list, const char* item)
+{
+ const char* p = list;
+ int itemlen = strlen(item);
+
+ if (list == NULL)
+ return 0;
+
+ while (*p) {
+ const char* q;
+
+ /* skip spaces */
+ while (*p == ' ' || *p == '\t')
+ p++;
+
+ /* find end of current list item */
+ q = p;
+ while (*q && *q != ' ' && *q != '\t')
+ q++;
+
+ if (itemlen == q-p && !memcmp(p, item, itemlen))
+ return 1;
+
+ /* skip to next item */
+ p = q;
+ }
+ return 0;
+}
+
+/* Parse an decimal integer starting from 'input', but not going further
+ * than 'limit'. Return the value into '*result'.
+ *
+ * NOTE: Does not skip over leading spaces, or deal with sign characters.
+ * NOTE: Ignores overflows.
+ *
+ * The function returns NULL in case of error (bad format), or the new
+ * position after the decimal number in case of success (which will always
+ * be <= 'limit').
+ */
+static const char*
+parse_decimal(const char* input, const char* limit, int* result)
+{
+ const char* p = input;
+ int val = 0;
+ while (p < limit) {
+ int d = (*p - '0');
+ if ((unsigned)d >= 10U)
+ break;
+ val = val*10 + d;
+ p++;
+ }
+ if (p == input)
+ return NULL;
+
+ *result = val;
+ return p;
+}
+
+/* This small data type is used to represent a CPU list / mask, as read
+ * from sysfs on Linux. See http://www.kernel.org/doc/Documentation/cputopology.txt
+ *
+ * For now, we don't expect more than 32 cores on mobile devices, so keep
+ * everything simple.
+ */
+typedef struct {
+ uint32_t mask;
+} CpuList;
+
+static __inline__ void
+cpulist_init(CpuList* list) {
+ list->mask = 0;
+}
+
+static __inline__ void
+cpulist_and(CpuList* list1, CpuList* list2) {
+ list1->mask &= list2->mask;
+}
+
+static __inline__ void
+cpulist_set(CpuList* list, int index) {
+ if ((unsigned)index < 32) {
+ list->mask |= (uint32_t)(1U << index);
+ }
+}
+
+static __inline__ int
+cpulist_count(CpuList* list) {
+ return __builtin_popcount(list->mask);
+}
+
+/* Parse a textual list of cpus and store the result inside a CpuList object.
+ * Input format is the following:
+ * - comma-separated list of items (no spaces)
+ * - each item is either a single decimal number (cpu index), or a range made
+ * of two numbers separated by a single dash (-). Ranges are inclusive.
+ *
+ * Examples: 0
+ * 2,4-127,128-143
+ * 0-1
+ */
+static void
+cpulist_parse(CpuList* list, const char* line, int line_len)
+{
+ const char* p = line;
+ const char* end = p + line_len;
+ const char* q;
+
+ /* NOTE: the input line coming from sysfs typically contains a
+ * trailing newline, so take care of it in the code below
+ */
+ while (p < end && *p != '\n')
+ {
+ int val, start_value, end_value;
+
+ /* Find the end of current item, and put it into 'q' */
+ q = memchr(p, ',', end-p);
+ if (q == NULL) {
+ q = end;
+ }
+
+ /* Get first value */
+ p = parse_decimal(p, q, &start_value);
+ if (p == NULL)
+ goto BAD_FORMAT;
+
+ end_value = start_value;
+
+ /* If we're not at the end of the item, expect a dash and
+ * and integer; extract end value.
+ */
+ if (p < q && *p == '-') {
+ p = parse_decimal(p+1, q, &end_value);
+ if (p == NULL)
+ goto BAD_FORMAT;
+ }
+
+ /* Set bits CPU list bits */
+ for (val = start_value; val <= end_value; val++) {
+ cpulist_set(list, val);
+ }
+
+ /* Jump to next item */
+ p = q;
+ if (p < end)
+ p++;
+ }
+
+BAD_FORMAT:
+ ;
+}
+
+/* Read a CPU list from one sysfs file */
+static void
+cpulist_read_from(CpuList* list, const char* filename)
+{
+ char file[64];
+ int filelen;
+
+ cpulist_init(list);
+
+ filelen = read_file(filename, file, sizeof file);
+ if (filelen < 0) {
+ D("Could not read %s: %s\n", filename, strerror(errno));
+ return;
+ }
+
+ cpulist_parse(list, file, filelen);
+}
+
+// See <asm/hwcap.h> kernel header.
+#define HWCAP_VFP (1 << 6)
+#define HWCAP_IWMMXT (1 << 9)
+#define HWCAP_NEON (1 << 12)
+#define HWCAP_VFPv3 (1 << 13)
+#define HWCAP_VFPv3D16 (1 << 14)
+#define HWCAP_VFPv4 (1 << 16)
+#define HWCAP_IDIVA (1 << 17)
+#define HWCAP_IDIVT (1 << 18)
+
+#define AT_HWCAP 16
+
+#if defined(__arm__)
+/* Compute the ELF HWCAP flags.
+ */
+static uint32_t
+get_elf_hwcap(const char* cpuinfo, int cpuinfo_len)
+{
+ /* IMPORTANT:
+ * Accessing /proc/self/auxv doesn't work anymore on all
+ * platform versions. More specifically, when running inside
+ * a regular application process, most of /proc/self/ will be
+ * non-readable, including /proc/self/auxv. This doesn't
+ * happen however if the application is debuggable, or when
+ * running under the "shell" UID, which is why this was not
+ * detected appropriately.
+ */
+#if 0
+ uint32_t result = 0;
+ const char filepath[] = "/proc/self/auxv";
+ int fd = open(filepath, O_RDONLY);
+ if (fd < 0) {
+ D("Could not open %s: %s\n", filepath, strerror(errno));
+ return 0;
+ }
+
+ struct { uint32_t tag; uint32_t value; } entry;
+
+ for (;;) {
+ int ret = read(fd, (char*)&entry, sizeof entry);
+ if (ret < 0) {
+ if (errno == EINTR)
+ continue;
+ D("Error while reading %s: %s\n", filepath, strerror(errno));
+ break;
+ }
+ // Detect end of list.
+ if (ret == 0 || (entry.tag == 0 && entry.value == 0))
+ break;
+ if (entry.tag == AT_HWCAP) {
+ result = entry.value;
+ break;
+ }
+ }
+ close(fd);
+ return result;
+#else
+ // Recreate ELF hwcaps by parsing /proc/cpuinfo Features tag.
+ uint32_t hwcaps = 0;
+
+ char* cpuFeatures = extract_cpuinfo_field(cpuinfo, cpuinfo_len, "Features");
+
+ if (cpuFeatures != NULL) {
+ D("Found cpuFeatures = '%s'\n", cpuFeatures);
+
+ if (has_list_item(cpuFeatures, "vfp"))
+ hwcaps |= HWCAP_VFP;
+ if (has_list_item(cpuFeatures, "vfpv3"))
+ hwcaps |= HWCAP_VFPv3;
+ if (has_list_item(cpuFeatures, "vfpv3d16"))
+ hwcaps |= HWCAP_VFPv3D16;
+ if (has_list_item(cpuFeatures, "vfpv4"))
+ hwcaps |= HWCAP_VFPv4;
+ if (has_list_item(cpuFeatures, "neon"))
+ hwcaps |= HWCAP_NEON;
+ if (has_list_item(cpuFeatures, "idiva"))
+ hwcaps |= HWCAP_IDIVA;
+ if (has_list_item(cpuFeatures, "idivt"))
+ hwcaps |= HWCAP_IDIVT;
+ if (has_list_item(cpuFeatures, "idiv"))
+ hwcaps |= HWCAP_IDIVA | HWCAP_IDIVT;
+ if (has_list_item(cpuFeatures, "iwmmxt"))
+ hwcaps |= HWCAP_IWMMXT;
+
+ free(cpuFeatures);
+ }
+ return hwcaps;
+#endif
+}
+#endif /* __arm__ */
+
+/* Return the number of cpus present on a given device.
+ *
+ * To handle all weird kernel configurations, we need to compute the
+ * intersection of the 'present' and 'possible' CPU lists and count
+ * the result.
+ */
+static int
+get_cpu_count(void)
+{
+ CpuList cpus_present[1];
+ CpuList cpus_possible[1];
+
+ cpulist_read_from(cpus_present, "/sys/devices/system/cpu/present");
+ cpulist_read_from(cpus_possible, "/sys/devices/system/cpu/possible");
+
+ /* Compute the intersection of both sets to get the actual number of
+ * CPU cores that can be used on this device by the kernel.
+ */
+ cpulist_and(cpus_present, cpus_possible);
+
+ return cpulist_count(cpus_present);
+}
+
+static void
+android_cpuInitFamily(void)
+{
+#if defined(__ARM_ARCH__)
+ g_cpuFamily = ANDROID_CPU_FAMILY_ARM;
+#elif defined(__i386__)
+ g_cpuFamily = ANDROID_CPU_FAMILY_X86;
+#elif defined(_MIPS_ARCH)
+ g_cpuFamily = ANDROID_CPU_FAMILY_MIPS;
+#else
+ g_cpuFamily = ANDROID_CPU_FAMILY_UNKNOWN;
+#endif
+}
+
+static void
+android_cpuInit(void)
+{
+ char* cpuinfo = NULL;
+ int cpuinfo_len;
+
+ android_cpuInitFamily();
+
+ g_cpuFeatures = 0;
+ g_cpuCount = 1;
+ g_inited = 1;
+
+ cpuinfo_len = get_file_size("/proc/cpuinfo");
+ if (cpuinfo_len < 0) {
+ D("cpuinfo_len cannot be computed!");
+ return;
+ }
+ cpuinfo = malloc(cpuinfo_len);
+ if (cpuinfo == NULL) {
+ D("cpuinfo buffer could not be allocated");
+ return;
+ }
+ cpuinfo_len = read_file("/proc/cpuinfo", cpuinfo, cpuinfo_len);
+ D("cpuinfo_len is (%d):\n%.*s\n", cpuinfo_len,
+ cpuinfo_len >= 0 ? cpuinfo_len : 0, cpuinfo);
+
+ if (cpuinfo_len < 0) /* should not happen */ {
+ free(cpuinfo);
+ return;
+ }
+
+ /* Count the CPU cores, the value may be 0 for single-core CPUs */
+ g_cpuCount = get_cpu_count();
+ if (g_cpuCount == 0) {
+ g_cpuCount = 1;
+ }
+
+ D("found cpuCount = %d\n", g_cpuCount);
+
+#ifdef __ARM_ARCH__
+ {
+ char* features = NULL;
+ char* architecture = NULL;
+
+ /* Extract architecture from the "CPU Architecture" field.
+ * The list is well-known, unlike the the output of
+ * the 'Processor' field which can vary greatly.
+ *
+ * See the definition of the 'proc_arch' array in
+ * $KERNEL/arch/arm/kernel/setup.c and the 'c_show' function in
+ * same file.
+ */
+ char* cpuArch = extract_cpuinfo_field(cpuinfo, cpuinfo_len, "CPU architecture");
+
+ if (cpuArch != NULL) {
+ char* end;
+ long archNumber;
+ int hasARMv7 = 0;
+
+ D("found cpuArch = '%s'\n", cpuArch);
+
+ /* read the initial decimal number, ignore the rest */
+ archNumber = strtol(cpuArch, &end, 10);
+
+ /* Here we assume that ARMv8 will be upwards compatible with v7
+ * in the future. Unfortunately, there is no 'Features' field to
+ * indicate that Thumb-2 is supported.
+ */
+ if (end > cpuArch && archNumber >= 7) {
+ hasARMv7 = 1;
+ }
+
+ /* Unfortunately, it seems that certain ARMv6-based CPUs
+ * report an incorrect architecture number of 7!
+ *
+ * See http://code.google.com/p/android/issues/detail?id=10812
+ *
+ * We try to correct this by looking at the 'elf_format'
+ * field reported by the 'Processor' field, which is of the
+ * form of "(v7l)" for an ARMv7-based CPU, and "(v6l)" for
+ * an ARMv6-one.
+ */
+ if (hasARMv7) {
+ char* cpuProc = extract_cpuinfo_field(cpuinfo, cpuinfo_len,
+ "Processor");
+ if (cpuProc != NULL) {
+ D("found cpuProc = '%s'\n", cpuProc);
+ if (has_list_item(cpuProc, "(v6l)")) {
+ D("CPU processor and architecture mismatch!!\n");
+ hasARMv7 = 0;
+ }
+ free(cpuProc);
+ }
+ }
+
+ if (hasARMv7) {
+ g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_ARMv7;
+ }
+
+ /* The LDREX / STREX instructions are available from ARMv6 */
+ if (archNumber >= 6) {
+ g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_LDREX_STREX;
+ }
+
+ free(cpuArch);
+ }
+
+ /* Extract the list of CPU features from ELF hwcaps */
+ uint32_t hwcaps = get_elf_hwcap(cpuinfo, cpuinfo_len);
+
+ if (hwcaps != 0) {
+ int has_vfp = (hwcaps & HWCAP_VFP);
+ int has_vfpv3 = (hwcaps & HWCAP_VFPv3);
+ int has_vfpv3d16 = (hwcaps & HWCAP_VFPv3D16);
+ int has_vfpv4 = (hwcaps & HWCAP_VFPv4);
+ int has_neon = (hwcaps & HWCAP_NEON);
+ int has_idiva = (hwcaps & HWCAP_IDIVA);
+ int has_idivt = (hwcaps & HWCAP_IDIVT);
+ int has_iwmmxt = (hwcaps & HWCAP_IWMMXT);
+
+ // The kernel does a poor job at ensuring consistency when
+ // describing CPU features. So lots of guessing is needed.
+
+ // 'vfpv4' implies VFPv3|VFP_FMA|FP16
+ if (has_vfpv4)
+ g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_VFPv3 |
+ ANDROID_CPU_ARM_FEATURE_VFP_FP16 |
+ ANDROID_CPU_ARM_FEATURE_VFP_FMA;
+
+ // 'vfpv3' or 'vfpv3d16' imply VFPv3. Note that unlike GCC,
+ // a value of 'vfpv3' doesn't necessarily mean that the D32
+ // feature is present, so be conservative. All CPUs in the
+ // field that support D32 also support NEON, so this should
+ // not be a problem in practice.
+ if (has_vfpv3 || has_vfpv3d16)
+ g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_VFPv3;
+
+ // 'vfp' is super ambiguous. Depending on the kernel, it can
+ // either mean VFPv2 or VFPv3. Make it depend on ARMv7.
+ if (has_vfp) {
+ if (g_cpuFeatures & ANDROID_CPU_ARM_FEATURE_ARMv7)
+ g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_VFPv3;
+ else
+ g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_VFPv2;
+ }
+
+ // Neon implies VFPv3|D32, and if vfpv4 is detected, NEON_FMA
+ if (has_neon) {
+ g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_VFPv3 |
+ ANDROID_CPU_ARM_FEATURE_NEON |
+ ANDROID_CPU_ARM_FEATURE_VFP_D32;
+ if (has_vfpv4)
+ g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_NEON_FMA;
+ }
+
+ // VFPv3 implies VFPv2 and ARMv7
+ if (g_cpuFeatures & ANDROID_CPU_ARM_FEATURE_VFPv3)
+ g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_VFPv2 |
+ ANDROID_CPU_ARM_FEATURE_ARMv7;
+
+ // Note that some buggy kernels do not report these even when
+ // the CPU actually support the division instructions. However,
+ // assume that if 'vfpv4' is detected, then the CPU supports
+ // sdiv/udiv properly.
+ if (has_idiva || has_vfpv4)
+ g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_IDIV_ARM;
+ if (has_idivt || has_vfpv4)
+ g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_IDIV_THUMB2;
+
+ if (has_iwmmxt)
+ g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_iWMMXt;
+ }
+ }
+#endif /* __ARM_ARCH__ */
+
+#ifdef __i386__
+ int regs[4];
+
+/* According to http://en.wikipedia.org/wiki/CPUID */
+#define VENDOR_INTEL_b 0x756e6547
+#define VENDOR_INTEL_c 0x6c65746e
+#define VENDOR_INTEL_d 0x49656e69
+
+ x86_cpuid(0, regs);
+ int vendorIsIntel = (regs[1] == VENDOR_INTEL_b &&
+ regs[2] == VENDOR_INTEL_c &&
+ regs[3] == VENDOR_INTEL_d);
+
+ x86_cpuid(1, regs);
+ if ((regs[2] & (1 << 9)) != 0) {
+ g_cpuFeatures |= ANDROID_CPU_X86_FEATURE_SSSE3;
+ }
+ if ((regs[2] & (1 << 23)) != 0) {
+ g_cpuFeatures |= ANDROID_CPU_X86_FEATURE_POPCNT;
+ }
+ if (vendorIsIntel && (regs[2] & (1 << 22)) != 0) {
+ g_cpuFeatures |= ANDROID_CPU_X86_FEATURE_MOVBE;
+ }
+#endif
+
+ free(cpuinfo);
+}
+
+
+AndroidCpuFamily
+android_getCpuFamily(void)
+{
+ pthread_once(&g_once, android_cpuInit);
+ return g_cpuFamily;
+}
+
+
+uint64_t
+android_getCpuFeatures(void)
+{
+ pthread_once(&g_once, android_cpuInit);
+ return g_cpuFeatures;
+}
+
+
+int
+android_getCpuCount(void)
+{
+ pthread_once(&g_once, android_cpuInit);
+ return g_cpuCount;
+}
+
+static void
+android_cpuInitDummy(void)
+{
+ g_inited = 1;
+}
+
+int
+android_setCpu(int cpu_count, uint64_t cpu_features)
+{
+ /* Fail if the library was already initialized. */
+ if (g_inited)
+ return 0;
+
+ android_cpuInitFamily();
+ g_cpuCount = (cpu_count <= 0 ? 1 : cpu_count);
+ g_cpuFeatures = cpu_features;
+ pthread_once(&g_once, android_cpuInitDummy);
+
+ return 1;
+}
+
+/*
+ * Technical note: Making sense of ARM's FPU architecture versions.
+ *
+ * FPA was ARM's first attempt at an FPU architecture. There is no Android
+ * device that actually uses it since this technology was already obsolete
+ * when the project started. If you see references to FPA instructions
+ * somewhere, you can be sure that this doesn't apply to Android at all.
+ *
+ * FPA was followed by "VFP", soon renamed "VFPv1" due to the emergence of
+ * new versions / additions to it. ARM considers this obsolete right now,
+ * and no known Android device implements it either.
+ *
+ * VFPv2 added a few instructions to VFPv1, and is an *optional* extension
+ * supported by some ARMv5TE, ARMv6 and ARMv6T2 CPUs. Note that a device
+ * supporting the 'armeabi' ABI doesn't necessarily support these.
+ *
+ * VFPv3-D16 adds a few instructions on top of VFPv2 and is typically used
+ * on ARMv7-A CPUs which implement a FPU. Note that it is also mandated
+ * by the Android 'armeabi-v7a' ABI. The -D16 suffix in its name means
+ * that it provides 16 double-precision FPU registers (d0-d15) and 32
+ * single-precision ones (s0-s31) which happen to be mapped to the same
+ * register banks.
+ *
+ * VFPv3-D32 is the name of an extension to VFPv3-D16 that provides 16
+ * additional double precision registers (d16-d31). Note that there are
+ * still only 32 single precision registers.
+ *
+ * VFPv3xD is a *subset* of VFPv3-D16 that only provides single-precision
+ * registers. It is only used on ARMv7-M (i.e. on micro-controllers) which
+ * are not supported by Android. Note that it is not compatible with VFPv2.
+ *
+ * NOTE: The term 'VFPv3' usually designate either VFPv3-D16 or VFPv3-D32
+ * depending on context. For example GCC uses it for VFPv3-D32, but
+ * the Linux kernel code uses it for VFPv3-D16 (especially in
+ * /proc/cpuinfo). Always try to use the full designation when
+ * possible.
+ *
+ * NEON, a.k.a. "ARM Advanced SIMD" is an extension that provides
+ * instructions to perform parallel computations on vectors of 8, 16,
+ * 32, 64 and 128 bit quantities. NEON requires VFPv32-D32 since all
+ * NEON registers are also mapped to the same register banks.
+ *
+ * VFPv4-D16, adds a few instructions on top of VFPv3-D16 in order to
+ * perform fused multiply-accumulate on VFP registers, as well as
+ * half-precision (16-bit) conversion operations.
+ *
+ * VFPv4-D32 is VFPv4-D16 with 32, instead of 16, FPU double precision
+ * registers.
+ *
+ * VPFv4-NEON is VFPv4-D32 with NEON instructions. It also adds fused
+ * multiply-accumulate instructions that work on the NEON registers.
+ *
+ * NOTE: Similarly, "VFPv4" might either reference VFPv4-D16 or VFPv4-D32
+ * depending on context.
+ *
+ * The following information was determined by scanning the binutils-2.22
+ * sources:
+ *
+ * Basic VFP instruction subsets:
+ *
+ * #define FPU_VFP_EXT_V1xD 0x08000000 // Base VFP instruction set.
+ * #define FPU_VFP_EXT_V1 0x04000000 // Double-precision insns.
+ * #define FPU_VFP_EXT_V2 0x02000000 // ARM10E VFPr1.
+ * #define FPU_VFP_EXT_V3xD 0x01000000 // VFPv3 single-precision.
+ * #define FPU_VFP_EXT_V3 0x00800000 // VFPv3 double-precision.
+ * #define FPU_NEON_EXT_V1 0x00400000 // Neon (SIMD) insns.
+ * #define FPU_VFP_EXT_D32 0x00200000 // Registers D16-D31.
+ * #define FPU_VFP_EXT_FP16 0x00100000 // Half-precision extensions.
+ * #define FPU_NEON_EXT_FMA 0x00080000 // Neon fused multiply-add
+ * #define FPU_VFP_EXT_FMA 0x00040000 // VFP fused multiply-add
+ *
+ * FPU types (excluding NEON)
+ *
+ * FPU_VFP_V1xD (EXT_V1xD)
+ * |
+ * +--------------------------+
+ * | |
+ * FPU_VFP_V1 (+EXT_V1) FPU_VFP_V3xD (+EXT_V2+EXT_V3xD)
+ * | |
+ * | |
+ * FPU_VFP_V2 (+EXT_V2) FPU_VFP_V4_SP_D16 (+EXT_FP16+EXT_FMA)
+ * |
+ * FPU_VFP_V3D16 (+EXT_Vx3D+EXT_V3)
+ * |
+ * +--------------------------+
+ * | |
+ * FPU_VFP_V3 (+EXT_D32) FPU_VFP_V4D16 (+EXT_FP16+EXT_FMA)
+ * | |
+ * | FPU_VFP_V4 (+EXT_D32)
+ * |
+ * FPU_VFP_HARD (+EXT_FMA+NEON_EXT_FMA)
+ *
+ * VFP architectures:
+ *
+ * ARCH_VFP_V1xD (EXT_V1xD)
+ * |
+ * +------------------+
+ * | |
+ * | ARCH_VFP_V3xD (+EXT_V2+EXT_V3xD)
+ * | |
+ * | ARCH_VFP_V3xD_FP16 (+EXT_FP16)
+ * | |
+ * | ARCH_VFP_V4_SP_D16 (+EXT_FMA)
+ * |
+ * ARCH_VFP_V1 (+EXT_V1)
+ * |
+ * ARCH_VFP_V2 (+EXT_V2)
+ * |
+ * ARCH_VFP_V3D16 (+EXT_V3xD+EXT_V3)
+ * |
+ * +-------------------+
+ * | |
+ * | ARCH_VFP_V3D16_FP16 (+EXT_FP16)
+ * |
+ * +-------------------+
+ * | |
+ * | ARCH_VFP_V4_D16 (+EXT_FP16+EXT_FMA)
+ * | |
+ * | ARCH_VFP_V4 (+EXT_D32)
+ * | |
+ * | ARCH_NEON_VFP_V4 (+EXT_NEON+EXT_NEON_FMA)
+ * |
+ * ARCH_VFP_V3 (+EXT_D32)
+ * |
+ * +-------------------+
+ * | |
+ * | ARCH_VFP_V3_FP16 (+EXT_FP16)
+ * |
+ * ARCH_VFP_V3_PLUS_NEON_V1 (+EXT_NEON)
+ * |
+ * ARCH_NEON_FP16 (+EXT_FP16)
+ *
+ * -fpu=<name> values and their correspondance with FPU architectures above:
+ *
+ * {"vfp", FPU_ARCH_VFP_V2},
+ * {"vfp9", FPU_ARCH_VFP_V2},
+ * {"vfp3", FPU_ARCH_VFP_V3}, // For backwards compatbility.
+ * {"vfp10", FPU_ARCH_VFP_V2},
+ * {"vfp10-r0", FPU_ARCH_VFP_V1},
+ * {"vfpxd", FPU_ARCH_VFP_V1xD},
+ * {"vfpv2", FPU_ARCH_VFP_V2},
+ * {"vfpv3", FPU_ARCH_VFP_V3},
+ * {"vfpv3-fp16", FPU_ARCH_VFP_V3_FP16},
+ * {"vfpv3-d16", FPU_ARCH_VFP_V3D16},
+ * {"vfpv3-d16-fp16", FPU_ARCH_VFP_V3D16_FP16},
+ * {"vfpv3xd", FPU_ARCH_VFP_V3xD},
+ * {"vfpv3xd-fp16", FPU_ARCH_VFP_V3xD_FP16},
+ * {"neon", FPU_ARCH_VFP_V3_PLUS_NEON_V1},
+ * {"neon-fp16", FPU_ARCH_NEON_FP16},
+ * {"vfpv4", FPU_ARCH_VFP_V4},
+ * {"vfpv4-d16", FPU_ARCH_VFP_V4D16},
+ * {"fpv4-sp-d16", FPU_ARCH_VFP_V4_SP_D16},
+ * {"neon-vfpv4", FPU_ARCH_NEON_VFP_V4},
+ *
+ *
+ * Simplified diagram that only includes FPUs supported by Android:
+ * Only ARCH_VFP_V3D16 is actually mandated by the armeabi-v7a ABI,
+ * all others are optional and must be probed at runtime.
+ *
+ * ARCH_VFP_V3D16 (EXT_V1xD+EXT_V1+EXT_V2+EXT_V3xD+EXT_V3)
+ * |
+ * +-------------------+
+ * | |
+ * | ARCH_VFP_V3D16_FP16 (+EXT_FP16)
+ * |
+ * +-------------------+
+ * | |
+ * | ARCH_VFP_V4_D16 (+EXT_FP16+EXT_FMA)
+ * | |
+ * | ARCH_VFP_V4 (+EXT_D32)
+ * | |
+ * | ARCH_NEON_VFP_V4 (+EXT_NEON+EXT_NEON_FMA)
+ * |
+ * ARCH_VFP_V3 (+EXT_D32)
+ * |
+ * +-------------------+
+ * | |
+ * | ARCH_VFP_V3_FP16 (+EXT_FP16)
+ * |
+ * ARCH_VFP_V3_PLUS_NEON_V1 (+EXT_NEON)
+ * |
+ * ARCH_NEON_FP16 (+EXT_FP16)
+ *
+ */
--- /dev/null
+/*
+ * 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 */
projects / platform / upstream / opencv.git / commitdiff