libwebp: update snapshot to v0.2.0-rc1

third_party/libwebp/dsp/cpu-features.c

+/*
+ * 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 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  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 %1, %%ebx\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
+
+/* 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, len;
+
+    fd = open(pathname, O_RDONLY);
+    if (fd < 0)
+        return -1;
+
+    do {
+        len = read(fd, buffer, buffsize);
+    } while (len < 0 && errno == EINTR);
+
+    close(fd);
+
+    return len;
+}
+
+/* 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(char* buffer, int buflen, const char* field)
+{
+    int  fieldlen = strlen(field);
+    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);
+}
+
+/* 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_cpuInit(void)
+{
+    char cpuinfo[4096];
+    int  cpuinfo_len;
+
+    g_cpuFamily   = DEFAULT_CPU_FAMILY;
+    g_cpuFeatures = 0;
+    g_cpuCount    = 1;
+
+    cpuinfo_len = read_file("/proc/cpuinfo", cpuinfo, sizeof cpuinfo);
+    D("cpuinfo_len is (%d):\n%.*s\n", cpuinfo_len,
+      cpuinfo_len >= 0 ? cpuinfo_len : 0, cpuinfo);
+
+    if (cpuinfo_len < 0)  /* should not happen */ {
+        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 'Features' field */
+        char* cpuFeatures = extract_cpuinfo_field(cpuinfo, cpuinfo_len, "Features");
+
+        if (cpuFeatures != NULL) {
+
+            D("found cpuFeatures = '%s'\n", cpuFeatures);
+
+            if (has_list_item(cpuFeatures, "vfpv3"))
+                g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_VFPv3;
+
+            else if (has_list_item(cpuFeatures, "vfpv3d16"))
+                g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_VFPv3;
+
+            if (has_list_item(cpuFeatures, "neon")) {
+                /* Note: Certain kernels only report neon but not vfpv3
+                    *       in their features list. However, ARM mandates
+                    *       that if Neon is implemented, so must be VFPv3
+                    *       so always set the flag.
+                    */
+                g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_NEON |
+                                 ANDROID_CPU_ARM_FEATURE_VFPv3;
+            }
+            free(cpuFeatures);
+        }
+    }
+#endif /* __ARM_ARCH__ */
+
+#ifdef __i386__
+    g_cpuFamily = ANDROID_CPU_FAMILY_X86;
+
+    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
+
+#ifdef _MIPS_ARCH
+    g_cpuFamily = ANDROID_CPU_FAMILY_MIPS;
+#endif /* _MIPS_ARCH */
+}
+
+
+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;
+}