Merge commit '096abfa15052977eed93f0b5e01afd2d47c53c1f'

* commit '096abfa15052977eed93f0b5e01afd2d47c53c1f':
  parser: fix large overreads
  bitstream: add get_bits64() to support reading more than 32 bits at once
  arm: detect cpu features at runtime on Linux

Conflicts:
	libavcodec/parser.c
	libavformat/mpegts.c

Merged-by: Michael Niedermayer <michaelni@gmx.at>

1 files changed, 83 insertions, 0 deletions

diff --git a/libavutil/arm/cpu.c b/libavutil/arm/cpu.c
index 7058aeb1f1..041afc985a 100644
--- a/libavutil/arm/cpu.c
+++ b/libavutil/arm/cpu.c
@@ -19,6 +19,87 @@
 #include "libavutil/cpu.h"
 #include "config.h"
 
+#define CORE_FLAG(f) \
+    (AV_CPU_FLAG_ ## f * (HAVE_ ## f ## _EXTERNAL || HAVE_ ## f ## _INLINE))
+
+#define CORE_CPU_FLAGS                          \
+    (CORE_FLAG(ARMV5TE) |                       \
+     CORE_FLAG(ARMV6)   |                       \
+     CORE_FLAG(ARMV6T2) |                       \
+     CORE_FLAG(VFP)     |                       \
+     CORE_FLAG(VFPV3)   |                       \
+     CORE_FLAG(NEON))
+
+#if defined __linux__ || defined __ANDROID__
+
+#include <stdint.h>
+#include <stdio.h>
+
+#define AT_HWCAP        16
+
+/* Relevant HWCAP values from kernel headers */
+#define HWCAP_VFP       (1 << 6)
+#define HWCAP_EDSP      (1 << 7)
+#define HWCAP_THUMBEE   (1 << 11)
+#define HWCAP_NEON      (1 << 12)
+#define HWCAP_VFPv3     (1 << 13)
+#define HWCAP_TLS       (1 << 15)
+
+static int get_hwcap(uint32_t *hwcap)
+{
+    struct { uint32_t a_type; uint32_t a_val; } auxv;
+    FILE *f = fopen("/proc/self/auxv", "r");
+    int err = -1;
+
+    if (!f)
+        return -1;
+
+    while (fread(&auxv, sizeof(auxv), 1, f) > 0) {
+        if (auxv.a_type == AT_HWCAP) {
+            *hwcap = auxv.a_val;
+            err = 0;
+            break;
+        }
+    }
+
+    fclose(f);
+    return err;
+}
+
+int ff_get_cpu_flags_arm(void)
+{
+    int flags = CORE_CPU_FLAGS;
+    uint32_t hwcap;
+
+    if (get_hwcap(&hwcap) < 0)
+        return flags;
+
+#define check_cap(cap, flag) do {               \
+        if (hwcap & HWCAP_ ## cap)              \
+            flags |= AV_CPU_FLAG_ ## flag;      \
+    } while (0)
+
+    /* No flags explicitly indicate v6 or v6T2 so check others which
+       imply support. */
+    check_cap(EDSP,    ARMV5TE);
+    check_cap(TLS,     ARMV6);
+    check_cap(THUMBEE, ARMV6T2);
+    check_cap(VFP,     VFP);
+    check_cap(VFPv3,   VFPV3);
+    check_cap(NEON,    NEON);
+
+    /* The v6 checks above are not reliable so let higher flags
+       trickle down. */
+    if (flags & (AV_CPU_FLAG_VFPV3 | AV_CPU_FLAG_NEON))
+        flags |= AV_CPU_FLAG_ARMV6T2;
+    if (flags & AV_CPU_FLAG_ARMV6T2)
+        flags |= AV_CPU_FLAG_ARMV6;
+
+    return flags;
+}
+
+#else
+
 int ff_get_cpu_flags_arm(void)
 {
     return AV_CPU_FLAG_ARMV5TE * HAVE_ARMV5TE |
@@ -28,3 +109,5 @@ int ff_get_cpu_flags_arm(void)
            AV_CPU_FLAG_VFPV3   * HAVE_VFPV3   |
            AV_CPU_FLAG_NEON    * HAVE_NEON;
 }
+
+#endif