diff options
Diffstat (limited to 'src/3rdparty/libwebp/src/utils/utils.h')
-rw-r--r-- | src/3rdparty/libwebp/src/utils/utils.h | 42 |
1 files changed, 40 insertions, 2 deletions
diff --git a/src/3rdparty/libwebp/src/utils/utils.h b/src/3rdparty/libwebp/src/utils/utils.h index 8bdf0f0..f2c498a 100644 --- a/src/3rdparty/libwebp/src/utils/utils.h +++ b/src/3rdparty/libwebp/src/utils/utils.h @@ -35,10 +35,13 @@ extern "C" { // somewhere (like: malloc(num_pixels * sizeof(*something))). That's why this // safe malloc() borrows the signature from calloc(), pointing at the dangerous // underlying multiply involved. -void* WebPSafeMalloc(uint64_t nmemb, size_t size); +WEBP_EXTERN(void*) WebPSafeMalloc(uint64_t nmemb, size_t size); // Note that WebPSafeCalloc() expects the second argument type to be 'size_t' // in order to favor the "calloc(num_foo, sizeof(foo))" pattern. -void* WebPSafeCalloc(uint64_t nmemb, size_t size); +WEBP_EXTERN(void*) WebPSafeCalloc(uint64_t nmemb, size_t size); + +// Companion deallocation function to the above allocations. +WEBP_EXTERN(void) WebPSafeFree(void* const ptr); //------------------------------------------------------------------------------ // Reading/writing data. @@ -74,6 +77,41 @@ static WEBP_INLINE void PutLE32(uint8_t* const data, uint32_t val) { PutLE16(data + 2, (int)(val >> 16)); } +// Returns (int)floor(log2(n)). n must be > 0. +// use GNU builtins where available. +#if defined(__GNUC__) && \ + ((__GNUC__ == 3 && __GNUC_MINOR__ >= 4) || __GNUC__ >= 4) +static WEBP_INLINE int BitsLog2Floor(uint32_t n) { + return 31 ^ __builtin_clz(n); +} +#elif defined(_MSC_VER) && _MSC_VER > 1310 && \ + (defined(_M_X64) || defined(_M_IX86)) +#include <intrin.h> +#pragma intrinsic(_BitScanReverse) + +static WEBP_INLINE int BitsLog2Floor(uint32_t n) { + uint32_t first_set_bit; + _BitScanReverse(&first_set_bit, n); + return first_set_bit; +} +#else +static WEBP_INLINE int BitsLog2Floor(uint32_t n) { + int log = 0; + uint32_t value = n; + int i; + + for (i = 4; i >= 0; --i) { + const int shift = (1 << i); + const uint32_t x = value >> shift; + if (x != 0) { + value = x; + log += shift; + } + } + return log; +} +#endif + //------------------------------------------------------------------------------ #ifdef __cplusplus |