bswap: add 64 bit endianness helper get_be64

Add a new get_be64 macro to enable 64 bit endian conversions on memory
that may or may not be aligned.

Signed-off-by: Ben Peart <benpeart@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/compat/bswap.h b/compat/bswap.h
index 7d063e9e40a213ce378d90377a9ac2b1f04ddbe3..5078ce5eccfaf17620c21e0a7f7133b3badef3d3 100644 (file)
--- a/compat/bswap.h
+++ b/compat/bswap.h
@@ -158,7 +158,9 @@ static inline uint64_t git_bswap64(uint64_t x)
 
 #define get_be16(p)    ntohs(*(unsigned short *)(p))
 #define get_be32(p)    ntohl(*(unsigned int *)(p))
 
 #define get_be16(p)    ntohs(*(unsigned short *)(p))
 #define get_be32(p)    ntohl(*(unsigned int *)(p))

+#define get_be64(p)    ntohll(*(uint64_t *)(p))

 #define put_be32(p, v) do { *(unsigned int *)(p) = htonl(v); } while (0)
 #define put_be32(p, v) do { *(unsigned int *)(p) = htonl(v); } while (0)

+#define put_be64(p, v) do { *(uint64_t *)(p) = htonll(v); } while (0)

 
 #else
 
 
 #else
 


@@ -178,6 +180,13 @@ static inline uint32_t get_be32(const void *ptr)
                (uint32_t)p[3] <<  0;
 }
 
                (uint32_t)p[3] <<  0;
 }
 

+static inline uint64_t get_be64(const void *ptr)
+{
+       const unsigned char *p = ptr;
+       return  (uint64_t)get_be32(&p[0]) << 32 |
+               (uint64_t)get_be32(&p[4]) <<  0;
+}
+

 static inline void put_be32(void *ptr, uint32_t value)
 {
        unsigned char *p = ptr;
 static inline void put_be32(void *ptr, uint32_t value)
 {
        unsigned char *p = ptr;


@@ -187,4 +196,17 @@ static inline void put_be32(void *ptr, uint32_t value)
        p[3] = value >>  0;
 }
 
        p[3] = value >>  0;
 }
 

+static inline void put_be64(void *ptr, uint64_t value)
+{
+       unsigned char *p = ptr;
+       p[0] = value >> 56;
+       p[1] = value >> 48;
+       p[2] = value >> 40;
+       p[3] = value >> 32;
+       p[4] = value >> 24;
+       p[5] = value >> 16;
+       p[6] = value >>  8;
+       p[7] = value >>  0;
+}
+

 #endif
 #endif