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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-09 13:34:27 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-09 13:34:27 +0000
commit4dbdc42d9e7c3968ff7f690d00680419c9b8cb0f (patch)
tree47c1d492e9c956c1cd2b74dbd3b9d8b0db44dc4e /compat/bswap.h
parentInitial commit. (diff)
downloadgit-4dbdc42d9e7c3968ff7f690d00680419c9b8cb0f.tar.xz
git-4dbdc42d9e7c3968ff7f690d00680419c9b8cb0f.zip
Adding upstream version 1:2.43.0.upstream/1%2.43.0
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'compat/bswap.h')
-rw-r--r--compat/bswap.h193
1 files changed, 193 insertions, 0 deletions
diff --git a/compat/bswap.h b/compat/bswap.h
new file mode 100644
index 0000000..512f6f4
--- /dev/null
+++ b/compat/bswap.h
@@ -0,0 +1,193 @@
+#ifndef COMPAT_BSWAP_H
+#define COMPAT_BSWAP_H
+
+/*
+ * Let's make sure we always have a sane definition for ntohl()/htonl().
+ * Some libraries define those as a function call, just to perform byte
+ * shifting, bringing significant overhead to what should be a simple
+ * operation.
+ */
+
+/*
+ * Default version that the compiler ought to optimize properly with
+ * constant values.
+ */
+static inline uint32_t default_swab32(uint32_t val)
+{
+ return (((val & 0xff000000) >> 24) |
+ ((val & 0x00ff0000) >> 8) |
+ ((val & 0x0000ff00) << 8) |
+ ((val & 0x000000ff) << 24));
+}
+
+static inline uint64_t default_bswap64(uint64_t val)
+{
+ return (((val & (uint64_t)0x00000000000000ffULL) << 56) |
+ ((val & (uint64_t)0x000000000000ff00ULL) << 40) |
+ ((val & (uint64_t)0x0000000000ff0000ULL) << 24) |
+ ((val & (uint64_t)0x00000000ff000000ULL) << 8) |
+ ((val & (uint64_t)0x000000ff00000000ULL) >> 8) |
+ ((val & (uint64_t)0x0000ff0000000000ULL) >> 24) |
+ ((val & (uint64_t)0x00ff000000000000ULL) >> 40) |
+ ((val & (uint64_t)0xff00000000000000ULL) >> 56));
+}
+
+#undef bswap32
+#undef bswap64
+
+#if defined(__GNUC__) && (defined(__i386__) || defined(__x86_64__))
+
+#define bswap32 git_bswap32
+static inline uint32_t git_bswap32(uint32_t x)
+{
+ uint32_t result;
+ if (__builtin_constant_p(x))
+ result = default_swab32(x);
+ else
+ __asm__("bswap %0" : "=r" (result) : "0" (x));
+ return result;
+}
+
+#define bswap64 git_bswap64
+#if defined(__x86_64__)
+static inline uint64_t git_bswap64(uint64_t x)
+{
+ uint64_t result;
+ if (__builtin_constant_p(x))
+ result = default_bswap64(x);
+ else
+ __asm__("bswap %q0" : "=r" (result) : "0" (x));
+ return result;
+}
+#else
+static inline uint64_t git_bswap64(uint64_t x)
+{
+ union { uint64_t i64; uint32_t i32[2]; } tmp, result;
+ if (__builtin_constant_p(x))
+ result.i64 = default_bswap64(x);
+ else {
+ tmp.i64 = x;
+ result.i32[0] = git_bswap32(tmp.i32[1]);
+ result.i32[1] = git_bswap32(tmp.i32[0]);
+ }
+ return result.i64;
+}
+#endif
+
+#elif defined(_MSC_VER) && (defined(_M_IX86) || defined(_M_X64) || defined(_M_ARM64))
+
+#include <stdlib.h>
+
+#define bswap32(x) _byteswap_ulong(x)
+#define bswap64(x) _byteswap_uint64(x)
+
+#endif
+
+#if defined(bswap32)
+
+#undef ntohl
+#undef htonl
+#define ntohl(x) bswap32(x)
+#define htonl(x) bswap32(x)
+
+#endif
+
+#if defined(bswap64)
+
+#undef ntohll
+#undef htonll
+#define ntohll(x) bswap64(x)
+#define htonll(x) bswap64(x)
+
+#else
+
+#undef ntohll
+#undef htonll
+
+#if defined(__BYTE_ORDER) && defined(__LITTLE_ENDIAN) && defined(__BIG_ENDIAN)
+
+# define GIT_BYTE_ORDER __BYTE_ORDER
+# define GIT_LITTLE_ENDIAN __LITTLE_ENDIAN
+# define GIT_BIG_ENDIAN __BIG_ENDIAN
+
+#elif defined(BYTE_ORDER) && defined(LITTLE_ENDIAN) && defined(BIG_ENDIAN)
+
+# define GIT_BYTE_ORDER BYTE_ORDER
+# define GIT_LITTLE_ENDIAN LITTLE_ENDIAN
+# define GIT_BIG_ENDIAN BIG_ENDIAN
+
+#else
+
+# define GIT_BIG_ENDIAN 4321
+# define GIT_LITTLE_ENDIAN 1234
+
+# if defined(_BIG_ENDIAN) && !defined(_LITTLE_ENDIAN)
+# define GIT_BYTE_ORDER GIT_BIG_ENDIAN
+# elif defined(_LITTLE_ENDIAN) && !defined(_BIG_ENDIAN)
+# define GIT_BYTE_ORDER GIT_LITTLE_ENDIAN
+# elif defined(__THW_BIG_ENDIAN__) && !defined(__THW_LITTLE_ENDIAN__)
+# define GIT_BYTE_ORDER GIT_BIG_ENDIAN
+# elif defined(__THW_LITTLE_ENDIAN__) && !defined(__THW_BIG_ENDIAN__)
+# define GIT_BYTE_ORDER GIT_LITTLE_ENDIAN
+# else
+# error "Cannot determine endianness"
+# endif
+
+#endif
+
+#if GIT_BYTE_ORDER == GIT_BIG_ENDIAN
+# define ntohll(n) (n)
+# define htonll(n) (n)
+#else
+# define ntohll(n) default_bswap64(n)
+# define htonll(n) default_bswap64(n)
+#endif
+
+#endif
+
+static inline uint16_t get_be16(const void *ptr)
+{
+ const unsigned char *p = ptr;
+ return (uint16_t)p[0] << 8 |
+ (uint16_t)p[1] << 0;
+}
+
+static inline uint32_t get_be32(const void *ptr)
+{
+ const unsigned char *p = ptr;
+ return (uint32_t)p[0] << 24 |
+ (uint32_t)p[1] << 16 |
+ (uint32_t)p[2] << 8 |
+ (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;
+ p[0] = value >> 24;
+ p[1] = value >> 16;
+ p[2] = value >> 8;
+ 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 /* COMPAT_BSWAP_H */