From: Sam James Date: Wed, 27 Nov 2024 03:07:57 +0000 Subject: sysendian.h: fix aliasing violations Accessing a e.g. uint32_t as uint8_t is an aliasing violation. The helpers here are nearly idiomatic for avoiding that anyway, so fix them up accordingly. --- sysendian.h | 102 +++++++++++++++++++++++++----------------------------------- 1 file changed, 42 insertions(+), 60 deletions(-) diff --git a/sysendian.h b/sysendian.h index af1ecdc..21a2d8c 100644 --- a/sysendian.h +++ b/sysendian.h @@ -49,95 +49,77 @@ #endif static INLINE uint32_t -be32dec(const void *pp) +be32dec(const unsigned char* p) { - const uint8_t *p = (uint8_t const *)pp; - - return ((uint32_t)(p[3]) + ((uint32_t)(p[2]) << 8) + - ((uint32_t)(p[1]) << 16) + ((uint32_t)(p[0]) << 24)); + return ((uint32_t)p[0] << 24) | ((uint32_t)p[1] << 16) | ((uint32_t)p[2] << 8) | + ((uint32_t)p[3] << 0); } static INLINE void -be32enc(void *pp, uint32_t x) +be32enc(unsigned char* p, const uint32_t x) { - uint8_t * p = (uint8_t *)pp; - - p[3] = x & 0xff; - p[2] = (x >> 8) & 0xff; - p[1] = (x >> 16) & 0xff; - p[0] = (x >> 24) & 0xff; + p[0] = (x >> 24); + p[1] = (x >> 16); + p[2] = (x >> 8); + p[3] = (x >> 0); } static INLINE uint64_t -be64dec(const void *pp) +be64dec(const unsigned char* p) { - const uint8_t *p = (uint8_t const *)pp; - - return ((uint64_t)(p[7]) + ((uint64_t)(p[6]) << 8) + - ((uint64_t)(p[5]) << 16) + ((uint64_t)(p[4]) << 24) + - ((uint64_t)(p[3]) << 32) + ((uint64_t)(p[2]) << 40) + - ((uint64_t)(p[1]) << 48) + ((uint64_t)(p[0]) << 56)); + return ((uint64_t)p[0] << 0) | ((uint64_t)p[1] << 8) | ((uint64_t)p[2] << 16) | + ((uint64_t)p[3] << 24) | ((uint64_t)p[4] << 32) | ((uint64_t)p[5] << 40) | + ((uint64_t)p[6] << 48) | ((uint64_t)p[7] << 56); } static INLINE void -be64enc(void *pp, uint64_t x) +be64enc(unsigned char* p, const uint64_t x) { - uint8_t * p = (uint8_t *)pp; - - p[7] = x & 0xff; - p[6] = (x >> 8) & 0xff; - p[5] = (x >> 16) & 0xff; - p[4] = (x >> 24) & 0xff; - p[3] = (x >> 32) & 0xff; - p[2] = (x >> 40) & 0xff; - p[1] = (x >> 48) & 0xff; - p[0] = (x >> 56) & 0xff; + p[0] = (x >> 56); + p[1] = (x >> 48); + p[2] = (x >> 40); + p[3] = (x >> 32); + p[4] = (x >> 24); + p[5] = (x >> 16); + p[6] = (x >> 8); + p[7] = (x >> 0); } static INLINE uint32_t -le32dec(const void *pp) +le32dec(const unsigned char* p) { - const uint8_t *p = (uint8_t const *)pp; - - return ((uint32_t)(p[0]) + ((uint32_t)(p[1]) << 8) + - ((uint32_t)(p[2]) << 16) + ((uint32_t)(p[3]) << 24)); + return ((uint32_t)p[0] << 0) | ((uint32_t)p[1] << 8) | ((uint32_t)p[2] << 16) | + ((uint32_t)p[3] << 24); } static INLINE void -le32enc(void *pp, uint32_t x) +le32enc(unsigned char* p, const uint32_t x) { - uint8_t * p = (uint8_t *)pp; - - p[0] = x & 0xff; - p[1] = (x >> 8) & 0xff; - p[2] = (x >> 16) & 0xff; - p[3] = (x >> 24) & 0xff; + p[0] = (x >> 0); + p[1] = (x >> 8); + p[2] = (x >> 16); + p[3] = (x >> 24); } static INLINE uint64_t -le64dec(const void *pp) +le64dec(const unsigned char* p) { - const uint8_t *p = (uint8_t const *)pp; - - return ((uint64_t)(p[0]) + ((uint64_t)(p[1]) << 8) + - ((uint64_t)(p[2]) << 16) + ((uint64_t)(p[3]) << 24) + - ((uint64_t)(p[4]) << 32) + ((uint64_t)(p[5]) << 40) + - ((uint64_t)(p[6]) << 48) + ((uint64_t)(p[7]) << 56)); + return ((uint64_t)p[0] << 0) | ((uint64_t)p[1] << 8) | ((uint64_t)p[2] << 16) | + ((uint64_t)p[3] << 24) | ((uint64_t)p[4] << 32) | ((uint64_t)p[5] << 40) | + ((uint64_t)p[6] << 48) | ((uint64_t)p[7] << 56); } static INLINE void -le64enc(void *pp, uint64_t x) +le64enc(unsigned char* p, const uint64_t x) { - uint8_t * p = (uint8_t *)pp; - - p[0] = x & 0xff; - p[1] = (x >> 8) & 0xff; - p[2] = (x >> 16) & 0xff; - p[3] = (x >> 24) & 0xff; - p[4] = (x >> 32) & 0xff; - p[5] = (x >> 40) & 0xff; - p[6] = (x >> 48) & 0xff; - p[7] = (x >> 56) & 0xff; + p[0] = (x >> 0); + p[1] = (x >> 8); + p[2] = (x >> 16); + p[3] = (x >> 24); + p[4] = (x >> 32); + p[5] = (x >> 40); + p[6] = (x >> 48); + p[7] = (x >> 56); } #endif /* !HAVE_SYS_ENDIAN_H */