From fc051295976bd79c44b9980044e335c424dc2170 Mon Sep 17 00:00:00 2001 From: Mats Kindahl Date: Fri, 9 Feb 2024 21:24:42 +0100 Subject: Add integer comparison functions Introduce functions pg_cmp_xyz() that will standardize integer comparison for implementing comparison function for qsort(). The functions will returns negative, 0, or positive integer without risking overflow as a result of subtracting the two integers, which is otherwise a common pattern for implementing this. For integer sizes less than sizeof(int) we can use normal subtraction, which is faster, but for integers with size greater than or equal to sizeof(int) we need to handle this differently. --- src/include/common/int.h | 47 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 47 insertions(+) diff --git a/src/include/common/int.h b/src/include/common/int.h index fedf7b3999..5aa856980a 100644 --- a/src/include/common/int.h +++ b/src/include/common/int.h @@ -438,4 +438,51 @@ pg_mul_u64_overflow(uint64 a, uint64 b, uint64 *result) #endif } +/*------------------------------------------------------------------------ + * Comparison routines for integers + *------------------------------------------------------------------------ + */ + +static inline int +pg_cmp_s16(int16 a, int16 b) +{ + return (int32)a - (int32)b; +} + +static inline int +pg_cmp_u16(uint16 a, uint16 b) +{ + return (int32)a - (int32)b; +} + +static inline int +pg_cmp_s32(int32 a, int32 b) +{ + return (a > b) - (a < b); /* Comparison operators return int 0 or 1 */ +} + +static inline int +pg_cmp_u32(uint32 a, uint32 b) +{ + return (a > b) - (a < b); /* Comparison operators return int 0 or 1 */ +} + +static inline int +pg_cmp_s64(int64 a, int64 b) +{ + return (a > b) - (a < b); /* Comparison operators return int 0 or 1 */ +} + +static inline int +pg_cmp_u64(uint64 a, uint64 b) +{ + return (a > b) - (a < b); /* Comparison operators return int 0 or 1 */ +} + +static inline int +pg_cmp_size(size_t a, size_t b) +{ + return (a > b) - (a < b); /* Comparison operators return int 0 or 1 */ +} + #endif /* COMMON_INT_H */ -- 2.34.1