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Fix portability issues in pg_bitutils

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We were using uint64 function arguments as "long int" arguments to
compiler builtins, which fails on machines where long ints are 32 bits:
the upper half of the uint64 was being ignored.  Fix by using the "ll"
builtin variants instead, which on those machines take 64 bit arguments.

Also, remove configure tests for __builtin_popcountl() (as well as
"long" variants for ctz and clz): the theory here is that any compiler
version will provide all widths or none, so one test suffices.  Were
this theory to be wrong, we'd have to add tests for
__builtin_popcountll() and friends, which would be tedious.

Per failures in buildfarm member lapwing and ensuing discussion.
This commit is contained in:
Alvaro Herrera
2019-02-13 20:09:48 -03:00
parent 80c468b4a4
commit 109de05cbb
6 changed files with 98 additions and 256 deletions
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73
src/port/pg_bitutils.c
View File

@ -23,87 +23,62 @@
#include "port/pg_bitutils.h"
#if defined(HAVE__GET_CPUID) && (defined(HAVE__BUILTIN_POPCOUNT) || defined(HAVE__BUILTIN_POPCOUNTL))
static bool pg_popcount_available(void);
#endif
#if defined(HAVE__BUILTIN_POPCOUNT) && defined(HAVE__GET_CPUID)
static bool pg_popcount_available(void);
static int pg_popcount32_choose(uint32 word);
static int pg_popcount32_sse42(uint32 word);
#endif
static int pg_popcount32_slow(uint32 word);
#if defined(HAVE__BUILTIN_POPCOUNTL) && defined(HAVE__GET_CPUID)
static int pg_popcount64_choose(uint64 word);
static int pg_popcount64_sse42(uint64 word);
#endif
static int pg_popcount32_slow(uint32 word);
static int pg_popcount64_slow(uint64 word);
#if defined(HAVE__GET_CPUID) && (defined(HAVE__BUILTIN_CTZ) || defined(HAVE__BUILTIN_CTZL) || defined(HAVE__BUILTIN_CLZ) || defined(HAVE__BUILTIN_CLZL))
#if defined(HAVE__GET_CPUID) && (defined(HAVE__BUILTIN_CTZ) || defined(HAVE__BUILTIN_CLZ))
static bool pg_lzcnt_available(void);
#endif
#if defined(HAVE__BUILTIN_CTZ) && defined(HAVE__GET_CPUID)
static int pg_rightmost_one32_choose(uint32 word);
static int pg_rightmost_one32_abm(uint32 word);
#endif
static int pg_rightmost_one32_slow(uint32 word);
#if defined(HAVE__BUILTIN_CTZL) && defined(HAVE__GET_CPUID)
static int pg_rightmost_one64_choose(uint64 word);
static int pg_rightmost_one64_abm(uint64 word);
#endif
static int pg_rightmost_one32_slow(uint32 word);
static int pg_rightmost_one64_slow(uint64 word);
#if defined(HAVE__BUILTIN_CLZ) && defined(HAVE__GET_CPUID)
static int pg_leftmost_one32_choose(uint32 word);
static int pg_leftmost_one32_abm(uint32 word);
#endif
static int pg_leftmost_one32_slow(uint32 word);
#if defined(HAVE__BUILTIN_CLZL) && defined(HAVE__GET_CPUID)
static int pg_leftmost_one64_choose(uint64 word);
static int pg_leftmost_one64_abm(uint64 word);
#endif
static int pg_leftmost_one32_slow(uint32 word);
static int pg_leftmost_one64_slow(uint64 word);
#if defined(HAVE__BUILTIN_POPCOUNT) && defined(HAVE__GET_CPUID)
int (*pg_popcount32) (uint32 word) = pg_popcount32_choose;
#else
int (*pg_popcount32) (uint32 word) = pg_popcount32_slow;
#endif
#if defined(HAVE__BUILTIN_POPCOUNTL) && defined(HAVE__GET_CPUID)
int (*pg_popcount64) (uint64 word) = pg_popcount64_choose;
#else
int (*pg_popcount32) (uint32 word) = pg_popcount32_slow;
int (*pg_popcount64) (uint64 word) = pg_popcount64_slow;
#endif
#if defined(HAVE__BUILTIN_CTZ) && defined(HAVE__GET_CPUID)
int (*pg_rightmost_one32) (uint32 word) = pg_rightmost_one32_choose;
#else
int (*pg_rightmost_one32) (uint32 word) = pg_rightmost_one32_slow;
#endif
#if defined(HAVE__BUILTIN_CTZL) && defined(HAVE__GET_CPUID)
int (*pg_rightmost_one64) (uint64 word) = pg_rightmost_one64_choose;
#else
int (*pg_rightmost_one32) (uint32 word) = pg_rightmost_one32_slow;
int (*pg_rightmost_one64) (uint64 word) = pg_rightmost_one64_slow;
#endif
#if defined(HAVE__BUILTIN_CLZ) && defined(HAVE__GET_CPUID)
int (*pg_leftmost_one32) (uint32 word) = pg_leftmost_one32_choose;
#else
int (*pg_leftmost_one32) (uint32 word) = pg_leftmost_one32_slow;
#endif
#if defined(HAVE__BUILTIN_CLZL) && defined(HAVE__GET_CPUID)
int (*pg_leftmost_one64) (uint64 word) = pg_leftmost_one64_choose;
#else
int (*pg_leftmost_one32) (uint32 word) = pg_leftmost_one32_slow;
int (*pg_leftmost_one64) (uint64 word) = pg_leftmost_one64_slow;
#endif
/* Array marking the number of 1-bits for each value of 0-255. */
static const uint8 number_of_ones[256] = {
0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4,
@ -172,7 +147,7 @@ static const uint8 leftmost_one_pos[256] = {
7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7
};
#if defined(HAVE__GET_CPUID) && (defined(HAVE__BUILTIN_POPCOUNT) || defined(HAVE__BUILTIN_POPCOUNTL))
#if defined(HAVE__GET_CPUID) && defined(HAVE__BUILTIN_POPCOUNT)
static bool
pg_popcount_available(void)
@ -279,7 +254,7 @@ pg_popcount(const char *buf, int bytes)
return popcnt;
}
#if defined(HAVE__GET_CPUID) && defined(HAVE__BUILTIN_POPCOUNTL)
#if defined(HAVE__GET_CPUID) && defined(HAVE__BUILTIN_POPCOUNT)
/*
* This gets called on the first call. It replaces the function pointer
@ -299,7 +274,14 @@ pg_popcount64_choose(uint64 word)
static int
pg_popcount64_sse42(uint64 word)
{
#if defined(HAVE_LONG_INT_64)
return __builtin_popcountl(word);
#elif defined(HAVE_LONG_LONG_INT_64)
return __builtin_popcountll(word);
#else
/* shouldn't happen */
#error must have a working 64-bit integer datatype
#endif
}
#endif
@ -322,7 +304,7 @@ pg_popcount64_slow(uint64 word)
return result;
}
#if defined(HAVE__GET_CPUID) && (defined(HAVE__BUILTIN_CTZ) || defined(HAVE__BUILTIN_CTZL) || defined(HAVE__BUILTIN_CLZ) || defined(HAVE__BUILTIN_CLZL))
#if defined(HAVE__GET_CPUID) && (defined(HAVE__BUILTIN_CTZ) || defined(HAVE__BUILTIN_CLZ))
static bool
pg_lzcnt_available(void)
@ -388,7 +370,7 @@ pg_rightmost_one32_slow(uint32 word)
return result;
}
#if defined(HAVE__GET_CPUID) && defined(HAVE__BUILTIN_CTZL)
#if defined(HAVE__GET_CPUID) && defined(HAVE__BUILTIN_CTZ)
/*
* This gets called on the first call. It replaces the function pointer
* so that subsequent calls are routed directly to the chosen implementation.
@ -407,7 +389,14 @@ pg_rightmost_one64_choose(uint64 word)
static int
pg_rightmost_one64_abm(uint64 word)
{
#if defined(HAVE_LONG_INT_64)
return __builtin_ctzl(word);
#elif defined(HAVE_LONG_LONG_INT_64)
return __builtin_ctzll(word);
#else
/* shouldn't happen */
#error must have a working 64-bit integer datatype
#endif
}
#endif
@ -474,7 +463,7 @@ pg_leftmost_one32_slow(uint32 word)
return shift + leftmost_one_pos[(word >> shift) & 255];
}
#if defined(HAVE__GET_CPUID) && defined(HAVE__BUILTIN_CLZL)
#if defined(HAVE__GET_CPUID) && defined(HAVE__BUILTIN_CLZ)
/*
* This gets called on the first call. It replaces the function pointer
* so that subsequent calls are routed directly to the chosen implementation.
@ -493,7 +482,15 @@ pg_leftmost_one64_choose(uint64 word)
static int
pg_leftmost_one64_abm(uint64 word)
{
#if defined(HAVE_LONG_INT_64)
return 63 - __builtin_clzl(word);
#elif defined(HAVE_LONG_LONG_INT_64)
return 63 - __builtin_clzll(word);
#else
/* shouldn't happen */
#error must have a working 64-bit integer datatype
#endif
}
#endif