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Fix some incorrect preprocessor tests in tuplesort specializations

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697492434 added 3 new quicksort specialization functions for common
datatypes.

That commit was not very consistent in how it would determine if we're
compiling for 32-bit or 64-bit machines.  It would sometimes use
USE_FLOAT8_BYVAL and at other times check if SIZEOF_DATUM == 8.  This
could cause theoretical problems due to the way USE_FLOAT8_BYVAL is now
defined based on SIZEOF_VOID_P >= 8.  If pointers for some reason were
ever larger than 8-bytes then we'd end up doing 32-bit comparisons
mistakenly.  Let's just always check SIZEOF_DATUM >= 8.

It also seems that ssup_datum_signed_cmp is just never used on 32-bit
builds, so let's just ifdef that out to make sure we never accidentally
use that comparison function on such machines.  This also allows us to
ifdef out 1 of the 3 new specialization quicksort functions in 32-bit
builds which seems to shrink down the binary by over 4KB on my machine.

In passing, also add the missing DatumGetInt32() / DatumGetInt64() macros
in the comparison functions.

Discussion: https://postgr.es/m/CAApHDvqcQExRhtRa9hJrJB_5egs3SUfOcutP3m+3HO8A+fZTPA@mail.gmail.com
Reviewed-by: John Naylor
This commit is contained in:
David Rowley 2022-05-11 11:38:13 +12:00
parent aff45c879e
commit c90c16591c
4 changed files with 18 additions and 13 deletions
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4
src/backend/access/nbtree/nbtcompare.c
View File

@ -142,7 +142,7 @@ btint8cmp(PG_FUNCTION_ARGS)
PG_RETURN_INT32(A_LESS_THAN_B);
}
#ifndef USE_FLOAT8_BYVAL
#if SIZEOF_DATUM < 8
static int
btint8fastcmp(Datum x, Datum y, SortSupport ssup)
{
@ -163,7 +163,7 @@ btint8sortsupport(PG_FUNCTION_ARGS)
{
SortSupport ssup = (SortSupport) PG_GETARG_POINTER(0);
#ifdef USE_FLOAT8_BYVAL
#if SIZEOF_DATUM >= 8
ssup->comparator = ssup_datum_signed_cmp;
#else
ssup->comparator = btint8fastcmp;

4
src/backend/utils/adt/timestamp.c
View File

@ -2176,7 +2176,7 @@ timestamp_cmp(PG_FUNCTION_ARGS)
PG_RETURN_INT32(timestamp_cmp_internal(dt1, dt2));
}
#ifndef USE_FLOAT8_BYVAL
#if SIZEOF_DATUM < 8
/* note: this is used for timestamptz also */
static int
timestamp_fastcmp(Datum x, Datum y, SortSupport ssup)
@ -2193,7 +2193,7 @@ timestamp_sortsupport(PG_FUNCTION_ARGS)
{
SortSupport ssup = (SortSupport) PG_GETARG_POINTER(0);
#ifdef USE_FLOAT8_BYVAL
#if SIZEOF_DATUM >= 8
/*
* If this build has pass-by-value timestamps, then we can use a standard
* comparator function.

21
src/backend/utils/sort/tuplesort.c
View File

@ -715,6 +715,7 @@ qsort_tuple_unsigned_compare(SortTuple *a, SortTuple *b, Tuplesortstate *state)
return state->comparetup(a, b, state);
}
#if SIZEOF_DATUM >= 8
/* Used if first key's comparator is ssup_datum_signed_compare */
static pg_attribute_always_inline int
qsort_tuple_signed_compare(SortTuple *a, SortTuple *b, Tuplesortstate *state)
@ -737,6 +738,7 @@ qsort_tuple_signed_compare(SortTuple *a, SortTuple *b, Tuplesortstate *state)
return state->comparetup(a, b, state);
}
#endif
/* Used if first key's comparator is ssup_datum_int32_compare */
static pg_attribute_always_inline int
@ -779,6 +781,7 @@ qsort_tuple_int32_compare(SortTuple *a, SortTuple *b, Tuplesortstate *state)
#define ST_DEFINE
#include "lib/sort_template.h"
#if SIZEOF_DATUM >= 8
#define ST_SORT qsort_tuple_signed
#define ST_ELEMENT_TYPE SortTuple
#define ST_COMPARE(a, b, state) qsort_tuple_signed_compare(a, b, state)
@ -787,6 +790,7 @@ qsort_tuple_int32_compare(SortTuple *a, SortTuple *b, Tuplesortstate *state)
#define ST_SCOPE static
#define ST_DEFINE
#include "lib/sort_template.h"
#endif
#define ST_SORT qsort_tuple_int32
#define ST_ELEMENT_TYPE SortTuple
@ -3666,6 +3670,7 @@ tuplesort_sort_memtuples(Tuplesortstate *state)
state);
return;
}
#if SIZEOF_DATUM >= 8
else if (state->sortKeys[0].comparator == ssup_datum_signed_cmp)
{
elog(DEBUG1, "qsort_tuple_signed");
@ -3674,6 +3679,7 @@ tuplesort_sort_memtuples(Tuplesortstate *state)
state);
return;
}
#endif
else if (state->sortKeys[0].comparator == ssup_datum_int32_cmp)
{
elog(DEBUG1, "qsort_tuple_int32");
@ -4905,16 +4911,12 @@ ssup_datum_unsigned_cmp(Datum x, Datum y, SortSupport ssup)
return 0;
}
#if SIZEOF_DATUM >= 8
int
ssup_datum_signed_cmp(Datum x, Datum y, SortSupport ssup)
{
#if SIZEOF_DATUM == 8
int64 xx = (int64) x;
int64 yy = (int64) y;
#else
int32 xx = (int32) x;
int32 yy = (int32) y;
#endif
int64 xx = DatumGetInt64(x);
int64 yy = DatumGetInt64(y);
if (xx < yy)
return -1;
@ -4923,12 +4925,13 @@ ssup_datum_signed_cmp(Datum x, Datum y, SortSupport ssup)
else
return 0;
}
#endif
int
ssup_datum_int32_cmp(Datum x, Datum y, SortSupport ssup)
{
int32 xx = (int32) x;
int32 yy = (int32) y;
int32 xx = DatumGetInt32(x);
int32 yy = DatumGetInt32(y);
if (xx < yy)
return -1;

2
src/include/utils/sortsupport.h
View File

@ -379,7 +379,9 @@ ApplySortAbbrevFullComparator(Datum datum1, bool isNull1,
* are eligible for faster sorting.
*/
extern int ssup_datum_unsigned_cmp(Datum x, Datum y, SortSupport ssup);
#if SIZEOF_DATUM >= 8
extern int ssup_datum_signed_cmp(Datum x, Datum y, SortSupport ssup);
#endif
extern int ssup_datum_int32_cmp(Datum x, Datum y, SortSupport ssup);
/* Other functions in utils/sort/sortsupport.c */