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Revert attempts to use POPCNT etc instructions

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This reverts commits fc6c72747a, 109de05cbb, d0b4663c23 and
711bab1e4d.

Somebody will have to try harder before submitting this patch again.
I've spent entirely too much time on it already, and the #ifdef maze yet
to be written in order for it to build at all got on my nerves.  The
amount of work needed to get a platform-specific performance improvement
that's barely above the noise level is not worth it.
This commit is contained in:
Alvaro Herrera
2019-02-15 16:32:30 -03:00
parent e89f14e2bb
commit 457aef0f1f
14 changed files with 167 additions and 707 deletions
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73
src/backend/access/heap/visibilitymap.c
View File

@ -89,12 +89,12 @@
#include "access/visibilitymap.h"
#include "access/xlog.h"
#include "miscadmin.h"
#include "port/pg_bitutils.h"
#include "storage/bufmgr.h"
#include "storage/lmgr.h"
#include "storage/smgr.h"
#include "utils/inval.h"
/*#define TRACE_VISIBILITYMAP */
/*
@ -115,9 +115,43 @@
#define HEAPBLK_TO_MAPBYTE(x) (((x) % HEAPBLOCKS_PER_PAGE) / HEAPBLOCKS_PER_BYTE)
#define HEAPBLK_TO_OFFSET(x) (((x) % HEAPBLOCKS_PER_BYTE) * BITS_PER_HEAPBLOCK)
/* Masks for bit counting bits in the visibility map. */
#define VISIBLE_MASK64 0x5555555555555555 /* The lower bit of each bit pair */
#define FROZEN_MASK64 0xaaaaaaaaaaaaaaaa /* The upper bit of each bit pair */
/* tables for fast counting of set bits for visible and frozen */
static const uint8 number_of_ones_for_visible[256] = {
0, 1, 0, 1, 1, 2, 1, 2, 0, 1, 0, 1, 1, 2, 1, 2,
1, 2, 1, 2, 2, 3, 2, 3, 1, 2, 1, 2, 2, 3, 2, 3,
0, 1, 0, 1, 1, 2, 1, 2, 0, 1, 0, 1, 1, 2, 1, 2,
1, 2, 1, 2, 2, 3, 2, 3, 1, 2, 1, 2, 2, 3, 2, 3,
1, 2, 1, 2, 2, 3, 2, 3, 1, 2, 1, 2, 2, 3, 2, 3,
2, 3, 2, 3, 3, 4, 3, 4, 2, 3, 2, 3, 3, 4, 3, 4,
1, 2, 1, 2, 2, 3, 2, 3, 1, 2, 1, 2, 2, 3, 2, 3,
2, 3, 2, 3, 3, 4, 3, 4, 2, 3, 2, 3, 3, 4, 3, 4,
0, 1, 0, 1, 1, 2, 1, 2, 0, 1, 0, 1, 1, 2, 1, 2,
1, 2, 1, 2, 2, 3, 2, 3, 1, 2, 1, 2, 2, 3, 2, 3,
0, 1, 0, 1, 1, 2, 1, 2, 0, 1, 0, 1, 1, 2, 1, 2,
1, 2, 1, 2, 2, 3, 2, 3, 1, 2, 1, 2, 2, 3, 2, 3,
1, 2, 1, 2, 2, 3, 2, 3, 1, 2, 1, 2, 2, 3, 2, 3,
2, 3, 2, 3, 3, 4, 3, 4, 2, 3, 2, 3, 3, 4, 3, 4,
1, 2, 1, 2, 2, 3, 2, 3, 1, 2, 1, 2, 2, 3, 2, 3,
2, 3, 2, 3, 3, 4, 3, 4, 2, 3, 2, 3, 3, 4, 3, 4
};
static const uint8 number_of_ones_for_frozen[256] = {
0, 0, 1, 1, 0, 0, 1, 1, 1, 1, 2, 2, 1, 1, 2, 2,
0, 0, 1, 1, 0, 0, 1, 1, 1, 1, 2, 2, 1, 1, 2, 2,
1, 1, 2, 2, 1, 1, 2, 2, 2, 2, 3, 3, 2, 2, 3, 3,
1, 1, 2, 2, 1, 1, 2, 2, 2, 2, 3, 3, 2, 2, 3, 3,
0, 0, 1, 1, 0, 0, 1, 1, 1, 1, 2, 2, 1, 1, 2, 2,
0, 0, 1, 1, 0, 0, 1, 1, 1, 1, 2, 2, 1, 1, 2, 2,
1, 1, 2, 2, 1, 1, 2, 2, 2, 2, 3, 3, 2, 2, 3, 3,
1, 1, 2, 2, 1, 1, 2, 2, 2, 2, 3, 3, 2, 2, 3, 3,
1, 1, 2, 2, 1, 1, 2, 2, 2, 2, 3, 3, 2, 2, 3, 3,
1, 1, 2, 2, 1, 1, 2, 2, 2, 2, 3, 3, 2, 2, 3, 3,
2, 2, 3, 3, 2, 2, 3, 3, 3, 3, 4, 4, 3, 3, 4, 4,
2, 2, 3, 3, 2, 2, 3, 3, 3, 3, 4, 4, 3, 3, 4, 4,
1, 1, 2, 2, 1, 1, 2, 2, 2, 2, 3, 3, 2, 2, 3, 3,
1, 1, 2, 2, 1, 1, 2, 2, 2, 2, 3, 3, 2, 2, 3, 3,
2, 2, 3, 3, 2, 2, 3, 3, 3, 3, 4, 4, 3, 3, 4, 4,
2, 2, 3, 3, 2, 2, 3, 3, 3, 3, 4, 4, 3, 3, 4, 4
};
/* prototypes for internal routines */
static Buffer vm_readbuf(Relation rel, BlockNumber blkno, bool extend);
@ -374,16 +408,18 @@ void
visibilitymap_count(Relation rel, BlockNumber *all_visible, BlockNumber *all_frozen)
{
BlockNumber mapBlock;
BlockNumber nvisible = 0;
BlockNumber nfrozen = 0;
/* all_visible must be specified */
Assert(all_visible);
*all_visible = 0;
if (all_frozen)
*all_frozen = 0;
for (mapBlock = 0;; mapBlock++)
{
Buffer mapBuffer;
uint64 *map;
unsigned char *map;
int i;
/*
@ -400,30 +436,17 @@ visibilitymap_count(Relation rel, BlockNumber *all_visible, BlockNumber *all_fro
* immediately stale anyway if anyone is concurrently setting or
* clearing bits, and we only really need an approximate value.
*/
map = (uint64 *) PageGetContents(BufferGetPage(mapBuffer));
map = (unsigned char *) PageGetContents(BufferGetPage(mapBuffer));
StaticAssertStmt(MAPSIZE % sizeof(uint64) == 0,
"unsupported MAPSIZE");
if (all_frozen == NULL)
for (i = 0; i < MAPSIZE; i++)
{
for (i = 0; i < MAPSIZE / sizeof(uint64); i++)
nvisible += pg_popcount64(map[i] & VISIBLE_MASK64);
}
else
{
for (i = 0; i < MAPSIZE / sizeof(uint64); i++)
{
nvisible += pg_popcount64(map[i] & VISIBLE_MASK64);
nfrozen += pg_popcount64(map[i] & FROZEN_MASK64);
}
*all_visible += number_of_ones_for_visible[map[i]];
if (all_frozen)
*all_frozen += number_of_ones_for_frozen[map[i]];
}
ReleaseBuffer(mapBuffer);
}
*all_visible = nvisible;
if (all_frozen)
*all_frozen = nfrozen;
}
/*