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Move builtin_ctzl portability into zend_bitset.h
Use this function in both zend_mm_bitset_find_one and zend_bitset_first. Maybe zend_bitset.h is not quite the right place for it, but I did not want to include this in a globally included header like zend_long.h or zend_portability.h.
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2 files changed

+46
-52
lines changed

2 files changed

+46
-52
lines changed

Zend/zend_alloc.c

Lines changed: 4 additions & 42 deletions
Original file line numberDiff line numberDiff line change
@@ -58,6 +58,7 @@
5858
#include "zend_globals.h"
5959
#include "zend_operators.h"
6060
#include "zend_multiply.h"
61+
#include "zend_bitset.h"
6162

6263
#ifdef HAVE_SIGNAL_H
6364
# include <signal.h>
@@ -546,45 +547,6 @@ static zend_always_inline int zend_mm_bitset_nts(zend_mm_bitset bitset)
546547
#endif
547548
}
548549

549-
/* number of trailing zero bits (0x01 -> 1; 0x40 -> 6; 0x00 -> LEN) */
550-
static zend_always_inline int zend_mm_bitset_ntz(zend_mm_bitset bitset)
551-
{
552-
#if (defined(__GNUC__) || __has_builtin(__builtin_ctzl)) && SIZEOF_ZEND_LONG == SIZEOF_LONG && defined(PHP_HAVE_BUILTIN_CTZL)
553-
return __builtin_ctzl(bitset);
554-
#elif (defined(__GNUC__) || __has_builtin(__builtin_ctzll)) && defined(PHP_HAVE_BUILTIN_CTZLL)
555-
return __builtin_ctzll(bitset);
556-
#elif defined(_WIN32)
557-
unsigned long index;
558-
559-
#if defined(_WIN64)
560-
if (!BitScanForward64(&index, bitset)) {
561-
#else
562-
if (!BitScanForward(&index, bitset)) {
563-
#endif
564-
/* undefined behavior */
565-
return 32;
566-
}
567-
568-
return (int)index;
569-
#else
570-
int n;
571-
572-
if (bitset == (zend_mm_bitset)0) return ZEND_MM_BITSET_LEN;
573-
574-
n = 1;
575-
#if SIZEOF_ZEND_LONG == 8
576-
if (sizeof(zend_mm_bitset) == 8) {
577-
if ((bitset & 0xffffffff) == 0) {n += 32; bitset = bitset >> Z_UL(32);}
578-
}
579-
#endif
580-
if ((bitset & 0x0000ffff) == 0) {n += 16; bitset = bitset >> 16;}
581-
if ((bitset & 0x000000ff) == 0) {n += 8; bitset = bitset >> 8;}
582-
if ((bitset & 0x0000000f) == 0) {n += 4; bitset = bitset >> 4;}
583-
if ((bitset & 0x00000003) == 0) {n += 2; bitset = bitset >> 2;}
584-
return n - (bitset & 1);
585-
#endif
586-
}
587-
588550
static zend_always_inline int zend_mm_bitset_find_zero(zend_mm_bitset *bitset, int size)
589551
{
590552
int i = 0;
@@ -606,7 +568,7 @@ static zend_always_inline int zend_mm_bitset_find_one(zend_mm_bitset *bitset, in
606568
do {
607569
zend_mm_bitset tmp = bitset[i];
608570
if (tmp != 0) {
609-
return i * ZEND_MM_BITSET_LEN + zend_mm_bitset_ntz(tmp);
571+
return i * ZEND_MM_BITSET_LEN + zend_ulong_ntz(tmp);
610572
}
611573
i++;
612574
} while (i < size);
@@ -941,7 +903,7 @@ static void *zend_mm_alloc_pages(zend_mm_heap *heap, int pages_count ZEND_FILE_L
941903
tmp = *(bitset++);
942904
}
943905
/* find first 1 bit */
944-
len = (i + zend_mm_bitset_ntz(tmp)) - page_num;
906+
len = (i + zend_ulong_ntz(tmp)) - page_num;
945907
if (len >= pages_count) {
946908
goto found;
947909
}
@@ -998,7 +960,7 @@ static void *zend_mm_alloc_pages(zend_mm_heap *heap, int pages_count ZEND_FILE_L
998960
tmp = *(bitset++);
999961
}
1000962
/* find first 1 bit */
1001-
len = i + zend_mm_bitset_ntz(tmp) - page_num;
963+
len = i + zend_ulong_ntz(tmp) - page_num;
1002964
if (len >= pages_count) {
1003965
if (len == pages_count) {
1004966
goto found;

Zend/zend_bitset.h

Lines changed: 42 additions & 10 deletions
Original file line numberDiff line numberDiff line change
@@ -36,16 +36,54 @@ typedef zend_ulong *zend_bitset;
3636
# define ZEND_BITSET_BIT_NUM(n) ((n) % (sizeof(zend_long) * 8))
3737
#endif
3838

39+
#define ZEND_BITSET_ALLOCA(n, use_heap) \
40+
(zend_bitset)do_alloca((n) * ZEND_BITSET_ELM_SIZE, use_heap)
41+
42+
/* Number of trailing zero bits (0x01 -> 0; 0x40 -> 6; 0x00 -> LEN) */
43+
static zend_always_inline int zend_ulong_ntz(zend_ulong num)
44+
{
45+
#if (defined(__GNUC__) || __has_builtin(__builtin_ctzl)) \
46+
&& SIZEOF_ZEND_LONG == SIZEOF_LONG && defined(PHP_HAVE_BUILTIN_CTZL)
47+
return __builtin_ctzl(num);
48+
#elif (defined(__GNUC__) || __has_builtin(__builtin_ctzll)) && defined(PHP_HAVE_BUILTIN_CTZLL)
49+
return __builtin_ctzll(num);
50+
#elif defined(_WIN32)
51+
unsigned long index;
52+
53+
#if defined(_WIN64)
54+
if (!BitScanForward64(&index, num)) {
55+
#else
56+
if (!BitScanForward(&index, num)) {
57+
#endif
58+
/* undefined behavior */
59+
return 32;
60+
}
61+
62+
return (int) index;
63+
#else
64+
int n;
65+
66+
if (num == Z_UL(0)) return ZEND_MM_BITSET_LEN;
67+
68+
n = 1;
69+
#if SIZEOF_ZEND_LONG == 8
70+
if ((num & 0xffffffff) == 0) {n += 32; num = num >> Z_UL(32);}
71+
#endif
72+
if ((num & 0x0000ffff) == 0) {n += 16; num = num >> 16;}
73+
if ((num & 0x000000ff) == 0) {n += 8; num = num >> 8;}
74+
if ((num & 0x0000000f) == 0) {n += 4; num = num >> 4;}
75+
if ((num & 0x00000003) == 0) {n += 2; num = num >> 2;}
76+
return n - (num & 1);
77+
#endif
78+
}
79+
3980
/* Returns the number of zend_ulong words needed to store a bitset that is N
4081
bits long. */
4182
static inline uint32_t zend_bitset_len(uint32_t n)
4283
{
4384
return (n + ((sizeof(zend_long) * 8) - 1)) / (sizeof(zend_long) * 8);
4485
}
4586

46-
#define ZEND_BITSET_ALLOCA(n, use_heap) \
47-
(zend_bitset)do_alloca((n) * ZEND_BITSET_ELM_SIZE, use_heap)
48-
4987
static inline zend_bool zend_bitset_in(zend_bitset set, uint32_t n)
5088
{
5189
return (set[ZEND_BITSET_ELM_NUM(n)] & (Z_UL(1) << ZEND_BITSET_BIT_NUM(n))) != Z_UL(0);
@@ -155,13 +193,7 @@ static inline int zend_bitset_first(zend_bitset set, uint32_t len)
155193

156194
for (i = 0; i < len; i++) {
157195
if (set[i]) {
158-
int j = ZEND_BITSET_ELM_SIZE * 8 * i;
159-
zend_ulong x = set[i];
160-
while ((x & Z_UL(1)) == 0) {
161-
x = x >> Z_UL(1);
162-
j++;
163-
}
164-
return j;
196+
return ZEND_BITSET_ELM_SIZE * 8 * i + zend_ulong_ntz(set[i]);
165197
}
166198
}
167199
return -1; /* empty set */

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