Coverage Report

Created: 2025-08-24 07:03

/src/cpython/Objects/stringlib/find_max_char.h
Line
Count
Source
1
/* Finding the optimal width of unicode characters in a buffer */
2
3
/* find_max_char for one-byte will work for bytes objects as well. */
4
#if !STRINGLIB_IS_UNICODE && STRINGLIB_SIZEOF_CHAR > 1
5
# error "find_max_char.h is specific to Unicode"
6
#endif
7
8
/* Mask to quickly check whether a C 'size_t' contains a
9
   non-ASCII, UTF8-encoded char. */
10
#if (SIZEOF_SIZE_T == 8)
11
660M
# define UCS1_ASCII_CHAR_MASK 0x8080808080808080ULL
12
#elif (SIZEOF_SIZE_T == 4)
13
# define UCS1_ASCII_CHAR_MASK 0x80808080U
14
#else
15
# error C 'size_t' size should be either 4 or 8!
16
#endif
17
18
#if STRINGLIB_SIZEOF_CHAR == 1
19
20
Py_LOCAL_INLINE(Py_UCS4)
21
STRINGLIB(find_max_char)(const STRINGLIB_CHAR *begin, const STRINGLIB_CHAR *end)
22
55.4M
{
23
55.4M
    const unsigned char *p = (const unsigned char *) begin;
24
55.4M
    const unsigned char *_end = (const unsigned char *)end;
25
26
386M
    while (p < _end) {
27
353M
        if (_Py_IS_ALIGNED(p, ALIGNOF_SIZE_T)) {
28
            /* Help register allocation */
29
51.1M
            const unsigned char *_p = p;
30
692M
            while (_p + SIZEOF_SIZE_T <= _end) {
31
660M
                size_t value = *(const size_t *) _p;
32
660M
                if (value & UCS1_ASCII_CHAR_MASK)
33
18.7M
                    return 255;
34
641M
                _p += SIZEOF_SIZE_T;
35
641M
            }
36
32.4M
            p = _p;
37
32.4M
            if (p == _end)
38
623k
                break;
39
32.4M
        }
40
334M
        if (*p++ & 0x80)
41
3.73M
            return 255;
42
334M
    }
43
33.0M
    return 127;
44
55.4M
}
unicodeobject.c:ucs1lib_find_max_char
Line
Count
Source
22
55.4M
{
23
55.4M
    const unsigned char *p = (const unsigned char *) begin;
24
55.4M
    const unsigned char *_end = (const unsigned char *)end;
25
26
386M
    while (p < _end) {
27
353M
        if (_Py_IS_ALIGNED(p, ALIGNOF_SIZE_T)) {
28
            /* Help register allocation */
29
51.1M
            const unsigned char *_p = p;
30
692M
            while (_p + SIZEOF_SIZE_T <= _end) {
31
660M
                size_t value = *(const size_t *) _p;
32
660M
                if (value & UCS1_ASCII_CHAR_MASK)
33
18.7M
                    return 255;
34
641M
                _p += SIZEOF_SIZE_T;
35
641M
            }
36
32.4M
            p = _p;
37
32.4M
            if (p == _end)
38
623k
                break;
39
32.4M
        }
40
334M
        if (*p++ & 0x80)
41
3.73M
            return 255;
42
334M
    }
43
33.0M
    return 127;
44
55.4M
}
Unexecuted instantiation: unicodeobject.c:asciilib_find_max_char
Unexecuted instantiation: bytes_methods.c:stringlib_find_max_char
45
46
#undef ASCII_CHAR_MASK
47
48
#else /* STRINGLIB_SIZEOF_CHAR == 1 */
49
50
75.8M
#define MASK_ASCII 0xFFFFFF80
51
51.5M
#define MASK_UCS1 0xFFFFFF00
52
24.3M
#define MASK_UCS2 0xFFFF0000
53
54
47.6M
#define MAX_CHAR_ASCII 0x7f
55
22.9M
#define MAX_CHAR_UCS1  0xff
56
33.7M
#define MAX_CHAR_UCS2  0xffff
57
19.0M
#define MAX_CHAR_UCS4  0x10ffff
58
59
Py_LOCAL_INLINE(Py_UCS4)
60
STRINGLIB(find_max_char)(const STRINGLIB_CHAR *begin, const STRINGLIB_CHAR *end)
61
47.6M
{
62
#if STRINGLIB_SIZEOF_CHAR == 2
63
28.5M
    const Py_UCS4 mask_limit = MASK_UCS1;
64
28.5M
    const Py_UCS4 max_char_limit = MAX_CHAR_UCS2;
65
#elif STRINGLIB_SIZEOF_CHAR == 4
66
19.0M
    const Py_UCS4 mask_limit = MASK_UCS2;
67
19.0M
    const Py_UCS4 max_char_limit = MAX_CHAR_UCS4;
68
#else
69
#error Invalid STRINGLIB_SIZEOF_CHAR (must be 1, 2 or 4)
70
#endif
71
47.6M
    Py_UCS4 mask;
72
47.6M
    Py_ssize_t n = end - begin;
73
47.6M
    const STRINGLIB_CHAR *p = begin;
74
47.6M
    const STRINGLIB_CHAR *unrolled_end = begin + _Py_SIZE_ROUND_DOWN(n, 4);
75
47.6M
    Py_UCS4 max_char;
76
77
47.6M
    max_char = MAX_CHAR_ASCII;
78
47.6M
    mask = MASK_ASCII;
79
2.79G
    while (p < unrolled_end) {
80
2.76G
        STRINGLIB_CHAR bits = p[0] | p[1] | p[2] | p[3];
81
2.76G
        if (bits & mask) {
82
43.1M
            if (mask == mask_limit) {
83
                /* Limit reached */
84
17.2M
                return max_char_limit;
85
17.2M
            }
86
25.8M
            if (mask == MASK_ASCII) {
87
21.3M
                max_char = MAX_CHAR_UCS1;
88
21.3M
                mask = MASK_UCS1;
89
21.3M
            }
90
4.48M
            else {
91
                /* mask can't be MASK_UCS2 because of mask_limit above */
92
4.48M
                assert(mask == MASK_UCS1);
93
4.48M
                max_char = MAX_CHAR_UCS2;
94
4.48M
                mask = MASK_UCS2;
95
4.48M
            }
96
            /* We check the new mask on the same chars in the next iteration */
97
25.8M
            continue;
98
43.1M
        }
99
2.72G
        p += 4;
100
2.72G
    }
101
93.0M
    while (p < end) {
102
63.6M
        if (p[0] & mask) {
103
3.22M
            if (mask == mask_limit) {
104
                /* Limit reached */
105
876k
                return max_char_limit;
106
876k
            }
107
2.35M
            if (mask == MASK_ASCII) {
108
1.61M
                max_char = MAX_CHAR_UCS1;
109
1.61M
                mask = MASK_UCS1;
110
1.61M
            }
111
736k
            else {
112
                /* mask can't be MASK_UCS2 because of mask_limit above */
113
736k
                assert(mask == MASK_UCS1);
114
736k
                max_char = MAX_CHAR_UCS2;
115
736k
                mask = MASK_UCS2;
116
736k
            }
117
            /* We check the new mask on the same chars in the next iteration */
118
2.35M
            continue;
119
3.22M
        }
120
60.3M
        p++;
121
60.3M
    }
122
29.4M
    return max_char;
123
30.3M
}
unicodeobject.c:ucs4lib_find_max_char
Line
Count
Source
61
19.0M
{
62
#if STRINGLIB_SIZEOF_CHAR == 2
63
    const Py_UCS4 mask_limit = MASK_UCS1;
64
    const Py_UCS4 max_char_limit = MAX_CHAR_UCS2;
65
#elif STRINGLIB_SIZEOF_CHAR == 4
66
19.0M
    const Py_UCS4 mask_limit = MASK_UCS2;
67
19.0M
    const Py_UCS4 max_char_limit = MAX_CHAR_UCS4;
68
#else
69
#error Invalid STRINGLIB_SIZEOF_CHAR (must be 1, 2 or 4)
70
#endif
71
19.0M
    Py_UCS4 mask;
72
19.0M
    Py_ssize_t n = end - begin;
73
19.0M
    const STRINGLIB_CHAR *p = begin;
74
19.0M
    const STRINGLIB_CHAR *unrolled_end = begin + _Py_SIZE_ROUND_DOWN(n, 4);
75
19.0M
    Py_UCS4 max_char;
76
77
19.0M
    max_char = MAX_CHAR_ASCII;
78
19.0M
    mask = MASK_ASCII;
79
850M
    while (p < unrolled_end) {
80
833M
        STRINGLIB_CHAR bits = p[0] | p[1] | p[2] | p[3];
81
833M
        if (bits & mask) {
82
11.7M
            if (mask == mask_limit) {
83
                /* Limit reached */
84
1.58M
                return max_char_limit;
85
1.58M
            }
86
10.1M
            if (mask == MASK_ASCII) {
87
5.62M
                max_char = MAX_CHAR_UCS1;
88
5.62M
                mask = MASK_UCS1;
89
5.62M
            }
90
4.48M
            else {
91
                /* mask can't be MASK_UCS2 because of mask_limit above */
92
4.48M
                assert(mask == MASK_UCS1);
93
4.48M
                max_char = MAX_CHAR_UCS2;
94
4.48M
                mask = MASK_UCS2;
95
4.48M
            }
96
            /* We check the new mask on the same chars in the next iteration */
97
10.1M
            continue;
98
11.7M
        }
99
821M
        p += 4;
100
821M
    }
101
54.5M
    while (p < end) {
102
37.0M
        if (p[0] & mask) {
103
1.65M
            if (mask == mask_limit) {
104
                /* Limit reached */
105
98.9k
                return max_char_limit;
106
98.9k
            }
107
1.55M
            if (mask == MASK_ASCII) {
108
818k
                max_char = MAX_CHAR_UCS1;
109
818k
                mask = MASK_UCS1;
110
818k
            }
111
736k
            else {
112
                /* mask can't be MASK_UCS2 because of mask_limit above */
113
736k
                assert(mask == MASK_UCS1);
114
736k
                max_char = MAX_CHAR_UCS2;
115
736k
                mask = MASK_UCS2;
116
736k
            }
117
            /* We check the new mask on the same chars in the next iteration */
118
1.55M
            continue;
119
1.65M
        }
120
35.4M
        p++;
121
35.4M
    }
122
17.4M
    return max_char;
123
17.5M
}
unicodeobject.c:ucs2lib_find_max_char
Line
Count
Source
61
28.5M
{
62
28.5M
#if STRINGLIB_SIZEOF_CHAR == 2
63
28.5M
    const Py_UCS4 mask_limit = MASK_UCS1;
64
28.5M
    const Py_UCS4 max_char_limit = MAX_CHAR_UCS2;
65
#elif STRINGLIB_SIZEOF_CHAR == 4
66
    const Py_UCS4 mask_limit = MASK_UCS2;
67
    const Py_UCS4 max_char_limit = MAX_CHAR_UCS4;
68
#else
69
#error Invalid STRINGLIB_SIZEOF_CHAR (must be 1, 2 or 4)
70
#endif
71
28.5M
    Py_UCS4 mask;
72
28.5M
    Py_ssize_t n = end - begin;
73
28.5M
    const STRINGLIB_CHAR *p = begin;
74
28.5M
    const STRINGLIB_CHAR *unrolled_end = begin + _Py_SIZE_ROUND_DOWN(n, 4);
75
28.5M
    Py_UCS4 max_char;
76
77
28.5M
    max_char = MAX_CHAR_ASCII;
78
28.5M
    mask = MASK_ASCII;
79
1.94G
    while (p < unrolled_end) {
80
1.93G
        STRINGLIB_CHAR bits = p[0] | p[1] | p[2] | p[3];
81
1.93G
        if (bits & mask) {
82
31.4M
            if (mask == mask_limit) {
83
                /* Limit reached */
84
15.6M
                return max_char_limit;
85
15.6M
            }
86
15.7M
            if (mask == MASK_ASCII) {
87
15.7M
                max_char = MAX_CHAR_UCS1;
88
15.7M
                mask = MASK_UCS1;
89
15.7M
            }
90
0
            else {
91
                /* mask can't be MASK_UCS2 because of mask_limit above */
92
0
                assert(mask == MASK_UCS1);
93
0
                max_char = MAX_CHAR_UCS2;
94
0
                mask = MASK_UCS2;
95
0
            }
96
            /* We check the new mask on the same chars in the next iteration */
97
15.7M
            continue;
98
31.4M
        }
99
1.90G
        p += 4;
100
1.90G
    }
101
38.5M
    while (p < end) {
102
26.5M
        if (p[0] & mask) {
103
1.57M
            if (mask == mask_limit) {
104
                /* Limit reached */
105
777k
                return max_char_limit;
106
777k
            }
107
797k
            if (mask == MASK_ASCII) {
108
797k
                max_char = MAX_CHAR_UCS1;
109
797k
                mask = MASK_UCS1;
110
797k
            }
111
0
            else {
112
                /* mask can't be MASK_UCS2 because of mask_limit above */
113
0
                assert(mask == MASK_UCS1);
114
0
                max_char = MAX_CHAR_UCS2;
115
0
                mask = MASK_UCS2;
116
0
            }
117
            /* We check the new mask on the same chars in the next iteration */
118
797k
            continue;
119
1.57M
        }
120
24.9M
        p++;
121
24.9M
    }
122
12.0M
    return max_char;
123
12.8M
}
124
125
#undef MASK_ASCII
126
#undef MASK_UCS1
127
#undef MASK_UCS2
128
#undef MAX_CHAR_ASCII
129
#undef MAX_CHAR_UCS1
130
#undef MAX_CHAR_UCS2
131
#undef MAX_CHAR_UCS4
132
133
#endif /* STRINGLIB_SIZEOF_CHAR == 1 */
134