Coverage Report

Created: 2025-08-29 06:15

/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
599M
# 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
52.0M
{
23
52.0M
    const unsigned char *p = (const unsigned char *) begin;
24
52.0M
    const unsigned char *_end = (const unsigned char *)end;
25
26
353M
    while (p < _end) {
27
323M
        if (_Py_IS_ALIGNED(p, ALIGNOF_SIZE_T)) {
28
            /* Help register allocation */
29
47.4M
            const unsigned char *_p = p;
30
629M
            while (_p + SIZEOF_SIZE_T <= _end) {
31
599M
                size_t value = *(const size_t *) _p;
32
599M
                if (value & UCS1_ASCII_CHAR_MASK)
33
17.1M
                    return 255;
34
582M
                _p += SIZEOF_SIZE_T;
35
582M
            }
36
30.3M
            p = _p;
37
30.3M
            if (p == _end)
38
661k
                break;
39
30.3M
        }
40
305M
        if (*p++ & 0x80)
41
3.77M
            return 255;
42
305M
    }
43
31.0M
    return 127;
44
52.0M
}
unicodeobject.c:ucs1lib_find_max_char
Line
Count
Source
22
52.0M
{
23
52.0M
    const unsigned char *p = (const unsigned char *) begin;
24
52.0M
    const unsigned char *_end = (const unsigned char *)end;
25
26
353M
    while (p < _end) {
27
323M
        if (_Py_IS_ALIGNED(p, ALIGNOF_SIZE_T)) {
28
            /* Help register allocation */
29
47.4M
            const unsigned char *_p = p;
30
629M
            while (_p + SIZEOF_SIZE_T <= _end) {
31
599M
                size_t value = *(const size_t *) _p;
32
599M
                if (value & UCS1_ASCII_CHAR_MASK)
33
17.1M
                    return 255;
34
582M
                _p += SIZEOF_SIZE_T;
35
582M
            }
36
30.3M
            p = _p;
37
30.3M
            if (p == _end)
38
661k
                break;
39
30.3M
        }
40
305M
        if (*p++ & 0x80)
41
3.77M
            return 255;
42
305M
    }
43
31.0M
    return 127;
44
52.0M
}
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
76.7M
#define MASK_ASCII 0xFFFFFF80
51
50.6M
#define MASK_UCS1 0xFFFFFF00
52
26.1M
#define MASK_UCS2 0xFFFF0000
53
54
48.4M
#define MAX_CHAR_ASCII 0x7f
55
22.7M
#define MAX_CHAR_UCS1  0xff
56
33.4M
#define MAX_CHAR_UCS2  0xffff
57
20.5M
#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
48.4M
{
62
#if STRINGLIB_SIZEOF_CHAR == 2
63
27.8M
    const Py_UCS4 mask_limit = MASK_UCS1;
64
27.8M
    const Py_UCS4 max_char_limit = MAX_CHAR_UCS2;
65
#elif STRINGLIB_SIZEOF_CHAR == 4
66
20.5M
    const Py_UCS4 mask_limit = MASK_UCS2;
67
20.5M
    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
48.4M
    Py_UCS4 mask;
72
48.4M
    Py_ssize_t n = end - begin;
73
48.4M
    const STRINGLIB_CHAR *p = begin;
74
48.4M
    const STRINGLIB_CHAR *unrolled_end = begin + _Py_SIZE_ROUND_DOWN(n, 4);
75
48.4M
    Py_UCS4 max_char;
76
77
48.4M
    max_char = MAX_CHAR_ASCII;
78
48.4M
    mask = MASK_ASCII;
79
2.44G
    while (p < unrolled_end) {
80
2.41G
        STRINGLIB_CHAR bits = p[0] | p[1] | p[2] | p[3];
81
2.41G
        if (bits & mask) {
82
43.0M
            if (mask == mask_limit) {
83
                /* Limit reached */
84
16.9M
                return max_char_limit;
85
16.9M
            }
86
26.0M
            if (mask == MASK_ASCII) {
87
21.1M
                max_char = MAX_CHAR_UCS1;
88
21.1M
                mask = MASK_UCS1;
89
21.1M
            }
90
4.85M
            else {
91
                /* mask can't be MASK_UCS2 because of mask_limit above */
92
4.85M
                assert(mask == MASK_UCS1);
93
4.85M
                max_char = MAX_CHAR_UCS2;
94
4.85M
                mask = MASK_UCS2;
95
4.85M
            }
96
            /* We check the new mask on the same chars in the next iteration */
97
26.0M
            continue;
98
43.0M
        }
99
2.36G
        p += 4;
100
2.36G
    }
101
97.1M
    while (p < end) {
102
66.6M
        if (p[0] & mask) {
103
3.20M
            if (mask == mask_limit) {
104
                /* Limit reached */
105
873k
                return max_char_limit;
106
873k
            }
107
2.33M
            if (mask == MASK_ASCII) {
108
1.60M
                max_char = MAX_CHAR_UCS1;
109
1.60M
                mask = MASK_UCS1;
110
1.60M
            }
111
728k
            else {
112
                /* mask can't be MASK_UCS2 because of mask_limit above */
113
728k
                assert(mask == MASK_UCS1);
114
728k
                max_char = MAX_CHAR_UCS2;
115
728k
                mask = MASK_UCS2;
116
728k
            }
117
            /* We check the new mask on the same chars in the next iteration */
118
2.33M
            continue;
119
3.20M
        }
120
63.4M
        p++;
121
63.4M
    }
122
30.5M
    return max_char;
123
31.4M
}
unicodeobject.c:ucs4lib_find_max_char
Line
Count
Source
61
20.5M
{
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
20.5M
    const Py_UCS4 mask_limit = MASK_UCS2;
67
20.5M
    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
20.5M
    Py_UCS4 mask;
72
20.5M
    Py_ssize_t n = end - begin;
73
20.5M
    const STRINGLIB_CHAR *p = begin;
74
20.5M
    const STRINGLIB_CHAR *unrolled_end = begin + _Py_SIZE_ROUND_DOWN(n, 4);
75
20.5M
    Py_UCS4 max_char;
76
77
20.5M
    max_char = MAX_CHAR_ASCII;
78
20.5M
    mask = MASK_ASCII;
79
810M
    while (p < unrolled_end) {
80
792M
        STRINGLIB_CHAR bits = p[0] | p[1] | p[2] | p[3];
81
792M
        if (bits & mask) {
82
12.5M
            if (mask == mask_limit) {
83
                /* Limit reached */
84
1.77M
                return max_char_limit;
85
1.77M
            }
86
10.7M
            if (mask == MASK_ASCII) {
87
5.92M
                max_char = MAX_CHAR_UCS1;
88
5.92M
                mask = MASK_UCS1;
89
5.92M
            }
90
4.85M
            else {
91
                /* mask can't be MASK_UCS2 because of mask_limit above */
92
4.85M
                assert(mask == MASK_UCS1);
93
4.85M
                max_char = MAX_CHAR_UCS2;
94
4.85M
                mask = MASK_UCS2;
95
4.85M
            }
96
            /* We check the new mask on the same chars in the next iteration */
97
10.7M
            continue;
98
12.5M
        }
99
779M
        p += 4;
100
779M
    }
101
59.1M
    while (p < end) {
102
40.4M
        if (p[0] & mask) {
103
1.61M
            if (mask == mask_limit) {
104
                /* Limit reached */
105
88.5k
                return max_char_limit;
106
88.5k
            }
107
1.53M
            if (mask == MASK_ASCII) {
108
802k
                max_char = MAX_CHAR_UCS1;
109
802k
                mask = MASK_UCS1;
110
802k
            }
111
728k
            else {
112
                /* mask can't be MASK_UCS2 because of mask_limit above */
113
728k
                assert(mask == MASK_UCS1);
114
728k
                max_char = MAX_CHAR_UCS2;
115
728k
                mask = MASK_UCS2;
116
728k
            }
117
            /* We check the new mask on the same chars in the next iteration */
118
1.53M
            continue;
119
1.61M
        }
120
38.8M
        p++;
121
38.8M
    }
122
18.6M
    return max_char;
123
18.7M
}
unicodeobject.c:ucs2lib_find_max_char
Line
Count
Source
61
27.8M
{
62
27.8M
#if STRINGLIB_SIZEOF_CHAR == 2
63
27.8M
    const Py_UCS4 mask_limit = MASK_UCS1;
64
27.8M
    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
27.8M
    Py_UCS4 mask;
72
27.8M
    Py_ssize_t n = end - begin;
73
27.8M
    const STRINGLIB_CHAR *p = begin;
74
27.8M
    const STRINGLIB_CHAR *unrolled_end = begin + _Py_SIZE_ROUND_DOWN(n, 4);
75
27.8M
    Py_UCS4 max_char;
76
77
27.8M
    max_char = MAX_CHAR_ASCII;
78
27.8M
    mask = MASK_ASCII;
79
1.63G
    while (p < unrolled_end) {
80
1.61G
        STRINGLIB_CHAR bits = p[0] | p[1] | p[2] | p[3];
81
1.61G
        if (bits & mask) {
82
30.4M
            if (mask == mask_limit) {
83
                /* Limit reached */
84
15.2M
                return max_char_limit;
85
15.2M
            }
86
15.2M
            if (mask == MASK_ASCII) {
87
15.2M
                max_char = MAX_CHAR_UCS1;
88
15.2M
                mask = MASK_UCS1;
89
15.2M
            }
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
15.2M
            continue;
98
30.4M
        }
99
1.58G
        p += 4;
100
1.58G
    }
101
38.0M
    while (p < end) {
102
26.1M
        if (p[0] & mask) {
103
1.59M
            if (mask == mask_limit) {
104
                /* Limit reached */
105
785k
                return max_char_limit;
106
785k
            }
107
804k
            if (mask == MASK_ASCII) {
108
804k
                max_char = MAX_CHAR_UCS1;
109
804k
                mask = MASK_UCS1;
110
804k
            }
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
804k
            continue;
119
1.59M
        }
120
24.5M
        p++;
121
24.5M
    }
122
11.8M
    return max_char;
123
12.6M
}
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