Coverage Report

Created: 2025-07-18 06:09

/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
600M
# 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
52.8M
{
23
52.8M
    const unsigned char *p = (const unsigned char *) begin;
24
52.8M
    const unsigned char *_end = (const unsigned char *)end;
25
26
359M
    while (p < _end) {
27
328M
        if (_Py_IS_ALIGNED(p, ALIGNOF_SIZE_T)) {
28
            /* Help register allocation */
29
48.5M
            const unsigned char *_p = p;
30
631M
            while (_p + SIZEOF_SIZE_T <= _end) {
31
600M
                size_t value = *(const size_t *) _p;
32
600M
                if (value & UCS1_ASCII_CHAR_MASK)
33
17.7M
                    return 255;
34
583M
                _p += SIZEOF_SIZE_T;
35
583M
            }
36
30.8M
            p = _p;
37
30.8M
            if (p == _end)
38
572k
                break;
39
30.8M
        }
40
310M
        if (*p++ & 0x80)
41
3.78M
            return 255;
42
310M
    }
43
31.3M
    return 127;
44
52.8M
}
unicodeobject.c:ucs1lib_find_max_char
Line
Count
Source
22
52.8M
{
23
52.8M
    const unsigned char *p = (const unsigned char *) begin;
24
52.8M
    const unsigned char *_end = (const unsigned char *)end;
25
26
359M
    while (p < _end) {
27
328M
        if (_Py_IS_ALIGNED(p, ALIGNOF_SIZE_T)) {
28
            /* Help register allocation */
29
48.5M
            const unsigned char *_p = p;
30
631M
            while (_p + SIZEOF_SIZE_T <= _end) {
31
600M
                size_t value = *(const size_t *) _p;
32
600M
                if (value & UCS1_ASCII_CHAR_MASK)
33
17.7M
                    return 255;
34
583M
                _p += SIZEOF_SIZE_T;
35
583M
            }
36
30.8M
            p = _p;
37
30.8M
            if (p == _end)
38
572k
                break;
39
30.8M
        }
40
310M
        if (*p++ & 0x80)
41
3.78M
            return 255;
42
310M
    }
43
31.3M
    return 127;
44
52.8M
}
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
82.4M
#define MASK_ASCII 0xFFFFFF80
51
54.6M
#define MASK_UCS1 0xFFFFFF00
52
27.7M
#define MASK_UCS2 0xFFFF0000
53
54
52.8M
#define MAX_CHAR_ASCII 0x7f
55
24.0M
#define MAX_CHAR_UCS1  0xff
56
36.1M
#define MAX_CHAR_UCS2  0xffff
57
22.2M
#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
52.8M
{
62
#if STRINGLIB_SIZEOF_CHAR == 2
63
30.6M
    const Py_UCS4 mask_limit = MASK_UCS1;
64
30.6M
    const Py_UCS4 max_char_limit = MAX_CHAR_UCS2;
65
#elif STRINGLIB_SIZEOF_CHAR == 4
66
22.2M
    const Py_UCS4 mask_limit = MASK_UCS2;
67
22.2M
    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
52.8M
    Py_UCS4 mask;
72
52.8M
    Py_ssize_t n = end - begin;
73
52.8M
    const STRINGLIB_CHAR *p = begin;
74
52.8M
    const STRINGLIB_CHAR *unrolled_end = begin + _Py_SIZE_ROUND_DOWN(n, 4);
75
52.8M
    Py_UCS4 max_char;
76
77
52.8M
    max_char = MAX_CHAR_ASCII;
78
52.8M
    mask = MASK_ASCII;
79
2.64G
    while (p < unrolled_end) {
80
2.61G
        STRINGLIB_CHAR bits = p[0] | p[1] | p[2] | p[3];
81
2.61G
        if (bits & mask) {
82
45.8M
            if (mask == mask_limit) {
83
                /* Limit reached */
84
18.4M
                return max_char_limit;
85
18.4M
            }
86
27.4M
            if (mask == MASK_ASCII) {
87
22.5M
                max_char = MAX_CHAR_UCS1;
88
22.5M
                mask = MASK_UCS1;
89
22.5M
            }
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
27.4M
            continue;
98
45.8M
        }
99
2.56G
        p += 4;
100
2.56G
    }
101
107M
    while (p < end) {
102
74.2M
        if (p[0] & mask) {
103
2.99M
            if (mask == mask_limit) {
104
                /* Limit reached */
105
802k
                return max_char_limit;
106
802k
            }
107
2.19M
            if (mask == MASK_ASCII) {
108
1.50M
                max_char = MAX_CHAR_UCS1;
109
1.50M
                mask = MASK_UCS1;
110
1.50M
            }
111
683k
            else {
112
                /* mask can't be MASK_UCS2 because of mask_limit above */
113
683k
                assert(mask == MASK_UCS1);
114
683k
                max_char = MAX_CHAR_UCS2;
115
683k
                mask = MASK_UCS2;
116
683k
            }
117
            /* We check the new mask on the same chars in the next iteration */
118
2.19M
            continue;
119
2.99M
        }
120
71.2M
        p++;
121
71.2M
    }
122
33.6M
    return max_char;
123
34.4M
}
unicodeobject.c:ucs4lib_find_max_char
Line
Count
Source
61
22.2M
{
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
22.2M
    const Py_UCS4 mask_limit = MASK_UCS2;
67
22.2M
    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
22.2M
    Py_UCS4 mask;
72
22.2M
    Py_ssize_t n = end - begin;
73
22.2M
    const STRINGLIB_CHAR *p = begin;
74
22.2M
    const STRINGLIB_CHAR *unrolled_end = begin + _Py_SIZE_ROUND_DOWN(n, 4);
75
22.2M
    Py_UCS4 max_char;
76
77
22.2M
    max_char = MAX_CHAR_ASCII;
78
22.2M
    mask = MASK_ASCII;
79
877M
    while (p < unrolled_end) {
80
857M
        STRINGLIB_CHAR bits = p[0] | p[1] | p[2] | p[3];
81
857M
        if (bits & mask) {
82
12.9M
            if (mask == mask_limit) {
83
                /* Limit reached */
84
2.01M
                return max_char_limit;
85
2.01M
            }
86
10.9M
            if (mask == MASK_ASCII) {
87
6.06M
                max_char = MAX_CHAR_UCS1;
88
6.06M
                mask = MASK_UCS1;
89
6.06M
            }
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
10.9M
            continue;
98
12.9M
        }
99
844M
        p += 4;
100
844M
    }
101
63.7M
    while (p < end) {
102
43.6M
        if (p[0] & mask) {
103
1.55M
            if (mask == mask_limit) {
104
                /* Limit reached */
105
97.3k
                return max_char_limit;
106
97.3k
            }
107
1.46M
            if (mask == MASK_ASCII) {
108
778k
                max_char = MAX_CHAR_UCS1;
109
778k
                mask = MASK_UCS1;
110
778k
            }
111
683k
            else {
112
                /* mask can't be MASK_UCS2 because of mask_limit above */
113
683k
                assert(mask == MASK_UCS1);
114
683k
                max_char = MAX_CHAR_UCS2;
115
683k
                mask = MASK_UCS2;
116
683k
            }
117
            /* We check the new mask on the same chars in the next iteration */
118
1.46M
            continue;
119
1.55M
        }
120
42.0M
        p++;
121
42.0M
    }
122
20.1M
    return max_char;
123
20.2M
}
unicodeobject.c:ucs2lib_find_max_char
Line
Count
Source
61
30.6M
{
62
30.6M
#if STRINGLIB_SIZEOF_CHAR == 2
63
30.6M
    const Py_UCS4 mask_limit = MASK_UCS1;
64
30.6M
    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
30.6M
    Py_UCS4 mask;
72
30.6M
    Py_ssize_t n = end - begin;
73
30.6M
    const STRINGLIB_CHAR *p = begin;
74
30.6M
    const STRINGLIB_CHAR *unrolled_end = begin + _Py_SIZE_ROUND_DOWN(n, 4);
75
30.6M
    Py_UCS4 max_char;
76
77
30.6M
    max_char = MAX_CHAR_ASCII;
78
30.6M
    mask = MASK_ASCII;
79
1.76G
    while (p < unrolled_end) {
80
1.75G
        STRINGLIB_CHAR bits = p[0] | p[1] | p[2] | p[3];
81
1.75G
        if (bits & mask) {
82
32.8M
            if (mask == mask_limit) {
83
                /* Limit reached */
84
16.4M
                return max_char_limit;
85
16.4M
            }
86
16.4M
            if (mask == MASK_ASCII) {
87
16.4M
                max_char = MAX_CHAR_UCS1;
88
16.4M
                mask = MASK_UCS1;
89
16.4M
            }
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
16.4M
            continue;
98
32.8M
        }
99
1.72G
        p += 4;
100
1.72G
    }
101
44.0M
    while (p < end) {
102
30.5M
        if (p[0] & mask) {
103
1.43M
            if (mask == mask_limit) {
104
                /* Limit reached */
105
705k
                return max_char_limit;
106
705k
            }
107
729k
            if (mask == MASK_ASCII) {
108
729k
                max_char = MAX_CHAR_UCS1;
109
729k
                mask = MASK_UCS1;
110
729k
            }
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
729k
            continue;
119
1.43M
        }
120
29.1M
        p++;
121
29.1M
    }
122
13.5M
    return max_char;
123
14.2M
}
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