gistfile1.txt

import timeit
import time
import subprocess

lines = [
    "a = ''",
    "a = ' '",
    "a = '               '",
    "a = 'a'",
    "a = 'a b a b '*100",
    "a = 'a b a b '*10000",
    "a = 'a1 b2 a3 b4 '*100",
    "a = 'a1 b2 a3 b4 '*10000",
    "a = 'value value'",
    "a = 'value value '*100",
    "a = 'value value '*10000",
    "a = 'valuevalue valuevalue '",
    "a = 'valuevalue valuevalue '*100",
    "a = 'valuevalue valuevalue '*10000",
    "a = 'value'*100 + ' 1 2 3'",
    "a = 'value'*1000 + ' 1 2 3'",
    "a = 'value'*10000 + ' 1 2 3'",
    "a = 'value'*100000 + ' 1 2 3'",
    "a = (('x'*100)+' ')*1000",
    "a = (('x'*1000)+' ')*100",
    "a = (('x'*10000)+' ')*10",
]

for line in lines:
    outputs = {}
    times = {}
    for name, python in [("new", "./python"), ("old", "./python2")]:
        out = subprocess.check_output([python, "-c", line + "; print(a.split(' '))"])
        outputs[name] = out
        out = subprocess.check_output([python, "-m", "timeit", "-s", line, "a.split(' ')"])
        time = out.decode().split(":")[1].strip()
        times[name] = time

    vals = {"nsec": 1, "usec": 1000, "msec": 1000*1000}
    get = lambda ts: float(ts[0]) * vals[ts[1]]
    oldtime = get(times["old"].split())
    newtime = get(times["new"].split())
    mult = oldtime / newtime
    if mult < 1:
        mult = -(newtime / oldtime)

    assert outputs["new"] == outputs["old"]

    print '{:<35} | {:<20} | {:<20} | {:.3}x'.format(line, times["old"], times["new"], mult)

gistfile2.txt

#if STRINGLIB_SIZEOF_CHAR == 1
    const STRINGLIB_CHAR* loc = str;
    while (maxcount-- > 0) {
        loc = memchr(loc, ch, str_len-j);
        if (loc == NULL)
            break;
        j = loc - str;
        SPLIT_ADD(str, i, j);
        i = j = j + 1;
        loc++;
    }
#else
    while ((j < str_len) && (maxcount-- > 0)) {
        for(; j < str_len; j++) {
            /* I found that using memchr makes no difference */
            if (str[j] == ch) {
                SPLIT_ADD(str, i, j);
                i = j = j + 1;
                break;
            }
        }
    }
#endif

ub14.txt

a = ''                              | 149 nsec per loop    | 150 nsec per loop    | -1.01x
a = ' '                             | 177 nsec per loop    | 180 nsec per loop    | -1.02x
a = '               '               | 322 nsec per loop    | 355 nsec per loop    | -1.1x
a = 'a'                             | 160 nsec per loop    | 163 nsec per loop    | -1.02x
a = 'a b a b '*100                  | 4.3 usec per loop    | 5.3 usec per loop    | -1.23x
a = 'a b a b '*10000                | 359 usec per loop    | 446 usec per loop    | -1.24x
a = 'a1 b2 a3 b4 '*100              | 9.76 usec per loop   | 10.6 usec per loop   | -1.09x
a = 'a1 b2 a3 b4 '*10000            | 1.41 msec per loop   | 1.47 msec per loop   | -1.04x
a = 'value value'                   | 206 nsec per loop    | 209 nsec per loop    | -1.01x
a = 'value value '*100              | 5.42 usec per loop   | 5.57 usec per loop   | -1.03x
a = 'value value '*10000            | 688 usec per loop    | 722 usec per loop    | -1.05x
a = 'valuevalue valuevalue '        | 221 nsec per loop    | 220 nsec per loop    | 1.0x
a = 'valuevalue valuevalue '*100    | 5.7 usec per loop    | 5.8 usec per loop    | -1.02x
a = 'valuevalue valuevalue '*10000  | 760 usec per loop    | 769 usec per loop    | -1.01x
a = 'value'*100 + ' 1 2 3'          | 410 nsec per loop    | 272 nsec per loop    | 1.51x
a = 'value'*1000 + ' 1 2 3'         | 1.84 usec per loop   | 460 nsec per loop    | 4.0x
a = 'value'*10000 + ' 1 2 3'        | 16.9 usec per loop   | 3.2 usec per loop    | 5.28x
a = 'value'*100000 + ' 1 2 3'       | 179 usec per loop    | 45.7 usec per loop   | 3.92x
a = (('x'*100)+' ')*1000            | 73.5 usec per loop   | 43.1 usec per loop   | 1.71x
a = (('x'*1000)+' ')*100            | 40.8 usec per loop   | 12 usec per loop     | 3.4x
a = (('x'*10000)+' ')*10            | 34.7 usec per loop   | 7.53 usec per loop   | 4.61x

ub16.txt

a.split(' ')                        | old                  | new                  | improvement 
a = ''                              | 175 nsec per loop    | 178 nsec per loop    | 0.983x 
a = ' '                             | 211 nsec per loop    | 222 nsec per loop    | 0.95x 
a = '          '                    | 325 nsec per loop    | 356 nsec per loop    | 0.913x 
a = 'a'                             | 204 nsec per loop    | 196 nsec per loop    | 1.04x 
a = 'value value'                   | 253 nsec per loop    | 260 nsec per loop    | 0.973x 
a = 'value value '                  | 267 nsec per loop    | 274 nsec per loop    | 0.974x 
a = 'value value '*100              | 7.86 usec per loop   | 7.82 usec per loop   | 1.01x 
a = 'value value '*10000            | 963 usec per loop    | 960 usec per loop    | 1.0x 
a = 'valuevalue valuevalue '        | 273 nsec per loop    | 277 nsec per loop    | 0.986x 
a = 'valuevalue valuevalue '*100    | 8.43 usec per loop   | 7.91 usec per loop   | 1.07x 
a = 'valuevalue valuevalue '*10000  | 1.04 msec per loop   | 1.01 msec per loop   | 1.03x 
a = 'value'*100 + ' 1 2 3'          | 634 nsec per loop    | 329 nsec per loop    | 1.93x 
a = 'value'*1000 + ' 1 2 3'         | 3.65 usec per loop   | 544 nsec per loop    | 6.71x 
a = 'value'*10000 + ' 1 2 3'        | 35.1 usec per loop   | 3.83 usec per loop   | 9.16x 
a = 'value'*100000 + ' 1 2 3'       | 360 usec per loop    | 54.4 usec per loop   | 6.62x 
a = (('x'*100)+' ')*1000            | 115 usec per loop    | 51.7 usec per loop   | 2.22x 
a = (('x'*1000)+' ')*100            | 77.9 usec per loop   | 15.4 usec per loop   | 5.06x 
a = (('x'*10000)+' ')*10            | 69.8 usec per loop   | 8.51 usec per loop   | 8.2x