ext/bcmath: optimized divmod() and mod() take 2

[SakiTakamachi]

Benchmarks

1:

for ($i = 0; $i < 2000000; $i++) {
    bcdiv('1.23', '2', 5);
    // bcdivmod('1.23', '2', 5);
    // bcmod('1.23', '2', 5);
}

2:

for ($i = 0; $i < 2000000; $i++) {
    bcdiv('5.2345678', '2.1234567', 10);
    // bcdivmod('5.2345678', '2.1234567', 10);
    // bcmod('5.2345678', '2.1234567', 10);
}

3:

for ($i = 0; $i < 2000000; $i++) {
    bcdiv('12345678.901234', '1.2345678912', 10);
    // bcdivmod('12345678.901234', '1.2345678912', 10);
    // bcmod('12345678.901234', '1.2345678912', 10);
}

div

In theory, it will be slower because there are more branches, but it seems to make little difference.

1:

Benchmark 1: /php-dev/sapi/cli/php /mount/bc/divmod/1.php
  Time (mean ± σ):     308.9 ms ±   6.5 ms    [User: 297.1 ms, System: 6.0 ms]
  Range (min … max):   300.9 ms … 323.5 ms    10 runs
 
Benchmark 2: /master/sapi/cli/php /mount/bc/divmod/1.php
  Time (mean ± σ):     303.5 ms ±   5.3 ms    [User: 292.3 ms, System: 5.5 ms]
  Range (min … max):   298.1 ms … 313.0 ms    10 runs
 
Summary
  '/master/sapi/cli/php /mount/bc/divmod/1.php' ran
    1.02 ± 0.03 times faster than '/php-dev/sapi/cli/php /mount/bc/divmod/1.php'

2:

Benchmark 1: /php-dev/sapi/cli/php /mount/bc/divmod/2.php
  Time (mean ± σ):     379.5 ms ±   6.8 ms    [User: 370.4 ms, System: 3.6 ms]
  Range (min … max):   368.5 ms … 390.2 ms    10 runs
 
Benchmark 2: /master/sapi/cli/php /mount/bc/divmod/2.php
  Time (mean ± σ):     386.2 ms ±  18.8 ms    [User: 376.2 ms, System: 4.6 ms]
  Range (min … max):   370.3 ms … 432.2 ms    10 runs
 
Summary
  '/php-dev/sapi/cli/php /mount/bc/divmod/2.php' ran
    1.02 ± 0.05 times faster than '/master/sapi/cli/php /mount/bc/divmod/2.php'

3:

Benchmark 1: /php-dev/sapi/cli/php /mount/bc/divmod/3.php
  Time (mean ± σ):     526.3 ms ±  14.4 ms    [User: 514.7 ms, System: 6.2 ms]
  Range (min … max):   507.4 ms … 557.3 ms    10 runs
 
Benchmark 2: /master/sapi/cli/php /mount/bc/divmod/3.php
  Time (mean ± σ):     529.8 ms ±  14.2 ms    [User: 519.3 ms, System: 4.9 ms]
  Range (min … max):   517.2 ms … 553.8 ms    10 runs
 
Summary
  '/php-dev/sapi/cli/php /mount/bc/divmod/3.php' ran
    1.01 ± 0.04 times faster than '/master/sapi/cli/php /mount/bc/divmod/3.php'

divmod

This is faster because there are no extra calculations involved.

1:

Benchmark 1: /php-dev/sapi/cli/php /mount/bc/divmod/1.php
  Time (mean ± σ):     457.5 ms ±   9.5 ms    [User: 446.7 ms, System: 5.2 ms]
  Range (min … max):   448.2 ms … 473.7 ms    10 runs
 
Benchmark 2: /master/sapi/cli/php /mount/bc/divmod/1.php
  Time (mean ± σ):     518.5 ms ±   8.9 ms    [User: 508.0 ms, System: 5.3 ms]
  Range (min … max):   511.2 ms … 535.5 ms    10 runs
 
Summary
  '/php-dev/sapi/cli/php /mount/bc/divmod/1.php' ran
    1.13 ± 0.03 times faster than '/master/sapi/cli/php /mount/bc/divmod/1.php'

2:

Benchmark 1: /php-dev/sapi/cli/php /mount/bc/divmod/2.php
  Time (mean ± σ):     487.0 ms ±   9.8 ms    [User: 476.0 ms, System: 4.4 ms]
  Range (min … max):   476.4 ms … 503.4 ms    10 runs
 
Benchmark 2: /master/sapi/cli/php /mount/bc/divmod/2.php
  Time (mean ± σ):     585.8 ms ±   8.8 ms    [User: 576.1 ms, System: 4.2 ms]
  Range (min … max):   576.3 ms … 607.8 ms    10 runs
 
Summary
  '/php-dev/sapi/cli/php /mount/bc/divmod/2.php' ran
    1.20 ± 0.03 times faster than '/master/sapi/cli/php /mount/bc/divmod/2.php'

3:

Benchmark 1: /php-dev/sapi/cli/php /mount/bc/divmod/3.php
  Time (mean ± σ):     581.4 ms ±   4.6 ms    [User: 570.5 ms, System: 5.1 ms]
  Range (min … max):   573.4 ms … 590.0 ms    10 runs
 
Benchmark 2: /master/sapi/cli/php /mount/bc/divmod/3.php
  Time (mean ± σ):     791.4 ms ±  26.3 ms    [User: 780.6 ms, System: 5.2 ms]
  Range (min … max):   771.4 ms … 843.2 ms    10 runs
 
Summary
  '/php-dev/sapi/cli/php /mount/bc/divmod/3.php' ran
    1.36 ± 0.05 times faster than '/master/sapi/cli/php /mount/bc/divmod/3.php'

mod

It's faster for the same reasons as divmod, and it's even faster because it doesn't need to generate bc_num for quot.

1:

Benchmark 1: /php-dev/sapi/cli/php /mount/bc/divmod/1.php
  Time (mean ± σ):     321.5 ms ±  10.3 ms    [User: 311.8 ms, System: 4.4 ms]
  Range (min … max):   311.4 ms … 348.2 ms    10 runs
 
Benchmark 2: /master/sapi/cli/php /mount/bc/divmod/1.php
  Time (mean ± σ):     401.1 ms ±  10.4 ms    [User: 391.1 ms, System: 4.8 ms]
  Range (min … max):   389.9 ms … 426.9 ms    10 runs
 
Summary
  '/php-dev/sapi/cli/php /mount/bc/divmod/1.php' ran
    1.25 ± 0.05 times faster than '/master/sapi/cli/php /mount/bc/divmod/1.php'

2:

Benchmark 1: /php-dev/sapi/cli/php /mount/bc/divmod/2.php
  Time (mean ± σ):     348.5 ms ±   6.4 ms    [User: 338.2 ms, System: 4.7 ms]
  Range (min … max):   337.8 ms … 358.3 ms    10 runs
 
Benchmark 2: /master/sapi/cli/php /mount/bc/divmod/2.php
  Time (mean ± σ):     481.3 ms ±  19.2 ms    [User: 470.4 ms, System: 5.4 ms]
  Range (min … max):   468.1 ms … 528.5 ms    10 runs
 
Summary
  '/php-dev/sapi/cli/php /mount/bc/divmod/2.php' ran
    1.38 ± 0.06 times faster than '/master/sapi/cli/php /mount/bc/divmod/2.php'

3:

Benchmark 1: /php-dev/sapi/cli/php /mount/bc/divmod/3.php
  Time (mean ± σ):     433.1 ms ±   9.3 ms    [User: 422.9 ms, System: 4.7 ms]
  Range (min … max):   424.0 ms … 456.8 ms    10 runs
 
Benchmark 2: /master/sapi/cli/php /mount/bc/divmod/3.php
  Time (mean ± σ):     660.2 ms ±   7.5 ms    [User: 650.1 ms, System: 4.7 ms]
  Range (min … max):   650.9 ms … 673.1 ms    10 runs
 
Summary
  '/php-dev/sapi/cli/php /mount/bc/divmod/3.php' ran
    1.52 ± 0.04 times faster than '/master/sapi/cli/php /mount/bc/divmod/3.php'