RIOT-OS/RIOT — pull request #1868 by haukepetersen (2014-10-23 17:03:30+00:00)
Title: cpu/stm32f4: optimized GPIO driver implementation

And the same game for the STM32F4, results (for `tests/periph_gpio_int`):

before:

```
text data bss dec hex
13364 112 14216 27692 6c2c
```

and after:

```
text data bss dec hex
12484 112 14216 26812 68bc
```