Re: [PATCH v2] ata: increase retry count but shorten duration for Calxeda controller

[Clemens Ladisch <clemens@ladisch.de>]

Sergei Shtylyov wrote:
> On 30-05-2013 18:26, Timur Tabi wrote:
>>> +    const unsigned long timing[] = { 5, 100, 500};
>
>> You'll save space and time if you also make this array "static",
>> otherwise the compiler will build the array every time this function is
>> called.
>
> No, *const* specifier is enough to not build this array every time. It will be put into the .const section.

gcc disagrees:

$ cat const_static.c
int f(int x) {
	const unsigned long timing[] = { 5, 100, 500};
	static const unsigned long timing2[] = { 5, 100, 500};
	return timing[x] + timing2[x];
}
$ gcc -Os -S const_static.c
$ cat const_static.s
	...
timing2.0:
        .long   5
        .long   100
        .long   500
	...
        movl    8(%ebp), %edx
        movl    $5, -16(%ebp)
        movl    $100, -12(%ebp)
        movl    $500, -8(%ebp)
        movl    timing2.0(,%edx,4), %eax
        addl    -16(%ebp,%edx,4), %eax


Regards,
Clemens