Problems with pragma and attribute optimize.

[Allan Sandfeld Jensen <carewolf at gmail dot com>]

Hi,

I have been experimenting with marking specific functions to be auto-
vectorized in GCC, but have had problems getting it to work.

It seems the optimize attribute works sometimes, but only if the function it 
is used on is not static, but pragma optimize never seems to work.

See the attached test-case. If you compile it with -ftree-vectorizer-verbose, 
you will see that only the first function is vectorized, but the two last are 
not. 

Anyone know what is wrong here?

Best regards
`Allan

#include <stdint.h>

void  __attribute__((optimize("tree-vectorize"))) innerloop_1(int16_t* destination, const int16_t* source1, const int16_t* source2, int length)
{
    while (length--) {
        *(destination++) = *(source1++) + *(source2++);
    }
}

static void  __attribute__((optimize("tree-vectorize"))) innerloop_2(int16_t* destination, const int16_t* source1, const int16_t* source2, int length)
{
    while (length--) {
        *(destination++) = *(source1++) + *(source2++);
    }
}

void caller(int16_t* destination, const int16_t* source1, const int16_t* source2, int length)
{
    innerloop_2(destination, source1, source2, length);
}

#pragma GCC optimize("tree-vectorize")

void innerloop_3(int16_t* destination, const int16_t* source1, const int16_t* source2, int length)
{
    while (length--) {
        *(destination++) = *(source1++) + *(source2++);
    }
}