[Bug c/92276] Embedded __attribute__ ((optimize("unroll-loops"))) is not working together with '__attribute__ ((__always_inline__))'

[Lijian.Zhang at arm dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92276

--- Comment #2 from Lijian Zhang <Lijian.Zhang at arm dot com> ---
(In reply to Richard Biener from comment #1)
> Instead of trying to force the compiler to unroll with -funroll-loops you can
> use #pragma GCC unroll N on individual loops instead.
> 
> The attributes should not conflict in any way.

Sorry, I made a mistake that in my case '__attribute__
((optimize("unroll-loops")))' should be used for the caller, not the callee.
#pragma GCC optimize ("unroll-loops") is also working.
Thanks for your suggestion!

/////////////////////
#include <stdio.h>
#include <stdlib.h>
#include <arm_acle.h>

static inline __attribute__ ((__always_inline__))
unsigned int clib_crc32c (unsigned int v, unsigned char * s, int len)
{
  for (; len >= 8; len -= 8, s += 8)
    v = __crc32cd (v, *((unsigned long *) s));

  for (; len >= 4; len -= 4, s += 4)
    v = __crc32cw (v, *((unsigned int *) s));

  for (; len >= 2; len -= 2, s += 2)
    v = __crc32ch (v, *((unsigned short *) s));

  for (; len >= 1; len -= 1, s += 1)
    v = __crc32cb (v, *((unsigned char *) s));

  return v;
}

__attribute__ ((optimize("unroll-loops")))
int main (int argc, char *argv[])
{
    unsigned char s[40] = {argc, 0, argc, 0};
    unsigned char ss[32] = {argc, 0, argc, 0, argc, 0};
    unsigned int v = 0xbeefdead, vv = 0xdeadbeef;
    int len = strtol (argv[1], NULL, 10);

        v = clib_crc32c (v, s, 40);
        vv = clib_crc32c (vv, ss, 32);

    printf ("%8X\n", v);
    printf ("%8X\n", vv);
    return 0;
}