[Bug target/53315] simple xtest program generates ICE

[andi-gcc at firstfloor dot org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53315

--- Comment #9 from Andi Kleen <andi-gcc at firstfloor dot org> 2012-05-11 
21:35:47 UTC ---
Sorry I was wrong earlier. Retested now fully with a full test case and HJs
patch and i always get aborts

The xbegin gets miscompiled now, the in transaction branch disappears.

  400460:       48 83 ec 08             sub    $0x8,%rsp
  400464:       b8 ff ff ff ff          mov    $0xffffffff,%eax
  400469:       c7 f8 00 00 00 00       xbeginq 40046f <main+0xf>
  40046f:       bf d8 06 40 00          mov    $0x4006d8,%edi
  400474:       31 f6                   xor    %esi,%esi
  400476:       31 c0                   xor    %eax,%eax
  400478:       e8 b3 ff ff ff          callq  400430 <printf@plt>
  40047d:       31 ff                   xor    %edi,%edi
  40047f:       e8 bc ff ff ff          callq  400440 <exit@plt>




/* PR53315 and PR53291 */
/* { dg-do run } */
/* { dg-options "-O2 -mrtm" } */

#include <immintrin.h>
#include <cpuid.h>
#include <stdlib.h>
#include <stdio.h>

static int cpu_has_rtm(void)
{
    if (__get_cpuid_max(0, NULL) >= 7) {
        unsigned a, b, c, d;
        __cpuid_count(7, 0, a, b, c, d);
        return !!(b & bit_RTM);
    }
    return 0;
}


int main(void)
{
        int flag = -1;
        unsigned status;

    if (!cpu_has_rtm) { 
        printf("no tsx support. untested\n");
        exit(0);
    }

        if ((status = _xbegin()) == _XBEGIN_STARTED) {
                flag = _xtest();
                _xend();
        } else {
        /* Note this is legal according to the TSX spec */
                printf("unexpected abort %x. untested\n", status);
        exit(0);
    }

    if (flag != 1)
        abort();
    if (_xtest() != 0)
        abort();
    return 0;
}