From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugs-return-308417-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org>
Received: (qmail 25547 invoked by alias); 12 Feb 2010 13:27:49 -0000
Received: (qmail 25494 invoked by uid 48); 12 Feb 2010 13:27:33 -0000
Date: Fri, 12 Feb 2010 13:27:00 -0000
Subject: [Bug debug/43051]  New: [4.5 Regression] VTA causes a stack living parameter unavailable in most of the function
X-Bugzilla-Reason: CC
Message-ID: <bug-43051-87@http.gcc.gnu.org/bugzilla/>
Reply-To: gcc-bugzilla@gcc.gnu.org
To: gcc-bugs@gcc.gnu.org
From: "jakub at gcc dot gnu dot org" <gcc-bugzilla@gcc.gnu.org>
Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm
Precedence: bulk
List-Id: <gcc-bugs.gcc.gnu.org>
List-Archive: <http://gcc.gnu.org/ml/gcc-bugs/>
List-Post: <mailto:gcc-bugs@gcc.gnu.org>
List-Help: <mailto:gcc-bugs-help@gcc.gnu.org>
Sender: gcc-bugs-owner@gcc.gnu.org
X-SW-Source: 2010-02/txt/msg01169.txt.bz2

static void __attribute__((noinline))
foo (const char *x, long long y, int z)
{
  asm volatile ("" : : "r" (x), "r" ((int) y), "r" (z) : "memory");
}

typedef struct S
{
  struct S *n;
  int v;
} *P;

P
bar (P c, int v, P e)
{
  register int si asm ("esi"), di asm ("edi"), bx asm ("ebx");
  asm volatile ("" : "=r" (si), "=r" (di), "=r" (bx));
  while (c < e)
    {
      foo ("c", (unsigned int) c, 0);
      foo ("v", v, 0);
      foo ("e", (unsigned int) e, 0);
      if (c->v == v) return c;
      foo ("c", (unsigned int) c, 0);
      foo ("v", v, 0);
      foo ("e", (unsigned int) e, 0);
      c++;
    }
  asm volatile ("" : : "r" (si), "r" (di), "r" (bx));
  return 0;
}

at -g -O2 -m32 makes c unavailable in most of the function, while the c var is
for the whole time living in the parameter stack slot.  GCC 4.4.x and earlier
emit correct location info in this case.


-- 
           Summary: [4.5 Regression] VTA causes a stack living parameter
                    unavailable in most of the function
           Product: gcc
           Version: 4.5.0
            Status: UNCONFIRMED
          Keywords: wrong-debug
          Severity: normal
          Priority: P3
         Component: debug
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: jakub at gcc dot gnu dot org
GCC target triplet: i686-linux


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43051