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Date: Tue, 25 Jan 2005 23:22:00 -0000
From: "rth at gcc dot gnu dot org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Message-ID: <20050125232202.19633.rth@gcc.gnu.org>
Reply-To: gcc-bugzilla@gcc.gnu.org
Subject: [Bug tree-optimization/19633] New: local address incorrectly thought to escape
X-Bugzilla-Reason: CC
X-SW-Source: 2005-01/txt/msg03779.txt.bz2
List-Id: <gcc-bugs.sourceware.org>

struct S { int w, x, y, z; };
struct T { int r; struct S s; };
void bar (struct S, int);
void foo (int a, struct T b)
{
  struct S *c = 0;
  if (a)
    c = &b.s;
  bar (*c, a);
}


The call to bar appears to not be marked [tail-call] because b is marked
as a call-clobbered local variable.  Which IIRC means that the aliasing code
thinks that the address of b escapes.  Which is untrue -- no address escapes
from this function.

-- 
           Summary: local address incorrectly thought to escape
           Product: gcc
           Version: 4.0.0
            Status: UNCONFIRMED
          Keywords: missed-optimization
          Severity: enhancement
          Priority: P2
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: rth at gcc dot gnu dot org
                CC: dnovillo at gcc dot gnu dot org,gcc-bugs at gcc dot gnu
                    dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19633