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Date: Fri, 29 Jul 2005 13:40:00 -0000
From: "pinskia at gcc dot gnu dot org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Message-ID: <20050729134001.23134.pinskia@gcc.gnu.org>
Reply-To: gcc-bugzilla@gcc.gnu.org
Subject: [Bug tree-optimization/23134] New: Address escapes even though the called function does not cause it to escape
X-Bugzilla-Reason: CC
X-SW-Source: 2005-07/txt/msg03882.txt.bz2
List-Id: <gcc-bugs.sourceware.org>

Take this "stupid" example (even though this most likely shows up in GCC but I don't know for sure):
int g1(int);
static void h(int *a) { *a = 1; }

int g(void)
{
  int t = 0;
  h(&t);
  int t1 = t;
  g1(t1);
  return t1 == t;
}

That return should have been turned into "return 1" as t does not escape via h as h only touches it.
Compile with -O3 -fno-inline to see the problem.

-- 
           Summary: Address escapes even though the called function does not
                    cause it to escape
           Product: gcc
           Version: 4.1.0
            Status: UNCONFIRMED
          Keywords: missed-optimization
          Severity: enhancement
          Priority: P2
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: pinskia at gcc dot gnu dot org
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23134