Date: Tue, 11 May 1999 14:17:30 +0200
Message-Id: <9905111217.AA01112@alsroma>
X-Sender: impagnat AT roma DOT alespazio DOT it
X-Mailer: Windows Eudora Version 1.4.4
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
To: pgcc AT delorie DOT com
From: impagnat AT roma DOT alespazio DOT it (Ing. Fabrizio Impagnatiello)
Subject: pgcc 1.1.3 bug advisory
Reply-To: pgcc AT delorie DOT com

Dear pgcc developers,

I found run-time anomalies compiling a FORTRAN code with PGCC 1.1.3 that
does not happen if EGCS 1.1.2 is used.

The addressed subroutine source code, that belong to a larger code (about
80kB) that could be supplied if required, performs a double nibble (4-bits)
extraction from a byte stream using the MVBITS statement. If the
optimization '-O6' flag is applied the subroutine does not perform the
nibble sxtraction and gives back 0x00000000 into the fourth argument of
mvbits() parameters. The FORTRAN code lines are:


        subroutine data8bit(frame,n,data_i,data_q)

        character*1     frame(*)
        integer*4       reg32,          n
        character*1     seq(4)
        integer*4       data_i(*),      data_q(*)

        equivalence     (reg32,seq)

        do i=1,n
           seq(4)=frame(i)
           data_i(i)=0
           data_q(i)=0
           call mvbits(reg32,28,4,data_i(i),0)
           call mvbits(reg32,24,4,data_q(i),0)
        end do

        return
        end


Thank for attention


Fabrizio Impagnatiello

System Engineering
Alenia Aerospazio
via Saccomuro, 24
00131 - Rome
ITALY