i386-modes.def

linux下的gcc编译器

/* Definitions of target machine for GNU compiler for IA-32.
   Copyright (C) 2002 Free Software Foundation, Inc.

This file is part of GNU CC.

GNU CC is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.

GNU CC is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with GNU CC; see the file COPYING.  If not, write to
the Free Software Foundation, 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */

/* Add any extra modes needed to represent the condition code.

   For the i386, we need separate modes when floating-point
   equality comparisons are being done.

   Add CCNO to indicate comparisons against zero that requires
   Overflow flag to be unset.  Sign bit test is used instead and
   thus can be used to form "a&b>0" type of tests.

   Add CCGC to indicate comparisons agains zero that allows
   unspecified garbage in the Carry flag.  This mode is used
   by inc/dec instructions.

   Add CCGOC to indicate comparisons agains zero that allows
   unspecified garbage in the Carry and Overflow flag. This
   mode is used to simulate comparisons of (a-b) and (a+b)
   against zero using sub/cmp/add operations.

   Add CCZ to indicate that only the Zero flag is valid.  */

CC (CCGC)
CC (CCGOC)
CC (CCNO)
CC (CCZ)
CC (CCFP)
CC (CCFPU)