mmix-modes.def

gcc-you can use this code to learn something about gcc, and inquire further into linux,

/* Definitions of target machine for GNU compiler, for MMIX.
   Copyright (C) 2002 Free Software Foundation, Inc.
   Contributed by Hans-Peter Nilsson ([e-mail])

This file is part of GCC.

GCC 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.

GCC 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 GCC; see the file COPYING.  If not, write to
the Free Software Foundation, 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */

/* Node: Condition Code */

/* Like other non-CC0 ports, MMIX need to code which combination of
   comparison insn and branch insn or conditional-set insn to use into the
   condition mode.  The CC mode depends partly on which condition is used
   and partly on the type of the operands.  */

/* The "usual" CC mode is used for a signed operands integer comparison,
   where the CMP insn is used and the result is (integer) -1, 0 or 1 for
   respectively a < b, a == b and a > b.  */

/* The CC_UNS mode is for an unsigned operands integer comparison using
   the CMPU insn.  Result values correspond to those in CCmode.  */
CC (CC_UNS)

/* The CC_FP mode is for an non-equality floating-point comparison, using
   the FCMP or FCMPE insn.  The result is (integer) -1 or 1 for
   espectively a < b and a > b, otherwise 0.  */
CC (CC_FP)

/* The CC_FPEQ mode is for an equality floating-point comparison, using
   the FEQL or FEQLE insn.  The result is (integer) 1 for a == b,
   otherwise 0 (including NaN:s).  */
CC (CC_FPEQ)

/* The CC_FUN mode is for an ordering comparison, using the FUN or FUNE
   insn.  The result is (integer) 1 if a is unordered to b, otherwise the
   result is 0.  */
CC (CC_FUN)