view lwar/lwar.h @ 418:3832a68d83ef

Fix internal compiler error on "var2 = var1 + 1" patterns This appears to be the correct fix. It was provided by Tormod Volden (debian.tormod@gmail.com). The final commit is substantially different from Tormod's submission mostly due to housecleaning (removing the old patches and updating the README). Tormod's comments follow. The original addhi_mem_1 "insn" instruction pattern /matches/ two memory operands, just with the /constraint/ that these are the same location. A pattern match tells the compiler "you should be able to use this, but you might have to work on it to meet the constraints". For typical constraints on registers the compiler can add "reloads", moving stuff between registers or from memory, until the constraints are met and the instruction can be used. However, in this case, no amount of reloads can make two memory locations the same if they already weren't, so the compiler breaks down and cries "unable to generate reloads". It seems this issue only appears if optimization is enabled. The proof is in gcc's reload.c and is left as an exercise to the reader. Limiting the matching pattern to identical memory operands avoids these situations, while allowing the common "var++" cases. References: The pattern/constraints difference is explained in https://gcc.gnu.org/onlinedocs/gccint/Simple-Constraints.html#index-other-register-constraints-3335
author William Astle <lost@l-w.ca>
date Tue, 29 Mar 2016 21:21:49 -0600
parents 2c24602be78f
children 45df37e81741
line wrap: on
line source

/*
lwar.h
Copyright © 2009 William Astle

This file is part of LWAR.

LWAR 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 3 of the License, or (at your option) any later
version.

This program 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
this program. If not, see <http://www.gnu.org/licenses/>.

Contains the main defs used by the linker
*/


#define LWAR_OP_LIST	1
#define LWAR_OP_ADD		2
#define LWAR_OP_REMOVE	3
#define LWAR_OP_CREATE	4
#define LWAR_OP_EXTRACT	5
#define LWAR_OP_REPLACE	6

#ifndef __lwar_h_seen__
#define __lwar_h_seen__

#ifndef __lwar_c_seen__

extern char *archive_file;
extern int debug_level;
extern int operation;
extern int nfiles;
extern char **files;
extern int mergeflag;

//typedef void * ARHANDLE;

#define AR_MODE_RD		1
#define AR_MODE_WR		2
#define AR_MODE_RW		3
#define AR_MODE_CREATE	4


#define __lwar_E__ extern
#else
#define __lwar_E__
#endif // __lwar_c_seen__

__lwar_E__ void add_file_name(char *fn);

//__lwar_E__ ARHANDLE open_archive(char *fn, int mode);

#undef __lwar_E__

#endif //__lwar_h_seen__