Mercurial > hg > index.cgi
view lwar/main.c @ 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 | 221b5f58d8ad |
children | 45df37e81741 |
line wrap: on
line source
/* main.c 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/>. Implements the program startup code */ #include <errno.h> #include <stdio.h> #include <stdlib.h> #include <sys/types.h> #include <sys/stat.h> #include <lw_cmdline.h> #include <lw_version.h> #include "lwar.h" #ifdef _MSC_VER #include <lw_win.h> // windows build #else #include <unistd.h> #endif // command line option handling #define PROGVER "lwar from " PACKAGE_STRING char *program_name; static int parse_opts(int key, char *arg, void *state) { switch (key) { case 'd': // debug debug_level++; break; case 'a': // add members operation = LWAR_OP_ADD; break; case 'c': // create archive operation = LWAR_OP_CREATE; break; case 'm': mergeflag = 1; break; case 'r': // replace members operation = LWAR_OP_REPLACE; break; case 'l': // list members operation = LWAR_OP_LIST; break; case 'x': // extract members operation = LWAR_OP_EXTRACT; break; case lw_cmdline_key_arg: if (archive_file) { // add archive member to list add_file_name(arg); } else archive_file = arg; break; default: return lw_cmdline_err_unknown; } return 0; } static struct lw_cmdline_options options[] = { { "replace", 'r', 0, 0, "Add or replace archive members" }, { "extract", 'x', 0, 0, "Extract members from the archive" }, { "add", 'a', 0, 0, "Add members to the archive" }, { "list", 'l', 0, 0, "List the contents of the archive" }, { "create", 'c', 0, 0, "Create new archive (or truncate existing one)" }, { "merge", 'm', 0, 0, "Add the contents of archive arguments instead of the archives themselves" }, { "debug", 'd', 0, 0, "Set debug mode"}, { 0 } }; static struct lw_cmdline_parser argparser = { options, parse_opts, "ARCHIVE [FILE ...]", "lwar, a library file manager for lwlink", PROGVER }; extern void do_list(void); extern void do_add(void); extern void do_remove(void); extern void do_replace(void); extern void do_extract(void); // main function; parse command line, set up assembler state, and run the // assembler on the first file int main(int argc, char **argv) { program_name = argv[0]; lw_cmdline_parse(&argparser, argc, argv, 0, 0, NULL); if (archive_file == NULL) { fprintf(stderr, "You must specify an archive file.\n"); exit(1); } if (operation == 0) { fprintf(stderr, "You must specify an operation.\n"); exit(1); } if (operation == LWAR_OP_LIST || operation == LWAR_OP_REMOVE || operation == LWAR_OP_EXTRACT) { struct stat stbuf; // make sure the archive exists if (stat(archive_file, &stbuf) < 0) { fprintf(stderr, "Cannot open archive file %s:\n", archive_file); perror(""); exit(2); } } if (operation == LWAR_OP_CREATE) { struct stat stbuf; // check if the archive exists if (stat(archive_file, &stbuf) < 0) { if (errno != ENOENT) { fprintf(stderr, "Cannot create archive file %s:\n", archive_file); perror(""); exit(2); } } else { if (unlink(archive_file) < 0) { fprintf(stderr, "Cannot create archive file %s:\n", archive_file); perror(""); exit(2); } } } switch (operation) { case LWAR_OP_LIST: do_list(); break; case LWAR_OP_ADD: case LWAR_OP_CREATE: do_add(); break; case LWAR_OP_REMOVE: do_remove(); break; case LWAR_OP_REPLACE: do_replace(); break; case LWAR_OP_EXTRACT: do_extract(); break; } exit(0); }