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Groups > comp.os.msdos.programmer > #1098
| From | "Rod Pemberton" <dont_use_email@xnohavenotit.cnm> |
|---|---|
| Newsgroups | comp.os.msdos.programmer, alt.os.development |
| Subject | Re: Smaller C compiler |
| Date | 2013-12-03 12:23 -0500 |
| Organization | Aioe.org NNTP Server |
| Message-ID | <op.w7i09vlh5zc71u@localhost> (permalink) |
| References | <be56d70d-0ac7-4d76-a3f9-481808f2899e@googlegroups.com> |
Cross-posted to 2 groups.
On Sun, 01 Dec 2013 11:15:37 -0500, Alexei A. Frounze <alexfrunews@gmail.com> wrote: > [snip] > - doesn't have its own libc, though it should be easy to implement a > basic library for DOS (the compiler itself needs only a handful of > ctype/string/clib/stdio functions to operate) I mentioned Steve's I/O routines in the other post with a link to his website. It looks like you may be using far more C library functions than he implemented, but you can whittle down or eliminate a bunch of them. > Opinions? Auric mentioned your included functions. It's possible to reduce the quantity used, or implement them internally for bootstrapping. That may have a negative impact on speed though. exit -> suggested to rework to use return() atoi -> obsolete -usually strtod(), strtol(), strtoul() are recommended -sscanf() or fscanf() can also be used strlen strcpy strchr strcmp strncmp -> can usually be converted to strcmp(), -if you terminate '\0' the strings at 'n' memmove -> usually can be changed to use memcpy() memcpy memset Most of the str*() functions and mem*() functions are easy to implement. Most are just loops with one simple operation and/or a check for the '\0' null terminator. You could also used reduced versions with less than normal functionality, e.g., for strcmp(). Comparing for equal or not equal is much simpler than producing -1/false, 0, and 1/true. If you use files instead of memory, you can eliminate most of these also. isspace isdigit isalpha isalnum If you desire, you can replace is*() functions by using strchr() or strrchr() with a string, or a 128 or 256 char arrays as a lookup table, or even use character based procedures, e.g., with a switch(c) or even if()'s. fopen -> keep it. fclose -> keep it. putchar -> can use fputc to stdout fputc -> keep it. fgetc -> keep it. puts -> can use fprintf() to stdout with '\n' fputs -> can use fprintf() with '\n' sprintf -> sometimes can rework for printf() or fprintf() printf -> can use fprintf() to stdin or stdout fprintf -> keep it. It's hard to eliminate sprintf() and fprintf() when you need the formatting options. They are also long and complicated routines. puts(), of course, is faster. However, with some work, you can usually eliminate all internal code that uses memory by preferencing file I/O functions. So, you can eliminate sprintf(), sscanf(), in favor of fprintf(), fscanf(), etc. Some compilers implement tmpfile() as a memory file. That can provide a large speed boost. You effectively get random access memory - as a file - with convenient to use functions. vsprintf() vprintf() vfprintf() I've not use v*printf() functions much. So, it should be possible to eliminate these by using other printf functions, depending on what you're using them for. If you're using them to handle variadic argument lists, then you could use a stack. > Testers/test-drivers? ;) That's coming up next... I was going to try compiling it with DJGPP, perhaps OpenWatcom. I'll probably need to review Aurics post to figure out how to link it. It has C++ style comments, so I'm wondering about warnings: gcc -Wall -ansi -pedantic wcl/l=dos -wx wcl386/l=dos4g -wx Rod Pemberton
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Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2013-12-01 08:15 -0800
Re: Smaller C compiler "Auric__" <not.my.real@email.address> - 2013-12-01 18:42 +0000
Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2013-12-01 19:14 -0800
Re: Smaller C compiler "Auric__" <not.my.real@email.address> - 2013-12-02 11:13 +0000
Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2013-12-02 03:21 -0800
Re: Smaller C compiler "Auric__" <not.my.real@email.address> - 2013-12-03 06:21 +0000
Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2013-12-02 23:17 -0800
Re: Smaller C compiler "Auric__" <not.my.real@email.address> - 2013-12-03 13:31 +0000
Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2013-12-03 06:05 -0800
Re: Smaller C compiler "Rod Pemberton" <dont_use_email@xnohavenotit.cnm> - 2013-12-03 10:47 -0500
Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2013-12-03 21:18 -0800
Re: Smaller C compiler "Rod Pemberton" <dont_use_email@xnohavenotit.cnm> - 2013-12-03 12:23 -0500
Re: Smaller C compiler "Rod Pemberton" <dont_use_email@xnohavenotit.cnm> - 2013-12-03 16:26 -0500
Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2013-12-03 23:58 -0800
Re: Smaller C compiler "Rod Pemberton" <dont_use_email@xnohavenotit.cnm> - 2013-12-04 04:31 -0500
Re: Smaller C compiler "Rod Pemberton" <dont_use_email@xnohavenotit.cnm> - 2013-12-04 05:01 -0500
Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2013-12-04 02:20 -0800
Re: Smaller C compiler "Rod Pemberton" <dont_use_email@xnohavenotit.cnm> - 2013-12-05 06:33 -0500
Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2013-12-05 21:37 -0800
Re: Smaller C compiler "Rod Pemberton" <dont_use_email@xnohavenotit.cnm> - 2013-12-06 12:19 -0500
Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2013-12-06 22:23 -0800
Re: Smaller C compiler "Rod Pemberton" <dont_use_email@xnohavenotit.cnm> - 2013-12-07 13:48 -0500
Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2013-12-07 16:34 -0800
Re: Smaller C compiler "Rod Pemberton" <dont_use_email@xnohavenotit.cnm> - 2013-12-08 02:12 -0500
Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2013-12-13 03:32 -0800
Re: Smaller C compiler "Rod Pemberton" <dont_use_email@xnohavenotit.cnm> - 2013-12-15 04:47 -0500
Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2013-12-15 02:14 -0800
Re: Smaller C compiler "Rod Pemberton" <dont_use_email@xnohavenotit.cnm> - 2013-12-15 13:21 -0500
Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2013-12-04 23:39 -0800
Re: Smaller C compiler "Rod Pemberton" <dont_use_email@xnohavenotit.cnm> - 2013-12-05 06:38 -0500
Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2013-12-05 21:40 -0800
Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2013-12-06 04:19 -0800
Re: Smaller C compiler "Rod Pemberton" <dont_use_email@xnohavenotit.cnm> - 2013-12-06 13:40 -0500
Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2013-12-14 21:07 -0800
Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2013-12-03 22:22 -0800
Re: Smaller C compiler "Rod Pemberton" <dont_use_email@xnohavenotit.cnm> - 2013-12-04 04:30 -0500
Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2013-12-04 23:21 -0800
Re: Smaller C compiler "Rod Pemberton" <dont_use_email@xnohavenotit.cnm> - 2013-12-05 04:23 -0500
Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2013-12-05 21:31 -0800
Re: Smaller C compiler "Auric__" <not.my.real@email.address> - 2013-12-10 04:59 +0000
Re: Smaller C compiler "Auric__" <not.my.real@email.address> - 2013-12-10 06:17 +0000
Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2013-12-11 02:36 -0800
Re: Smaller C compiler "Auric__" <not.my.real@email.address> - 2013-12-11 13:44 +0000
Re: Smaller C compiler Harry Potter <rose.joseph12@yahoo.com> - 2013-12-10 10:41 -0800
Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2013-12-11 03:06 -0800
Re: Smaller C compiler "Rod Pemberton" <dont_use_email@xnohavenotit.cnm> - 2013-12-11 10:47 -0500
Re: Smaller C compiler Harry Potter <rose.joseph12@yahoo.com> - 2013-12-11 08:01 -0800
Re: Smaller C compiler "Rod Pemberton" <dont_use_email@xnohavenotit.cnm> - 2013-12-11 13:40 -0500
Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2013-12-11 22:07 -0800
Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2013-12-25 02:33 -0800
Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2013-12-29 03:24 -0800
Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2013-12-21 15:55 -0800
Re: Smaller C compiler "Auric__" <not.my.real@email.address> - 2013-12-29 17:16 +0000
Re: Smaller C compiler "Rod Pemberton" <dont_use_email@xnohavenotit.cnm> - 2013-12-29 21:54 -0500
Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2013-12-29 19:38 -0800
Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2013-12-29 19:36 -0800
Re: Smaller C compiler "Auric__" <not.my.real@email.address> - 2013-12-30 05:07 +0000
Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2013-12-29 21:58 -0800
Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2014-01-05 19:43 -0800
Re: Smaller C compiler "Auric__" <not.my.real@email.address> - 2014-01-06 15:27 +0000
Re: Smaller C compiler "Rod Pemberton" <dont_use_email@xnohavenotit.cnm> - 2014-01-06 19:51 -0500
Re: Smaller C compiler "Auric__" <not.my.real@email.address> - 2014-01-07 04:27 +0000
Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2014-01-06 21:52 -0800
Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2014-02-16 22:57 -0800
Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2014-02-25 00:17 -0800
Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2014-03-01 21:31 -0800
Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2014-03-10 01:46 -0700
Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2014-04-20 20:19 -0700
Re: Smaller C compiler Harry Potter <rose.joseph12@yahoo.com> - 2014-04-23 11:20 -0700
Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2014-04-23 11:41 -0700
Re: Smaller C compiler Harry Potter <rose.joseph12@yahoo.com> - 2014-04-25 06:08 -0700
Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2014-09-14 03:06 -0700
Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2014-11-09 03:26 -0800
Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2014-11-28 04:06 -0800
Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2014-12-21 01:56 -0800
Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2015-01-10 10:37 -0800
Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2015-04-19 23:55 -0700
Re: Smaller C compiler "Auric__" <not.my.real@email.address> - 2015-04-22 06:13 +0000
Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2015-04-22 00:12 -0700
Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2015-04-25 21:11 -0700
Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2015-05-16 17:49 -0700
Re: Smaller C compiler "Bill Buckels" <bbuckels@mts.net> - 2015-05-19 20:01 -0500
Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2015-05-19 18:18 -0700
Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2015-08-15 02:13 -0700
Re: Smaller C compiler "Alexei A. Frounze" <alexfrunews@gmail.com> - 2015-09-06 15:55 -0700
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