Rename hint.txt and hint.text to README.md

2011/richards/README.md

@@ -0,0 +1,76 @@
+# Most surprisingly portable
+
+Gregor Richards  
+<Richards@codu.org>  
+
+
+## Judges' comments:
+### To build:
+
+    make richards
+
+### To run:
+
+    ./richards
+
+### Try:
+
+    echo '10 9 8 7 6 5 4 3 2 1*p*p*p*p*p*p*p*p*p' | ./richards
+
+### Selected Judges Remarks:
+
+Oh no, yet another dc-style calculator? (see 2000/dlowe using an embedded Perl
+interpreter and deemed Worst Abuse of the Rules). 
+Well, this one does it (expression calculation, that is, not the rule abuse) in a different way. 
+The author claims that his calculator does just-in-time compilation.
+What would you do to prove or disprove his claim without attempting to unravel the source?
+
+## Author's comments:
+This is an implementation of the classic UNIX dc command, the reverse-polish
+calculator. Actually it's a pretty bad implementation, since it only implements
+32-bit integers (well, sizeof(int)-sized integers). It only implements the
+commands +, -, *, /, p (only for numbers), register stacks, macros and
+comparisons. Wow, you'd think I could've done better in 2K of code.
+
+OH! I forgot to mention! It's a JIT.
+
+Wait, don't stop reading! I know what you're thinking, platform-specific code
+is discouraged in IOCCC. But do you see any platform-specific code? There's no
+assembler here! This JIT works on a dozen platforms, and the only
+platform-specific assumptions it makes are that the stack grows down and
+integers are at least 32-bit.
+
+You will probably get warnings while compiling the code. In particular:
+
+ * If your system requires the inclusion of alloca.h to use alloca, use the
+   compile flag -DAH
+ * If your system cannot use mmap, use the compile flag -DNM
+ * I don't include any headers I don't strictly need to, so you'll get warnings
+   about (at least) memcpy, isdigit, atoi, calloc, malloc and alloca if you
+   didn't use -DAH.
+ * GCC likes to complain about while (a = b) (assignments as a condition).
+ * I don't return from main, even though it's declared to return int.
+
+Platforms on which all known/tested optimization levels work with no additional
+flags:
+
+ * gcc 4.6.2 + x86[_64] + GNU/Linux, Mac OS X or Windows
+ * clang 2.9-16 + x86[_64] + GNU/Linux or Mac OS X
+ * tcc 0.9.25
+ * gcc 4.4.5 + alpha, arm, mips[el], powerpc[64], s390x (IBM zSeries)
+ * gcc 4.1.3 + vax + NetBSD
+
+Platforms which work but not at all optimization levels or needing special
+flags:
+
+ * owcc 1.9 + x86 + Windows: Needs -DNM -DAH -fno-stack-check
+ * gcc 4.4.5 + sh4: -O0 works, higher optimization levels don't work for unknown reasons.
+
+--------------------------------------------------------------------------------
+<!--
+(c) Copyright 1984-2012, [Leo Broukhis, Simon Cooper, Landon Curt Noll][judges] - All rights reserved
+This work is licensed under a [Creative Commons Attribution-ShareAlike 3.0 Unported License][cc].
+
+[judges]: http://www.ioccc.org/judges.html
+[cc]: http://creativecommons.org/licenses/by-sa/3.0/
+-->