From 5204e7cc4f46cec7cfc8c70522a4daceade43ab5 Mon Sep 17 00:00:00 2001
From: tg <tg@mirbsd.org>
Date: Sun, 22 Apr 2012 21:50:35 +0000
Subject: [PATCH] after discussion with ciruZ, switch mksh from NZAT to NZAAT
 fully to get rid of the bias introduced by making the hash never zero
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… he also pointed out a memory (heap) usage optimisation… which
may impact code size a bit though as I’d need to pass an additional
argument on hashtable function calls… or, forgo the benefit of not
having to pointer-align the key in the structure, which can be as
much as 3/7 octets per item, heap storage… OTOH the saved space is
4/8 octets per not-allocated item, possibly some code (use of an
multiply-add opcode), but the function call overhead/cost would
possibly be quite a bit… I guess I’ll have to measure…
---
 check.t |  6 +++---
 eval.c  |  4 ++--
 mksh.1  |  6 +++---
 sh.h    | 15 +++------------
 var.c   |  4 ++--
 5 files changed, 13 insertions(+), 22 deletions(-)

diff --git a/check.t b/check.t
index d257067..fd28e6b 100644
--- a/check.t
+++ b/check.t
@@ -1,4 +1,4 @@
-# $MirOS: src/bin/mksh/check.t,v 1.532 2012/04/14 16:07:44 tg Exp $
+# $MirOS: src/bin/mksh/check.t,v 1.533 2012/04/22 21:50:29 tg Exp $
 # $OpenBSD: bksl-nl.t,v 1.2 2001/01/28 23:04:56 niklas Exp $
 # $OpenBSD: history.t,v 1.5 2001/01/28 23:04:56 niklas Exp $
 # $OpenBSD: read.t,v 1.3 2003/03/10 03:48:16 david Exp $
@@ -29,7 +29,7 @@
 # http://www.freebsd.org/cgi/cvsweb.cgi/src/tools/regression/bin/test/regress.sh?rev=HEAD
 
 expected-stdout:
-	@(#)MIRBSD KSH R40 2012/04/14
+	@(#)MIRBSD KSH R40 2012/04/22
 description:
 	Check version of shell.
 stdin:
@@ -7089,7 +7089,7 @@ stdin:
 	print ${foo@#123} ${bar@#456} ${baz@#789} .
 	print ${foo@#bla} ${bar@#bar} ${baz@#OPTIND} .
 expected-stdout:
-	D50219A0 20E5DB5B 00000001 .
+	D50219A0 20E5DB5B 00000000 .
 	554A1C76 004A212E CB209562 .
 	6B21CF91 20E5DB5B 124EA49D .
 ---
diff --git a/eval.c b/eval.c
index 3c691cc..c71c66f 100644
--- a/eval.c
+++ b/eval.c
@@ -23,7 +23,7 @@
 
 #include "sh.h"
 
-__RCSID("$MirOS: src/bin/mksh/eval.c,v 1.116 2012/04/06 14:07:52 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/eval.c,v 1.117 2012/04/22 21:50:31 tg Exp $");
 
 /*
  * string expansion
@@ -392,7 +392,7 @@ expand(const char *cp,	/* input word */
 						h = seed;
 						NZATUpdateString(h,
 						    str_val(st->var));
-						NZATFinish(h);
+						NZAATFinish(h);
 						x.str = shf_smprintf("%08X",
 						    (unsigned int)h);
 						break;
diff --git a/mksh.1 b/mksh.1
index 4616bdc..1d4576d 100644
--- a/mksh.1
+++ b/mksh.1
@@ -1,4 +1,4 @@
-.\" $MirOS: src/bin/mksh/mksh.1,v 1.284 2012/04/14 12:51:34 tg Exp $
+.\" $MirOS: src/bin/mksh/mksh.1,v 1.285 2012/04/22 21:50:32 tg Exp $
 .\" $OpenBSD: ksh.1,v 1.141 2011/09/03 22:59:08 jmc Exp $
 .\"-
 .\" Copyright © 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009,
@@ -74,7 +74,7 @@
 .\" with -mandoc, it might implement .Mx itself, but we want to
 .\" use our own definition. And .Dd must come *first*, always.
 .\"
-.Dd $Mdocdate: April 14 2012 $
+.Dd $Mdocdate: April 22 2012 $
 .\"
 .\" Check which macro package we use, and do other -mdoc setup.
 .\"
@@ -1626,7 +1626,7 @@ The internal hash of the expansion of
 .Ar name ,
 with an optional (defaulting to zero)
 .Ar seed .
-At the moment, this is NZAT (a never-zero 32-bit hash based on
+At the moment, this is NZAAT (a 32-bit hash based on
 Bob Jenkins' one-at-a-time hash), but this is not set.
 This is the hash the shell uses internally for its associative arrays.
 .El
diff --git a/sh.h b/sh.h
index a22bef1..996f1aa 100644
--- a/sh.h
+++ b/sh.h
@@ -152,9 +152,9 @@
 #endif
 
 #ifdef EXTERN
-__RCSID("$MirOS: src/bin/mksh/sh.h,v 1.549 2012/04/14 16:07:48 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/sh.h,v 1.550 2012/04/22 21:50:33 tg Exp $");
 #endif
-#define MKSH_VERSION "R40 2012/04/14"
+#define MKSH_VERSION "R40 2012/04/22"
 
 /* arithmetic types: C implementation */
 #if !HAVE_CAN_INTTYPES
@@ -1491,7 +1491,7 @@ EXTERN struct timeval j_usrtime, j_systime;
 } while (/* CONSTCOND */ 0)
 
 
-/* NZAT/NZAAT hashes based on Bob Jenkins' one-at-a-time hash */
+/* NZAAT hash based on Bob Jenkins' one-at-a-time hash */
 
 /* From: src/kern/include/nzat.h,v 1.2 2011/07/18 00:35:40 tg Exp $ */
 
@@ -1524,15 +1524,6 @@ EXTERN struct timeval j_usrtime, j_systime;
 		NZATUpdateByte((h), NZATUpdateString_c);	\
 } while (/* CONSTCOND */ 0)
 
-/* not zero after termination */
-#define NZATFinish(h) do {					\
-	if ((h) == 0)						\
-		++(h);						\
-	else							\
-		NZAATFinish(h);					\
-} while (/* CONSTCOND */ 0)
-
-/* NULs zählen an allen Teilen */
 #define NZAATFinish(h) do {					\
 	(h) += (h) << 10;					\
 	(h) ^= (h) >> 6;					\
diff --git a/var.c b/var.c
index fcaf6e5..26462f0 100644
--- a/var.c
+++ b/var.c
@@ -27,7 +27,7 @@
 #include <sys/sysctl.h>
 #endif
 
-__RCSID("$MirOS: src/bin/mksh/var.c,v 1.146 2012/04/14 14:35:13 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/var.c,v 1.147 2012/04/22 21:50:35 tg Exp $");
 
 /*-
  * Variables
@@ -1471,7 +1471,7 @@ hash(const void *s)
 
 	NZATInit(h);
 	NZATUpdateString(h, s);
-	NZATFinish(h);
+	NZAATFinish(h);
 	return (h);
 }