Improve seed()

Added charbit.h to define CALC_CHARBIT which is either CHAR_BIT
from <limits.h> or 8 or a value set by the Makefile variable
CALC_CHARBIT.  Added have_limits.h to determine if <limits.h>
is a system include file.

.gitignore

@@ -16,6 +16,7 @@ calc.1
 calc.usage
 calcerr.c
 calcerr.h
+charbit.h
 conf.h
 cscript/.all
 cscript/4dsphere
@@ -43,6 +44,7 @@ have_getpgid.h
 have_getprid.h
 have_getsid.h
 have_gettime.h
+have_limits.h
 have_memmv.h
 have_newstr.h
 have_offscl.h

CHANGES

@@ -28,6 +28,11 @@ The following are the changes from calc version 2.14.0.11 to date:
     Fixed how Makefile variable SHELL is set on macOS vs. linux.
     Using /bin/sh on macOS due to how zsh treats globs by default.
 
+    Added charbit.h to define CALC_CHARBIT which is either CHAR_BIT
+    from <limits.h> or 8 or a value set by the Makefile variable
+    CALC_CHARBIT.  Added have_limits.h to determine if <limits.h>
+    is a system include file.
+
 
 The following are the changes from calc version 2.14.0.9 to 2.14.0.10:
 

Makefile

@@ -464,6 +464,10 @@ endian_calc.h:
 	${Q} ${MAKE} ${XARG} -f ${MAKE_FILE} $@ ${XVAR}
 	${V} echo '=-=-=-=-= private Makefile $@ rule end =-=-=-=-='
 
+charbit.h:
+	${V} echo '=-=-=-=-= private Makefile $@ rule start =-=-=-=-='
+	${Q} ${MAKE} ${XARG} -f ${MAKE_FILE} $@ ${XVAR}
+
 longbits.h:
 	${V} echo '=-=-=-=-= private Makefile $@ rule start =-=-=-=-='
 	${Q} ${MAKE} ${XARG} -f ${MAKE_FILE} $@ ${XVAR}

Makefile.ship

@@ -223,6 +223,19 @@ CALC_BYTE_ORDER=
 #CALC_BYTE_ORDER= -DBIG_ENDIAN
 #CALC_BYTE_ORDER= -DLITTLE_ENDIAN
 
+# Determine the number of bits in a byte
+#
+# If in doubt, leave CALC_CHARBIT empty.  This Makefile will run
+# the charbits program to determine the length.
+#
+# In order to avoid make brain damage in some systems, we avoid placing
+# a space after the ='s below.
+#
+# Select CALC_CHARBIT= 8 for DJGPP.
+#
+CALC_CHARBIT=
+#CALC_CHARBIT= 8
+
 # Determine the number of bits in a long
 #
 # If in doubt, leave LONG_BITS empty.  This Makefile will run
@@ -659,6 +672,20 @@ HAVE_UNISTD_H=
 #HAVE_UNISTD_H= YES
 #HAVE_UNISTD_H= NO
 
+# Determine if we have the <limits.h> include file.
+#
+#    HAVE_LIMITS_H=		let the Makefile look for the include file
+#    HAVE_LIMITS_H= YES		assume that the include file exists
+#    HAVE_LIMITS_H= NO		assume that the include file does not exist
+#
+# Select HAVE_LIMITS_H= YES for DJGPP.
+#
+# When in doubt, leave HAVE_LIMITS_H empty.
+#
+HAVE_LIMITS_H=
+#HAVE_LIMITS_H= YES
+#HAVE_LIMITS_H= NO
+
 # Determine if our compiler allows the unused attribute
 #
 # If HAVE_UNUSED is empty, this Makefile will run the have_unused program
@@ -1945,7 +1972,8 @@ BUILD_H_SRC= align32.h args.h calcerr.h conf.h endian_calc.h \
 	have_posscl.h have_rusage.h have_stdlib.h have_strdup.h \
 	have_string.h have_strlcat.h have_strlcpy.h have_times.h \
 	have_uid_t.h have_unistd.h have_unused.h have_urandom.h \
-	have_ustat.h longbits.h terminal.h have_environ.h have_arc4random.h
+	have_ustat.h longbits.h terminal.h have_environ.h \
+	have_arc4random.h have_limits.h charbit.h
 
 # we build these .c files during the make
 #
@@ -1961,7 +1989,7 @@ UTIL_C_SRC= align32.c endian.c longbits.c have_newstr.c have_uid_t.c \
 	have_ustat.c have_getsid.c have_getpgid.c have_environ.c \
 	have_gettime.c have_getprid.c have_rusage.c have_strdup.c \
 	have_unused.c have_ban_pragma.c have_strlcpy.c have_strlcat.c \
-	have_arc4random.c
+	have_arc4random.c charbit.c
 
 # these awk and sed tools are used in the process of building BUILD_H_SRC
 # and BUILD_C_SRC
@@ -1979,7 +2007,7 @@ UTIL_OBJS= endian.o longbits.o have_newstr.o have_uid_t.o \
 	have_ustat.o have_getsid.o have_getpgid.o have_environ.o \
 	have_gettime.o have_getprid.o ver_calc.o have_rusage.o have_strdup.o \
 	have_unused.o have_ban_pragma.o have_strlcpy.o have_strlcat.o \
-	have_arc4random.o
+	have_arc4random.o charbit.o
 
 # these temp files may be created (and removed) during the build of BUILD_C_SRC
 #
@@ -1997,7 +2025,8 @@ UTIL_PROGS= align32${EXT} fposval${EXT} have_uid_t${EXT} have_const${EXT} \
 	ver_calc${EXT} have_strdup${EXT} have_environ{EXT} \
 	have_unused${EXT} have_fpos${EXT} have_fpos_pos${EXT} \
 	have_offscl${EXT} have_rusage${EXT} have_ban_pragma${EXT} \
-	have_strlcpy${EXT} have_strlcat${EXT} have_arc4random${EXT}
+	have_strlcpy${EXT} have_strlcat${EXT} have_arc4random${EXT} \
+	charbit${EXT}
 
 # these utility files and scripts may be created in the process of building
 # the BUILD_H_SRC file set
@@ -2673,7 +2702,43 @@ endian_calc.h: endian.c have_stdlib.h have_unistd.h \
 	    ${TRUE}; \
 	fi
 
-longbits.h: longbits.c have_unistd.h have_stdlib.h \
+charbit.h: charbit.c have_limits.h \
+	banned.h have_ban_pragma.h ${MAKE_FILE} ${LOC_MKF}
+	${Q} ${RM} -f charbit.o charbit${EXT} $@
+	${H} echo 'forming $@'
+	${Q} echo '/*' > $@
+	${Q} echo ' * DO NOT EDIT -- generated by the Makefile' >> $@
+	${Q} echo ' */' >> $@
+	${Q} echo '' >> $@
+	${Q} echo '' >> $@
+	${Q} echo '#if !defined(CALC_CHARBIT_H)' >> $@
+	${Q} echo '#define CALC_CHARBIT_H' >> $@
+	${Q} echo '' >> $@
+	${Q} echo '' >> $@
+	-@if [ -z ${CALC_CHARBIT} ]; then \
+	    ${LCC} ${ICFLAGS} charbit.c -c ${S}; \
+	    ${LCC} ${ILDFLAGS} charbit.o -o charbit${EXT} ${S}; \
+	    ./charbit${EXT} >> $@ ${E}; \
+	else \
+	    echo '#define CALC_CHARBIT ${CALC_CHARBIT} ' \
+		 '/* set by Makefile.ship */' >> $@; \
+	fi
+	${Q} echo '' >> $@
+	${Q} echo '' >> $@
+	${Q} echo '#endif /* !CALC_CHARBIT_H */' >> $@
+	${H} echo '$@ formed'
+	${Q} ${RM} -f charbit.o charbit${EXT}
+	-@if [ -z "${Q}" ]; then \
+	    echo ''; \
+	    echo '=-=-= start of $@ =-=-='; \
+	    ${CAT} $@; \
+	    echo '=-=-= end of $@ =-=-='; \
+	    echo ''; \
+	else \
+	    ${TRUE}; \
+	fi
+
+longbits.h: longbits.c charbit.h have_unistd.h have_stdlib.h \
 	banned.h have_ban_pragma.h ${MAKE_FILE} ${LOC_MKF}
 	${Q} ${RM} -f longbits.o longbits${EXT} $@
 	${H} echo 'forming $@'
@@ -2842,6 +2907,42 @@ have_unistd.h: ${MAKE_FILE} ${LOC_MKF}
 	    ${TRUE}; \
 	fi
 
+have_limits.h: ${MAKE_FILE} ${LOC_MKF}
+	${Q} ${RM} -f $@
+	${H} echo 'forming $@'
+	${Q} echo '/*' > $@
+	${Q} echo ' * DO NOT EDIT -- generated by the Makefile' >> $@
+	${Q} echo ' */' >> $@
+	${Q} echo '' >> $@
+	${Q} echo '' >> $@
+	${Q} echo '#if !defined(CALC_HAVE_LIMITS_H)' >> $@
+	${Q} echo '#define CALC_HAVE_LIMITS_H' >> $@
+	${Q} echo '' >> $@
+	${Q} echo '' >> $@
+	${Q} echo '/* do we have <limits.h>? */' >> $@
+	-${Q} if [ X"${HAVE_LIMITS_H}" = X"YES" ]; then \
+	    echo '#define HAVE_LIMITS_H	/* yes */' >> $@; \
+	elif [ X"${HAVE_LIMITS_H}" = X"NO" ]; then \
+	    echo '#undef HAVE_LIMITS_H  /* no */' >> $@; \
+	elif echo '#include <limits.h>' | ${CC} -E - ${S}; then \
+	    echo '#define HAVE_LIMITS_H	 /* yes */' >> $@; \
+	else \
+	    echo '#undef HAVE_LIMITS_H	/* no */' >> $@; \
+	fi
+	${Q} echo '' >> $@
+	${Q} echo '' >> $@
+	${Q} echo '#endif /* !CALC_HAVE_LIMITS_H */' >> $@
+	${H} echo '$@ formed'
+	-@if [ -z "${Q}" ]; then \
+	    echo ''; \
+	    echo '=-=-= start of $@ =-=-='; \
+	    ${CAT} $@; \
+	    echo '=-=-= end of $@ =-=-='; \
+	    echo ''; \
+	else \
+	    ${TRUE}; \
+	fi
+
 have_string.h: ${MAKE_FILE} ${LOC_MKF}
 	${Q} ${RM} -f $@
 	${H} echo 'forming $@'
@@ -4298,7 +4399,7 @@ version:
 
 ver_calc${EXT}: version.c strl.c have_string.h have_const.h have_newstr.h \
 	have_strlcpy.h have_memmv.h have_strlcat.h endian_calc.h longbits.h \
-	have_unused.h
+	have_unused.h charbit.h
 	${RM} -f $@
 	${LCC} ${ICFLAGS} -DCALC_VER ${ILDFLAGS} version.c strl.c -o $@
 
@@ -4551,6 +4652,7 @@ env:
 	@echo 'HAVE_GETRUSAGE=${HAVE_GETRUSAGE}'; echo ''
 	@echo 'HAVE_GETSID=${HAVE_GETSID}'; echo ''
 	@echo 'HAVE_GETTIME=${HAVE_GETTIME}'; echo ''
+	@echo 'HAVE_LIMITS_H=${HAVE_LIMITS_H}'; echo ''
 	@echo 'HAVE_MEMMOVE=${HAVE_MEMMOVE}'; echo ''
 	@echo 'HAVE_NEWSTR=${HAVE_NEWSTR}'; echo ''
 	@echo 'HAVE_OFFSCL=${HAVE_OFFSCL}'; echo ''
@@ -5655,6 +5757,10 @@ calcerr.o: calcerr.c
 calcerr.o: calcerr.h
 calcerr.o: have_ban_pragma.h
 calcerr.o: have_const.h
+charbit.o: banned.h
+charbit.o: charbit.c
+charbit.o: have_ban_pragma.h
+charbit.o: have_limits.h
 codegen.o: alloc.h
 codegen.o: banned.h
 codegen.o: block.h
@@ -6226,7 +6332,9 @@ listfunc.o: value.h
 listfunc.o: zmath.h
 listfunc.o: zrand.h
 longbits.o: banned.h
+longbits.o: charbit.h
 longbits.o: have_ban_pragma.h
+longbits.o: have_limits.h
 longbits.o: have_stdlib.h
 longbits.o: have_unistd.h
 longbits.o: longbits.c

charbit.c

@@ -0,0 +1,67 @@
+/*
+ * charbit - determine what CHAR_BIT is and define CALC_CHARBIT
+ *
+ * Copyright (C) 2021  Landon Curt Noll
+ *
+ * Calc is open software; you can redistribute it and/or modify it under
+ * the terms of the version 2.1 of the GNU Lesser General Public License
+ * as published by the Free Software Foundation.
+ *
+ * Calc 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 Lesser General
+ * Public License for more details.
+ *
+ * A copy of version 2.1 of the GNU Lesser General Public License is
+ * distributed with calc under the filename COPYING-LGPL.  You should have
+ * received a copy with calc; if not, write to Free Software Foundation, Inc.
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ *
+ * Under source code control:	2021/12/07 20:57:50
+ * File existed as early as:	2021
+ *
+ * chongo <was here> /\oo/\	http://www.isthe.com/chongo/
+ * Share and enjoy!  :-)	http://www.isthe.com/chongo/tech/comp/calc/
+ */
+
+/*
+ * usage:
+ *	charbit
+ *
+ * This prog outputs several defines:
+ *
+ *	CALC_CHARBIT
+ *		after including have_limits.h and perhaps <limits.h>,
+ *		output CALC_CHARBIT as CHAR_BIT (from <limits.h>, or as 8.
+ */
+
+#include <stdio.h>
+#include "have_limits.h"
+#if defined(HAVE_LIMITS_H)
+#include <limits.h>
+#endif
+
+
+#include "banned.h"	/* include after system header <> includes */
+
+
+int
+main(void)
+{
+	printf("#include \"have_limits.h\"\n");
+	printf("#if defined(HAVE_LIMITS_H)\n");
+	printf("#include <limits.h>\n");
+	printf("#endif\n\n");
+#if defined(CHAR_BIT)
+
+	printf("#define CALC_CHARBIT (CHAR_BIT) /* from <limits.h> */\n");
+
+#else /* CHAR_BIT */
+
+	printf("#define CALC_CHARBIT (8) /* no CHAR_BIT, assume 8 */\n");
+
+#endif /* CHAR_BIT */
+
+	/* exit(0); */
+	return 0;
+}

longbits.c

@@ -92,6 +92,8 @@
 # include <stdlib.h>
 #endif
 
+#include "charbit.h"
+
 
 #include "banned.h"	/* include after system header <> includes */
 
@@ -118,7 +120,7 @@ main(int argc, char **argv)
 		/* ignore empty or leading space args */
 		if (argv[1][0] == '\0' ||
 		    (isascii((int)argv[1][0]) && isspace((int)argv[1][0]))) {
-			long_bits = sizeof(long)*8;
+			long_bits = sizeof(long)*CALC_CHARBIT;
 		/* process the forced size arg */
 		} else {
 			forced_size = 1;

seed.c

@@ -80,7 +80,8 @@
 #endif
 #if defined(HAVE_STDLIB_H)
 # include <stdlib.h>
-# define RANDOM_CNT (16)	/* random() call repeat count */
+/* NOTE: RANDOM_CNT should remain 32 to circular shift 31-bit returns */
+# define RANDOM_CNT (32) /* random() call repeat and circular shift */
 # define INITSTATE_SIZE (256)	/* initstate pool size */
 #endif
 #include <setjmp.h>
@@ -464,6 +465,7 @@ pseudo_seed(void)
     /**/
 
 #if defined(HAVE_STDLIB_H)
+    unsigned long tmp;			/* temp holder of 31-bit random() */
     unsigned past_hash;			/* prev hash or xor-folded prev hash */
     long random_before[RANDOM_CNT];	/* random() pre initstate() */
     char *initstate_ret;		/* return from initstate() call */
@@ -642,9 +644,10 @@ pseudo_seed(void)
 
     /* classic 31-bit random seeded with time of day, count, prev hash */
     srandom((unsigned)(sdata.time) ^ (unsigned)call_count ^ past_hash);
-    for (j=0; j < RANDOM_CNT; j += 2) {
+    for (j=0; j < RANDOM_CNT; ++j) {
-	random_before[j] = random();
+	tmp = random();	/* 31-bit value */
-	random_before[j+1] = (random() << 1);
+	/* we 32-bit circular shift to spread 31-bit returns around */
+	random_before[j] = (tmp << j) | (tmp >> (RANDOM_CNT-j));
     }
 
     /* initialize random state with the FNV hash of sdata */
@@ -659,9 +662,10 @@ pseudo_seed(void)
 #endif /* HAVE_B64 */
 
     /* use 31-bit random some more with the new random state */
-    for (j=0; j < RANDOM_CNT; j += 2) {
+    for (j=0; j < RANDOM_CNT; ++j) {
-	random_after[j] = random();
+	tmp = random();	/* 31-bit value */
-	random_after[j+1] = (random() << 1);
+	/* we 32-bit circular shift to spread 31-bit returns around */
+	random_after[j] = (tmp << j) | (tmp >> (RANDOM_CNT-j));
     }
 
     /* restore previous state */

win32.mkdef

@@ -1,6 +1,7 @@
 TERMCONTROL=-DUSE_WIN32
 HAVE_VSNPRINTF=-UDONT_HAVE_VSNPRINTF
 BYTE_ORDER=-DLITTLE_ENDIAN
+CALC_CHARBIT=8
 LONG_BITS=32
 HAVE_FPOS=-DHAVE_NO_FPOS
 HAVE_FPOS_POS=-DHAVE_NO_FPOS_POS
@@ -32,6 +33,7 @@ HAVE_SYS_TIMES_H=NO
 HAVE_TIME_H=YES
 HAVE_SYS_TIME_H=NO
 HAVE_UNISTD_H=NO
+HAVE_LIMITS_H=YES
 HAVE_ENVIRON=-DHAVE_NO_ENVIRON
 HAVE_ARC4RANDOM=-DHAVE_NO_ARC4RANDOM