--- /dev/null
+/* Everything you wanted to know about your machine and C compiler,
+ but didn't know who to ask.
+ Author: Steven Pemberton, CWI, Amsterdam; steven@cwi.nl
+ Bugfixes and upgrades gratefully received.
+
+ Name changed to `hard-params' by Richard Stallman, April 89.
+ xmalloc function defined, Richard Stallman, June 89.
+
+ Copyright (c) 1988, 1989 Steven Pemberton, CWI, Amsterdam.
+ All rights reserved.
+
+ COMPILING
+ With luck and a following wind, just the following will work:
+ cc hard-params.c -o hard-params
+
+ If your compiler doesn't support: add flag:
+ signed char (eg pcc) -DNO_SC
+ unsigned char -DNO_UC
+ unsigned short and long -DNO_UI
+ signal(), or setjmp/longjmp() -DNO_SIG
+
+ Try it first with no flags, and see if you get any errors - you might be
+ surprised. (Most non-ANSI compilers need -DNO_SC, though.)
+ Some compilers need a -f flag for floating point.
+
+ Don't use any optimisation flags: the program may not work if you do.
+ Though "while (a+1.0-a-1.0 == 0.0)" may look like "while(1)" to an
+ optimiser, to a floating-point unit there's a world of difference.
+
+ Some compilers offer various flags for different floating point
+ modes; it's worth trying all possible combinations of these.
+
+ Add -DID=\"name\" if you want the machine/flags identified in the output.
+
+ SYSTEM DEPENDENCIES
+ You may possibly need to add some calls to signal() for other sorts of
+ exception on your machine than SIGFPE, and SIGOVER. See lines beginning
+ #ifdef SIGxxx in main() (and communicate the differences to me!).
+
+ If your C preprocessor doesn't have the predefined __FILE__ macro, and
+ you want to call this file anything other than hard-params.c, change the
+ #define command for __FILE__ accordingly. If it doesn't accept macro
+ names at all in #include lines, order a new C compiler. While you're
+ waiting for it to arrive, change the last #include in this file (the
+ last but one line) accordingly.
+
+ OUTPUT
+ Run without argument to get the information as English text. If run
+ with argument -l (e.g. hard-params -l), output is a series of #define's for
+ the ANSI standard limits.h include file, excluding MB_MAX_CHAR. If run
+ with argument -f, output is a series of #define's for the ANSI standard
+ float.h include file. Flag -v gives verbose output: output includes the
+ English text above as C comments. The program exit(0)'s if everything
+ went ok, otherwise it exits with a positive number, telling how many
+ problems there were.
+
+ VERIFYING THE COMPILER
+ If, having produced the float.h and limits.h header files, you want to
+ verify that the compiler reads them back correctly (there are a lot of
+ boundary cases, of course, like minimum and maximum numbers), you can
+ recompile hard-params.c with -DVERIFY set (plus the other flags that you used
+ when compiling the version that produced the header files). This then
+ recompiles the program so that it #includes "limits.h" and "float.h",
+ and checks that the constants it finds there are the same as the
+ constants it produces. Run the resulting program with hard-params -fl. As of
+ this writing, of 21 compiler/flags combinations only 1 compiler has
+ passed without error! (The honour goes to 'pcc' on an IBM RT.)
+
+ You can also use this option if your compiler already has both files,
+ and you want to confirm that this program produces the right results.
+
+ TROUBLE SHOOTING.
+ This program is now quite trustworthy, and suspicious and wrong output
+ may well be caused by bugs in the compiler, not in the program (however
+ of course, this is not guaranteed, and no responsibility can be
+ accepted, etc.)
+
+ The program only works if overflows are ignored by the C system or
+ are catchable with signal().
+
+ If the program fails to run to completion (often with the error message
+ "Unexpected signal at point x"), this often turns out to be a bug in the
+ C compiler's run-time system. Check what was about to be printed, and
+ try to narrow the problem down.
+
+ Another possible problem is that you have compiled the program to produce
+ loss-of-precision arithmetic traps. The program cannot cope with these,
+ and you should re-compile without them. (They should never be the default).
+
+ Make sure you compiled with optimisation turned off.
+
+ Output preceded by *** WARNING: identifies behaviour of the C system
+ deemed incorrect by the program. Likely problems are that printf or
+ scanf don't cope properly with certain boundary numbers. For each float
+ and double that is printed, the printed value is checked that it is
+ correct by using sscanf to read it back. Care is taken that numbers are
+ printed with enough digits to uniquely identify them, and therefore that
+ they can be read back identically. If the number read back is different,
+ the program prints a warning message. If the two numbers in the warning
+ look identical, then printf is more than likely rounding the last
+ digit(s) incorrectly. To put you at ease that the two really are
+ different, the bit patterns of the two numbers are also printed. The
+ difference is very likely in the last bit. Many scanf's read the
+ minimum double back as 0.0, and similarly cause overflow when reading
+ the maximum double. The program quite ruthlessly declares all these
+ behaviours faulty.
+
+ The warning that "a cast didn't work" refers to cases like this:
+
+ float f;
+ #define C 1.234567890123456789
+ f= C;
+ if (f != (float) C) printf ("Wrong!");
+
+ A faulty compiler will widen f to double and ignore the cast to float,
+ and because there is more accuracy in a double than a float, fail to
+ recognise that they are the same. In the actual case in point, f and C
+ are passed as parameters to a function that discovers they are not equal,
+ so it's just possible that the error was in the parameter passing,
+ not in the cast (see function Validate()).
+ For ANSI C, which has float constants, the error message is "constant has
+ wrong precision".
+
+ REPORTING PROBLEMS
+ If the program doesn't work for you for any reason that can't be
+ narrowed down to a problem in the C compiler, or it has to be changed in
+ order to get it to compile, or it produces suspicious output (like a very
+ low maximum float, for instance), please mail the problem and an example
+ of the incorrect output to steven@cwi.nl or mcvax!steven.uucp, so that
+ improvements can be worked into future versions; mcvax/cwi.nl is the
+ European backbone, and is connected to uunet and other fine hosts.
+
+ This version of the program is the first to try to catch and diagnose
+ bugs in the compiler/run-time system. I would be especially pleased to
+ have reports of failures so that I can improve this service.
+
+ I apologise unreservedly for the contorted use of the preprocessor...
+
+ THE SMALL PRINT
+ You may copy and distribute verbatim copies of this source file.
+
+ You may modify this source file, and copy and distribute such
+ modified versions, provided that you leave the copyright notice
+ at the top of the file and also cause the modified file to carry
+ prominent notices stating that you changed the files and the date
+ of any change; and cause the whole of any work that you distribute
+ or publish, that in whole or in part contains or is a derivative of
+ this program or any part thereof, to be licensed at no charge to
+ all third parties on terms identical to those here.
+
+ If you do have a fix to any problem, please send it to me, so that
+ other people can have the benefits.
+
+ While every effort has been taken to make this program as reliable as
+ possible, no responsibility can be taken for the correctness of the
+ output, or suitability for any particular use.
+
+ ACKNOWLEDGEMENTS
+ Many people have given time and ideas to making this program what it is.
+ To all of them thanks, and apologies for not mentioning them by name.
+*/
+
+#ifndef __FILE__
+#define __FILE__ "hard-params.c"
+#endif
+
+#ifndef PASS
+#define PASS 1
+#define PASS1 1
+#define VERSION "4.1"
+
+/* Procedure just marks the functions that don't return a result */
+#ifdef Procedure
+#undef Procedure
+#endif
+#define Procedure
+
+#define Vprintf if (V) printf
+
+/* stdc is used in tests like if (stdc) */
+#ifdef __STDC__
+#define stdc 1
+#else
+#define stdc 0
+#endif
+
+/* volatile is used to reduce the chance of optimisation,
+ and to prevent variables being put in registers (when setjmp/longjmp
+ wouldn't work as we want) */
+#ifndef __STDC__
+#define volatile static
+#endif
+
+#include <stdio.h>
+
+#ifdef VERIFY
+#include "limits.h"
+#include "float.h"
+#endif
+
+#ifdef NO_SIG /* There's no signal(), or setjmp/longjmp() */
+
+ /* Dummy routines instead */
+ int lab=1;
+ int setjmp(lab) int lab; { return(0); }
+ signal(i, p) int i, (*p)(); {}
+
+#else
+
+#include <signal.h>
+#include <setjmp.h>
+
+ jmp_buf lab;
+ overflow(sig) int sig; { /* what to do on overflow/underflow */
+ signal(sig, overflow);
+ longjmp(lab, 1);
+ }
+
+#endif /*NO_SIG*/
+
+#define Unexpected(place) if (setjmp(lab)!=0) croak(place)
+
+int V= 0, /* verbose */
+ L= 0, /* produce limits.h */
+ F= 0, /* produce float.h */
+ bugs=0; /* The number of (possible) bugs in the output */
+
+char co[4], oc[4]; /* Comment starter and ender symbols */
+
+int bits_per_byte; /* the number of bits per unit returned by sizeof() */
+
+#ifdef TEST
+/* Set the fp modes on a SUN with 68881 chip, to check that different
+ rounding modes etc. get properly detected.
+ Compile with additional flag -DTEST, and run with additional parameter
+ +hex-number, to set the 68881 mode register to hex-number
+*/
+
+/* Bits 0x30 = rounding mode: */
+#define ROUND_BITS 0x30
+#define TO_NEAREST 0x00
+#define TO_ZERO 0x10
+#define TO_MINUS_INF 0x20
+#define TO_PLUS_INF 0x30 /* The SUN FP user's guide seems to be wrong here */
+
+/* Bits 0xc0 = extended rounding: */
+#define EXT_BITS 0xc0
+#define ROUND_EXTENDED 0x00
+#define ROUND_SINGLE 0x40
+#define ROUND_DOUBLE 0x80
+
+/* Enabled traps: */
+#define EXE_INEX1 0x100
+#define EXE_INEX2 0x200
+#define EXE_DZ 0x400
+#define EXE_UNFL 0x800
+#define EXE_OVFL 0x1000
+#define EXE_OPERR 0x2000
+#define EXE_SNAN 0x4000
+#define EXE_BSUN 0x8000
+
+printmode(new) unsigned new; {
+ fpmode_(&new);
+ printf("New fp mode:\n");
+ printf(" Round toward ");
+ switch (new & ROUND_BITS) {
+ case TO_NEAREST: printf("nearest"); break;
+ case TO_ZERO: printf("zero"); break;
+ case TO_MINUS_INF: printf("minus infinity"); break;
+ case TO_PLUS_INF: printf("plus infinity"); break;
+ default: printf("???"); break;
+ }
+
+ printf("\n Extended rounding precision: ");
+
+ switch (new & EXT_BITS) {
+ case ROUND_EXTENDED: printf("extended"); break;
+ case ROUND_SINGLE: printf("single"); break;
+ case ROUND_DOUBLE: printf("double"); break;
+ default: printf("???"); break;
+ }
+
+ printf("\n Enabled exceptions:");
+ if (new & (unsigned) EXE_INEX1) printf(" inex1");
+ if (new & (unsigned) EXE_INEX2) printf(" inex2");
+ if (new & (unsigned) EXE_DZ) printf(" dz");
+ if (new & (unsigned) EXE_UNFL) printf(" unfl");
+ if (new & (unsigned) EXE_OVFL) printf(" ovfl");
+ if (new & (unsigned) EXE_OPERR) printf(" operr");
+ if (new & (unsigned) EXE_SNAN) printf(" snan");
+ if (new & (unsigned) EXE_BSUN) printf(" bsun");
+ printf("\n");
+}
+
+int setmode(s) char *s; {
+ unsigned mode=0, dig;
+ char c;
+
+ while (*s) {
+ c= *s++;
+ if (c>='0' && c<='9') dig= c-'0';
+ else if (c>='a' && c<='f') dig= c-'a'+10;
+ else if (c>='A' && c<='F') dig= c-'A'+10;
+ else return 1;
+ mode= mode<<4 | dig;
+ }
+ printmode(mode);
+ return 0;
+}
+#else
+int setmode(s) char *s; {
+ fprintf(stderr, "Can't set mode: not compiled with TEST\n");
+ return(1);
+}
+#endif
+
+croak(place) int place; {
+ printf("*** Unexpected signal at point %d\n", place);
+ exit(bugs+1); /* An exit isn't essential here, but avoids loops */
+}
+
+/* This is here in case alloca.c is used. That wants to call this. */
+
+char *
+xmalloc(size) unsigned size; {
+ char *malloc();
+ char *value = malloc(size);
+ if (value == 0) {
+ fprintf(stderr, "Virtual memory exceeded\n");
+ exit(bugs+1);
+ }
+ return value;
+}
+
+main(argc, argv) int argc; char *argv[]; {
+ int dprec, fprec, lprec, basic(), fprop(), dprop(), efprop(), edprop();
+ char *malloc();
+ unsigned int size;
+ long total;
+ int i; char *s; int bad;
+
+#ifdef SIGFPE
+ signal(SIGFPE, overflow);
+#endif
+#ifdef SIGOVER
+ signal(SIGOVER, overflow);
+#endif
+/* Add more calls as necessary */
+
+ Unexpected(1);
+
+ bad=0;
+ for (i=1; i < argc; i++) {
+ s= argv[i];
+ if (*s == '-') {
+ s++;
+ while (*s) {
+ switch (*(s++)) {
+ case 'v': V=1; break;
+ case 'l': L=1; break;
+ case 'f': F=1; break;
+ default: bad=1; break;
+ }
+ }
+ } else if (*s == '+') {
+ s++;
+ bad= setmode(s);
+ } else bad= 1;
+ }
+ if (bad) {
+ fprintf(stderr,
+ "Usage: %s [-vlf]\n v=Verbose l=Limits.h f=Float.h\n",
+ argv[0]);
+ exit(1);
+ }
+ if (L || F) {
+ co[0]= '/'; oc[0]= ' ';
+ co[1]= '*'; oc[1]= '*';
+ co[2]= ' '; oc[2]= '/';
+ co[3]= '\0'; oc[3]= '\0';
+ } else {
+ co[0]= '\0'; oc[0]= '\0';
+ V=1;
+ }
+
+ if (L) printf("%slimits.h%s\n", co, oc);
+ if (F) printf("%sfloat.h%s\n", co, oc);
+#ifdef ID
+ printf("%sProduced on %s by hard-params version %s, CWI, Amsterdam%s\n",
+ co, ID, VERSION, oc);
+#else
+ printf("%sProduced by hard-params version %s, CWI, Amsterdam%s\n",
+ co, VERSION, oc);
+#endif
+
+#ifdef VERIFY
+ printf("%sVerification phase%s\n", co, oc);
+#endif
+
+#ifdef NO_SIG
+ Vprintf("%sCompiled without signal(): %s%s\n",
+ co,
+ "there's nothing that can be done if overflow occurs",
+ oc);
+#endif
+#ifdef NO_SC
+ Vprintf("%sCompiled without signed char%s\n", co, oc);
+#endif
+#ifdef NO_UC
+ Vprintf("%Compiled without unsigned char%s\n", co, oc);
+#endif
+#ifdef NO_UI
+ Vprintf("%Compiled without unsigned short or long%s\n", co, oc);
+#endif
+#ifdef __STDC__
+ Vprintf("%sCompiler claims to be ANSI C level %d%s\n",
+ co, __STDC__, oc);
+#else
+ Vprintf("%sCompiler does not claim to be ANSI C%s\n", co, oc);
+#endif
+ printf("\n");
+ bits_per_byte= basic();
+ Vprintf("\n");
+ if (F||V) {
+ fprec= fprop(bits_per_byte);
+ dprec= dprop(bits_per_byte);
+ lprec= ldprop(bits_per_byte);
+ efprop(fprec, dprec, lprec);
+ edprop(fprec, dprec, lprec);
+ eldprop(fprec, dprec, lprec);
+ }
+ if (V) {
+ /* An extra goody: the approximate amount of data-space */
+ /* Allocate store until no more available */
+ size=1<<((bits_per_byte*sizeof(int))-2);
+ total=0;
+ while (size!=0) {
+ while (malloc(size)!=(char *)NULL) total+=(size/2);
+ size/=2;
+ }
+
+ Vprintf("%sMemory mallocatable ~= %ld Kbytes%s\n",
+ co, (total+511)/512, oc);
+ }
+ exit(bugs);
+}
+
+Procedure eek_a_bug(problem) char *problem; {
+ printf("\n%s*** WARNING: %s%s\n", co, problem, oc);
+ bugs++;
+}
+
+Procedure i_define(sort, name, val, req) char *sort, *name; long val, req; {
+ if (val >= 0) {
+ printf("#define %s%s %ld\n", sort, name, val);
+ } else {
+ printf("#define %s%s (%ld)\n", sort, name, val);
+ }
+ if (val != req) {
+ printf("%s*** Verify failed for above #define!\n", co);
+ printf(" Compiler has %ld for value%s\n\n", req, oc);
+ bugs++;
+ }
+ Vprintf("\n");
+}
+
+#ifndef NO_UI
+
+#ifdef __STDC__
+#define U "U"
+#else
+#define U ""
+#endif
+
+Procedure u_define(sort, name, val, req) char *sort, *name; unsigned long val, req; {
+ printf("#define %s%s %lu%s\n", sort, name, val, U);
+ if (val != req) {
+ printf("%s*** Verify failed for above #define!\n", co);
+ printf(" Compiler has %lu for value%s\n\n", req, oc);
+ bugs++;
+ }
+ Vprintf("\n");
+}
+#endif
+
+/* Long_double is the longest floating point type available: */
+#ifdef __STDC__
+#define Long_double long double
+#else
+#define Long_double double
+#endif
+
+char *f_rep();
+
+Procedure f_define(sort, name, precision, val, mark)
+ char *sort, *name; int precision; Long_double val; char *mark; {
+ if (stdc) {
+ printf("#define %s%s %s%s\n",
+ sort, name, f_rep(precision, val), mark);
+ } else if (*mark == 'F') {
+ /* non-ANSI C has no float constants, so cast the constant */
+ printf("#define %s%s ((float)%s)\n",
+ sort, name, f_rep(precision, val));
+ } else {
+ printf("#define %s%s %s\n", sort, name, f_rep(precision, val));
+ }
+ Vprintf("\n");
+}
+
+int floor_log(base, x) int base; Long_double x; { /* return floor(log base(x)) */
+ int r=0;
+ while (x>=base) { r++; x/=base; }
+ return r;
+}
+
+int ceil_log(base, x) int base; Long_double x; {
+ int r=0;
+ while (x>1.0) { r++; x/=base; }
+ return r;
+}
+
+int exponent(x, fract, exp) Long_double x; double *fract; int *exp; {
+ /* Split x into a fraction and a power of ten;
+ returns 0 if x is unusable, 1 otherwise.
+ Only used for error messages about faulty output.
+ */
+ int r=0, neg=0;
+ Long_double old;
+ *fract=0.0; *exp=0;
+ if (x<0.0) {
+ x= -x;
+ neg= 1;
+ }
+ if (x==0.0) return 1;
+ if (x>=10.0) {
+ while (x>=10.0) {
+ old=x; r++; x/=10.0;
+ if (old==x) return 0;
+ }
+ } else {
+ while (x<1.0) {
+ old=x; r--; x*=10.0;
+ if (old==x) return 0;
+ }
+ }
+ if (neg) *fract= -x;
+ else *fract=x;
+ *exp=r;
+ return 1;
+}
+
+#define fabs(x) (((x)<0.0)?(-x):(x))
+
+char *f_rep(precision, val) int precision; Long_double val; {
+ static char buf[1024];
+ char *f1;
+ if (sizeof(double) == sizeof(Long_double)) {
+ /* Assume they're the same, and use non-stdc format */
+ /* This is for stdc compilers using non-stdc libraries */
+ f1= "%.*e";
+ } else {
+ /* It had better support Le then */
+ f1= "%.*Le";
+ }
+ sprintf(buf, f1, precision, val);
+ return buf;
+}
+
+Procedure bitpattern(p, size) char *p; int size; {
+ char c;
+ int i, j;
+
+ for (i=1; i<=size; i++) {
+ c= *p;
+ p++;
+ for (j=bits_per_byte-1; j>=0; j--)
+ printf("%c", (c>>j)&1 ? '1' : '0');
+ if (i!=size) printf(" ");
+ }
+}
+
+#define Order(x, px, mode)\
+ printf("%s %s ", co, mode); for (i=0; i<sizeof(x); i++) px[i]= c[i]; \
+ for (i=1; i<=sizeof(x); i++) { putchar((char)((x>>(bits_per_byte*(sizeof(x)-i)))&mask)); }\
+ printf("%s\n", oc);
+
+Procedure endian(bits_per_byte) int bits_per_byte; {
+ /*unsigned*/ short s=0;
+ /*unsigned*/ int j=0;
+ /*unsigned*/ long l=0;
+
+ char *ps= (char *) &s,
+ *pj= (char *) &j,
+ *pl= (char *) &l,
+ *c= "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
+ unsigned int mask, i;
+
+ mask=0;
+ for (i=1; i<=bits_per_byte; i++) mask= (mask<<1)|1;
+
+ if (V) {
+ printf("%sCharacter order:%s\n", co, oc);
+ Order(s, ps, "short:");
+ Order(j, pj, "int: ");
+ Order(l, pl, "long: ");
+ }
+}
+
+#ifdef VERIFY
+#ifndef SCHAR_MAX
+#define SCHAR_MAX char_max
+#define SCHAR_MIN char_min
+#endif
+#ifndef UCHAR_MAX
+#define UCHAR_MAX char_max
+#endif
+#else
+#define CHAR_BIT char_bit
+#define CHAR_MAX char_max
+#define CHAR_MIN char_min
+#define SCHAR_MAX char_max
+#define SCHAR_MIN char_min
+#define UCHAR_MAX char_max
+#endif /* VERIFY */
+
+int cprop() { /* Properties of character */
+ volatile char c, char_max, char_min;
+ volatile int bits_per_byte, is_signed;
+ long char_bit;
+
+ Unexpected(2);
+
+ /* Calculate number of bits per character *************************/
+ c=1; bits_per_byte=0;
+ do { c=c<<1; bits_per_byte++; } while(c!=0);
+ c= (char)(-1);
+ if (((int)c)<0) is_signed=1;
+ else is_signed=0;
+ Vprintf("%sChar = %d bits, %ssigned%s\n",
+ co, (int)sizeof(c)*bits_per_byte, (is_signed?"":"un"), oc);
+ char_bit=(long)(sizeof(c)*bits_per_byte);
+ if (L) i_define("CHAR", "_BIT", char_bit, (long) CHAR_BIT);
+
+ c=0; char_max=0;
+ c++;
+ if (setjmp(lab)==0) { /* Yields char_max */
+ while (c>char_max) {
+ char_max=c;
+ c++;
+ }
+ } else {
+ Vprintf("%sCharacter overflow generates a trap!%s\n", co, oc);
+ }
+ c=0; char_min=0;
+ c--;
+ if (setjmp(lab)==0) { /* Yields char_min */
+ while (c<char_min) {
+ char_min=c;
+ c--;
+ }
+ }
+ Unexpected(3);
+
+ if (L) {
+ i_define("CHAR", "_MAX", (long) char_max, (long) CHAR_MAX);
+ i_define("CHAR", "_MIN", (long) char_min, (long) CHAR_MIN);
+ if (is_signed) {
+ i_define("SCHAR", "_MAX", (long) char_max,
+ (long) SCHAR_MAX);
+ i_define("SCHAR", "_MIN", (long) char_min,
+ (long) SCHAR_MIN);
+ } else {
+ i_define("UCHAR", "_MAX", (long) char_max,
+ (long) UCHAR_MAX);
+ }
+
+ if (is_signed) {
+#ifndef NO_UC
+ volatile unsigned char c, char_max;
+ c=0; char_max=0;
+ c++;
+ if (setjmp(lab)==0) { /* Yields char_max */
+ while (c>char_max) {
+ char_max=c;
+ c++;
+ }
+ }
+ Unexpected(4);
+ i_define("UCHAR", "_MAX", (long) char_max,
+ (long) UCHAR_MAX);
+#endif
+ } else {
+#ifndef NO_SC /* Define NO_SC if the next line gives a syntax error */
+ volatile signed char c, char_max, char_min;
+ c=0; char_max=0;
+ c++;
+ if (setjmp(lab)==0) { /* Yields char_max */
+ while (c>char_max) {
+ char_max=c;
+ c++;
+ }
+ }
+ c=0; char_min=0;
+ c--;
+ if (setjmp(lab)==0) { /* Yields char_min */
+ while (c<char_min) {
+ char_min=c;
+ c--;
+ }
+ }
+ Unexpected(5);
+ i_define("SCHAR", "_MIN", (long) char_min,
+ (long) SCHAR_MIN);
+ i_define("SCHAR", "_MAX", (long) char_max,
+ (long) SCHAR_MAX);
+#endif /* NO_SC */
+ }
+ }
+ return bits_per_byte;
+}
+
+int basic() {
+ /* The properties of the basic types.
+ Returns number of bits per sizeof unit */
+ volatile int bits_per_byte;
+
+ bits_per_byte= cprop();
+
+ /* Shorts, ints and longs *****************************************/
+ Vprintf("%sShort=%d int=%d long=%d float=%d double=%d bits %s\n",
+ co,
+ (int) sizeof(short)*bits_per_byte,
+ (int) sizeof(int)*bits_per_byte,
+ (int) sizeof(long)*bits_per_byte,
+ (int) sizeof(float)*bits_per_byte,
+ (int) sizeof(double)*bits_per_byte, oc);
+ if (stdc) {
+ Vprintf("%sLong double=%d bits%s\n",
+ co, (int) sizeof(Long_double)*bits_per_byte, oc);
+ }
+ Vprintf("%sChar pointers = %d bits%s%s\n",
+ co, (int)sizeof(char *)*bits_per_byte,
+ sizeof(char *)>sizeof(int)?" BEWARE! larger than int!":"",
+ oc);
+ Vprintf("%sInt pointers = %d bits%s%s\n",
+ co, (int)sizeof(int *)*bits_per_byte,
+ sizeof(int *)>sizeof(int)?" BEWARE! larger than int!":"",
+ oc);
+ sprop();
+ iprop();
+ lprop();
+ usprop();
+ uiprop();
+ ulprop();
+
+ Unexpected(6);
+
+ /* Alignment constants ********************************************/
+ Vprintf("%sAlignments used for char=%d short=%d int=%d long=%d%s\n",
+ co,
+ (int)sizeof(struct{char i1; char c1;})-(int)sizeof(char),
+ (int)sizeof(struct{short i2; char c2;})-(int)sizeof(short),
+ (int)sizeof(struct{int i3; char c3;})-(int)sizeof(int),
+ (int)sizeof(struct{long i4; char c4;})-(int)sizeof(long),
+ oc);
+
+ /* Ten little endians *********************************************/
+
+ endian(bits_per_byte);
+
+ /* Pointers *******************************************************/
+ if (V) {
+ if ("abcd"=="abcd")
+ printf("%sStrings are shared%s\n", co, oc);
+ else printf("%sStrings are not shared%s\n", co, oc);
+ }
+
+ return bits_per_byte;
+}
+
+#endif /* ifndef PASS */
+
+/* As I said, I apologise for the contortions below. The functions are
+ expanded by the preprocessor twice or three times (for float and double,
+ and maybe for long double, and for short, int and long). That way,
+ I never make a change to one that I forget to make to the other.
+ You can look on it as C's fault for not supporting multi-line macro's.
+ This whole file is read 3 times by the preprocessor, with PASSn set for
+ n=1, 2 or 3, to decide which parts to reprocess.
+*/
+
+/* #undef on an already undefined thing is (wrongly) flagged as an error
+ by some compilers, therefore the #ifdef that follows:
+*/
+#ifdef Number
+#undef Number
+#undef THING
+#undef Thing
+#undef thing
+#undef FPROP
+#undef Fname
+#undef Store
+#undef Sum
+#undef Diff
+#undef Mul
+#undef Div
+#undef Self
+#undef F_check
+#undef Validate
+#undef EPROP
+#undef MARK
+
+#undef F_RADIX
+#undef F_MANT_DIG
+#undef F_DIG
+#undef F_ROUNDS
+#undef F_EPSILON
+#undef F_MIN_EXP
+#undef F_MIN
+#undef F_MIN_10_EXP
+#undef F_MAX_EXP
+#undef F_MAX
+#undef F_MAX_10_EXP
+#endif
+
+#ifdef Integer
+#undef Integer
+#undef INT
+#undef IPROP
+#undef Iname
+#undef UPROP
+#undef Uname
+#undef OK_UI
+
+#undef I_MAX
+#undef I_MIN
+#undef U_MAX
+#endif
+
+#ifdef PASS1
+
+#define Number float
+#define THING "FLOAT"
+#define Thing "Float"
+#define thing "float"
+#define Fname "FLT"
+#define FPROP fprop
+#define Store fStore
+#define Sum fSum
+#define Diff fDiff
+#define Mul fMul
+#define Div fDiv
+#define Self fSelf
+#define F_check fCheck
+#define Validate fValidate
+#define MARK "F"
+
+#define EPROP efprop
+
+#define Integer short
+#define INT "short"
+#define IPROP sprop
+#define Iname "SHRT"
+#ifndef NO_UI
+#define OK_UI 1
+#endif
+
+#define UPROP usprop
+#define Uname "USHRT"
+
+#ifdef VERIFY
+#define I_MAX SHRT_MAX
+#define I_MIN SHRT_MIN
+#define U_MAX USHRT_MAX
+
+#define F_RADIX FLT_RADIX
+#define F_MANT_DIG FLT_MANT_DIG
+#define F_DIG FLT_DIG
+#define F_ROUNDS FLT_ROUNDS
+#define F_EPSILON FLT_EPSILON
+#define F_MIN_EXP FLT_MIN_EXP
+#define F_MIN FLT_MIN
+#define F_MIN_10_EXP FLT_MIN_10_EXP
+#define F_MAX_EXP FLT_MAX_EXP
+#define F_MAX FLT_MAX
+#define F_MAX_10_EXP FLT_MAX_10_EXP
+#endif /* VERIFY */
+
+#endif /* PASS1 */
+
+#ifdef PASS2
+
+#define Number double
+#define THING "DOUBLE"
+#define Thing "Double"
+#define thing "double"
+#define Fname "DBL"
+#define FPROP dprop
+#define Store dStore
+#define Sum dSum
+#define Diff dDiff
+#define Mul dMul
+#define Div dDiv
+#define Self dSelf
+#define F_check dCheck
+#define Validate dValidate
+#define MARK ""
+
+#define EPROP edprop
+
+#define Integer int
+#define INT "int"
+#define IPROP iprop
+#define Iname "INT"
+#define OK_UI 1 /* Unsigned int is always possible */
+
+#define UPROP uiprop
+#define Uname "UINT"
+
+#ifdef VERIFY
+#define I_MAX INT_MAX
+#define I_MIN INT_MIN
+#define U_MAX UINT_MAX
+
+#define F_MANT_DIG DBL_MANT_DIG
+#define F_DIG DBL_DIG
+#define F_EPSILON DBL_EPSILON
+#define F_MIN_EXP DBL_MIN_EXP
+#define F_MIN DBL_MIN
+#define F_MIN_10_EXP DBL_MIN_10_EXP
+#define F_MAX_EXP DBL_MAX_EXP
+#define F_MAX DBL_MAX
+#define F_MAX_10_EXP DBL_MAX_10_EXP
+#endif /* VERIFY */
+
+#endif /* PASS2 */
+
+#ifdef PASS3
+
+#ifdef __STDC__
+#define Number long double
+#endif
+
+#define THING "LONG DOUBLE"
+#define Thing "Long double"
+#define thing "long double"
+#define Fname "LDBL"
+#define FPROP ldprop
+#define Store ldStore
+#define Sum ldSum
+#define Diff ldDiff
+#define Mul ldMul
+#define Div ldDiv
+#define Self ldSelf
+#define F_check ldCheck
+#define Validate ldValidate
+#define MARK "L"
+
+#define EPROP eldprop
+
+#define Integer long
+#define INT "long"
+#define IPROP lprop
+#define Iname "LONG"
+#ifndef NO_UI
+#define OK_UI 1
+#endif
+
+#define UPROP ulprop
+#define Uname "ULONG"
+
+#ifdef VERIFY
+#define I_MAX LONG_MAX
+#define I_MIN LONG_MIN
+#define U_MAX ULONG_MAX
+
+#define F_MANT_DIG LDBL_MANT_DIG
+#define F_DIG LDBL_DIG
+#define F_EPSILON LDBL_EPSILON
+#define F_MIN_EXP LDBL_MIN_EXP
+#define F_MIN LDBL_MIN
+#define F_MIN_10_EXP LDBL_MIN_10_EXP
+#define F_MAX_EXP LDBL_MAX_EXP
+#define F_MAX LDBL_MAX
+#define F_MAX_10_EXP LDBL_MAX_10_EXP
+#endif /* VERIFY */
+
+#endif /* PASS3 */
+
+#ifndef VERIFY
+#define I_MAX int_max
+#define I_MIN int_min
+#define U_MAX int_max
+
+#define F_RADIX f_radix
+#define F_MANT_DIG f_mant_dig
+#define F_DIG f_dig
+#define F_ROUNDS f_rounds
+#define F_EPSILON f_epsilon
+#define F_MIN_EXP f_min_exp
+#define F_MIN f_min
+#define F_MIN_10_EXP f_min_10_exp
+#define F_MAX_EXP f_max_exp
+#define F_MAX f_max
+#define F_MAX_10_EXP f_max_10_exp
+#endif
+
+Procedure IPROP() { /* for short, int, and long */
+ volatile Integer newi, int_max, maxeri, int_min, minneri;
+ volatile int ibits, ipower, two=2;
+
+ /* Calculate max short/int/long ***********************************/
+ /* Calculate 2**n-1 until overflow - then use the previous value */
+
+ newi=1; int_max=0;
+
+ if (setjmp(lab)==0) { /* Yields int_max */
+ for(ipower=0; newi>int_max; ipower++) {
+ int_max=newi;
+ newi=newi*two+1;
+ }
+ Vprintf("%sOverflow of a%s %s does not generate a trap%s\n",
+ co, INT[0]=='i'?"n":"", INT, oc);
+ } else {
+ Vprintf("%sOverflow of a%s %s generates a trap%s\n",
+ co, INT[0]=='i'?"n":"", INT, oc);
+ }
+ Unexpected(7);
+
+ /* Minimum value: assume either two's or one's complement *********/
+ int_min= -int_max;
+ if (setjmp(lab)==0) { /* Yields int_min */
+ if (int_min-1 < int_min) int_min--;
+ }
+ Unexpected(8);
+
+ /* Now for those daft Cybers: */
+
+ maxeri=0; newi=int_max;
+
+ if (setjmp(lab)==0) { /* Yields maxeri */
+ for(ibits=ipower; newi>maxeri; ibits++) {
+ maxeri=newi;
+ newi=newi+newi+1;
+ }
+ }
+ Unexpected(9);
+
+ minneri= -maxeri;
+ if (setjmp(lab)==0) { /* Yields minneri */
+ if (minneri-1 < minneri) minneri--;
+ }
+ Unexpected(10);
+
+ Vprintf("%sMaximum %s = %ld (= 2**%d-1)%s\n",
+ co, INT, (long)int_max, ipower, oc);
+ Vprintf("%sMinimum %s = %ld%s\n", co, INT, (long)int_min, oc);
+
+ if (L) i_define(Iname, "_MAX", (long) int_max, (long) I_MAX);
+ if (L) i_define(Iname, "_MIN", (long) int_min, (long) I_MIN);
+
+ if (maxeri>int_max) {
+ Vprintf("%sThere is a larger %s, %ld (= 2**%d-1), %s %s%s\n",
+ co, INT, (long)maxeri, ibits,
+ "but only for addition, not multiplication",
+ "(I smell a Cyber!)",
+ oc);
+ }
+
+ if (minneri<int_min) {
+ Vprintf("%sThere is a smaller %s, %ld, %s %s%s\n",
+ co, INT, (long)minneri,
+ "but only for addition, not multiplication",
+ "(I smell a Cyber!)",
+ oc);
+ }
+}
+
+Procedure UPROP () { /* unsigned short/int/long */
+#ifdef OK_UI
+ volatile unsigned Integer int_max, newi, two;
+ newi=1; int_max=0; two=2;
+
+ if (setjmp(lab)==0) { /* Yields int_max */
+ while(newi>int_max) {
+ int_max=newi;
+ newi=newi*two+1;
+ }
+ }
+ Unexpected(11);
+ Vprintf("%sMaximum unsigned %s = %lu%s\n",
+ co, INT, (unsigned long) int_max, oc);
+ if (L) u_define(Uname, "_MAX", (unsigned long) int_max,
+ (unsigned long) U_MAX);
+#endif
+}
+
+
+#ifdef Number
+
+/* These routines are intended to defeat any attempt at optimisation
+ or use of extended precision, and to defeat faulty narrowing casts:
+*/
+Procedure Store(a, b) Number a, *b; { *b=a; }
+Number Sum(a, b) Number a, b; { Number r; Store(a+b, &r); return (r); }
+Number Diff(a, b) Number a, b; { Number r; Store(a-b, &r); return (r); }
+Number Mul(a, b) Number a, b; { Number r; Store(a*b, &r); return (r); }
+Number Div(a, b) Number a, b; { Number r; Store(a/b, &r); return (r); }
+Number Self(a) Number a; { Number r; Store(a, &r); return (r); }
+
+Procedure F_check(precision, val1) int precision; Long_double val1; {
+ /* You don't think I'm going to go to all the trouble of writing
+ a program that works out what all sorts of values are, only to
+ have printf go and print the wrong values out, do you?
+ No, you're right, so this function tries to see if printf
+ has written the right value, by reading it back again.
+ This introduces a new problem of course: suppose printf writes
+ the correct value, and scanf reads it back wrong... oh well.
+ But I'm adamant about this: the precision given is enough
+ to uniquely identify the printed number, therefore I insist
+ that sscanf read the number back identically. Harsh yes, but
+ sometimes you've got to be cruel to be kind.
+ */
+ Long_double new1;
+ Number val, new, diff;
+ double rem;
+ int e;
+ char *rep;
+ char *f2;
+
+ if (sizeof(double) == sizeof(Long_double)) {
+ /* Assume they're the same, and use non-stdc format */
+ /* This is for stdc compilers using non-stdc libraries */
+ f2= "%le"; /* Input */
+ } else {
+ /* It had better support Le then */
+ f2= "%Le";
+ }
+ val= val1;
+ rep= f_rep(precision, (Long_double) val);
+ if (setjmp(lab)==0) {
+ sscanf(rep, f2, &new1);
+ } else {
+ eek_a_bug("sscanf caused a trap");
+ printf("%s scanning: %s format: %s%s\n\n", co, rep, f2, oc);
+ Unexpected(12);
+ return;
+ }
+
+ if (setjmp(lab)==0) { /* See if new is usable */
+ new= new1;
+ if (new != 0.0) {
+ diff= val/new - 1.0;
+ if (diff < 0.1) diff= 1.0;
+ /* That should be enough to generate a trap */
+ }
+ } else {
+ eek_a_bug("sscanf returned an unusable number");
+ printf("%s scanning: %s with format: %s%s\n\n",
+ co, rep, f2, oc);
+ Unexpected(13);
+ return;
+ }
+
+ Unexpected(14);
+ if (new != val) {
+ eek_a_bug("Possibly bad output from printf above");
+ if (!exponent(val, &rem, &e)) {
+ printf("%s but value was an unusable number%s\n\n",
+ co, oc);
+ return;
+ }
+ printf("%s expected value around %.*fe%d, bit pattern:\n ",
+ co, precision, rem, e);
+ bitpattern((char *) &val, sizeof(val));
+ printf ("%s\n", oc);
+ printf("%s sscanf gave %s, bit pattern:\n ",
+ co, f_rep(precision, (Long_double) new));
+ bitpattern((char *) &new, sizeof(new));
+ printf ("%s\n", oc);
+ printf("%s difference= %s%s\n\n",
+ co, f_rep(precision, (Long_double) (val-new)), oc);
+ }
+}
+
+Procedure Validate(prec, val, req, same) int prec, same; Long_double val, req; {
+ Unexpected(15);
+ if (!same) {
+ printf("%s*** Verify failed for above #define!\n", co);
+ if (setjmp(lab) == 0) { /* for the case that req == nan */
+ printf(" Compiler has %s for value%s\n",
+ f_rep(prec, req), oc);
+ } else {
+ printf(" Compiler has %s for value%s\n",
+ "an unusable number", oc);
+ }
+ if (setjmp(lab) == 0) {
+ F_check(prec, (Long_double) req);
+ } /*else forget it*/
+ if (setjmp(lab) == 0) {
+ if (req > 0.0 && val > 0.0) {
+ printf("%s difference= %s%s\n",
+ co, f_rep(prec, val-req), oc);
+ }
+ } /*else forget it*/
+ Unexpected(16);
+ printf("\n");
+ bugs++;
+ } else if (val != req) {
+ if (stdc) {
+ printf("%s*** Verify failed for above #define!\n", co);
+ printf(" Constant has the wrong precision%s\n",
+ oc);
+ bugs++;
+ } else eek_a_bug("the cast didn't work");
+ printf("\n");
+ }
+}
+
+int FPROP(bits_per_byte) int bits_per_byte; {
+ /* Properties of floating types, using algorithms by Cody and Waite
+ from MA Malcolm, as modified by WM Gentleman and SB Marovich.
+ Further extended by S Pemberton.
+
+ Returns the number of digits in the fraction.
+ */
+
+ volatile int i, f_radix, iexp, irnd, mrnd, f_rounds, f_mant_dig,
+ iz, k, inf, machep, f_max_exp, f_min_exp, mx, negeps,
+ mantbits, digs, f_dig, trap,
+ hidden, normal, f_min_10_exp, f_max_10_exp;
+ volatile Number a, b, base, basein, basem1, f_epsilon, epsneg,
+ f_max, newxmax, f_min, xminner, y, y1, z, z1, z2;
+
+ Unexpected(17);
+
+ Vprintf("%sPROPERTIES OF %s:%s\n", co, THING, oc);
+
+ /* Base and size of mantissa **************************************/
+ /* First repeatedly double until adding 1 has no effect. */
+ /* For instance, if base is 10, with 3 significant digits */
+ /* it will try 1, 2, 4, 8, ... 512, 1024, and stop there, */
+ /* since 1024 is only representable as 1020. */
+ a=1.0;
+ if (setjmp(lab)==0) { /* inexact trap? */
+ do { a=Sum(a, a); }
+ while (Diff(Diff(Sum(a, 1.0), a), 1.0) == 0.0);
+ } else {
+ fprintf(stderr, "*** Program got loss-of-precision trap!\n");
+ /* And supporting those is just TOO much trouble! */
+ exit(bugs+1);
+ }
+ Unexpected(18);
+ /* Now double until you find a number that can be added to the */
+ /* above number. For 1020 this is 8 or 16, depending whether the */
+ /* result is rounded or truncated. */
+ /* In either case the result is 1030. 1030-1020= the base, 10. */
+ b=1.0;
+ do { b=Sum(b, b); } while ((base=Diff(Sum(a, b), a)) == 0.0);
+ f_radix=base;
+ Vprintf("%sBase = %d%s\n", co, f_radix, oc);
+
+ /* Sanity check; if base<2, I can't guarantee the rest will work */
+ if (f_radix < 2) {
+ eek_a_bug("Function return or parameter passing faulty? (This is a guess.)");
+ printf("\n");
+ return(0);
+ }
+
+#ifdef PASS1 /* only for FLT */
+ if (F) i_define("FLT", "_RADIX", (long) f_radix, (long) F_RADIX);
+#endif
+
+ /* Now the number of digits precision: */
+ f_mant_dig=0; b=1.0;
+ do { f_mant_dig++; b=Mul(b, base); }
+ while (Diff(Diff(Sum(b,1.0),b),1.0) == 0.0);
+ f_dig=floor_log(10, (Long_double)(b/base)) + (base==10?1:0);
+ Vprintf("%sSignificant base digits = %d %s %d %s%s\n",
+ co, f_mant_dig, "(= at least", f_dig, "decimal digits)", oc);
+ if (F) i_define(Fname, "_MANT_DIG", (long) f_mant_dig,
+ (long) F_MANT_DIG);
+ if (F) i_define(Fname, "_DIG", (long) f_dig, (long) F_DIG);
+ digs= ceil_log(10, (Long_double)b); /* the number of digits to printf */
+
+ /* Rounding *******************************************************/
+ basem1=Diff(base, 0.5);
+ if (Diff(Sum(a, basem1), a) != 0.0) {
+ if (f_radix == 2) basem1=0.375;
+ else basem1=1.0;
+ if (Diff(Sum(a, basem1), a) != 0.0) irnd=2; /* away from 0 */
+ else irnd=1; /* to nearest */
+ } else irnd=0; /* towards 0 */
+
+ basem1=Diff(base, 0.5);
+
+ if (Diff(Diff(-a, basem1), -a) != 0.0) {
+ if (f_radix == 2) basem1=0.375;
+ else basem1=1.0;
+ if (Diff(Diff(-a, basem1), -a) != 0.0) mrnd=2; /* away from 0*/
+ else mrnd=1; /* to nearest */
+ } else mrnd=0; /* towards 0 */
+
+ f_rounds=4; /* Unknown rounding */
+ if (irnd==0 && mrnd==0) f_rounds=0; /* zero = chops */
+ if (irnd==1 && mrnd==1) f_rounds=1; /* nearest */
+ if (irnd==2 && mrnd==0) f_rounds=2; /* +inf */
+ if (irnd==0 && mrnd==2) f_rounds=3; /* -inf */
+
+ if (f_rounds != 4) {
+ Vprintf("%sArithmetic rounds towards ", co);
+ switch (f_rounds) {
+ case 0: Vprintf("zero (i.e. it chops)"); break;
+ case 1: Vprintf("nearest"); break;
+ case 2: Vprintf("+infinity"); break;
+ case 3: Vprintf("-infinity"); break;
+ default: Vprintf("???"); break;
+ }
+ Vprintf("%s\n", oc);
+ } else { /* Hmm, try to give some help here: */
+ Vprintf("%sArithmetic rounds oddly: %s\n", co, oc);
+ Vprintf("%s Negative numbers %s%s\n",
+ co, mrnd==0 ? "towards zero" :
+ mrnd==1 ? "to nearest" :
+ "away from zero",
+ oc);
+ Vprintf("%s Positive numbers %s%s\n",
+ co, irnd==0 ? "towards zero" :
+ irnd==1 ? "to nearest" :
+ "away from zero",
+ oc);
+ }
+ /* An extra goody */
+ if (f_radix == 2 && f_rounds == 1) {
+ if (Diff(Sum(a, 1.0), a) != 0.0) {
+ Vprintf("%s Tie breaking rounds up%s\n", co, oc);
+ } else if (Diff(Sum(a, 3.0), a) == 4.0) {
+ Vprintf("%s Tie breaking rounds to even%s\n", co, oc);
+ } else {
+ Vprintf("%s Tie breaking rounds down%s\n", co, oc);
+ }
+ }
+#ifdef PASS1 /* only for FLT */
+ if (F) i_define("FLT", "_ROUNDS", (long) f_rounds, (long) F_ROUNDS);
+#endif
+
+ /* Various flavours of epsilon ************************************/
+ negeps=f_mant_dig+f_mant_dig;
+ basein=1.0/base;
+ a=1.0;
+ for(i=1; i<=negeps; i++) a*=basein;
+
+ b=a;
+ while (Diff(Diff(1.0, a), 1.0) == 0.0) {
+ a*=base;
+ negeps--;
+ }
+ negeps= -negeps;
+ Vprintf("%sSmallest x such that 1.0-base**x != 1.0 = %d%s\n",
+ co, negeps, oc);
+
+ epsneg=a;
+ if ((f_radix!=2) && irnd) {
+ /* a=(a*(1.0+a))/(1.0+1.0); => */
+ a=Div(Mul(a, Sum(1.0, a)), Sum(1.0, 1.0));
+ /* if ((1.0-a)-1.0 != 0.0) epsneg=a; => */
+ if (Diff(Diff(1.0, a), 1.0) != 0.0) epsneg=a;
+ }
+ Vprintf("%sSmall x such that 1.0-x != 1.0 = %s%s\n",
+ co, f_rep(digs, (Long_double) epsneg), oc);
+ /* it may not be the smallest */
+ if (V) F_check(digs, (Long_double) epsneg);
+ Unexpected(19);
+
+ machep= -f_mant_dig-f_mant_dig;
+ a=b;
+ while (Diff(Sum(1.0, a), 1.0) == 0.0) { a*=base; machep++; }
+ Vprintf("%sSmallest x such that 1.0+base**x != 1.0 = %d%s\n",
+ co, machep, oc);
+
+ f_epsilon=a;
+ if ((f_radix!=2) && irnd) {
+ /* a=(a*(1.0+a))/(1.0+1.0); => */
+ a=Div(Mul(a, Sum(1.0, a)), Sum(1.0, 1.0));
+ /* if ((1.0+a)-1.0 != 0.0) f_epsilon=a; => */
+ if (Diff(Sum(1.0, a), 1.0) != 0.0) f_epsilon=a;
+ }
+ Vprintf("%sSmallest x such that 1.0+x != 1.0 = %s%s\n",
+ co, f_rep(digs, (Long_double) f_epsilon), oc);
+ /* Possible loss of precision warnings here from non-stdc compilers: */
+ if (F) f_define(Fname, "_EPSILON", digs, (Long_double) f_epsilon, MARK);
+ if (V || F) F_check(digs, (Long_double) f_epsilon);
+ Unexpected(20);
+ if (F) Validate(digs, (Long_double) f_epsilon, (Long_double) F_EPSILON,
+ f_epsilon == Self(F_EPSILON));
+ Unexpected(21);
+
+ /* Extra chop info *************************************************/
+ if (f_rounds == 0) {
+ if (Diff(Mul(Sum(1.0,f_epsilon),1.0),1.0) != 0.0) {
+ Vprintf("%sAlthough arithmetic chops, it uses guard digits%s\n", co, oc);
+ }
+ }
+
+ /* Size of and minimum normalised exponent ************************/
+ y=0; i=0; k=1; z=basein; z1=(1.0+f_epsilon)/base;
+
+ /* Coarse search for the largest power of two */
+ if (setjmp(lab)==0) { /* for underflow trap */ /* Yields i, k, y, y1 */
+ do {
+ y=z; y1=z1;
+ z=Mul(y,y); z1=Mul(z1, y);
+ a=Mul(z,1.0);
+ z2=Div(z1,y);
+ if (z2 != y1) break;
+ if ((Sum(a,a) == 0.0) || (fabs(z) >= y)) break;
+ i++;
+ k+=k;
+ } while(1);
+ } else {
+ Vprintf("%s%s underflow generates a trap%s\n", co, Thing, oc);
+ }
+ Unexpected(22);
+
+ if (f_radix != 10) {
+ iexp=i+1; /* for the sign */
+ mx=k+k;
+ } else {
+ iexp=2;
+ iz=f_radix;
+ while (k >= iz) { iz*=f_radix; iexp++; }
+ mx=iz+iz-1;
+ }
+
+ /* Fine tune starting with y and y1 */
+ if (setjmp(lab)==0) { /* for underflow trap */ /* Yields k, f_min */
+ do {
+ f_min=y; z1=y1;
+ y=Div(y,base); y1=Div(y1,base);
+ a=Mul(y,1.0);
+ z2=Mul(y1,base);
+ if (z2 != z1) break;
+ if ((Sum(a,a) == 0.0) || (fabs(y) >= f_min)) break;
+ k++;
+ } while (1);
+ }
+ Unexpected(23);
+
+ f_min_exp=(-k)+1;
+
+ if ((mx <= k+k-3) && (f_radix != 10)) { mx+=mx; iexp+=1; }
+ Vprintf("%sNumber of bits used for exponent = %d%s\n", co, iexp, oc);
+ Vprintf("%sMinimum normalised exponent = %d%s\n", co, f_min_exp, oc);
+ if (F) i_define(Fname, "_MIN_EXP", (long) f_min_exp, (long) F_MIN_EXP);
+
+ if (setjmp(lab)==0) {
+ Vprintf("%sMinimum normalised positive number = %s%s\n",
+ co, f_rep(digs, (Long_double) f_min), oc);
+ } else {
+ eek_a_bug("printf can't print the smallest normalised number");
+ printf("\n");
+ }
+ Unexpected(24);
+ /* Possible loss of precision warnings here from non-stdc compilers: */
+ if (setjmp(lab) == 0) {
+ if (F) f_define(Fname, "_MIN", digs, (Long_double) f_min, MARK);
+ if (V || F) F_check(digs, (Long_double) f_min);
+ } else {
+ eek_a_bug("xxx_MIN caused a trap");
+ printf("\n");
+ }
+
+ if (setjmp(lab) == 0) {
+ if (F) Validate(digs, (Long_double) f_min, (Long_double) F_MIN,
+ f_min == Self(F_MIN));
+ } else {
+ printf("%s*** Verify failed for above #define!\n %s %s\n\n",
+ co, "Compiler has an unusable number for value", oc);
+ bugs++;
+ }
+ Unexpected(25);
+
+ a=1.0; f_min_10_exp=0;
+ while (a > f_min*10.0) { a/=10.0; f_min_10_exp--; }
+ if (F) i_define(Fname, "_MIN_10_EXP", (long) f_min_10_exp,
+ (long) F_MIN_10_EXP);
+
+ /* Minimum exponent ************************************************/
+ if (setjmp(lab)==0) { /* for underflow trap */ /* Yields xminner */
+ do {
+ xminner=y;
+ y=Div(y,base);
+ a=Mul(y,1.0);
+ if ((Sum(a,a) == 0.0) || (fabs(y) >= xminner)) break;
+ } while (1);
+ }
+ Unexpected(26);
+
+ if (xminner != 0.0 && xminner != f_min) {
+ normal= 0;
+ Vprintf("%sThe smallest numbers are not kept normalised%s\n",
+ co, oc);
+ if (setjmp(lab)==0) {
+ Vprintf("%sSmallest unnormalised positive number = %s%s\n",
+ co, f_rep(digs, (Long_double) xminner), oc);
+ if (V) F_check(digs, (Long_double) xminner);
+ } else {
+ eek_a_bug("printf can't print the smallest unnormalised number.");
+ printf("\n");
+ }
+ Unexpected(27);
+ } else {
+ normal= 1;
+ Vprintf("%sThe smallest numbers are normalised%s\n", co, oc);
+ }
+
+ /* Maximum exponent ************************************************/
+ f_max_exp=2; f_max=1.0; newxmax=base+1.0;
+ inf=0; trap=0;
+ while (f_max<newxmax) {
+ f_max=newxmax;
+ if (setjmp(lab) == 0) { /* Yields inf, f_max_exp */
+ newxmax=Mul(newxmax, base);
+ } else {
+ trap=1;
+ break;
+ }
+ if (Div(newxmax, base) != f_max) {
+ inf=1; /* ieee infinity */
+ break;
+ }
+ f_max_exp++;
+ }
+ Unexpected(28);
+ if (trap) {
+ Vprintf("%s%s overflow generates a trap%s\n", co, Thing, oc);
+ }
+
+ if (inf) Vprintf("%sThere is an 'infinite' value%s\n", co, oc);
+ Vprintf("%sMaximum exponent = %d%s\n", co, f_max_exp, oc);
+ if (F) i_define(Fname, "_MAX_EXP", (long) f_max_exp, (long) F_MAX_EXP);
+
+ /* Largest number ***************************************************/
+ f_max=Diff(1.0, epsneg);
+ if (Mul(f_max,1.0) != f_max) f_max=Diff(1.0, Mul(base,epsneg));
+ for (i=1; i<=f_max_exp; i++) f_max=Mul(f_max, base);
+
+ if (setjmp(lab)==0) {
+ Vprintf("%sMaximum number = %s%s\n",
+ co, f_rep(digs, (Long_double) f_max), oc);
+ } else {
+ eek_a_bug("printf can't print the largest double.");
+ printf("\n");
+ }
+ if (setjmp(lab)==0) {
+ /* Possible loss of precision warnings here from non-stdc compilers: */
+ if (F) f_define(Fname, "_MAX", digs, (Long_double) f_max, MARK);
+ if (V || F) F_check(digs, (Long_double) f_max);
+ } else {
+ eek_a_bug("xxx_MAX caused a trap");
+ printf("\n");
+ }
+ if (setjmp(lab)==0) {
+ if (F) Validate(digs, (Long_double) f_max, (Long_double) F_MAX,
+ f_max == Self(F_MAX));
+ } else {
+ printf("%s*** Verify failed for above #define!\n %s %s\n\n",
+ co, "Compiler has an unusable number for value", oc);
+ bugs++;
+ }
+ Unexpected(29);
+
+ a=1.0; f_max_10_exp=0;
+ while (a < f_max/10.0) { a*=10.0; f_max_10_exp++; }
+ if (F) i_define(Fname, "_MAX_10_EXP", (long) f_max_10_exp,
+ (long) F_MAX_10_EXP);
+
+ /* Hidden bit + sanity check ****************************************/
+ if (f_radix != 10) {
+ hidden=0;
+ mantbits=floor_log(2, (Long_double)f_radix)*f_mant_dig;
+ if (mantbits+iexp == (int)sizeof(Number)*bits_per_byte) {
+ hidden=1;
+ Vprintf("%sArithmetic uses a hidden bit%s\n", co, oc);
+ } else if (mantbits+iexp+1 == (int)sizeof(Number)*bits_per_byte) {
+ Vprintf("%sArithmetic doesn't use a hidden bit%s\n",
+ co, oc);
+ } else {
+ printf("\n%s%s\n %s %s %s!%s\n\n",
+ co,
+ "*** Something fishy here!",
+ "Exponent size + mantissa size doesn't match",
+ "with the size of a", thing,
+ oc);
+ }
+ if (hidden && f_radix == 2 && f_max_exp+f_min_exp==3) {
+ Vprintf("%sIt looks like %s length IEEE format%s\n",
+ co, f_mant_dig==24 ? "single" :
+ f_mant_dig==53 ? "double" :
+ f_mant_dig >53 ? "extended" :
+ "some", oc);
+ if (f_rounds != 1 || normal) {
+ Vprintf("%s though ", co);
+ if (f_rounds != 1) {
+ Vprintf("the rounding is unusual");
+ if (normal) Vprintf(" and ");
+ }
+ if (normal) Vprintf("the normalisation is unusual");
+ Vprintf("%s\n", oc);
+ }
+ } else {
+ Vprintf("%sIt doesn't look like IEEE format%s\n",
+ co, oc);
+ }
+ }
+ printf("\n"); /* regardless of verbosity */
+ return f_mant_dig;
+}
+
+Procedure EPROP(fprec, dprec, lprec) int fprec, dprec, lprec; {
+ /* See if expressions are evaluated in extended precision.
+ Some compilers optimise even if you don't want it,
+ and then this function fails to produce the right result.
+ We try to diagnose this if it happens.
+ */
+ volatile int eprec;
+ volatile double a, b, base, old;
+ volatile Number d, oldd, dbase, one, zero;
+ volatile int bad=0;
+
+ /* Size of mantissa **************************************/
+ a=1.0;
+ if (setjmp(lab) == 0) { /* Yields nothing */
+ do { old=a; a=a+a; }
+ while ((((a+1.0)-a)-1.0) == 0.0 && a>old);
+ } else bad=1;
+ if (a <= old) bad=1;
+
+ if (!bad) {
+ b=1.0;
+ if (setjmp(lab) == 0) { /* Yields nothing */
+ do { old=b; b=b+b; }
+ while ((base=((a+b)-a)) == 0.0 && b>old);
+ if (b <= old) bad=1;
+ } else bad=1;
+ }
+
+ if (!bad) {
+ eprec=0; d=1.0; dbase=base; one=1.0; zero=0.0;
+ if (setjmp(lab) == 0) { /* Yields nothing */
+ do { eprec++; oldd=d; d=d*dbase; }
+ while ((((d+one)-d)-one) == zero && d>oldd);
+ if (d <= oldd) bad=1;
+ } else bad=1;
+ }
+
+ Unexpected(30);
+
+ if (bad) {
+ Vprintf("%sCan't determine precision for %s expressions:\n%s%s\n",
+ co, thing, " check that you compiled without optimisation!",
+ oc);
+ } else if (eprec==dprec) {
+ Vprintf("%s%s expressions are evaluated in double precision%s\n",
+ co, Thing, oc);
+ } else if (eprec==fprec) {
+ Vprintf("%s%s expressions are evaluated in float precision%s\n",
+ co, Thing, oc);
+ } else if (eprec==lprec) {
+ Vprintf("%s%s expressions are evaluated in long double precision%s\n",
+ co, Thing, oc);
+ } else {
+ Vprintf("%s%s expressions are evaluated in a %s %s %d %s%s\n",
+ co, Thing, eprec>dprec ? "higher" : "lower",
+ "precision than double,\n using",
+ eprec, "base digits",
+ oc);
+ }
+}
+
+#else /* Number */
+
+#ifdef FPROP
+/* ARGSUSED */
+int FPROP(bits_per_byte) int bits_per_byte; {
+ return 0;
+}
+#endif
+#ifdef EPROP
+/* ARGSUSED */
+Procedure EPROP(fprec, dprec, lprec) int fprec, dprec, lprec; {}
+#endif
+
+#endif /* ifdef Number */
+
+#ifdef PASS3
+#undef PASS
+#endif
+
+#ifdef PASS2
+#undef PASS2
+#define PASS3 1
+#endif
+
+#ifdef PASS1
+#undef PASS1
+#define PASS2 1
+#endif
+
+/* If your C compiler doesn't accept the next #include,
+ replace __FILE__ with the file name - and get a new C compiler... */
+
+#ifdef PASS
+#include __FILE__
+#endif
+
projects / mit-scheme.git / commitdiff