minix/lib/libc/gdtoa/arithchk.c
Ben Gras 2fe8fb192f Full switch to clang/ELF. Drop ack. Simplify.
There is important information about booting non-ack images in
docs/UPDATING. ack/aout-format images can't be built any more, and
booting clang/ELF-format ones is a little different. Updating to the
new boot monitor is recommended.

Changes in this commit:

	. drop boot monitor -> allowing dropping ack support
	. facility to copy ELF boot files to /boot so that old boot monitor
	  can still boot fairly easily, see UPDATING
	. no more ack-format libraries -> single-case libraries
	. some cleanup of OBJECT_FMT, COMPILER_TYPE, etc cases
	. drop several ack toolchain commands, but not all support
	  commands (e.g. aal is gone but acksize is not yet).
	. a few libc files moved to netbsd libc dir
	. new /bin/date as minix date used code in libc/
	. test compile fix
	. harmonize includes
	. /usr/lib is no longer special: without ack, /usr/lib plays no
	  kind of special bootstrapping role any more and bootstrapping
	  is done exclusively through packages, so releases depend even
	  less on the state of the machine making them now.
	. rename nbsd_lib* to lib*
	. reduce mtree
2012-02-14 14:52:02 +01:00

191 lines
4.2 KiB
C

/* $NetBSD: arithchk.c,v 1.3 2010/01/17 23:06:31 wiz Exp $ */
/****************************************************************
Copyright (C) 1997, 1998 Lucent Technologies
All Rights Reserved
Permission to use, copy, modify, and distribute this software and
its documentation for any purpose and without fee is hereby
granted, provided that the above copyright notice appear in all
copies and that both that the copyright notice and this
permission notice and warranty disclaimer appear in supporting
documentation, and that the name of Lucent or any of its entities
not be used in advertising or publicity pertaining to
distribution of the software without specific, written prior
permission.
LUCENT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS.
IN NO EVENT SHALL LUCENT OR ANY OF ITS ENTITIES BE LIABLE FOR ANY
SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER
IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF
THIS SOFTWARE.
****************************************************************/
/* Try to deduce arith.h from arithmetic properties. */
#include <stdio.h>
static int dalign;
typedef struct
Akind {
char *name;
int kind;
} Akind;
static Akind
IEEE_LITTLE_ENDIAN = { "IEEE_LITTLE_ENDIAN", 1 },
IEEE_BIG_ENDIAN = { "IEEE_BIG_ENDIAN", 2 },
IBM = { "IBM", 3 },
VAX = { "VAX", 4 },
CRAY = { "CRAY", 5};
static Akind *
Lcheck()
{
union {
double d;
long L[2];
} u;
struct {
double d;
long L;
} x[2];
if (sizeof(x) > 2*(sizeof(double) + sizeof(long)))
dalign = 1;
u.L[0] = u.L[1] = 0;
u.d = 1e13;
if (u.L[0] == 1117925532 && u.L[1] == -448790528)
return &IEEE_BIG_ENDIAN;
if (u.L[1] == 1117925532 && u.L[0] == -448790528)
return &IEEE_LITTLE_ENDIAN;
if (u.L[0] == -2065213935 && u.L[1] == 10752)
return &VAX;
if (u.L[0] == 1267827943 && u.L[1] == 704643072)
return &IBM;
return 0;
}
static Akind *
icheck()
{
union {
double d;
int L[2];
} u;
struct {
double d;
int L;
} x[2];
if (sizeof(x) > 2*(sizeof(double) + sizeof(int)))
dalign = 1;
u.L[0] = u.L[1] = 0;
u.d = 1e13;
if (u.L[0] == 1117925532 && u.L[1] == -448790528)
return &IEEE_BIG_ENDIAN;
if (u.L[1] == 1117925532 && u.L[0] == -448790528)
return &IEEE_LITTLE_ENDIAN;
if (u.L[0] == -2065213935 && u.L[1] == 10752)
return &VAX;
if (u.L[0] == 1267827943 && u.L[1] == 704643072)
return &IBM;
return 0;
}
char *emptyfmt = ""; /* avoid possible warning message with printf("") */
static Akind *
ccheck()
{
union {
double d;
long L;
} u;
long Cray1;
/* Cray1 = 4617762693716115456 -- without overflow on non-Crays */
Cray1 = printf(emptyfmt) < 0 ? 0 : 4617762;
if (printf(emptyfmt, Cray1) >= 0)
Cray1 = 1000000*Cray1 + 693716;
if (printf(emptyfmt, Cray1) >= 0)
Cray1 = 1000000*Cray1 + 115456;
u.d = 1e13;
if (u.L == Cray1)
return &CRAY;
return 0;
}
static int
fzcheck()
{
double a, b;
int i;
a = 1.;
b = .1;
for(i = 155;; b *= b, i >>= 1) {
if (i & 1) {
a *= b;
if (i == 1)
break;
}
}
b = a * a;
return b == 0.;
}
int
main()
{
Akind *a = 0;
int Ldef = 0;
FILE *f;
#ifdef WRITE_ARITH_H /* for Symantec's buggy "make" */
f = fopen("arith.h", "w");
if (!f) {
printf("Cannot open arith.h\n");
return 1;
}
#else
f = stdout;
#endif
if (sizeof(double) == 2*sizeof(long))
a = Lcheck();
else if (sizeof(double) == 2*sizeof(int)) {
Ldef = 1;
a = icheck();
}
else if (sizeof(double) == sizeof(long))
a = ccheck();
if (a) {
fprintf(f, "#define %s\n#define Arith_Kind_ASL %d\n",
a->name, a->kind);
if (Ldef)
fprintf(f, "#define Long int\n#define Intcast (int)(long)\n");
if (dalign)
fprintf(f, "#define Double_Align\n");
if (sizeof(char*) == 8)
fprintf(f, "#define X64_bit_pointers\n");
#ifndef NO_LONG_LONG
if (sizeof(long long) < 8)
#endif
fprintf(f, "#define NO_LONG_LONG\n");
if (a->kind <= 2 && fzcheck())
fprintf(f, "#define Sudden_Underflow\n");
#ifdef WRITE_ARITH_H
fclose(f);
#endif
return 0;
}
fprintf(f, "/* Unknown arithmetic */\n");
#ifdef WRITE_ARITH_H
fclose(f);
#endif
return 1;
}