arithchk.c File Reference

#include <stdio.h>

Include dependency graph for arithchk.c:

Go to the source code of this file.

Classes
struct	Akind

Typedefs
typedef struct Akind	Akind

Functions
static Akind *	Lcheck ()
static Akind *	icheck ()
static Akind *	ccheck ()
static int	fzcheck ()
int	main ()

Variables
static int	dalign
static Akind	IEEE_8087 = {"IEEE_8087", 1}
static Akind	IEEE_MC68k = {"IEEE_MC68k", 2}
static Akind	IBM = {"IBM", 3}
static Akind	VAX = {"VAX", 4}
static Akind	CRAY = {"CRAY", 5}

---

Class Documentation

Akind

struct Akind

Definition at line 30 of file arithchk.c.

Collaboration diagram for Akind:

Class Members
int	kind
char *	name

Typedef Documentation

Akind

typedef struct Akind Akind

Function Documentation

ccheck()

static Akind* ccheck ( )

static

Definition at line 95 of file arithchk.c.

{
    union
    {
        double d;
        long L;
    } u;
    long Cray1;

    /* Cray1 = 4617762693716115456 -- without overflow on non-Crays */
    Cray1 = printf("") < 0 ? 0 : 4617762;
    if(printf("%ld", Cray1) >= 0)
        Cray1 = 1000000 * Cray1 + 693716;
    if(printf("%ld", Cray1) >= 0)
        Cray1 = 1000000 * Cray1 + 115456;
    u.d = 1e13;
    if(u.L == Cray1)
        return &CRAY;
    return 0;
}

References CRAY.

Referenced by main().

fzcheck()

static int fzcheck ( )

static

Definition at line 116 of file arithchk.c.

{
    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.;
}

Referenced by main().

icheck()

static Akind* icheck ( )

static

Definition at line 67 of file arithchk.c.

{
    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_MC68k;
    if(u.L[1] == 1117925532 && u.L[0] == -448790528)
        return &IEEE_8087;
    if(u.L[0] == -2065213935 && u.L[1] == 10752)
        return &VAX;
    if(u.L[0] == 1267827943 && u.L[1] == 704643072)
        return &IBM;
    return 0;
}

References dalign, IBM, IEEE_8087, IEEE_MC68k, and VAX.

Referenced by main().

Lcheck()

static Akind* Lcheck ( )

static

Definition at line 39 of file arithchk.c.

{
    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_MC68k;
    if(u.L[1] == 1117925532 && u.L[0] == -448790528)
        return &IEEE_8087;
    if(u.L[0] == -2065213935 && u.L[1] == 10752)
        return &VAX;
    if(u.L[0] == 1267827943 && u.L[1] == 704643072)
        return &IBM;
    return 0;
}

References dalign, IBM, IEEE_8087, IEEE_MC68k, and VAX.

Referenced by main().

main()

int main

(

void

)

Definition at line 136 of file arithchk.c.

{
    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;
}

References ccheck(), dalign, fclose(), fopen(), fprintf(), fzcheck(), icheck(), Akind::kind, Lcheck(), and Akind::name.

Variable Documentation

CRAY

Akind CRAY = {"CRAY", 5}

static

Definition at line 37 of file arithchk.c.

Referenced by ccheck().

dalign

int dalign

static

Definition at line 29 of file arithchk.c.

Referenced by icheck(), Lcheck(), and main().

IBM

Akind IBM = {"IBM", 3}

static

Definition at line 36 of file arithchk.c.

Referenced by icheck(), Lcheck(), and strtod().

IEEE_8087

Akind IEEE_8087 = {"IEEE_8087", 1}

static

Definition at line 36 of file arithchk.c.

Referenced by icheck(), and Lcheck().

IEEE_MC68k

Akind IEEE_MC68k = {"IEEE_MC68k", 2}

static

Definition at line 36 of file arithchk.c.

Referenced by icheck(), and Lcheck().

VAX

Akind VAX = {"VAX", 4}

static

Definition at line 37 of file arithchk.c.

Referenced by icheck(), and Lcheck().