stdlib.inl

ecos为实时嵌入式操作系统

#ifndef CYGONCE_LIBC_STDLIB_INL
#define CYGONCE_LIBC_STDLIB_INL
//===========================================================================
//
//      stdlib.inl
//
//      Inline implementations for the ANSI standard utility functions
//      defined in section 7.10 of the standard
//
//===========================================================================
//####COPYRIGHTBEGIN####
//
// -------------------------------------------
// The contents of this file are subject to the Cygnus eCos Public License
// Version 1.0 (the "License"); you may not use this file except in
// compliance with the License.  You may obtain a copy of the License at
// http://sourceware.cygnus.com/ecos
// 
// Software distributed under the License is distributed on an "AS IS"
// basis, WITHOUT WARRANTY OF ANY KIND, either express or implied.  See the
// License for the specific language governing rights and limitations under
// the License.
// 
// The Original Code is eCos - Embedded Cygnus Operating System, released
// September 30, 1998.
// 
// The Initial Developer of the Original Code is Cygnus.  Portions created
// by Cygnus are Copyright (C) 1998,1999 Cygnus Solutions.  All Rights Reserved.
// -------------------------------------------
//
//####COPYRIGHTEND####
//===========================================================================
//#####DESCRIPTIONBEGIN####
//
// Author(s):    jlarmour
// Contributors: jlarmour@
// Date:         1999-03-02
// Purpose:     
// Description: 
// Usage:        Do not include this file directly - include <stdlib.h> instead
//
//####DESCRIPTIONEND####
//
//===========================================================================

// CONFIGURATION

#include <pkgconf/libc.h>   // Configuration header

// INCLUDES

#include <stddef.h>                 // NULL, wchar_t and size_t from compiler
#include <stdlib.h>                 // Header for this file, just in case
#include <cyg/infra/cyg_ass.h>      // Assertion support
#include <cyg/infra/cyg_trac.h>     // Tracing support

// FUNCTIONS

//===========================================================================

// 7.10.1 String conversion functions


CYGPRI_LIBC_INLINE double
atof( const char *nptr )
{
    return strtod( nptr, (char **)NULL );
} // atof()

CYGPRI_LIBC_INLINE int
atoi( const char *nptr )
{
    return (int)strtol( nptr, (char **)NULL, 10 );
} // atoi()


CYGPRI_LIBC_INLINE long
atol( const char *nptr )
{
    return strtol( nptr, (char **)NULL, 10 );
} // atol()

//===========================================================================

// 7.10.6 Integer arithmetic functions


CYGPRI_LIBC_INLINE int
abs( int __j )
{
    return (__j<0) ? -__j : __j;
} // abs()


CYGPRI_LIBC_INLINE div_t
div( int __numer, int __denom )
{
    div_t __ret;

    CYG_REPORT_FUNCNAMETYPE( "div", "quotient: %d");
    CYG_REPORT_FUNCARG2DV( __numer, __denom );
    // FIXME: what if they want it handled with SIGFPE? Should have option
    CYG_PRECONDITION(__denom != 0, "division by zero attempted!");
    
    __ret.quot = __numer / __denom;
    __ret.rem  = __numer % __denom;

    // But the modulo is implementation-defined for -ve numbers (ISO C 6.3.5)
    // and we are required to "round" to zero (ISO C 7.10.6.2)
    //
    // The cases we have to deal with are inexact division of:
    // a) + div +
    // b) + div -
    // c) - div +
    // d) - div -
    //
    // a) can never go wrong and the quotient and remainder are always positive
    // b) only goes wrong if the negative quotient has been "rounded" to
    //    -infinity - if so then the remainder will be negative when it
    //    should be positive or zero
    // c) only goes wrong if the negative quotient has been "rounded" to
    //    -infinity - if so then the remainder will be positive when it
    //    should be negative or zero
    // d) only goes wrong if the positive quotient has been rounded to
    //    +infinity - if so then the remainder will be positive when it
    //    should be negative or zero
    //
    // So the correct sign of the remainder corresponds to the sign of the
    // numerator. Which means we can say that the result needs adjusting
    // iff the sign of the numerator is different from the sign of the
    // remainder.
    //
    // You may be interested to know that the Berkeley version of div()
    // would get this wrong for e.g. (c) and (d) on some targets.
    // e.g. for (-5)/4 it could leave the result as -2R3

    if ((__ret.rem < 0) && (__numer > 0)) {
        ++__ret.quot;
        __ret.rem -= __denom;
    } else if ((__ret.rem > 0) && (__numer < 0)) {
        --__ret.quot;
        __ret.rem += __denom;
    } // else

    CYG_REPORT_RETVAL( __ret.quot );

    return __ret;
} // div()


CYGPRI_LIBC_INLINE long
labs( long __j )
{
    return (__j<0) ? -__j : __j;
} // labs()


CYGPRI_LIBC_INLINE ldiv_t
ldiv( long __numer, long __denom )
{
    ldiv_t __ret;

    CYG_REPORT_FUNCNAMETYPE( "ldiv", "quotient: %d");
    CYG_REPORT_FUNCARG2DV( __numer, __denom );
    // FIXME: what if they want it handled with SIGFPE? Should have option
    CYG_PRECONDITION(__denom != 0, "division by zero attempted!");
    
    __ret.quot = __numer / __denom;
    __ret.rem  = __numer % __denom;

    // But the modulo is implementation-defined for -ve numbers (ISO C 6.3.5)
    // and we are required to "round" to zero (ISO C 7.10.6.2)
    //
    // The cases we have to deal with are inexact division of:
    // a) + div +
    // b) + div -
    // c) - div +
    // d) - div -
    //
    // a) can never go wrong and the quotient and remainder are always positive
    // b) only goes wrong if the negative quotient has been "rounded" to
    //    -infinity - if so then the remainder will be negative when it
    //    should be positive or zero
    // c) only goes wrong if the negative quotient has been "rounded" to
    //    -infinity - if so then the remainder will be positive when it
    //    should be negative or zero
    // d) only goes wrong if the positive quotient has been rounded to
    //    +infinity - if so then the remainder will be positive when it
    //    should be negative or zero
    //
    // So the correct sign of the remainder corresponds to the sign of the
    // numerator. Which means we can say that the result needs adjusting
    // iff the sign of the numerator is different from the sign of the
    // remainder.
    //
    // You may be interested to know that the Berkeley version of ldiv()
    // would get this wrong for e.g. (c) and (d) on some targets.
    // e.g. for (-5)/4 it could leave the result as -2R3

    if ((__ret.rem < 0) && (__numer > 0)) {
        ++__ret.quot;
        __ret.rem -= __denom;
    } else if ((__ret.rem > 0) && (__numer < 0)) {
        --__ret.quot;
        __ret.rem += __denom;
    } // else

    CYG_REPORT_RETVAL( __ret.quot );

    return __ret;
} // ldiv()


#endif // CYGONCE_LIBC_STDLIB_INL multiple inclusion protection

// EOF stdlib.inl