_control87.c

Go to the documentation of this file.

/*
 * PROJECT:     ReactOS CRT
 * LICENSE:     MIT (https://spdx.org/licenses/MIT)
 * PURPOSE:     Implementation of _control87
 * COPYRIGHT:   Copyright 2022 Timo Kreuzer <timo.kreuzer@reactos.org>
 */
 
#include <xmmintrin.h>
#include <float.h>
 
unsigned int _get_native_fpcw(void);
void _set_native_fpcw(unsigned int value);
unsigned int _fpcw_native_to_abstract(unsigned int native);
unsigned int _fpcw_abstract_to_native(unsigned int abstract);
 
unsigned int __cdecl _control87(unsigned int newval, unsigned int mask)
{
    unsigned int native, oldval, updated;
 
    /* Sanatize the mask */
    mask &= _MCW_DN | _MCW_EM | _MCW_RC;
 
    /* Get native control word */
    native = _get_native_fpcw();
 
    /* Convert to abstract */
    oldval = _fpcw_native_to_abstract(native);
 
    /* Update it according to the given parameters */
    updated = (oldval & ~mask) | (newval & mask);
 
    /* Convert back to native */
    native = _fpcw_abstract_to_native(updated);
 
    /* Set the native value */
    _set_native_fpcw(native);
 
    return updated;
}