/*  Copyright © 2007 Apple Inc. All Rights Reserved.

    Disclaimer: IMPORTANT:  This Apple software is supplied to you by 

            Apple Inc. ("Apple") in consideration of your agreement to the

            following terms, and your use, installation, modification or

            redistribution of this Apple software constitutes acceptance of these

            terms.  If you do not agree with these terms, please do not use,

            install, modify or redistribute this Apple software.

            In consideration of your agreement to abide by the following terms, and

            subject to these terms, Apple grants you a personal, non-exclusive

            license, under Apple's copyrights in this original Apple software (the

            "Apple Software"), to use, reproduce, modify and redistribute the Apple

            Software, with or without modifications, in source and/or binary forms;

            provided that if you redistribute the Apple Software in its entirety and

            without modifications, you must retain this notice and the following

            text and disclaimers in all such redistributions of the Apple Software. 

            Neither the name, trademarks, service marks or logos of Apple Inc. 

            may be used to endorse or promote products derived from the Apple

            Software without specific prior written permission from Apple.  Except

            as expressly stated in this notice, no other rights or licenses, express

            or implied, are granted by Apple herein, including but not limited to

            any patent rights that may be infringed by your derivative works or by

            other works in which the Apple Software may be incorporated.

            The Apple Software is provided by Apple on an "AS IS" basis.  APPLE

            MAKES NO WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION

            THE IMPLIED WARRANTIES OF NON-INFRINGEMENT, MERCHANTABILITY AND FITNESS

            FOR A PARTICULAR PURPOSE, REGARDING THE APPLE SOFTWARE OR ITS USE AND

            OPERATION ALONE OR IN COMBINATION WITH YOUR PRODUCTS.

            IN NO EVENT SHALL APPLE BE LIABLE FOR ANY SPECIAL, INDIRECT, INCIDENTAL

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*/

#ifndef __FPU_h__

#define __FPU_h__

#include <TargetConditionals.h>

#if TARGET_OS_MAC && (TARGET_CPU_PPC || TARGET_CPU_PPC64)

    #define SET_ROUNDMODE \

        double oldSetting; \

        /* Set the FPSCR to round to -Inf mode */ \

        { \

            union { \

                double  d; \

                int     i[2]; \

            } setting; \

            register double newSetting; \

            /* Read the the current FPSCR value */ \

            __asm__ __volatile__ ( "mffs %0" : "=f" ( oldSetting ) ); \

            /* Store it to the stack */ \

            setting.d = oldSetting; \

            /* Read in the low 32 bits and mask off the last two bits so they are zero      */ \

            /* in the integer unit. These two bits set to zero means round to nearest mode. */ \

            /* Finally, then store the result back */ \

            setting.i[1] |= 3; \

            /* Load the new FPSCR setting into the FP register file again */ \

            newSetting = setting.d; \

            /* Change the volatile to the new setting */ \

            __asm__ __volatile__( "mtfsf 7, %0" : : "f" (newSetting ) ); \

        }

    #define RESTORE_ROUNDMODE \

        /* restore the old FPSCR setting */ \

        __asm__ __volatile__ ( "mtfsf 7, %0" : : "f" (oldSetting) );

    #define DISABLE_DENORMALS

    #define RESTORE_DENORMALS

#elif TARGET_OS_MAC && (TARGET_CPU_X86 || TARGET_CPU_X86_64)

    // our compiler does ALL floating point with SSE

    #define GETCSR()    ({ int _result; asm volatile ("stmxcsr %0" : "=m" (*&_result) ); /*return*/ _result; })

    #define SETCSR( a )    { int _temp = a; asm volatile( "ldmxcsr %0" : : "m" (*&_temp ) ); }

    #define DISABLE_DENORMALS int _savemxcsr = GETCSR(); SETCSR(_savemxcsr | 0x8040);

    #define RESTORE_DENORMALS SETCSR(_savemxcsr);

    #define ROUNDMODE_NEG_INF int _savemxcsr = GETCSR(); SETCSR((_savemxcsr & ~0x6000) | 0x2000);

    #define RESTORE_ROUNDMODE SETCSR(_savemxcsr);

    #define SET_ROUNDMODE       ROUNDMODE_NEG_INF

#else

    #define DISABLE_DENORMALS

    #define RESTORE_DENORMALS

    #define ROUNDMODE_NEG_INF

    #define RESTORE_ROUNDMODE

    #define SET_ROUNDMODE       ROUNDMODE_NEG_INF

#endif

// ____________________________________________________________________________

//

#if TARGET_OS_WIN32 && (TARGET_CPU_X86 || TARGET_CPU_X86_64)

    // x87 denormal handling

    inline double DenormalToZero(double f)

    {

        if (-1.0e-15 < f && f < 1.0e-15) {

            f = 0.0;

        }

        return f;

    }

    inline float DenormalToZero(float f)

    {

        if (-1.0e-15 < f && f < 1.0e-15) {

            f = 0.0f;

        }

        return f;

    }

#else

    // MacOS/X86 and PPC do not need this

    #define DenormalToZero(f) (f)

#endif

#endif // __FPU_h__