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			141 lines
		
	
	
		
			5.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			141 lines
		
	
	
		
			5.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| 
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| /*============================================================================
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| 
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| This C source file is part of the SoftFloat IEEE Floating-Point Arithmetic
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| Package, Release 3e, by John R. Hauser.
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| 
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| Copyright 2011, 2012, 2013, 2014, 2015 The Regents of the University of
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| California.  All rights reserved.
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| 
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| Redistribution and use in source and binary forms, with or without
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| modification, are permitted provided that the following conditions are met:
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| 
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|  1. Redistributions of source code must retain the above copyright notice,
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|     this list of conditions, and the following disclaimer.
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| 
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|  2. Redistributions in binary form must reproduce the above copyright notice,
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|     this list of conditions, and the following disclaimer in the documentation
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|     and/or other materials provided with the distribution.
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| 
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|  3. Neither the name of the University nor the names of its contributors may
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|     be used to endorse or promote products derived from this software without
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|     specific prior written permission.
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| 
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| THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS "AS IS", AND ANY
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| EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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| WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ARE
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| DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY
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| DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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| (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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| LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
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| ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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| (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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| SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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| 
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| =============================================================================*/
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| 
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| #include <stdbool.h>
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| #include <stdint.h>
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| #include "platform.h"
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| #include "internals.h"
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| #include "specialize.h"
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| #include "softfloat.h"
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| 
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| float16_t f16_mul( float16_t a, float16_t b )
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| {
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|     union ui16_f16 uA;
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|     uint_fast16_t uiA;
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|     bool signA;
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|     int_fast8_t expA;
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|     uint_fast16_t sigA;
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|     union ui16_f16 uB;
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|     uint_fast16_t uiB;
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|     bool signB;
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|     int_fast8_t expB;
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|     uint_fast16_t sigB;
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|     bool signZ;
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|     uint_fast16_t magBits;
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|     struct exp8_sig16 normExpSig;
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|     int_fast8_t expZ;
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|     uint_fast32_t sig32Z;
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|     uint_fast16_t sigZ, uiZ;
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|     union ui16_f16 uZ;
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| 
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|     /*------------------------------------------------------------------------
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|     *------------------------------------------------------------------------*/
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|     uA.f = a;
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|     uiA = uA.ui;
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|     signA = signF16UI( uiA );
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|     expA  = expF16UI( uiA );
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|     sigA  = fracF16UI( uiA );
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|     uB.f = b;
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|     uiB = uB.ui;
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|     signB = signF16UI( uiB );
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|     expB  = expF16UI( uiB );
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|     sigB  = fracF16UI( uiB );
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|     signZ = signA ^ signB;
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|     /*------------------------------------------------------------------------
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|     *------------------------------------------------------------------------*/
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|     if ( expA == 0x1F ) {
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|         if ( sigA || ((expB == 0x1F) && sigB) ) goto propagateNaN;
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|         magBits = expB | sigB;
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|         goto infArg;
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|     }
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|     if ( expB == 0x1F ) {
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|         if ( sigB ) goto propagateNaN;
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|         magBits = expA | sigA;
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|         goto infArg;
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|     }
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|     /*------------------------------------------------------------------------
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|     *------------------------------------------------------------------------*/
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|     if ( ! expA ) {
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|         if ( ! sigA ) goto zero;
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|         normExpSig = softfloat_normSubnormalF16Sig( sigA );
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|         expA = normExpSig.exp;
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|         sigA = normExpSig.sig;
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|     }
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|     if ( ! expB ) {
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|         if ( ! sigB ) goto zero;
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|         normExpSig = softfloat_normSubnormalF16Sig( sigB );
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|         expB = normExpSig.exp;
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|         sigB = normExpSig.sig;
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|     }
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|     /*------------------------------------------------------------------------
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|     *------------------------------------------------------------------------*/
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|     expZ = expA + expB - 0xF;
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|     sigA = (sigA | 0x0400)<<4;
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|     sigB = (sigB | 0x0400)<<5;
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|     sig32Z = (uint_fast32_t) sigA * sigB;
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|     sigZ = sig32Z>>16;
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|     if ( sig32Z & 0xFFFF ) sigZ |= 1;
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|     if ( sigZ < 0x4000 ) {
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|         --expZ;
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|         sigZ <<= 1;
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|     }
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|     return softfloat_roundPackToF16( signZ, expZ, sigZ );
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|     /*------------------------------------------------------------------------
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|     *------------------------------------------------------------------------*/
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|  propagateNaN:
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|     uiZ = softfloat_propagateNaNF16UI( uiA, uiB );
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|     goto uiZ;
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|     /*------------------------------------------------------------------------
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|     *------------------------------------------------------------------------*/
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|  infArg:
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|     if ( ! magBits ) {
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|         softfloat_raiseFlags( softfloat_flag_invalid );
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|         uiZ = defaultNaNF16UI;
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|     } else {
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|         uiZ = packToF16UI( signZ, 0x1F, 0 );
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|     }
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|     goto uiZ;
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|     /*------------------------------------------------------------------------
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|     *------------------------------------------------------------------------*/
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|  zero:
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|     uiZ = packToF16UI( signZ, 0, 0 );
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|  uiZ:
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|     uZ.ui = uiZ;
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|     return uZ.f;
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| 
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| }
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| 
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