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authorAndrew Waterman <andrew@sifive.com>2018-07-11 01:16:28 -0700
committerAndrew Waterman <andrew@sifive.com>2018-07-11 01:16:28 -0700
commit5cd8d2b93fad2011fdf8f49a263d77697af35b32 (patch)
treef6fb9cb6d3bef2aa5c9903511b92e5a6e99e9519 /softfloat/f16_mul.c
parent8e69141749065ff957383d2112768f95a33429b6 (diff)
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Upgrade to SoftFloat 3e
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-rw-r--r--softfloat/f16_mul.c140
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diff --git a/softfloat/f16_mul.c b/softfloat/f16_mul.c
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+
+/*============================================================================
+
+This C source file is part of the SoftFloat IEEE Floating-Point Arithmetic
+Package, Release 3e, by John R. Hauser.
+
+Copyright 2011, 2012, 2013, 2014, 2015 The Regents of the University of
+California. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+ 1. Redistributions of source code must retain the above copyright notice,
+ this list of conditions, and the following disclaimer.
+
+ 2. Redistributions in binary form must reproduce the above copyright notice,
+ this list of conditions, and the following disclaimer in the documentation
+ and/or other materials provided with the distribution.
+
+ 3. Neither the name of the University nor the names of its contributors may
+ be used to endorse or promote products derived from this software without
+ specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS "AS IS", AND ANY
+EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ARE
+DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY
+DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+=============================================================================*/
+
+#include <stdbool.h>
+#include <stdint.h>
+#include "platform.h"
+#include "internals.h"
+#include "specialize.h"
+#include "softfloat.h"
+
+float16_t f16_mul( float16_t a, float16_t b )
+{
+ union ui16_f16 uA;
+ uint_fast16_t uiA;
+ bool signA;
+ int_fast8_t expA;
+ uint_fast16_t sigA;
+ union ui16_f16 uB;
+ uint_fast16_t uiB;
+ bool signB;
+ int_fast8_t expB;
+ uint_fast16_t sigB;
+ bool signZ;
+ uint_fast16_t magBits;
+ struct exp8_sig16 normExpSig;
+ int_fast8_t expZ;
+ uint_fast32_t sig32Z;
+ uint_fast16_t sigZ, uiZ;
+ union ui16_f16 uZ;
+
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
+ uA.f = a;
+ uiA = uA.ui;
+ signA = signF16UI( uiA );
+ expA = expF16UI( uiA );
+ sigA = fracF16UI( uiA );
+ uB.f = b;
+ uiB = uB.ui;
+ signB = signF16UI( uiB );
+ expB = expF16UI( uiB );
+ sigB = fracF16UI( uiB );
+ signZ = signA ^ signB;
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
+ if ( expA == 0x1F ) {
+ if ( sigA || ((expB == 0x1F) && sigB) ) goto propagateNaN;
+ magBits = expB | sigB;
+ goto infArg;
+ }
+ if ( expB == 0x1F ) {
+ if ( sigB ) goto propagateNaN;
+ magBits = expA | sigA;
+ goto infArg;
+ }
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
+ if ( ! expA ) {
+ if ( ! sigA ) goto zero;
+ normExpSig = softfloat_normSubnormalF16Sig( sigA );
+ expA = normExpSig.exp;
+ sigA = normExpSig.sig;
+ }
+ if ( ! expB ) {
+ if ( ! sigB ) goto zero;
+ normExpSig = softfloat_normSubnormalF16Sig( sigB );
+ expB = normExpSig.exp;
+ sigB = normExpSig.sig;
+ }
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
+ expZ = expA + expB - 0xF;
+ sigA = (sigA | 0x0400)<<4;
+ sigB = (sigB | 0x0400)<<5;
+ sig32Z = (uint_fast32_t) sigA * sigB;
+ sigZ = sig32Z>>16;
+ if ( sig32Z & 0xFFFF ) sigZ |= 1;
+ if ( sigZ < 0x4000 ) {
+ --expZ;
+ sigZ <<= 1;
+ }
+ return softfloat_roundPackToF16( signZ, expZ, sigZ );
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
+ propagateNaN:
+ uiZ = softfloat_propagateNaNF16UI( uiA, uiB );
+ goto uiZ;
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
+ infArg:
+ if ( ! magBits ) {
+ softfloat_raiseFlags( softfloat_flag_invalid );
+ uiZ = defaultNaNF16UI;
+ } else {
+ uiZ = packToF16UI( signZ, 0x1F, 0 );
+ }
+ goto uiZ;
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
+ zero:
+ uiZ = packToF16UI( signZ, 0, 0 );
+ uiZ:
+ uZ.ui = uiZ;
+ return uZ.f;
+
+}
+