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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/f128_to_f32.c
parent8e69141749065ff957383d2112768f95a33429b6 (diff)
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Upgrade to SoftFloat 3e
Diffstat (limited to 'softfloat/f128_to_f32.c')
-rw-r--r--softfloat/f128_to_f32.c95
1 files changed, 95 insertions, 0 deletions
diff --git a/softfloat/f128_to_f32.c b/softfloat/f128_to_f32.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"
+
+float32_t f128_to_f32( float128_t a )
+{
+ union ui128_f128 uA;
+ uint_fast64_t uiA64, uiA0;
+ bool sign;
+ int_fast32_t exp;
+ uint_fast64_t frac64;
+ struct commonNaN commonNaN;
+ uint_fast32_t uiZ, frac32;
+ union ui32_f32 uZ;
+
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
+ uA.f = a;
+ uiA64 = uA.ui.v64;
+ uiA0 = uA.ui.v0;
+ sign = signF128UI64( uiA64 );
+ exp = expF128UI64( uiA64 );
+ frac64 = fracF128UI64( uiA64 ) | (uiA0 != 0);
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
+ if ( exp == 0x7FFF ) {
+ if ( frac64 ) {
+ softfloat_f128UIToCommonNaN( uiA64, uiA0, &commonNaN );
+ uiZ = softfloat_commonNaNToF32UI( &commonNaN );
+ } else {
+ uiZ = packToF32UI( sign, 0xFF, 0 );
+ }
+ goto uiZ;
+ }
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
+ frac32 = softfloat_shortShiftRightJam64( frac64, 18 );
+ if ( ! (exp | frac32) ) {
+ uiZ = packToF32UI( sign, 0, 0 );
+ goto uiZ;
+ }
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
+ exp -= 0x3F81;
+ if ( sizeof (int_fast16_t) < sizeof (int_fast32_t) ) {
+ if ( exp < -0x1000 ) exp = -0x1000;
+ }
+ return softfloat_roundPackToF32( sign, exp, frac32 | 0x40000000 );
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
+ uiZ:
+ uZ.ui = uiZ;
+ return uZ.f;
+
+}
+