Update SoftFloat

[riscv-isa-sim.git] / softfloat / f16_to_f64.c

diff --git a/softfloat/f16_to_f64.c b/softfloat/f16_to_f64.c
new file mode 100644 (file)
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+++ b/softfloat/f16_to_f64.c
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+
+/*============================================================================
+
+This C source file is part of the SoftFloat IEEE Floating-Point Arithmetic
+Package, Release 3d, 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"
+
+float64_t f16_to_f64( float16_t a )
+{
+    union ui16_f16 uA;
+    uint_fast16_t uiA;
+    bool sign;
+    int_fast8_t exp;
+    uint_fast16_t frac;
+    struct commonNaN commonNaN;
+    uint_fast64_t uiZ;
+    struct exp8_sig16 normExpSig;
+    union ui64_f64 uZ;
+
+    /*------------------------------------------------------------------------
+    *------------------------------------------------------------------------*/
+    uA.f = a;
+    uiA = uA.ui;
+    sign = signF16UI( uiA );
+    exp  = expF16UI( uiA );
+    frac = fracF16UI( uiA );
+    /*------------------------------------------------------------------------
+    *------------------------------------------------------------------------*/
+    if ( exp == 0x1F ) {
+        if ( frac ) {
+            softfloat_f16UIToCommonNaN( uiA, &commonNaN );
+            uiZ = softfloat_commonNaNToF64UI( &commonNaN );
+        } else {
+            uiZ = packToF64UI( sign, 0x7FF, 0 );
+        }
+        goto uiZ;
+    }
+    /*------------------------------------------------------------------------
+    *------------------------------------------------------------------------*/
+    if ( ! exp ) {
+        if ( ! frac ) {
+            uiZ = packToF64UI( sign, 0, 0 );
+            goto uiZ;
+        }
+        normExpSig = softfloat_normSubnormalF16Sig( frac );
+        exp = normExpSig.exp - 1;
+        frac = normExpSig.sig;
+    }
+    /*------------------------------------------------------------------------
+    *------------------------------------------------------------------------*/
+    uiZ = packToF64UI( sign, exp + 0x3F0, (uint_fast64_t) frac<<42 );
+ uiZ:
+    uZ.ui = uiZ;
+    return uZ.f;
+
+}
+