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author | Andrew Waterman <andrew@sifive.com> | 2017-09-24 20:25:34 -0700 |
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committer | Andrew Waterman <andrew@sifive.com> | 2017-09-24 20:25:34 -0700 |
commit | bd85811c35ea38180d27440507fc222d585ef780 (patch) | |
tree | 214c6b615d7775f73da5ff9a94bd4a0a2772f9cf /softfloat/f64_to_f16.c | |
parent | b86f2a51f522f020ad0d90f598f4c501f41da232 (diff) | |
download | riscv-isa-sim-bd85811c35ea38180d27440507fc222d585ef780.zip riscv-isa-sim-bd85811c35ea38180d27440507fc222d585ef780.tar.gz riscv-isa-sim-bd85811c35ea38180d27440507fc222d585ef780.tar.bz2 |
Update SoftFloat
Diffstat (limited to 'softfloat/f64_to_f16.c')
-rw-r--r-- | softfloat/f64_to_f16.c | 88 |
1 files changed, 88 insertions, 0 deletions
diff --git a/softfloat/f64_to_f16.c b/softfloat/f64_to_f16.c new file mode 100644 index 0000000..325788c --- /dev/null +++ b/softfloat/f64_to_f16.c @@ -0,0 +1,88 @@ + +/*============================================================================ + +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" + +float16_t f64_to_f16( float64_t a ) +{ + union ui64_f64 uA; + uint_fast64_t uiA; + bool sign; + int_fast16_t exp; + uint_fast64_t frac; + struct commonNaN commonNaN; + uint_fast16_t uiZ, frac16; + union ui16_f16 uZ; + + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + uA.f = a; + uiA = uA.ui; + sign = signF64UI( uiA ); + exp = expF64UI( uiA ); + frac = fracF64UI( uiA ); + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + if ( exp == 0x7FF ) { + if ( frac ) { + softfloat_f64UIToCommonNaN( uiA, &commonNaN ); + uiZ = softfloat_commonNaNToF16UI( &commonNaN ); + } else { + uiZ = packToF16UI( sign, 0x1F, 0 ); + } + goto uiZ; + } + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + frac16 = softfloat_shortShiftRightJam64( frac, 38 ); + if ( ! (exp | frac16) ) { + uiZ = packToF16UI( sign, 0, 0 ); + goto uiZ; + } + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + return softfloat_roundPackToF16( sign, exp - 0x3F1, frac16 | 0x4000 ); + uiZ: + uZ.ui = uiZ; + return uZ.f; + +} + |