diff options
Diffstat (limited to 'src/libs/softfloat-3e/source/s_subMagsF16.c')
| -rw-r--r-- | src/libs/softfloat-3e/source/s_subMagsF16.c | 187 |
1 files changed, 187 insertions, 0 deletions
diff --git a/src/libs/softfloat-3e/source/s_subMagsF16.c b/src/libs/softfloat-3e/source/s_subMagsF16.c new file mode 100644 index 00000000..3a21efec --- /dev/null +++ b/src/libs/softfloat-3e/source/s_subMagsF16.c @@ -0,0 +1,187 @@ + +/*============================================================================ + +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, 2016, 2017 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 softfloat_subMagsF16( uint_fast16_t uiA, uint_fast16_t uiB SOFTFLOAT_STATE_DECL_COMMA ) +{ + int_fast8_t expA; + uint_fast16_t sigA; + int_fast8_t expB; + uint_fast16_t sigB; + int_fast8_t expDiff; + uint_fast16_t uiZ; + int_fast16_t sigDiff; + bool signZ; + int_fast8_t shiftDist, expZ; + uint_fast16_t sigZ, sigX, sigY; + uint_fast32_t sig32Z; + int_fast8_t roundingMode; + union ui16_f16 uZ; + + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + expA = expF16UI( uiA ); + sigA = fracF16UI( uiA ); + expB = expF16UI( uiB ); + sigB = fracF16UI( uiB ); + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + expDiff = expA - expB; + if ( ! expDiff ) { + /*-------------------------------------------------------------------- + *--------------------------------------------------------------------*/ + if ( expA == 0x1F ) { + if ( sigA | sigB ) goto propagateNaN; + softfloat_raiseFlags( softfloat_flag_invalid SOFTFLOAT_STATE_ARG_COMMA ); + uiZ = defaultNaNF16UI; + goto uiZ; + } + sigDiff = sigA - sigB; + if ( ! sigDiff ) { + uiZ = + packToF16UI( + (softfloat_roundingMode == softfloat_round_min), 0, 0 ); + goto uiZ; + } + if ( expA ) --expA; + signZ = signF16UI( uiA ); + if ( sigDiff < 0 ) { + signZ = ! signZ; + sigDiff = -sigDiff; + } + shiftDist = softfloat_countLeadingZeros16( sigDiff ) - 5; + expZ = expA - shiftDist; + if ( expZ < 0 ) { + shiftDist = expA; + expZ = 0; + } + sigZ = sigDiff<<shiftDist; + goto pack; + } else { + /*-------------------------------------------------------------------- + *--------------------------------------------------------------------*/ + signZ = signF16UI( uiA ); + if ( expDiff < 0 ) { + /*---------------------------------------------------------------- + *----------------------------------------------------------------*/ + signZ = ! signZ; + if ( expB == 0x1F ) { + if ( sigB ) goto propagateNaN; + uiZ = packToF16UI( signZ, 0x1F, 0 ); + goto uiZ; + } + if ( expDiff <= -13 ) { + uiZ = packToF16UI( signZ, expB, sigB ); + if ( expA | sigA ) goto subEpsilon; + goto uiZ; + } + expZ = expA + 19; + sigX = sigB | 0x0400; + sigY = sigA + (expA ? 0x0400 : sigA); + expDiff = -expDiff; + } else { + /*---------------------------------------------------------------- + *----------------------------------------------------------------*/ + uiZ = uiA; + if ( expA == 0x1F ) { + if ( sigA ) goto propagateNaN; + goto uiZ; + } + if ( 13 <= expDiff ) { + if ( expB | sigB ) goto subEpsilon; + goto uiZ; + } + expZ = expB + 19; + sigX = sigA | 0x0400; + sigY = sigB + (expB ? 0x0400 : sigB); + } + sig32Z = ((uint_fast32_t) sigX<<expDiff) - sigY; + shiftDist = softfloat_countLeadingZeros32( sig32Z ) - 1; + sig32Z <<= shiftDist; + expZ -= shiftDist; + sigZ = sig32Z>>16; + if ( sig32Z & 0xFFFF ) { + sigZ |= 1; + } else { + if ( ! (sigZ & 0xF) && ((unsigned int) expZ < 0x1E) ) { + sigZ >>= 4; + goto pack; + } + } + return softfloat_roundPackToF16( signZ, expZ, sigZ SOFTFLOAT_STATE_ARG_COMMA ); + } + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + propagateNaN: + uiZ = softfloat_propagateNaNF16UI( uiA, uiB SOFTFLOAT_STATE_ARG_COMMA ); + goto uiZ; + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + subEpsilon: + roundingMode = softfloat_roundingMode; + if ( roundingMode != softfloat_round_near_even ) { + if ( + (roundingMode == softfloat_round_minMag) + || (roundingMode + == (signF16UI( uiZ ) ? softfloat_round_max + : softfloat_round_min)) + ) { + --uiZ; + } +#ifdef SOFTFLOAT_ROUND_ODD + else if ( roundingMode == softfloat_round_odd ) { + uiZ = (uiZ - 1) | 1; + } +#endif + } + softfloat_exceptionFlags |= softfloat_flag_inexact; + goto uiZ; + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + pack: + uiZ = packToF16UI( signZ, expZ, sigZ ); + uiZ: + uZ.ui = uiZ; + return uZ.f; + +} + |