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Diffstat (limited to 'softfloat/s_roundToI32.c')
-rw-r--r-- | softfloat/s_roundToI32.c | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/softfloat/s_roundToI32.c b/softfloat/s_roundToI32.c new file mode 100644 index 0000000..63d2243 --- /dev/null +++ b/softfloat/s_roundToI32.c @@ -0,0 +1,98 @@ + +/*============================================================================ + +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" + +int_fast32_t + softfloat_roundToI32( + bool sign, uint_fast64_t sig, uint_fast8_t roundingMode, bool exact ) +{ + uint_fast16_t roundIncrement, roundBits; + uint_fast32_t sig32; + union { uint32_t ui; int32_t i; } uZ; + int_fast32_t z; + + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + roundIncrement = 0x800; + if ( + (roundingMode != softfloat_round_near_maxMag) + && (roundingMode != softfloat_round_near_even) + ) { + roundIncrement = 0; + if ( + sign + ? (roundingMode == softfloat_round_min) +#ifdef SOFTFLOAT_ROUND_ODD + || (roundingMode == softfloat_round_odd) +#endif + : (roundingMode == softfloat_round_max) + ) { + roundIncrement = 0xFFF; + } + } + roundBits = sig & 0xFFF; + sig += roundIncrement; + if ( sig & UINT64_C( 0xFFFFF00000000000 ) ) goto invalid; + sig32 = sig>>12; + if ( + (roundBits == 0x800) && (roundingMode == softfloat_round_near_even) + ) { + sig32 &= ~(uint_fast32_t) 1; + } + uZ.ui = sign ? -sig32 : sig32; + z = uZ.i; + if ( z && ((z < 0) ^ sign) ) goto invalid; + if ( roundBits ) { +#ifdef SOFTFLOAT_ROUND_ODD + if ( roundingMode == softfloat_round_odd ) z |= 1; +#endif + if ( exact ) softfloat_raiseFlags( softfloat_flag_inexact ); + } + return z; + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + invalid: + softfloat_raiseFlags( softfloat_flag_invalid ); + return sign ? i32_fromNegOverflow : i32_fromPosOverflow; + +} + |