diff options
Diffstat (limited to 'lib/libutils/isoc/arch/arm/softfloat/source/f32_rem.c')
| -rw-r--r-- | lib/libutils/isoc/arch/arm/softfloat/source/f32_rem.c | 168 |
1 files changed, 168 insertions, 0 deletions
diff --git a/lib/libutils/isoc/arch/arm/softfloat/source/f32_rem.c b/lib/libutils/isoc/arch/arm/softfloat/source/f32_rem.c new file mode 100644 index 0000000..b1997ef --- /dev/null +++ b/lib/libutils/isoc/arch/arm/softfloat/source/f32_rem.c @@ -0,0 +1,168 @@ + +/*============================================================================ + +This C source file is part of the SoftFloat IEEE Floating-Point Arithmetic +Package, Release 3a, by John R. Hauser. + +Copyright 2011, 2012, 2013, 2014 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 f32_rem( float32_t a, float32_t b ) +{ + union ui32_f32 uA; + uint_fast32_t uiA; + bool signA; + int_fast16_t expA; + uint_fast32_t sigA; + union ui32_f32 uB; + uint_fast32_t uiB; + int_fast16_t expB; + uint_fast32_t sigB; + struct exp16_sig32 normExpSig; + uint32_t rem; + int_fast16_t expDiff; + uint32_t q, recip32, altRem, meanRem; + bool signRem; + uint_fast32_t uiZ; + union ui32_f32 uZ; + + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + uA.f = a; + uiA = uA.ui; + signA = signF32UI( uiA ); + expA = expF32UI( uiA ); + sigA = fracF32UI( uiA ); + uB.f = b; + uiB = uB.ui; + expB = expF32UI( uiB ); + sigB = fracF32UI( uiB ); + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + if ( expA == 0xFF ) { + if ( sigA || ((expB == 0xFF) && sigB) ) goto propagateNaN; + goto invalid; + } + if ( expB == 0xFF ) { + if ( sigB ) goto propagateNaN; + return a; + } + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + if ( ! expB ) { + if ( ! sigB ) goto invalid; + normExpSig = softfloat_normSubnormalF32Sig( sigB ); + expB = normExpSig.exp; + sigB = normExpSig.sig; + } + if ( ! expA ) { + if ( ! sigA ) return a; + normExpSig = softfloat_normSubnormalF32Sig( sigA ); + expA = normExpSig.exp; + sigA = normExpSig.sig; + } + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + rem = sigA | 0x00800000; + sigB |= 0x00800000; + expDiff = expA - expB; + if ( expDiff < 1 ) { + if ( expDiff < -1 ) return a; + sigB <<= 6; + if ( expDiff ) { + rem <<= 5; + q = 0; + } else { + rem <<= 6; + q = (sigB <= rem); + if ( q ) rem -= sigB; + } + } else { + recip32 = softfloat_approxRecip32_1( sigB<<8 ); + /*-------------------------------------------------------------------- + | Changing the shift of `rem' here requires also changing the initial + | subtraction from `expDiff'. + *--------------------------------------------------------------------*/ + rem <<= 7; + expDiff -= 31; + /*-------------------------------------------------------------------- + | The scale of `sigB' affects how many bits are obtained during each + | cycle of the loop. Currently this is 29 bits per loop iteration, + | which is believed to be the maximum possible. + *--------------------------------------------------------------------*/ + sigB <<= 6; + for (;;) { + q = (rem * (uint_fast64_t) recip32)>>32; + if ( expDiff < 0 ) break; + rem = -(q * (uint32_t) sigB); + expDiff -= 29; + } + /*-------------------------------------------------------------------- + | (`expDiff' cannot be less than -30 here.) + *--------------------------------------------------------------------*/ + q >>= ~expDiff & 31; + rem = (rem<<(expDiff + 30)) - q * (uint32_t) sigB; + } + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + do { + altRem = rem; + ++q; + rem -= sigB; + } while ( ! (rem & 0x80000000) ); + meanRem = rem + altRem; + if ( (meanRem & 0x80000000) || (! meanRem && (q & 1)) ) rem = altRem; + signRem = signA; + if ( 0x80000000 <= rem ) { + signRem = ! signRem; + rem = -rem; + } + return softfloat_normRoundPackToF32( signRem, expB, rem ); + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + propagateNaN: + uiZ = softfloat_propagateNaNF32UI( uiA, uiB ); + goto uiZ; + invalid: + softfloat_raiseFlags( softfloat_flag_invalid ); + uiZ = defaultNaNF32UI; + uiZ: + uZ.ui = uiZ; + return uZ.f; + +} + |