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Diffstat (limited to 'source/luametatex/source/libraries/softposit/source/ui64_to_pX2.c')
| -rw-r--r-- | source/luametatex/source/libraries/softposit/source/ui64_to_pX2.c | 115 |
1 files changed, 115 insertions, 0 deletions
diff --git a/source/luametatex/source/libraries/softposit/source/ui64_to_pX2.c b/source/luametatex/source/libraries/softposit/source/ui64_to_pX2.c new file mode 100644 index 000000000..1250d26fd --- /dev/null +++ b/source/luametatex/source/libraries/softposit/source/ui64_to_pX2.c @@ -0,0 +1,115 @@ + +/*============================================================================ + +This C source file is part of the SoftPosit Posit Arithmetic Package +by S. H. Leong (Cerlane). + +Copyright 2017 2018 A*STAR. All rights reserved. + +This C source file was based on SoftFloat IEEE Floating-Point Arithmetic +Package, Release 3d, by John R. Hauser. + +Copyright 2011, 2012, 2013, 2014, 2015, 2016 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 <stdint.h> + +#include "platform.h" +#include "internals.h" + +posit_2_t ui64_to_pX2 ( uint64_t a, int x ) { + int_fast8_t k, log2 = 63;//length of bit (e.g. 18445618173802708991) in int (64 but because we have only 64 bits, so one bit off to accommodate that fact) + union ui32_pX2 uZ; + uint_fast64_t uiA=0; + uint_fast64_t mask = 0x8000000000000000, frac64A; + uint_fast32_t expA; + + //NaR + if (a == 0x8000000000000000 || x<2 || x>32) + uiA = 0x80000000; + else if (x==2){ + if (a>0) uiA=0x40000000; + } + else if ( a > 0xFFFBFFFFFFFFFFFF){//18445618173802708991 + uiA = 0x7FFFC000; // 18446744073709552000 + if (x<18) uiA&=((int32_t)0x80000000>>(x-1)); + } + else if ( a < 0x2 ) + uiA = (a << 30); + else { + frac64A = a; + while ( !(frac64A & mask) ) { + log2--; + frac64A <<= 1; + } + + k = (log2 >> 2); + + expA = (log2 & 0x3) ; + frac64A = (frac64A ^ mask); + + if(k>=(x-2)){//maxpos + uiA = 0x7FFFFFFF & ((int32_t)0x80000000>>(x-1)); + } + else if (k==(x-3)){//bitNPlusOne-> first exp bit //bitLast is zero + uiA = (0x7FFFFFFF ^ (0x3FFFFFFF >> k)); + if( (expA & 0x2) && ((expA&0x1) | frac64A) ) //bitNPlusOne //bitsMore + uiA |= ((uint32_t)0x80000000>>(x-1)); + } + else if (k==(x-4)){ + uiA = (0x7FFFFFFF ^ (0x3FFFFFFF >> k)) | ((expA &0x2)<< (27 - k)); + if(expA&0x1){ + if( (((uint32_t)0x80000000>>(x-1)) & uiA)|| frac64A) + uiA += ((uint32_t)0x80000000>>(x-1)); + } + + } + else if (k==(x-5)){ + uiA = (0x7FFFFFFF ^ (0x3FFFFFFF >> k)) | (expA<< (27 - k)); + mask = (uint64_t)0x800000000 << (k + 32-x); + if (mask & frac64A){ //bitNPlusOne + if (((mask - 1) & frac64A) | (expA&0x1)) { + uiA+= ((uint32_t)0x80000000>>(x-1)); + } + } + } + else{ + uiA = (0x7FFFFFFF ^ (0x3FFFFFFF >> k)) | (expA<< (27 - k)) | ((frac64A>>(k+36)) & ((int32_t)0x80000000>>(x-1))); + mask = (uint64_t)0x800000000 << (k + 32-x); //bitNPlusOne position + if (mask & frac64A) { + if (((mask - 1) & frac64A) | ((mask << 1) & frac64A)) { + uiA+= ((uint32_t)0x80000000>>(x-1)); + } + } + } + } + uZ.ui = uiA; + return uZ.p; +} |