diff options
Diffstat (limited to 'source/luametatex/source/libraries/softposit/source/i32_to_pX2.c')
| -rw-r--r-- | source/luametatex/source/libraries/softposit/source/i32_to_pX2.c | 121 |
1 files changed, 121 insertions, 0 deletions
diff --git a/source/luametatex/source/libraries/softposit/source/i32_to_pX2.c b/source/luametatex/source/libraries/softposit/source/i32_to_pX2.c new file mode 100644 index 000000000..ac31957fb --- /dev/null +++ b/source/luametatex/source/libraries/softposit/source/i32_to_pX2.c @@ -0,0 +1,121 @@ + +/*============================================================================ + +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 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 "platform.h" +#include "internals.h" + + +posit_2_t i32_to_pX2( int32_t iA, int x ) { + int_fast8_t k, log2 = 31;//length of bit (e.g. 4294966271) in int (32 but because we have only 32 bits, so one bit off to accomdate that fact) + union ui32_pX2 uZ; + uint_fast32_t uiA=0; + uint_fast32_t expA, mask = 0x80000000, fracA; + bool sign; + + if (iA < -2147483135){ + uZ.ui = 0x80500000; + return uZ.p; + } + + sign = iA>>31; + if(sign) iA = -iA &0xFFFFFFFF; + + //NaR + if (x<2 || x>32) + uiA = 0x80000000; + else if (x==2){ + if (iA>0) uiA=0x40000000; + } + else if ( iA > 2147483135){//2147483136 to 2147483647 rounds to P32 value (2147483648)=> 0x7FB00000 + uiA = 0x7FB00000; // 2147483648 + if (x<10) uiA&=((int32_t)0x80000000>>(x-1)); + else if (x<12) uiA = 0x7FF00000&((int32_t)0x80000000>>(x-1)); + } + else if ( iA < 0x2 ) + uiA = (iA << 30); + else { + fracA = iA; + while ( !(fracA & mask) ) { + log2--; + fracA <<= 1; + } + k = (log2 >> 2); + expA = (log2 & 0x3); + fracA = (fracA ^ 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) | fracA) ) //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)| fracA) + uiA += ((uint32_t)0x80000000>>(x-1)); + } + } + else if (k==(x-5)){ + uiA = (0x7FFFFFFF ^ (0x3FFFFFFF >> k)) | (expA<< (27 - k)); + mask = 0x8 << (k -x); + if (mask & fracA){ //bitNPlusOne + if (((mask - 1) & fracA) | (expA&0x1)) { + uiA+= ((uint32_t)0x80000000>>(x-1)); + } + } + } + else{ + uiA = ((0x7FFFFFFF ^ (0x3FFFFFFF >> k)) | (expA<< (27 - k)) | fracA>>(k+4)) & ((int32_t)0x80000000>>(x-1));; + mask = 0x8 << (k-x); //bitNPlusOne + if (mask & fracA) + if (((mask - 1) & fracA) | ((mask << 1) & fracA)) uiA+= ((uint32_t)0x80000000>>(x-1)); + } + + } + (sign) ? (uZ.ui = -uiA &0xFFFFFFFF) : (uZ.ui = uiA); + return uZ.p; +} + + |