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Diffstat (limited to 'source/luametatex/source/libraries/softposit/source/pX1_div.c')
| -rw-r--r-- | source/luametatex/source/libraries/softposit/source/pX1_div.c | 210 |
1 files changed, 210 insertions, 0 deletions
diff --git a/source/luametatex/source/libraries/softposit/source/pX1_div.c b/source/luametatex/source/libraries/softposit/source/pX1_div.c new file mode 100644 index 000000000..cd68c9bd7 --- /dev/null +++ b/source/luametatex/source/libraries/softposit/source/pX1_div.c @@ -0,0 +1,210 @@ +/*============================================================================ + +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, 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 <stdlib.h> + +#include "platform.h" +#include "internals.h" + +posit_1_t pX1_div( posit_1_t pA, posit_1_t pB, int x ) { + + union ui32_pX1 uA, uB, uZ; + int regA; + uint_fast32_t uiA, uiB, fracA, fracB, regime, tmp; + bool signA, signB, signZ, regSA, regSB, bitNPlusOne=0, bitsMore=0, rcarry; + int_fast8_t kA=0; + int_fast32_t expA; + uint_fast64_t frac64A, frac64Z, rem; + lldiv_t divresult; + + if (x<2 || x>32){ + uZ.ui = 0x80000000; + return uZ.p; + } + + uA.p = pA; + uiA = uA.ui; + uB.p = pB; + uiB = uB.ui; + + //Zero or infinity + if ( uiA==0x80000000 || uiB==0x80000000 || uiB==0){ +#ifdef SOFTPOSIT_EXACT + uZ.ui.v = 0x80000000; + uZ.ui.exact = 0; +#else + uZ.ui = 0x80000000; +#endif + return uZ.p; + } + else if (uiA==0){ +#ifdef SOFTPOSIT_EXACT + + uZ.ui.v = 0; + if ( (uiA==0 && uiA.ui.exact) || (uiB==0 && uiB.ui.exact) ) + uZ.ui.exact = 1; + else + uZ.ui.exact = 0; +#else + uZ.ui = 0; +#endif + return uZ.p; + } + + signA = signP32UI( uiA ); + signB = signP32UI( uiB ); + signZ = signA ^ signB; + if(signA) uiA = (-uiA & 0xFFFFFFFF); + if(signB) uiB = (-uiB & 0xFFFFFFFF); + regSA = signregP32UI(uiA); + regSB = signregP32UI(uiB); + + if (x==2){ + uZ.ui = 0x40000000; + } + else{ + tmp = (uiA<<2)&0xFFFFFFFF; + if (regSA){ + while (tmp>>31){ + kA++; + tmp= (tmp<<1) & 0xFFFFFFFF; + } + } + else{ + kA=-1; + while (!(tmp>>31)){ + kA--; + tmp= (tmp<<1) & 0xFFFFFFFF; + } + tmp&=0x7FFFFFFF; + } + expA = tmp>>30; //to get 1 bits + fracA = (tmp | 0x40000000) & 0x7FFFFFFF; + frac64A = (uint64_t) fracA << 30; + + tmp = (uiB<<2)&0xFFFFFFFF; + if (regSB){ + while (tmp>>31){ + kA--; + tmp= (tmp<<1) & 0xFFFFFFFF; + } + } + else{ + kA++; + while (!(tmp>>31)){ + kA++; + tmp= (tmp<<1) & 0xFFFFFFFF; + } + tmp&=0x7FFFFFFF; + } + expA -= tmp>>30; + fracB = (tmp | 0x40000000) & 0x7FFFFFFF; + + divresult = lldiv (frac64A,(uint_fast64_t)fracB); + frac64Z = divresult.quot; + rem = divresult.rem; + + if (expA<0){ + expA=1; + kA--; + } + if (frac64Z!=0){ + rcarry = frac64Z >> 30; // this is the hidden bit (14th bit) , extreme right bit is bit 0 + if (!rcarry){ + if (expA==0) kA --; + expA^=1; + frac64Z<<=1; + } + } + } + + if(kA<0){ + regA = -kA; + regSA = 0; + regime = 0x40000000>>regA; + } + else{ + regA = kA+1; + regSA=1; + regime = 0x7FFFFFFF - (0x7FFFFFFF>>regA); + } + + if(regA>(x-2)){ + //max or min pos. exp and frac does not matter. + uZ.ui=(regSA) ? (0x7FFFFFFF & ((int32_t)0x80000000>>(x-1)) ): (0x1 << (32-x)); + } + else{ + //remove carry and rcarry bits and shift to correct position + frac64Z &= 0x3FFFFFFF; + fracA = (uint_fast32_t)frac64Z >> (regA+1); + + //regime length is smaller than length of posit + if (regA<x){ + if (regA!=(x-2)){ + bitNPlusOne |= (((uint64_t)0x80000000>>(x-regA-1)) & frac64Z); + bitsMore = ((0x7FFFFFFF>>(x-regA-1)) & frac64Z); + fracA&=((int32_t)0x80000000>>(x-1)); + } + else if (frac64Z>0) { + fracA=0; + bitsMore=1; + } + if(regA==(x-2) && expA){ + bitNPlusOne=1; + expA=0; + } + if (rem) bitsMore =1; + } + else{ + regime=(regSA) ? (regime & ((int32_t)0x80000000>>(x-1)) ): (regime << (32-x)); + expA=0; + fracA=0; + } + + expA <<= (29-regA); + uZ.ui = packToP32UI(regime, expA, fracA); + if (bitNPlusOne) uZ.ui += (uint32_t)(((uZ.ui>>(32-x))&1) | bitsMore) << (32-x) ; + + } + + if (signZ) uZ.ui = -uZ.ui & 0xFFFFFFFF; + return uZ.p; +} + |