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Diffstat (limited to 'source/luametatex/source/libraries/softposit/source/quire16_fdp_add.c')
| -rw-r--r-- | source/luametatex/source/libraries/softposit/source/quire16_fdp_add.c | 185 |
1 files changed, 185 insertions, 0 deletions
diff --git a/source/luametatex/source/libraries/softposit/source/quire16_fdp_add.c b/source/luametatex/source/libraries/softposit/source/quire16_fdp_add.c new file mode 100644 index 000000000..959849ef7 --- /dev/null +++ b/source/luametatex/source/libraries/softposit/source/quire16_fdp_add.c @@ -0,0 +1,185 @@ +/*============================================================================ + +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. + +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 <inttypes.h> + +#include "platform.h" +#include "internals.h" + +quire16_t q16_fdp_add( quire16_t q, posit16_t pA, posit16_t pB ){ + + union ui16_p16 uA, uB; + union ui128_q16 uZ, uZ1, uZ2; + uint_fast16_t uiA, uiB; + uint_fast16_t fracA, tmp; + bool signA, signB, signZ2, regSA, regSB, rcarry; + int_fast8_t expA; + int_fast16_t kA=0, shiftRight=0; + uint_fast32_t frac32Z; + //For add + bool rcarryb, b1, b2, rcarryZ;//, rcarrySignZ; + + uZ1.q = q; + + uA.p = pA; + uiA = uA.ui; + uB.p = pB; + uiB = uB.ui; + + //NaR + if (isNaRQ16(q) || isNaRP16UI(uA.ui) || isNaRP16UI(uB.ui)){ + uZ2.ui[0]=0x8000000000000000ULL; + uZ2.ui[1] = 0; + return uZ2.q; + } + else if (uiA==0 || uiB==0) + return q; + + //max pos (sign plus and minus) + signA = signP16UI( uiA ); + signB = signP16UI( uiB ); + signZ2 = signA ^ signB; + + if(signA) uiA = (-uiA & 0xFFFF); + if(signB) uiB = (-uiB & 0xFFFF); + + regSA = signregP16UI(uiA); + regSB = signregP16UI(uiB); + + tmp = (uiA<<2) & 0xFFFF; + if (regSA){ + while (tmp>>15){ + kA++; + tmp= (tmp<<1) & 0xFFFF; + } + } + else{ + kA=-1; + while (!(tmp>>15)){ + kA--; + tmp= (tmp<<1) & 0xFFFF; + } + tmp&=0x7FFF; + } + expA = tmp>>14; + fracA = (0x4000 | tmp); + + tmp = (uiB<<2) & 0xFFFF; + if (regSB){ + while (tmp>>15){ + kA++; + tmp= (tmp<<1) & 0xFFFF; + } + } + else{ + kA--; + while (!(tmp>>15)){ + kA--; + tmp= (tmp<<1) & 0xFFFF; + } + tmp&=0x7FFF; + } + expA += tmp>>14; + frac32Z = (uint_fast32_t) fracA * (0x4000 | tmp); + + if (expA>1){ + kA++; + expA ^=0x2; + } + rcarry = frac32Z>>29;//3rd bit (position 2) of frac32Z, hidden bit is 4th bit (position 3) + if (rcarry){ + if (expA) kA ++; + expA^=1; + frac32Z>>=1; + } + + //default dot is between bit 71 and 72, extreme left bit is bit 0. Last right bit is bit 127. + //Scale = 2^es * k + e => 2k + e + int firstPos = 71 - (kA<<1) - expA; + + //No worries about hidden bit moving before position 4 because fraction is right aligned so + //there are 16 spare bits + if (firstPos>63){ //This means entire fraction is in right 64 bits + uZ2.ui[0] = 0; + shiftRight = firstPos-99;//99 = 63+ 4+ 32 + + uZ2.ui[1] = (shiftRight<0) ? ((uint64_t)frac32Z << -shiftRight) : ((uint64_t) frac32Z >> shiftRight); + + } + else{//frac32Z can be in both left64 and right64 + shiftRight = firstPos - 35;// -35= -3-32 + if (shiftRight<0) + uZ2.ui[0] = ((uint64_t)frac32Z) << -shiftRight; + else{ + uZ2.ui[0] = (uint64_t)frac32Z >> shiftRight; + uZ2.ui[1] = (uint64_t) frac32Z << (64 - shiftRight); + } + + } + + if (signZ2){ + if (uZ2.ui[1]>0){ + uZ2.ui[1] = - uZ2.ui[1]; + uZ2.ui[0] = ~uZ2.ui[0]; + } + else{ + uZ2.ui[0] = -uZ2.ui[0]; + } + } + + //Addition + b1 = uZ1.ui[1]&0x1; + b2 = uZ2.ui[1]&0x1; + rcarryb = b1 & b2; + uZ.ui[1] = (uZ1.ui[1]>>1) + (uZ2.ui[1]>>1) + rcarryb; + + rcarryZ = uZ.ui[1]>>63; + + uZ.ui[1] = (uZ.ui[1]<<1 | (b1^b2) ); + + b1 = uZ1.ui[0]&0x1; + b2 = uZ2.ui[0]&0x1; + rcarryb = b1 & b2 ; + int_fast8_t rcarryb3 = b1 + b2 + rcarryZ; + + uZ.ui[0] = (uZ1.ui[0]>>1) + (uZ2.ui[0]>>1) + ((rcarryb3>>1)& 0x1); + //rcarrySignZ = uZ.ui[0]>>63; + + uZ.ui[0] = (uZ.ui[0]<<1 | (rcarryb3 & 0x1) ); + + //Exception handling for NaR + if (isNaRQ16(uZ.q)) uZ.q.v[0] = 0; + + return uZ.q; +} |