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Diffstat (limited to 'source/luametatex/source/libraries/softposit/source/s_mulAddP16.c')
| -rw-r--r-- | source/luametatex/source/libraries/softposit/source/s_mulAddP16.c | 275 |
1 files changed, 275 insertions, 0 deletions
diff --git a/source/luametatex/source/libraries/softposit/source/s_mulAddP16.c b/source/luametatex/source/libraries/softposit/source/s_mulAddP16.c new file mode 100644 index 000000000..9b5cf6020 --- /dev/null +++ b/source/luametatex/source/libraries/softposit/source/s_mulAddP16.c @@ -0,0 +1,275 @@ + +/*============================================================================ + +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 "platform.h" +#include "internals.h" + +//softposit_mulAdd_subC => (uiA*uiB)-uiC +//softposit_mulAdd_subProd => uiC - (uiA*uiB) +//Default is always op==0 +posit16_t softposit_mulAddP16( uint_fast16_t uiA, uint_fast16_t uiB, uint_fast16_t uiC, uint_fast16_t op ){ + + + union ui16_p16 uZ; + uint_fast16_t regZ, fracA, fracZ, regime, tmp; + bool signA, signB, signC, signZ, regSA, regSB, regSC, regSZ, bitNPlusOne=0, bitsMore=0, rcarry; + int_fast8_t expA, expC, expZ; + int_fast16_t kA=0, kC=0, kZ=0, shiftRight; + uint_fast32_t frac32C=0, frac32Z=0; + + //NaR + if ( uiA==0x8000 || uiB==0x8000 || uiC==0x8000 ){ + uZ.ui = 0x8000; + return uZ.p; + } + else if (uiA==0 || uiB==0){ + if (op == softposit_mulAdd_subC) + uZ.ui = -uiC; + else + uZ.ui = uiC; + return uZ.p; + } + + signA = signP16UI( uiA ); + signB = signP16UI( uiB ); + signC = signP16UI( uiC );//^ (op == softposit_mulAdd_subC); + signZ = signA ^ signB;// ^ (op == softposit_mulAdd_subProd); + + if(signA) uiA = (-uiA & 0xFFFF); + if(signB) uiB = (-uiB & 0xFFFF); + if(signC) uiC = (-uiC & 0xFFFF); + + regSA = signregP16UI(uiA); + regSB = signregP16UI(uiB); + regSC = signregP16UI(uiC); + + 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 = (0x8000 | (tmp<<1)); //use first bit here for hidden bit to get more bits + + 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 * (0x8000 | (tmp <<1)); // first bit hidden bit + + if (expA>1){ + kA++; + expA ^=0x2; + } + + rcarry = frac32Z>>31;//1st bit of frac32Z + if (rcarry){ + if (expA) kA ++; + expA^=1; + frac32Z>>=1; + } + + //Add + if (uiC!=0){ + tmp = (uiC<<2) & 0xFFFF; + if (regSC){ + while (tmp>>15){ + kC++; + tmp= (tmp<<1) & 0xFFFF; + } + } + else{ + kC=-1; + while (!(tmp>>15)){ + kC--; + tmp= (tmp<<1) & 0xFFFF; + } + tmp&=0x7FFF; + } + expC = tmp>>14; + frac32C = (0x4000 | tmp) << 16; + shiftRight = ((kA-kC)<<1) + (expA-expC); //actually this is the scale + + if (shiftRight<0){ // |uiC| > |Prod Z| + if (shiftRight<=-31){ + bitsMore = 1; + frac32Z = 0; + } + else if (((frac32Z<<(32+shiftRight))&0xFFFFFFFF)!=0) bitsMore = 1; + if (signZ==signC) + frac32Z = frac32C + (frac32Z>>-shiftRight); + else {//different signs + frac32Z = frac32C - (frac32Z>>-shiftRight) ; + signZ=signC; + if (bitsMore) frac32Z-=1; + } + kZ = kC; + expZ = expC; + + } + else if (shiftRight>0){// |uiC| < |Prod| + //if (frac32C&((1<<shiftRight)-1)) bitsMore = 1; + if(shiftRight>=31){ + bitsMore = 1; + frac32C = 0; + } + else if (((frac32C<<(32-shiftRight))&0xFFFFFFFF)!=0) bitsMore = 1; + if (signZ==signC) + frac32Z = frac32Z + (frac32C>>shiftRight); + else{ + frac32Z = frac32Z - (frac32C>>shiftRight); + if (bitsMore) frac32Z-=1; + } + kZ = kA; + expZ = expA; + + } + else{ + if(frac32C==frac32Z && signZ!=signC ){ //check if same number + uZ.ui = 0; + return uZ.p; + } + else{ + if (signZ==signC) + frac32Z += frac32C; + else{ + if (frac32Z<frac32C){ + frac32Z = frac32C - frac32Z; + signZ = signC; + } + else{ + frac32Z -= frac32C; + } + } + } + kZ = kA;// actually can be kC too, no diff + expZ = expA; //same here + } + + rcarry = 0x80000000 & frac32Z; //first left bit + if(rcarry){ + if (expZ) kZ ++; + expZ^=1; + if (frac32Z&0x1) bitsMore = 1; + frac32Z=(frac32Z>>1)&0x7FFFFFFF; + } + else { + //for subtract cases + if (frac32Z!=0){ + while((frac32Z>>29)==0){ + kZ--; + frac32Z<<=2; + } + } + bool ecarry = (0x40000000 & frac32Z)>>30; + + if(!ecarry){ + if (expZ==0) kZ--; + expZ^=1; + frac32Z<<=1; + } + } + } + else{ + kZ = kA; + expZ=expA; + } + + if(kZ<0){ + regZ = (-kZ & 0xFFFF); + regSZ = 0; + regime = 0x4000>>regZ; + } + else{ + regZ = kZ+1; + regSZ=1; + regime = 0x7FFF - (0x7FFF>>regZ); + } + + if(regZ>14){ + //max or min pos. exp and frac does not matter. + (regSZ) ? (uZ.ui= 0x7FFF): (uZ.ui=0x1); + } + else{ + //remove hidden bits + frac32Z &= 0x3FFFFFFF; + fracZ = frac32Z >> (regZ + 17); + + if (regZ!=14) bitNPlusOne = (frac32Z>>regZ) & 0x10000; + else if (frac32Z>0){ + fracZ=0; + bitsMore =1; + } + if (regZ==14 && expZ) bitNPlusOne = 1; + uZ.ui = packToP16UI(regime, regZ, expZ, fracZ); + if (bitNPlusOne){ + if ( (frac32Z<<(16-regZ)) &0xFFFFFFFF ) bitsMore =1; + uZ.ui += (uZ.ui&1) | bitsMore; + } + } + + if (signZ) uZ.ui = -uZ.ui & 0xFFFF; + return uZ.p; + +} + |