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Diffstat (limited to 'source/luametatex/source/libraries/softposit/source/p32_mul.c')
| -rw-r--r-- | source/luametatex/source/libraries/softposit/source/p32_mul.c | 206 |
1 files changed, 206 insertions, 0 deletions
diff --git a/source/luametatex/source/libraries/softposit/source/p32_mul.c b/source/luametatex/source/libraries/softposit/source/p32_mul.c new file mode 100644 index 000000000..460d81aee --- /dev/null +++ b/source/luametatex/source/libraries/softposit/source/p32_mul.c @@ -0,0 +1,206 @@ + +/*============================================================================ + +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" + + +posit32_t p32_mul( posit32_t pA, posit32_t pB ){ + + + union ui32_p32 uA, uB, uZ; + uint_fast32_t uiA, uiB; + uint_fast32_t regA, fracA, regime, tmp; + bool signA, signB, signZ, regSA, regSB, bitNPlusOne=0, bitsMore=0, rcarry; + int_fast32_t expA; + int_fast8_t kA=0; + uint_fast64_t frac64Z; + + uA.p = pA; + uiA = uA.ui; + uB.p = pB; + uiB = uB.ui; + +#ifdef SOFTPOSIT_EXACT + uZ.ui.exact = (uiA.ui.exact & uiB.ui.exact); +#endif + //NaR or Zero + if ( uiA==0x80000000 || uiB==0x80000000 ){ + +#ifdef SOFTPOSIT_EXACT + uZ.ui.v = 0x80000000; + uZ.ui.exact = 0; +#else + uZ.ui = 0x80000000; +#endif + return uZ.p; + } + else if (uiA==0 || uiB==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); + + 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>>29; //to get 2 bits + fracA = ((tmp<<1) | 0x40000000) & 0x7FFFFFFF; + + 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>>29; + frac64Z = (uint_fast64_t) fracA * (((tmp<<1) | 0x40000000) & 0x7FFFFFFF); + + if (expA>3){ + kA++; + expA&=0x3; // -=4 + } + + rcarry = frac64Z>>61;//3rd bit of frac64Z + if (rcarry){ + expA++; + if (expA>3){ + kA ++; + expA&=0x3; + } + frac64Z>>=1; + } + + if(kA<0){ + regA = -kA; + regSA = 0; + regime = 0x40000000>>regA; + } + else{ + regA = kA+1; + regSA=1; + regime = 0x7FFFFFFF - (0x7FFFFFFF>>regA); + } + + + if(regA>30){ + //max or min pos. exp and frac does not matter. + (regSA) ? (uZ.ui= 0x7FFFFFFF): (uZ.ui=0x1); + } + else{ + //remove carry and rcarry bits and shift to correct position (2 bits exp, so + 1 than 16 bits) + frac64Z = (frac64Z&0xFFFFFFFFFFFFFFF) >> regA; + fracA = (uint_fast32_t) (frac64Z>>32); + if (regA<=28){ + bitNPlusOne |= (0x80000000 & frac64Z); + expA<<= (28-regA); + } + else { + if (regA==30){ + bitNPlusOne = expA&0x2; + bitsMore = (expA&0x1); + expA = 0; + } + else if (regA==29){ + bitNPlusOne = expA&0x1; + expA>>=1; //taken care of by the pack algo + } + if (fracA>0){ + fracA=0; + bitsMore =1; + } + + } + //sign is always zero + uZ.ui = packToP32UI(regime, expA, fracA); + //n+1 frac bit is 1. Need to check if another bit is 1 too if not round to even + if (bitNPlusOne){ + if (0x7FFFFFFF & frac64Z) bitsMore=1; + uZ.ui += (uZ.ui&1) | bitsMore; + } + } + + if (signZ) uZ.ui = -uZ.ui & 0xFFFFFFFF; + return uZ.p; + +} + |