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author | Hans Hagen <pragma@wxs.nl> | 2023-04-27 00:04:07 +0200 |
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committer | Context Git Mirror Bot <phg@phi-gamma.net> | 2023-04-27 00:04:07 +0200 |
commit | 6b25a7a970ba9553adf8077ef2eecb50a5d77818 (patch) | |
tree | f06e40077ba9e55af4bf6cab52313f79f8ea84a8 /source/luametatex/source/libraries/softposit/source/s_addMagsPX1.c | |
parent | 657457ef4a08c1f000f272e00f654f4064cc37bd (diff) | |
download | context-6b25a7a970ba9553adf8077ef2eecb50a5d77818.tar.gz |
2023-04-26 23:31:00
Diffstat (limited to 'source/luametatex/source/libraries/softposit/source/s_addMagsPX1.c')
-rw-r--r-- | source/luametatex/source/libraries/softposit/source/s_addMagsPX1.c | 190 |
1 files changed, 190 insertions, 0 deletions
diff --git a/source/luametatex/source/libraries/softposit/source/s_addMagsPX1.c b/source/luametatex/source/libraries/softposit/source/s_addMagsPX1.c new file mode 100644 index 000000000..608ca948c --- /dev/null +++ b/source/luametatex/source/libraries/softposit/source/s_addMagsPX1.c @@ -0,0 +1,190 @@ + +/*============================================================================ + +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 is part of the SoftFloat IEEE Floating-Point Arithmetic +Package, Release 3d, by John R. Hauser. + +Copyright 2011, 2012, 2013, 2014, 2015, 2016 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_1_t softposit_addMagsPX1( uint_fast32_t uiA, uint_fast32_t uiB, int x ) { + int regA; + uint_fast64_t frac64A=0, frac64B=0; + uint_fast32_t fracA=0, regime, tmp; + bool sign, regSA, regSB, rcarry=0, bitNPlusOne=0, bitsMore=0; + int_fast8_t kA=0; + int_fast32_t expA=0; + int_fast16_t shiftRight; + union ui32_pX1 uZ; + + + sign = signP32UI( uiA ); + if (sign){ + uiA = -uiA & 0xFFFFFFFF; + uiB = -uiB & 0xFFFFFFFF; + } + + if ((int_fast32_t)uiA < (int_fast32_t)uiB){ + uiA ^= uiB; + uiB ^= uiA; + uiA ^= uiB; + } + regSA = signregP32UI( uiA ); + regSB = signregP32UI( uiB ); + + if (x==2){ + uZ.ui = (regSA|regSB) ? (0x40000000) : (0x0); + } + 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 + frac64A = ((0x40000000ULL | tmp) & 0x7FFFFFFFULL) <<32; + shiftRight = kA; + + tmp = (uiB<<2) & 0xFFFFFFFF; + if (regSB){ + while (tmp>>31){ + shiftRight--; + tmp= (tmp<<1) & 0xFFFFFFFF; + } + } + else{ + shiftRight++; + while (!(tmp>>31)){ + shiftRight++; + tmp= (tmp<<1) & 0xFFFFFFFF; + } + tmp&=0x7FFFFFFF; + } + + frac64B = ((0x40000000ULL | tmp) & 0x7FFFFFFFULL) <<32; + //This is 2kZ + expZ; (where kZ=kA-kB and expZ=expA-expB) + shiftRight = (shiftRight<<1) + expA - (tmp>>30); + + if (shiftRight==0){ + frac64A += frac64B; + //rcarry is one + if (expA) kA ++; + expA^=1; + frac64A>>=1; + } + else{ + //Manage CLANG (LLVM) compiler when shifting right more than number of bits + (shiftRight>63) ? (frac64B=0): (frac64B >>= shiftRight); //frac64B >>= shiftRight + + frac64A += frac64B; + + rcarry = 0x8000000000000000 & frac64A; //first left bit + if (rcarry){ + if (expA) kA ++; + expA^=1;; + frac64A>>=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 hidden bits + frac64A = (frac64A & 0x3FFFFFFFFFFFFFFF) >>(regA + 1) ; // 2 bits exp + fracA = frac64A>>32; + + //regime length is smaller than length of posit + if (regA<x){ + if (regA!=(x-2)) + bitNPlusOne |= (((uint64_t)0x8000000000000000>>x) & frac64A); + else if (frac64A>0){ + fracA=0; + bitsMore =1; + } + if (regA==(x-2) && expA){ + bitNPlusOne = 1; + expA=0; + } + } + else{ + regime=(regSA) ? (regime & ((int32_t)0x80000000>>(x-1)) ): (regime << (32-x)); + expA=0; + fracA=0; + } + fracA &=((int32_t)0x80000000>>(x-1)); + + expA <<= (29-regA); + 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 ((0x7FFFFFFFFFFFFFFF>>x) & frac64A) bitsMore=1; + uZ.ui += (uint32_t)(((uZ.ui>>(32-x))&1) | bitsMore) << (32-x) ; + } + } + } + + if (sign) uZ.ui = -uZ.ui & 0xFFFFFFFF; + return uZ.p; +} + |