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Diffstat (limited to 'source/luametatex/source/libraries/softposit/source/pX1_to_p32.c')
-rw-r--r-- | source/luametatex/source/libraries/softposit/source/pX1_to_p32.c | 113 |
1 files changed, 113 insertions, 0 deletions
diff --git a/source/luametatex/source/libraries/softposit/source/pX1_to_p32.c b/source/luametatex/source/libraries/softposit/source/pX1_to_p32.c new file mode 100644 index 000000000..774249c6b --- /dev/null +++ b/source/luametatex/source/libraries/softposit/source/pX1_to_p32.c @@ -0,0 +1,113 @@ + +/*============================================================================ + +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. + +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 pX1_to_p32( posit_1_t pA ){ + + union ui32_pX1 uA; + union ui32_p32 uZ; + uint_fast32_t uiA, tmp, regime; + uint_fast32_t exp_frac32A=0; + bool sign, regSA, bitNPlusOne=0, bitsMore=0; + int_fast8_t kA=0, regA; + + uA.p = pA; + uiA = uA.ui; + + if (uiA==0x80000000 || uiA==0 ){ + uZ.ui = uiA; + return uZ.p; + } + + + sign = signP32UI( uiA ); + if (sign) uiA = -uiA & 0xFFFFFFFF; + regSA = signregP32UI(uiA); + + 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; + } + + + //2nd bit exp + exp_frac32A = tmp; + + if(kA<0){ + regA = -kA; + exp_frac32A |= ((uint32_t)(regA&0x1)<<31); + regA = (regA+1)>>1; + if (regA==0) regA=1; + regSA = 0; + regime = 0x40000000>>regA; + } + else{ + exp_frac32A |= ((uint32_t)(kA&0x1)<<31); + (kA==0) ? (regA=1) : (regA = (kA+2)>>1); + regSA=1; + regime = 0x7FFFFFFF - (0x7FFFFFFF>>regA); + } + + bitNPlusOne = (exp_frac32A >>(regA+1))&0x1; + bitsMore = exp_frac32A&(0x7FFFFFFF>>(31-regA)); + + exp_frac32A >>=(regA+2); //2 because of sign and regime terminating bit + uZ.ui = regime + exp_frac32A; + + if (bitNPlusOne){ + uZ.ui += (uZ.ui&1) | bitsMore; + } + + if (sign) uZ.ui = (-uZ.ui & 0xFFFFFFFF); + return uZ.p; +} + |