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Diffstat (limited to 'source/luametatex/source/libraries/softposit/source/p8_to_p16.c')
| -rw-r--r-- | source/luametatex/source/libraries/softposit/source/p8_to_p16.c | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/source/luametatex/source/libraries/softposit/source/p8_to_p16.c b/source/luametatex/source/libraries/softposit/source/p8_to_p16.c new file mode 100644 index 000000000..56773e7dd --- /dev/null +++ b/source/luametatex/source/libraries/softposit/source/p8_to_p16.c @@ -0,0 +1,107 @@ +/*============================================================================ + +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" + +posit16_t p8_to_p16( posit8_t pA ) { + + union ui8_p8 uA; + union ui16_p16 uZ; + uint_fast8_t uiA, tmp; + uint_fast16_t exp_frac16A=0, regime; + bool sign, regSA; + int_fast8_t kA=0, regA; + + uA.p = pA; + uiA = uA.ui; + + //NaR or zero + if (uiA==0x80 || uiA==0 ){ + uZ.ui = (uint16_t)uiA<<8; + return uZ.p; + } + + sign = signP8UI( uiA ); + + if (sign) uiA = -uiA & 0xFF; + regSA = signregP8UI(uiA); + + tmp = (uiA<<2) & 0xFF; + if (regSA){ + while (tmp>>7){ + kA++; + tmp= (tmp<<1) & 0xFF; + } + } + else{ + kA=-1; + while (!(tmp>>7)){ + kA--; + tmp= (tmp<<1) & 0xFF; + } + tmp&=0x7F; + } + exp_frac16A = tmp<<8; + + if(kA<0){ + regA = -kA; + if (regA&0x1) exp_frac16A |= 0x8000; + regA = (regA+1)>>1; + if (regA==0) regA=1; + regSA = 0; + regime = 0x4000>>regA; + } + else{ + if (kA&0x1) exp_frac16A |= 0x8000; + regA = (kA+2)>>1; + if (regA==0) regA=1; + regSA=1; + regime = 0x7FFF - (0x7FFF>>regA); + } + + exp_frac16A >>=(regA+2); //2 because of sign and regime terminating bit + + uZ.ui = regime + exp_frac16A; + + if (sign) uZ.ui = -uZ.ui & 0xFFFF; + + return uZ.p; +} + |