diff options
Diffstat (limited to 'source/luametatex/source/libraries/softposit/source/p32_to_pX2.c')
| -rw-r--r-- | source/luametatex/source/libraries/softposit/source/p32_to_pX2.c | 92 |
1 files changed, 92 insertions, 0 deletions
diff --git a/source/luametatex/source/libraries/softposit/source/p32_to_pX2.c b/source/luametatex/source/libraries/softposit/source/p32_to_pX2.c new file mode 100644 index 000000000..bce55adee --- /dev/null +++ b/source/luametatex/source/libraries/softposit/source/p32_to_pX2.c @@ -0,0 +1,92 @@ + +/*============================================================================ + +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" + +posit_2_t pX2_to_pX2( posit_2_t pA, int x ){ + posit32_t p32 = {.v = pA.v}; + return p32_to_pX2(p32, x); +} +posit_2_t p32_to_pX2( posit32_t pA, int x ){ + + union ui32_p32 uA; + union ui32_pX2 uZ; + uint_fast32_t uiA; + bool sign; + + + if (x<2 || x>32){ + uZ.ui = 0x80000000; + return uZ.p; + } + + 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; + + if (x==2){ + uZ.ui=(uiA>0)?(0x40000000):(0); + } + else if (x==32 || (((uint32_t)0xFFFFFFFF>>x) & uiA)==0 ){ + uZ.ui = uiA; + } + else { + + int shift = 32-x; + if( (uiA>>shift)!=(0x7FFFFFFF>>shift) ){ + if( ((uint32_t)0x80000000>>x) & uiA){ + if ( ( ((uint32_t)0x80000000>>(x-1)) & uiA) || (((uint32_t)0x7FFFFFFF>>x) & uiA) ) + uiA += (0x1<<shift); + } + } + uZ.ui = uiA & ((int32_t)0x80000000>>(x-1)); + if (uZ.ui==0) uZ.ui = 0x1<<shift; + + } + if (sign) uZ.ui = (-uZ.ui & 0xFFFFFFFF); + return uZ.p; +} + |