1 files changed, 74 insertions, 0 deletions
diff --git a/source/luametatex/source/libraries/softposit/source/ui64_to_p16.c b/source/luametatex/source/libraries/softposit/source/ui64_to_p16.c
new file mode 100644
index 000000000..b6620114c
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+++ b/source/luametatex/source/libraries/softposit/source/ui64_to_p16.c
@@ -0,0 +1,74 @@
+
+/*============================================================================
+
+This C source file is part of the SoftPosit Posit Arithmetic Package
+by S. H. Leong (Cerlane) and John Gustafson.
+
+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 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 <stdint.h>
+
+#include "platform.h"
+#include "internals.h"
+
+posit16_t ui64_to_p16( uint64_t a ) {
+    int_fast8_t k, log2 = 25;
+    union ui16_p16 uZ;
+    uint_fast16_t uiA;
+    uint_fast64_t expA, mask = 0x0000000002000000, fracA;
+
+    if ( a > 0x0000000008000000 ) uiA = 0x7FFF; //134217729 to MAX_INT round to maxpos
+    else if ( a > 0x0000000002FFFFFF ) uiA = 0x7FFE;
+    else if ( a < 2 ) uiA = (a << 14);
+    else {
+        fracA = a;
+        while ( !(fracA & mask) ) {
+            log2--;
+            fracA <<= 1;
+        }
+        k = log2 >> 1;
+        expA = (log2 & 0x1) << (12 - k);
+        fracA = fracA ^ mask;
+        uiA = (0x7FFF ^ (0x3FFF >> k)) | expA | (fracA  >> (k + 13));
+        mask = 0x1000 << k;
+        if (mask & fracA) {
+            if ( ((mask - 1) & fracA) | ((mask << 1) & fracA) ) uiA++;
+        }
+    }
+    uZ.ui = uiA;
+    return uZ.p;
+
+}