1 files changed, 90 insertions, 0 deletions
diff --git a/source/luametatex/source/libraries/softposit/source/i64_to_p8.c b/source/luametatex/source/libraries/softposit/source/i64_to_p8.c
new file mode 100644
index 000000000..646d7e4be
--- /dev/null
+++ b/source/luametatex/source/libraries/softposit/source/i64_to_p8.c
@@ -0,0 +1,90 @@
+
+/*============================================================================
+
+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"
+
+posit8_t i64_to_p8( int64_t iA ){
+    int_fast8_t k, log2 = 6;//length of bit
+    union ui8_p8 uZ;
+    uint_fast8_t uiA;
+    uint_fast64_t mask = 0x40, fracA;
+    bool sign;
+
+    if (iA < -48){ //-48 to -MAX_INT rounds to P32 value -268435456
+		uZ.ui = 0x81; //-maxpos
+		return uZ.p;
+	}
+
+    sign = iA>>63;
+    if(sign){
+    	iA = -iA;
+    }
+
+    if ( iA > 48 ) {
+        uiA = 0x7F;
+    }
+    else if ( iA < 2 ){
+        uiA = (iA << 6);
+    }
+    else {
+        fracA = iA;
+        while ( !(fracA & mask) ) {
+            log2--;
+            fracA <<= 1;
+        }
+
+        k = log2;
+
+		fracA = (fracA ^ mask);
+
+        uiA = (0x7F ^ (0x3F >> k)) | ( fracA >> (k+1) ) ;
+
+        mask = 0x1 << k; //bitNPlusOne
+        if (mask & fracA) {
+            if (((mask - 1) & fracA) | ((mask << 1) & fracA)) uiA++;
+        }
+    }
+    (sign) ? (uZ.ui = -uiA &0xFF) : (uZ.ui = uiA);
+    return uZ.p;
+}