1 files changed, 123 insertions, 0 deletions
diff --git a/source/luametatex/source/libraries/softposit/source/c_convertQuire8ToPosit8.c b/source/luametatex/source/libraries/softposit/source/c_convertQuire8ToPosit8.c
new file mode 100644
index 000000000..bd537320f
--- /dev/null
+++ b/source/luametatex/source/libraries/softposit/source/c_convertQuire8ToPosit8.c
@@ -0,0 +1,123 @@
+
+/*============================================================================
+
+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.
+
+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 <math.h>
+
+#include "platform.h"
+#include "internals.h"
+
+
+posit8_t q8_to_p8(quire8_t qA){
+
+	union ui32_q8 uZ;
+	union ui8_p8 uA;
+	uint_fast8_t regA, fracA = 0, shift=0, regime;
+	uint_fast32_t frac32A;
+	bool sign=0, regSA=0, bitNPlusOne=0, bitsMore=0;
+
+	if (isQ8Zero(qA)){
+		uA.ui=0;
+		return uA.p;
+	}
+	//handle NaR
+	else if (isNaRQ8(qA)){
+		uA.ui=0x80;
+		return uA.p;
+	}
+
+	uZ.q = qA;
+
+	sign = uZ.ui>>31;
+
+	if(sign){
+		uZ.ui = -uZ.ui & 0xFFFFFFFF;
+	}
+
+	int noLZ =0;
+
+	uint_fast32_t tmp = uZ.ui;
+
+	while (!(tmp>>31)){//==0
+		noLZ++;
+		tmp<<=1;
+	}
+	frac32A = tmp;
+
+	//default dot is between bit 19 and 20, extreme left bit is bit 0. Last right bit is bit 31.
+	//Scale =  k
+	int kA=(19-noLZ);
+
+	if(kA<0){
+		regA = (-kA & 0xFF);
+		regSA = 0;
+		regime = 0x40>>regA;
+	}
+	else{
+		regA = kA+1;
+		regSA=1;
+		regime = 0x7F-(0x7F>>regA);
+	}
+
+	if(regA>6){
+		//max or min pos. exp and frac does not matter.
+		(regSA) ? (uA.ui= 0x7F): (uA.ui=0x1);
+	}
+	else{
+		//remove hidden bit
+		frac32A&=0x7FFFFFFF;
+		shift = regA+25; // 1 sign bit and 1 r terminating bit , 16+7+2
+		fracA = frac32A>>shift;
+
+		bitNPlusOne = (frac32A>>(shift-1))&0x1 ;
+
+		uA.ui = packToP8UI(regime, fracA);
+
+		if (bitNPlusOne){
+			( (frac32A <<(33-shift)) & 0xFFFFFFFF ) ? (bitsMore=1) : (bitsMore=0);
+			uA.ui += (uA.ui&1) |  bitsMore;
+		}
+	}
+
+	if (sign) uA.ui = -uA.ui & 0xFF;
+
+	return uA.p;
+
+
+}
+
+
+