patch-2.4.20 linux-2.4.20/arch/parisc/math-emu/fcnvuf.c

• Lines: 319
• Date: Thu Nov 28 15:53:10 2002
• Orig file: linux-2.4.19/arch/parisc/math-emu/fcnvuf.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -urN linux-2.4.19/arch/parisc/math-emu/fcnvuf.c linux-2.4.20/arch/parisc/math-emu/fcnvuf.c
@@ -0,0 +1,318 @@
+/*
+ * Linux/PA-RISC Project (http://www.parisc-linux.org/)
+ *
+ * Floating-point emulation code
+ *  Copyright (C) 2001 Hewlett-Packard (Paul Bame) <bame@debian.org>
+ *
+ *    This program is free software; you can redistribute it and/or modify
+ *    it under the terms of the GNU General Public License as published by
+ *    the Free Software Foundation; either version 2, or (at your option)
+ *    any later version.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU General Public License for more details.
+ *
+ *    You should have received a copy of the GNU General Public License
+ *    along with this program; if not, write to the Free Software
+ *    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+/*
+ * BEGIN_DESC
+ *
+ *  File:
+ *	@(#)	pa/spmath/fcnvuf.c		$Revision: 1.1 $
+ *
+ *  Purpose:
+ *	Fixed point to Floating-point Converts
+ *
+ *  External Interfaces:
+ *	dbl_to_dbl_fcnvuf(srcptr,nullptr,dstptr,status)
+ *	dbl_to_sgl_fcnvuf(srcptr,nullptr,dstptr,status)
+ *	sgl_to_dbl_fcnvuf(srcptr,nullptr,dstptr,status)
+ *	sgl_to_sgl_fcnvuf(srcptr,nullptr,dstptr,status)
+ *
+ *  Internal Interfaces:
+ *
+ *  Theory:
+ *	<<please update with a overview of the operation of this file>>
+ *
+ * END_DESC
+*/
+
+
+#include "float.h"
+#include "sgl_float.h"
+#include "dbl_float.h"
+#include "cnv_float.h"
+
+/************************************************************************
+ *  Fixed point to Floating-point Converts				*
+ ************************************************************************/
+
+/*
+ *  Convert Single Unsigned Fixed to Single Floating-point format
+ */
+
+int
+sgl_to_sgl_fcnvuf(
+			unsigned int *srcptr,
+			unsigned int *nullptr,
+			sgl_floating_point *dstptr,
+			unsigned int *status)
+{
+	register unsigned int src, result = 0;
+	register int dst_exponent;
+
+	src = *srcptr;
+
+	/* Check for zero */ 
+	if (src == 0) { 
+	       	Sgl_setzero(result); 
+		*dstptr = result;
+	       	return(NOEXCEPTION); 
+	} 
+	/*
+	 * Generate exponent and normalized mantissa
+	 */
+	dst_exponent = 16;    /* initialize for normalization */
+	/*
+	 * Check word for most significant bit set.  Returns
+	 * a value in dst_exponent indicating the bit position,
+	 * between -1 and 30.
+	 */
+	Find_ms_one_bit(src,dst_exponent);
+	/*  left justify source, with msb at bit position 0  */
+	src <<= dst_exponent+1;
+	Sgl_set_mantissa(result, src >> SGL_EXP_LENGTH);
+	Sgl_set_exponent(result, 30+SGL_BIAS - dst_exponent);
+
+	/* check for inexact */
+	if (Suint_isinexact_to_sgl(src)) {
+		switch (Rounding_mode()) {
+			case ROUNDPLUS: 
+				Sgl_increment(result);
+				break;
+			case ROUNDMINUS: /* never negative */
+				break;
+			case ROUNDNEAREST:
+				Sgl_roundnearest_from_suint(src,result);
+				break;
+		}
+		if (Is_inexacttrap_enabled()) {
+			*dstptr = result;
+			return(INEXACTEXCEPTION);
+		}
+		else Set_inexactflag();
+	}
+	*dstptr = result;
+	return(NOEXCEPTION);
+}
+
+/*
+ *  Single Unsigned Fixed to Double Floating-point 
+ */
+
+int
+sgl_to_dbl_fcnvuf(
+			unsigned int *srcptr,
+			unsigned int *nullptr,
+			dbl_floating_point *dstptr,
+			unsigned int *status)
+{
+	register int dst_exponent;
+	register unsigned int src, resultp1 = 0, resultp2 = 0;
+
+	src = *srcptr;
+
+	/* Check for zero */
+	if (src == 0) {
+	       	Dbl_setzero(resultp1,resultp2);
+	       	Dbl_copytoptr(resultp1,resultp2,dstptr);
+	       	return(NOEXCEPTION);
+	}
+	/*
+	 * Generate exponent and normalized mantissa
+	 */
+	dst_exponent = 16;    /* initialize for normalization */
+	/*
+	 * Check word for most significant bit set.  Returns
+	 * a value in dst_exponent indicating the bit position,
+	 * between -1 and 30.
+	 */
+	Find_ms_one_bit(src,dst_exponent);
+	/*  left justify source, with msb at bit position 0  */
+	src <<= dst_exponent+1;
+	Dbl_set_mantissap1(resultp1, src >> DBL_EXP_LENGTH);
+	Dbl_set_mantissap2(resultp2, src << (32-DBL_EXP_LENGTH));
+	Dbl_set_exponent(resultp1, (30+DBL_BIAS) - dst_exponent);
+	Dbl_copytoptr(resultp1,resultp2,dstptr);
+	return(NOEXCEPTION);
+}
+
+/*
+ *  Double Unsigned Fixed to Single Floating-point 
+ */
+
+int
+dbl_to_sgl_fcnvuf(
+			dbl_unsigned *srcptr,
+			unsigned int *nullptr,
+			sgl_floating_point *dstptr,
+			unsigned int *status)
+{
+	int dst_exponent;
+	unsigned int srcp1, srcp2, result = 0;
+
+	Duint_copyfromptr(srcptr,srcp1,srcp2);
+
+	/* Check for zero */
+	if (srcp1 == 0 && srcp2 == 0) {
+	       	Sgl_setzero(result);
+	       	*dstptr = result;
+	       	return(NOEXCEPTION);
+	}
+	/*
+	 * Generate exponent and normalized mantissa
+	 */
+	dst_exponent = 16;    /* initialize for normalization */
+	if (srcp1 == 0) {
+		/*
+		 * Check word for most significant bit set.  Returns
+		 * a value in dst_exponent indicating the bit position,
+		 * between -1 and 30.
+		 */
+		Find_ms_one_bit(srcp2,dst_exponent);
+		/*  left justify source, with msb at bit position 0  */
+		srcp1 = srcp2 << dst_exponent+1;    
+		srcp2 = 0;
+		/*
+		 *  since msb set is in second word, need to 
+		 *  adjust bit position count
+		 */
+		dst_exponent += 32;
+	}
+	else {
+		/*
+		 * Check word for most significant bit set.  Returns
+		 * a value in dst_exponent indicating the bit position,
+		 * between -1 and 30.
+		 *
+		 */
+		Find_ms_one_bit(srcp1,dst_exponent);
+		/*  left justify source, with msb at bit position 0  */
+		if (dst_exponent >= 0) {
+			Variable_shift_double(srcp1,srcp2,(31-dst_exponent),
+			 srcp1); 
+			srcp2 <<= dst_exponent+1;
+		}
+	}
+	Sgl_set_mantissa(result, srcp1 >> SGL_EXP_LENGTH);
+	Sgl_set_exponent(result, (62+SGL_BIAS) - dst_exponent);
+
+	/* check for inexact */
+	if (Duint_isinexact_to_sgl(srcp1,srcp2)) {
+		switch (Rounding_mode()) {
+			case ROUNDPLUS: 
+				Sgl_increment(result);
+				break;
+			case ROUNDMINUS: /* never negative */
+				break;
+			case ROUNDNEAREST:
+				Sgl_roundnearest_from_duint(srcp1,srcp2,result);
+				break;
+		}
+		if (Is_inexacttrap_enabled()) {
+			*dstptr = result;
+			return(INEXACTEXCEPTION);
+		}
+		else Set_inexactflag();
+	}
+	*dstptr = result;
+	return(NOEXCEPTION);
+}
+
+/*
+ *  Double Unsigned Fixed to Double Floating-point 
+ */
+
+int
+dbl_to_dbl_fcnvuf(
+		    dbl_unsigned *srcptr,
+		    unsigned int *nullptr,
+		    dbl_floating_point *dstptr,
+		    unsigned int *status)
+{
+	register int dst_exponent;
+	register unsigned int srcp1, srcp2, resultp1 = 0, resultp2 = 0;
+
+	Duint_copyfromptr(srcptr,srcp1,srcp2);
+
+	/* Check for zero */
+	if (srcp1 == 0 && srcp2 ==0) {
+	       	Dbl_setzero(resultp1,resultp2);
+	       	Dbl_copytoptr(resultp1,resultp2,dstptr);
+	       	return(NOEXCEPTION);
+	}
+	/*
+	 * Generate exponent and normalized mantissa
+	 */
+	dst_exponent = 16;    /* initialize for normalization */
+	if (srcp1 == 0) {
+		/*
+		 * Check word for most significant bit set.  Returns
+		 * a value in dst_exponent indicating the bit position,
+		 * between -1 and 30.
+		 */
+		Find_ms_one_bit(srcp2,dst_exponent);
+		/*  left justify source, with msb at bit position 0  */
+		srcp1 = srcp2 << dst_exponent+1;
+		srcp2 = 0;
+		/*
+		 *  since msb set is in second word, need to 
+		 *  adjust bit position count
+		 */
+		dst_exponent += 32;
+	}
+	else {
+		/*
+		 * Check word for most significant bit set.  Returns
+		 * a value in dst_exponent indicating the bit position,
+		 * between -1 and 30.
+		 */
+		Find_ms_one_bit(srcp1,dst_exponent);
+		/*  left justify source, with msb at bit position 0  */
+		if (dst_exponent >= 0) {
+			Variable_shift_double(srcp1,srcp2,(31-dst_exponent),
+			 srcp1); 
+			srcp2 <<= dst_exponent+1;
+		}
+	}
+	Dbl_set_mantissap1(resultp1, srcp1 >> DBL_EXP_LENGTH);
+	Shiftdouble(srcp1,srcp2,DBL_EXP_LENGTH,resultp2);
+	Dbl_set_exponent(resultp1, (62+DBL_BIAS) - dst_exponent);
+
+	/* check for inexact */
+	if (Duint_isinexact_to_dbl(srcp2)) {
+		switch (Rounding_mode()) {
+			case ROUNDPLUS: 
+				Dbl_increment(resultp1,resultp2);
+				break;
+			case ROUNDMINUS: /* never negative */
+				break;
+			case ROUNDNEAREST:
+				Dbl_roundnearest_from_duint(srcp2,resultp1,
+				resultp2);
+				break;
+		}
+		if (Is_inexacttrap_enabled()) {
+			Dbl_copytoptr(resultp1,resultp2,dstptr);
+			return(INEXACTEXCEPTION);
+		}
+		else Set_inexactflag();
+	}
+	Dbl_copytoptr(resultp1,resultp2,dstptr);
+	return(NOEXCEPTION);
+}
+