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

• Lines: 387
• Date: Thu Nov 28 15:53:10 2002
• Orig file: linux-2.4.19/arch/parisc/math-emu/fcnvxf.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -urN linux-2.4.19/arch/parisc/math-emu/fcnvxf.c linux-2.4.20/arch/parisc/math-emu/fcnvxf.c
@@ -0,0 +1,386 @@
+/*
+ * 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/fcnvxf.c		$Revision: 1.1 $
+ *
+ *  Purpose:
+ *	Single Fixed-point to Single Floating-point
+ *	Single Fixed-point to Double Floating-point 
+ *	Double Fixed-point to Single Floating-point 
+ *	Double Fixed-point to Double Floating-point 
+ *
+ *  External Interfaces:
+ *	dbl_to_dbl_fcnvxf(srcptr,nullptr,dstptr,status)
+ *	dbl_to_sgl_fcnvxf(srcptr,nullptr,dstptr,status)
+ *	sgl_to_dbl_fcnvxf(srcptr,nullptr,dstptr,status)
+ *	sgl_to_sgl_fcnvxf(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"
+
+/*
+ *  Convert single fixed-point to single floating-point format
+ */
+
+int
+sgl_to_sgl_fcnvxf(
+		    int *srcptr,
+		    unsigned int *nullptr,
+		    sgl_floating_point *dstptr,
+		    unsigned int *status)
+{
+	register int src, dst_exponent;
+	register unsigned int result = 0;
+
+	src = *srcptr;
+	/* 
+	 * set sign bit of result and get magnitude of source 
+	 */
+	if (src < 0) {
+		Sgl_setone_sign(result);  
+		Int_negate(src);
+	}
+	else {
+		Sgl_setzero_sign(result);
+        	/* 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 1  */
+	if (dst_exponent >= 0) src <<= dst_exponent;
+	else src = 1 << 30;
+	Sgl_set_mantissa(result, src >> (SGL_EXP_LENGTH-1));
+	Sgl_set_exponent(result, 30+SGL_BIAS - dst_exponent);
+
+	/* check for inexact */
+	if (Int_isinexact_to_sgl(src)) {
+		switch (Rounding_mode()) {
+			case ROUNDPLUS: 
+				if (Sgl_iszero_sign(result)) 
+					Sgl_increment(result);
+				break;
+			case ROUNDMINUS: 
+				if (Sgl_isone_sign(result)) 
+					Sgl_increment(result);
+				break;
+			case ROUNDNEAREST:
+				Sgl_roundnearest_from_int(src,result);
+		}
+		if (Is_inexacttrap_enabled()) {
+			*dstptr = result;
+			return(INEXACTEXCEPTION);
+		}
+		else Set_inexactflag();
+	}
+	*dstptr = result;
+	return(NOEXCEPTION);
+}
+
+/*
+ *  Single Fixed-point to Double Floating-point 
+ */
+
+int
+sgl_to_dbl_fcnvxf(
+		    int *srcptr,
+		    unsigned int *nullptr,
+		    dbl_floating_point *dstptr,
+		    unsigned int *status)
+{
+	register int src, dst_exponent;
+	register unsigned int resultp1 = 0, resultp2 = 0;
+
+	src = *srcptr;
+	/* 
+	 * set sign bit of result and get magnitude of source 
+	 */
+	if (src < 0) {
+		Dbl_setone_sign(resultp1);  
+		Int_negate(src);
+	}
+	else {
+		Dbl_setzero_sign(resultp1);
+        	/* 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 1  */
+	if (dst_exponent >= 0) src <<= dst_exponent;
+	else src = 1 << 30;
+	Dbl_set_mantissap1(resultp1, src >> DBL_EXP_LENGTH - 1);
+	Dbl_set_mantissap2(resultp2, src << (33-DBL_EXP_LENGTH));
+	Dbl_set_exponent(resultp1, (30+DBL_BIAS) - dst_exponent);
+	Dbl_copytoptr(resultp1,resultp2,dstptr);
+	return(NOEXCEPTION);
+}
+
+/*
+ *  Double Fixed-point to Single Floating-point 
+ */
+
+int
+dbl_to_sgl_fcnvxf(
+			dbl_integer *srcptr,
+			unsigned int *nullptr,
+			sgl_floating_point *dstptr,
+			unsigned int *status)
+{
+	int dst_exponent, srcp1;
+	unsigned int result = 0, srcp2;
+
+	Dint_copyfromptr(srcptr,srcp1,srcp2);
+	/* 
+	 * set sign bit of result and get magnitude of source 
+	 */
+	if (srcp1 < 0) {
+		Sgl_setone_sign(result);  
+		Dint_negate(srcp1,srcp2);
+	}
+	else {
+		Sgl_setzero_sign(result);
+        	/* 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 1  */
+		if (dst_exponent >= 0) {
+			srcp1 = srcp2 << dst_exponent;    
+			srcp2 = 0;
+		}
+		else {
+			srcp1 = srcp2 >> 1;
+			srcp2 <<= 31; 
+		}
+		/*
+		 *  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 1  */
+		if (dst_exponent > 0) {
+			Variable_shift_double(srcp1,srcp2,(32-dst_exponent),
+			 srcp1); 
+			srcp2 <<= dst_exponent;
+		}
+		/*
+		 * If dst_exponent = 0, we don't need to shift anything.
+		 * If dst_exponent = -1, src = - 2**63 so we won't need to 
+		 * shift srcp2.
+		 */
+		else srcp1 >>= -(dst_exponent);
+	}
+	Sgl_set_mantissa(result, srcp1 >> SGL_EXP_LENGTH - 1);
+	Sgl_set_exponent(result, (62+SGL_BIAS) - dst_exponent);
+
+	/* check for inexact */
+	if (Dint_isinexact_to_sgl(srcp1,srcp2)) {
+		switch (Rounding_mode()) {
+			case ROUNDPLUS: 
+				if (Sgl_iszero_sign(result)) 
+					Sgl_increment(result);
+				break;
+			case ROUNDMINUS: 
+				if (Sgl_isone_sign(result)) 
+					Sgl_increment(result);
+				break;
+			case ROUNDNEAREST:
+				Sgl_roundnearest_from_dint(srcp1,srcp2,result);
+		}
+		if (Is_inexacttrap_enabled()) {
+			*dstptr = result;
+			return(INEXACTEXCEPTION);
+		}
+		else Set_inexactflag();
+	}
+	*dstptr = result;
+	return(NOEXCEPTION);
+}
+
+/*
+ *  Double Fixed-point to Double Floating-point 
+ */
+
+int
+dbl_to_dbl_fcnvxf(
+		    dbl_integer *srcptr,
+		    unsigned int *nullptr,
+		    dbl_floating_point *dstptr,
+		    unsigned int *status)
+{
+	register int srcp1, dst_exponent;
+	register unsigned int srcp2, resultp1 = 0, resultp2 = 0;
+
+	Dint_copyfromptr(srcptr,srcp1,srcp2);
+	/* 
+	 * set sign bit of result and get magnitude of source 
+	 */
+	if (srcp1 < 0) {
+		Dbl_setone_sign(resultp1);
+		Dint_negate(srcp1,srcp2);
+	}
+	else {
+		Dbl_setzero_sign(resultp1);
+        	/* 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 1  */
+		if (dst_exponent >= 0) {
+			srcp1 = srcp2 << dst_exponent;    
+			srcp2 = 0;
+		}
+		else {
+			srcp1 = srcp2 >> 1;
+			srcp2 <<= 31;
+		}
+		/*
+		 *  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 1  */
+		if (dst_exponent > 0) {
+			Variable_shift_double(srcp1,srcp2,(32-dst_exponent),
+			 srcp1); 
+			srcp2 <<= dst_exponent;
+		}
+		/*
+		 * If dst_exponent = 0, we don't need to shift anything.
+		 * If dst_exponent = -1, src = - 2**63 so we won't need to 
+		 * shift srcp2.
+		 */
+		else srcp1 >>= -(dst_exponent);
+	}
+	Dbl_set_mantissap1(resultp1, srcp1 >> (DBL_EXP_LENGTH-1));
+	Shiftdouble(srcp1,srcp2,DBL_EXP_LENGTH-1,resultp2);
+	Dbl_set_exponent(resultp1, (62+DBL_BIAS) - dst_exponent);
+
+	/* check for inexact */
+	if (Dint_isinexact_to_dbl(srcp2)) {
+		switch (Rounding_mode()) {
+			case ROUNDPLUS: 
+				if (Dbl_iszero_sign(resultp1)) {
+					Dbl_increment(resultp1,resultp2);
+				}
+				break;
+			case ROUNDMINUS: 
+				if (Dbl_isone_sign(resultp1)) {
+					Dbl_increment(resultp1,resultp2);
+				}
+				break;
+			case ROUNDNEAREST:
+				Dbl_roundnearest_from_dint(srcp2,resultp1,
+				resultp2);
+		}
+		if (Is_inexacttrap_enabled()) {
+			Dbl_copytoptr(resultp1,resultp2,dstptr);
+			return(INEXACTEXCEPTION);
+		}
+		else Set_inexactflag();
+	}
+	Dbl_copytoptr(resultp1,resultp2,dstptr);
+	return(NOEXCEPTION);
+}