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

• Lines: 310
• Date: Thu Nov 28 15:53:10 2002
• Orig file: linux-2.4.19/arch/parisc/math-emu/fcnvff.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -urN linux-2.4.19/arch/parisc/math-emu/fcnvff.c linux-2.4.20/arch/parisc/math-emu/fcnvff.c
@@ -0,0 +1,309 @@
+/*
+ * 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/fcnvff.c		$Revision: 1.1 $
+ *
+ *  Purpose:
+ *	Single Floating-point to Double Floating-point
+ *	Double Floating-point to Single Floating-point
+ *
+ *  External Interfaces:
+ *	dbl_to_sgl_fcnvff(srcptr,nullptr,dstptr,status)
+ *	sgl_to_dbl_fcnvff(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"
+
+/*
+ *  Single Floating-point to Double Floating-point 
+ */
+/*ARGSUSED*/
+int
+sgl_to_dbl_fcnvff(
+	    sgl_floating_point *srcptr,
+	    unsigned int *nullptr,
+	    dbl_floating_point *dstptr,
+	    unsigned int *status)
+{
+	register unsigned int src, resultp1, resultp2;
+	register int src_exponent;
+
+	src = *srcptr;
+	src_exponent = Sgl_exponent(src);
+	Dbl_allp1(resultp1) = Sgl_all(src);  /* set sign of result */
+	/* 
+ 	 * Test for NaN or infinity
+ 	 */
+	if (src_exponent == SGL_INFINITY_EXPONENT) {
+		/*
+		 * determine if NaN or infinity
+		 */
+		if (Sgl_iszero_mantissa(src)) {
+			/*
+			 * is infinity; want to return double infinity
+			 */
+			Dbl_setinfinity_exponentmantissa(resultp1,resultp2);
+			Dbl_copytoptr(resultp1,resultp2,dstptr);
+			return(NOEXCEPTION);
+		}
+		else {
+			/* 
+			 * is NaN; signaling or quiet?
+			 */
+			if (Sgl_isone_signaling(src)) {
+				/* trap if INVALIDTRAP enabled */
+				if (Is_invalidtrap_enabled())
+					return(INVALIDEXCEPTION);
+				/* make NaN quiet */
+				else {
+					Set_invalidflag();
+					Sgl_set_quiet(src);
+				}
+			}
+			/* 
+			 * NaN is quiet, return as double NaN 
+			 */
+			Dbl_setinfinity_exponent(resultp1);
+			Sgl_to_dbl_mantissa(src,resultp1,resultp2);
+			Dbl_copytoptr(resultp1,resultp2,dstptr);
+			return(NOEXCEPTION);
+		}
+	}
+	/* 
+ 	 * Test for zero or denormalized
+ 	 */
+	if (src_exponent == 0) {
+		/*
+		 * determine if zero or denormalized
+		 */
+		if (Sgl_isnotzero_mantissa(src)) {
+			/*
+			 * is denormalized; want to normalize
+			 */
+			Sgl_clear_signexponent(src);
+			Sgl_leftshiftby1(src);
+			Sgl_normalize(src,src_exponent);
+			Sgl_to_dbl_exponent(src_exponent,resultp1);
+			Sgl_to_dbl_mantissa(src,resultp1,resultp2);
+		}
+		else {
+			Dbl_setzero_exponentmantissa(resultp1,resultp2);
+		}
+		Dbl_copytoptr(resultp1,resultp2,dstptr);
+		return(NOEXCEPTION);
+	}
+	/*
+	 * No special cases, just complete the conversion
+	 */
+	Sgl_to_dbl_exponent(src_exponent, resultp1);
+	Sgl_to_dbl_mantissa(Sgl_mantissa(src), resultp1,resultp2);
+	Dbl_copytoptr(resultp1,resultp2,dstptr);
+	return(NOEXCEPTION);
+}
+
+/*
+ *  Double Floating-point to Single Floating-point 
+ */
+/*ARGSUSED*/
+int
+dbl_to_sgl_fcnvff(
+		    dbl_floating_point *srcptr,
+		    unsigned int *nullptr,
+		    sgl_floating_point *dstptr,
+		    unsigned int *status)
+{
+        register unsigned int srcp1, srcp2, result;
+        register int src_exponent, dest_exponent, dest_mantissa;
+        register boolean inexact = FALSE, guardbit = FALSE, stickybit = FALSE;
+	register boolean lsb_odd = FALSE;
+	boolean is_tiny;
+
+	Dbl_copyfromptr(srcptr,srcp1,srcp2);
+        src_exponent = Dbl_exponent(srcp1);
+	Sgl_all(result) = Dbl_allp1(srcp1);  /* set sign of result */
+        /* 
+         * Test for NaN or infinity
+         */
+        if (src_exponent == DBL_INFINITY_EXPONENT) {
+                /*
+                 * determine if NaN or infinity
+                 */
+                if (Dbl_iszero_mantissa(srcp1,srcp2)) {
+                        /*
+                         * is infinity; want to return single infinity
+                         */
+                        Sgl_setinfinity_exponentmantissa(result);
+                        *dstptr = result;
+                        return(NOEXCEPTION);
+                }
+                /* 
+                 * is NaN; signaling or quiet?
+                 */
+                if (Dbl_isone_signaling(srcp1)) {
+                        /* trap if INVALIDTRAP enabled */
+                        if (Is_invalidtrap_enabled()) return(INVALIDEXCEPTION);
+                        else {
+				Set_invalidflag();
+                        	/* make NaN quiet */
+                        	Dbl_set_quiet(srcp1);
+			}
+                }
+                /* 
+                 * NaN is quiet, return as single NaN 
+                 */
+                Sgl_setinfinity_exponent(result);
+		Sgl_set_mantissa(result,Dallp1(srcp1)<<3 | Dallp2(srcp2)>>29);
+		if (Sgl_iszero_mantissa(result)) Sgl_set_quiet(result);
+                *dstptr = result;
+                return(NOEXCEPTION);
+        }
+        /*
+         * Generate result
+         */
+        Dbl_to_sgl_exponent(src_exponent,dest_exponent);
+	if (dest_exponent > 0) {
+        	Dbl_to_sgl_mantissa(srcp1,srcp2,dest_mantissa,inexact,guardbit, 
+		stickybit,lsb_odd);
+	}
+	else {
+		if (Dbl_iszero_exponentmantissa(srcp1,srcp2)){
+			Sgl_setzero_exponentmantissa(result);
+			*dstptr = result;
+			return(NOEXCEPTION);
+		}
+                if (Is_underflowtrap_enabled()) {
+			Dbl_to_sgl_mantissa(srcp1,srcp2,dest_mantissa,inexact,
+			guardbit,stickybit,lsb_odd);
+                }
+		else {
+			/* compute result, determine inexact info,
+			 * and set Underflowflag if appropriate
+			 */
+			Dbl_to_sgl_denormalized(srcp1,srcp2,dest_exponent,
+			dest_mantissa,inexact,guardbit,stickybit,lsb_odd,
+			is_tiny);
+		}
+	}
+        /* 
+         * Now round result if not exact
+         */
+        if (inexact) {
+                switch (Rounding_mode()) {
+                        case ROUNDPLUS: 
+                                if (Sgl_iszero_sign(result)) dest_mantissa++;
+                                break;
+                        case ROUNDMINUS: 
+                                if (Sgl_isone_sign(result)) dest_mantissa++;
+                                break;
+                        case ROUNDNEAREST:
+                                if (guardbit) {
+                                   if (stickybit || lsb_odd) dest_mantissa++;
+                                   }
+                }
+        }
+        Sgl_set_exponentmantissa(result,dest_mantissa);
+
+        /*
+         * check for mantissa overflow after rounding
+         */
+        if ((dest_exponent>0 || Is_underflowtrap_enabled()) && 
+	    Sgl_isone_hidden(result)) dest_exponent++;
+
+        /* 
+         * Test for overflow
+         */
+        if (dest_exponent >= SGL_INFINITY_EXPONENT) {
+                /* trap if OVERFLOWTRAP enabled */
+                if (Is_overflowtrap_enabled()) {
+                        /* 
+                         * Check for gross overflow
+                         */
+                        if (dest_exponent >= SGL_INFINITY_EXPONENT+SGL_WRAP) 
+                        	return(UNIMPLEMENTEDEXCEPTION);
+                        
+                        /*
+                         * Adjust bias of result
+                         */
+			Sgl_setwrapped_exponent(result,dest_exponent,ovfl);
+			*dstptr = result;
+			if (inexact) 
+			    if (Is_inexacttrap_enabled())
+				return(OVERFLOWEXCEPTION|INEXACTEXCEPTION);
+			    else Set_inexactflag();
+                        return(OVERFLOWEXCEPTION);
+                }
+                Set_overflowflag();
+		inexact = TRUE;
+		/* set result to infinity or largest number */
+		Sgl_setoverflow(result);
+        }
+        /* 
+         * Test for underflow
+         */
+        else if (dest_exponent <= 0) {
+                /* trap if UNDERFLOWTRAP enabled */
+                if (Is_underflowtrap_enabled()) {
+                        /* 
+                         * Check for gross underflow
+                         */
+                        if (dest_exponent <= -(SGL_WRAP))
+                        	return(UNIMPLEMENTEDEXCEPTION);
+                        /*
+                         * Adjust bias of result
+                         */
+			Sgl_setwrapped_exponent(result,dest_exponent,unfl);
+			*dstptr = result;
+			if (inexact) 
+			    if (Is_inexacttrap_enabled())
+				return(UNDERFLOWEXCEPTION|INEXACTEXCEPTION);
+			    else Set_inexactflag();
+                        return(UNDERFLOWEXCEPTION);
+                }
+                 /* 
+                  * result is denormalized or signed zero
+                  */
+               if (inexact && is_tiny) Set_underflowflag();
+
+        }
+	else Sgl_set_exponent(result,dest_exponent);
+	*dstptr = result;
+        /* 
+         * Trap if inexact trap is enabled
+         */
+        if (inexact)
+        	if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION);
+        	else Set_inexactflag();
+        return(NOEXCEPTION);
+}