--- /dev/null
+/*
+ * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 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);
+}
Code Review / kvmfornfv.git / blobdiff