summaryrefslogtreecommitdiffstats
path: root/kernel/arch/parisc/math-emu/fcnvxf.c
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/arch/parisc/math-emu/fcnvxf.c')
-rw-r--r--kernel/arch/parisc/math-emu/fcnvxf.c386
1 files changed, 386 insertions, 0 deletions
diff --git a/kernel/arch/parisc/math-emu/fcnvxf.c b/kernel/arch/parisc/math-emu/fcnvxf.c
new file mode 100644
index 000000000..05c7fadb3
--- /dev/null
+++ b/kernel/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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 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);
+}