aboutsummaryrefslogtreecommitdiff
path: root/arch/parisc/math-emu/dfrem.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/parisc/math-emu/dfrem.c')
-rw-r--r--arch/parisc/math-emu/dfrem.c297
1 files changed, 297 insertions, 0 deletions
diff --git a/arch/parisc/math-emu/dfrem.c b/arch/parisc/math-emu/dfrem.c
new file mode 100644
index 00000000000..b9837853467
--- /dev/null
+++ b/arch/parisc/math-emu/dfrem.c
@@ -0,0 +1,297 @@
+/*
+ * 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/dfrem.c $Revision: 1.1 $
+ *
+ * Purpose:
+ * Double Precision Floating-point Remainder
+ *
+ * External Interfaces:
+ * dbl_frem(srcptr1,srcptr2,dstptr,status)
+ *
+ * Internal Interfaces:
+ *
+ * Theory:
+ * <<please update with a overview of the operation of this file>>
+ *
+ * END_DESC
+*/
+
+
+
+#include "float.h"
+#include "dbl_float.h"
+
+/*
+ * Double Precision Floating-point Remainder
+ */
+
+int
+dbl_frem (dbl_floating_point * srcptr1, dbl_floating_point * srcptr2,
+ dbl_floating_point * dstptr, unsigned int *status)
+{
+ register unsigned int opnd1p1, opnd1p2, opnd2p1, opnd2p2;
+ register unsigned int resultp1, resultp2;
+ register int opnd1_exponent, opnd2_exponent, dest_exponent, stepcount;
+ register boolean roundup = FALSE;
+
+ Dbl_copyfromptr(srcptr1,opnd1p1,opnd1p2);
+ Dbl_copyfromptr(srcptr2,opnd2p1,opnd2p2);
+ /*
+ * check first operand for NaN's or infinity
+ */
+ if ((opnd1_exponent = Dbl_exponent(opnd1p1)) == DBL_INFINITY_EXPONENT) {
+ if (Dbl_iszero_mantissa(opnd1p1,opnd1p2)) {
+ if (Dbl_isnotnan(opnd2p1,opnd2p2)) {
+ /* invalid since first operand is infinity */
+ if (Is_invalidtrap_enabled())
+ return(INVALIDEXCEPTION);
+ Set_invalidflag();
+ Dbl_makequietnan(resultp1,resultp2);
+ Dbl_copytoptr(resultp1,resultp2,dstptr);
+ return(NOEXCEPTION);
+ }
+ }
+ else {
+ /*
+ * is NaN; signaling or quiet?
+ */
+ if (Dbl_isone_signaling(opnd1p1)) {
+ /* trap if INVALIDTRAP enabled */
+ if (Is_invalidtrap_enabled())
+ return(INVALIDEXCEPTION);
+ /* make NaN quiet */
+ Set_invalidflag();
+ Dbl_set_quiet(opnd1p1);
+ }
+ /*
+ * is second operand a signaling NaN?
+ */
+ else if (Dbl_is_signalingnan(opnd2p1)) {
+ /* trap if INVALIDTRAP enabled */
+ if (Is_invalidtrap_enabled())
+ return(INVALIDEXCEPTION);
+ /* make NaN quiet */
+ Set_invalidflag();
+ Dbl_set_quiet(opnd2p1);
+ Dbl_copytoptr(opnd2p1,opnd2p2,dstptr);
+ return(NOEXCEPTION);
+ }
+ /*
+ * return quiet NaN
+ */
+ Dbl_copytoptr(opnd1p1,opnd1p2,dstptr);
+ return(NOEXCEPTION);
+ }
+ }
+ /*
+ * check second operand for NaN's or infinity
+ */
+ if ((opnd2_exponent = Dbl_exponent(opnd2p1)) == DBL_INFINITY_EXPONENT) {
+ if (Dbl_iszero_mantissa(opnd2p1,opnd2p2)) {
+ /*
+ * return first operand
+ */
+ Dbl_copytoptr(opnd1p1,opnd1p2,dstptr);
+ return(NOEXCEPTION);
+ }
+ /*
+ * is NaN; signaling or quiet?
+ */
+ if (Dbl_isone_signaling(opnd2p1)) {
+ /* trap if INVALIDTRAP enabled */
+ if (Is_invalidtrap_enabled()) return(INVALIDEXCEPTION);
+ /* make NaN quiet */
+ Set_invalidflag();
+ Dbl_set_quiet(opnd2p1);
+ }
+ /*
+ * return quiet NaN
+ */
+ Dbl_copytoptr(opnd2p1,opnd2p2,dstptr);
+ return(NOEXCEPTION);
+ }
+ /*
+ * check second operand for zero
+ */
+ if (Dbl_iszero_exponentmantissa(opnd2p1,opnd2p2)) {
+ /* invalid since second operand is zero */
+ if (Is_invalidtrap_enabled()) return(INVALIDEXCEPTION);
+ Set_invalidflag();
+ Dbl_makequietnan(resultp1,resultp2);
+ Dbl_copytoptr(resultp1,resultp2,dstptr);
+ return(NOEXCEPTION);
+ }
+
+ /*
+ * get sign of result
+ */
+ resultp1 = opnd1p1;
+
+ /*
+ * check for denormalized operands
+ */
+ if (opnd1_exponent == 0) {
+ /* check for zero */
+ if (Dbl_iszero_mantissa(opnd1p1,opnd1p2)) {
+ Dbl_copytoptr(opnd1p1,opnd1p2,dstptr);
+ return(NOEXCEPTION);
+ }
+ /* normalize, then continue */
+ opnd1_exponent = 1;
+ Dbl_normalize(opnd1p1,opnd1p2,opnd1_exponent);
+ }
+ else {
+ Dbl_clear_signexponent_set_hidden(opnd1p1);
+ }
+ if (opnd2_exponent == 0) {
+ /* normalize, then continue */
+ opnd2_exponent = 1;
+ Dbl_normalize(opnd2p1,opnd2p2,opnd2_exponent);
+ }
+ else {
+ Dbl_clear_signexponent_set_hidden(opnd2p1);
+ }
+
+ /* find result exponent and divide step loop count */
+ dest_exponent = opnd2_exponent - 1;
+ stepcount = opnd1_exponent - opnd2_exponent;
+
+ /*
+ * check for opnd1/opnd2 < 1
+ */
+ if (stepcount < 0) {
+ /*
+ * check for opnd1/opnd2 > 1/2
+ *
+ * In this case n will round to 1, so
+ * r = opnd1 - opnd2
+ */
+ if (stepcount == -1 &&
+ Dbl_isgreaterthan(opnd1p1,opnd1p2,opnd2p1,opnd2p2)) {
+ /* set sign */
+ Dbl_allp1(resultp1) = ~Dbl_allp1(resultp1);
+ /* align opnd2 with opnd1 */
+ Dbl_leftshiftby1(opnd2p1,opnd2p2);
+ Dbl_subtract(opnd2p1,opnd2p2,opnd1p1,opnd1p2,
+ opnd2p1,opnd2p2);
+ /* now normalize */
+ while (Dbl_iszero_hidden(opnd2p1)) {
+ Dbl_leftshiftby1(opnd2p1,opnd2p2);
+ dest_exponent--;
+ }
+ Dbl_set_exponentmantissa(resultp1,resultp2,opnd2p1,opnd2p2);
+ goto testforunderflow;
+ }
+ /*
+ * opnd1/opnd2 <= 1/2
+ *
+ * In this case n will round to zero, so
+ * r = opnd1
+ */
+ Dbl_set_exponentmantissa(resultp1,resultp2,opnd1p1,opnd1p2);
+ dest_exponent = opnd1_exponent;
+ goto testforunderflow;
+ }
+
+ /*
+ * Generate result
+ *
+ * Do iterative subtract until remainder is less than operand 2.
+ */
+ while (stepcount-- > 0 && (Dbl_allp1(opnd1p1) || Dbl_allp2(opnd1p2))) {
+ if (Dbl_isnotlessthan(opnd1p1,opnd1p2,opnd2p1,opnd2p2)) {
+ Dbl_subtract(opnd1p1,opnd1p2,opnd2p1,opnd2p2,opnd1p1,opnd1p2);
+ }
+ Dbl_leftshiftby1(opnd1p1,opnd1p2);
+ }
+ /*
+ * Do last subtract, then determine which way to round if remainder
+ * is exactly 1/2 of opnd2
+ */
+ if (Dbl_isnotlessthan(opnd1p1,opnd1p2,opnd2p1,opnd2p2)) {
+ Dbl_subtract(opnd1p1,opnd1p2,opnd2p1,opnd2p2,opnd1p1,opnd1p2);
+ roundup = TRUE;
+ }
+ if (stepcount > 0 || Dbl_iszero(opnd1p1,opnd1p2)) {
+ /* division is exact, remainder is zero */
+ Dbl_setzero_exponentmantissa(resultp1,resultp2);
+ Dbl_copytoptr(resultp1,resultp2,dstptr);
+ return(NOEXCEPTION);
+ }
+
+ /*
+ * Check for cases where opnd1/opnd2 < n
+ *
+ * In this case the result's sign will be opposite that of
+ * opnd1. The mantissa also needs some correction.
+ */
+ Dbl_leftshiftby1(opnd1p1,opnd1p2);
+ if (Dbl_isgreaterthan(opnd1p1,opnd1p2,opnd2p1,opnd2p2)) {
+ Dbl_invert_sign(resultp1);
+ Dbl_leftshiftby1(opnd2p1,opnd2p2);
+ Dbl_subtract(opnd2p1,opnd2p2,opnd1p1,opnd1p2,opnd1p1,opnd1p2);
+ }
+ /* check for remainder being exactly 1/2 of opnd2 */
+ else if (Dbl_isequal(opnd1p1,opnd1p2,opnd2p1,opnd2p2) && roundup) {
+ Dbl_invert_sign(resultp1);
+ }
+
+ /* normalize result's mantissa */
+ while (Dbl_iszero_hidden(opnd1p1)) {
+ dest_exponent--;
+ Dbl_leftshiftby1(opnd1p1,opnd1p2);
+ }
+ Dbl_set_exponentmantissa(resultp1,resultp2,opnd1p1,opnd1p2);
+
+ /*
+ * Test for underflow
+ */
+ testforunderflow:
+ if (dest_exponent <= 0) {
+ /* trap if UNDERFLOWTRAP enabled */
+ if (Is_underflowtrap_enabled()) {
+ /*
+ * Adjust bias of result
+ */
+ Dbl_setwrapped_exponent(resultp1,dest_exponent,unfl);
+ /* frem is always exact */
+ Dbl_copytoptr(resultp1,resultp2,dstptr);
+ return(UNDERFLOWEXCEPTION);
+ }
+ /*
+ * denormalize result or set to signed zero
+ */
+ if (dest_exponent >= (1 - DBL_P)) {
+ Dbl_rightshift_exponentmantissa(resultp1,resultp2,
+ 1-dest_exponent);
+ }
+ else {
+ Dbl_setzero_exponentmantissa(resultp1,resultp2);
+ }
+ }
+ else Dbl_set_exponent(resultp1,dest_exponent);
+ Dbl_copytoptr(resultp1,resultp2,dstptr);
+ return(NOEXCEPTION);
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-01 11:55:50 +0000