--- /dev/null
+/* libgcc1 routines for 68000 w/o floating-point hardware.
+ Copyright (C) 1994, 1996, 1997, 1998 Free Software Foundation, Inc.
+
+This file is part of GNU CC.
+
+GNU CC 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.
+
+In addition to the permissions in the GNU General Public License, the
+Free Software Foundation gives you unlimited permission to link the
+compiled version of this file with other programs, and to distribute
+those programs without any restriction coming from the use of this
+file. (The General Public License restrictions do apply in other
+respects; for example, they cover modification of the file, and
+distribution when not linked into another program.)
+
+This file 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; see the file COPYING. If not, write to
+the Free Software Foundation, 59 Temple Place - Suite 330,
+Boston, MA 02111-1307, USA. */
+
+/* As a special exception, if you link this library with files
+ compiled with GCC to produce an executable, this does not cause
+ the resulting executable to be covered by the GNU General Public License.
+ This exception does not however invalidate any other reasons why
+ the executable file might be covered by the GNU General Public License. */
+
+/* Use this one for any 680x0; assumes no floating point hardware.
+ The trailing " '" appearing on some lines is for ANSI preprocessors. Yuk.
+ Some of this code comes from MINIX, via the folks at ericsson.
+ D. V. Henkel-Wallace (gumby@cygnus.com) Fete Bastille, 1992
+*/
+
+/* These are predefined by new versions of GNU cpp. */
+
+#ifndef __USER_LABEL_PREFIX__
+#define __USER_LABEL_PREFIX__ _
+#endif
+
+#ifndef __REGISTER_PREFIX__
+#define __REGISTER_PREFIX__
+#endif
+
+#ifndef __IMMEDIATE_PREFIX__
+#define __IMMEDIATE_PREFIX__ #
+#endif
+
+/* ANSI concatenation macros. */
+
+#define CONCAT1(a, b) CONCAT2(a, b)
+#define CONCAT2(a, b) a ## b
+
+/* Use the right prefix for global labels. */
+
+#define SYM(x) CONCAT1 (__USER_LABEL_PREFIX__, x)
+
+/* Use the right prefix for registers. */
+
+#define REG(x) CONCAT1 (__REGISTER_PREFIX__, x)
+
+/* Use the right prefix for immediate values. */
+
+#define IMM(x) CONCAT1 (__IMMEDIATE_PREFIX__, x)
+
+#define d0 REG (d0)
+#define d1 REG (d1)
+#define d2 REG (d2)
+#define d3 REG (d3)
+#define d4 REG (d4)
+#define d5 REG (d5)
+#define d6 REG (d6)
+#define d7 REG (d7)
+#define a0 REG (a0)
+#define a1 REG (a1)
+#define a2 REG (a2)
+#define a3 REG (a3)
+#define a4 REG (a4)
+#define a5 REG (a5)
+#define a6 REG (a6)
+#define fp REG (fp)
+#define sp REG (sp)
+
+ .text
+ .proc
+ .globl SYM (__udivsi3)
+SYM (__udivsi3):
+#if !(defined(__mcf5200__) || defined(__mcoldfire__))
+ movel d2, sp@-
+ movel sp@(12), d1 /* d1 = divisor */
+ movel sp@(8), d0 /* d0 = dividend */
+
+ cmpl IMM (0x10000), d1 /* divisor >= 2 ^ 16 ? */
+ jcc L3 /* then try next algorithm */
+ movel d0, d2
+ clrw d2
+ swap d2
+ divu d1, d2 /* high quotient in lower word */
+ movew d2, d0 /* save high quotient */
+ swap d0
+ movew sp@(10), d2 /* get low dividend + high rest */
+ divu d1, d2 /* low quotient */
+ movew d2, d0
+ jra L6
+
+L3: movel d1, d2 /* use d2 as divisor backup */
+L4: lsrl IMM (1), d1 /* shift divisor */
+ lsrl IMM (1), d0 /* shift dividend */
+ cmpl IMM (0x10000), d1 /* still divisor >= 2 ^ 16 ? */
+ jcc L4
+ divu d1, d0 /* now we have 16 bit divisor */
+ andl IMM (0xffff), d0 /* mask out divisor, ignore remainder */
+
+/* Multiply the 16 bit tentative quotient with the 32 bit divisor. Because of
+ the operand ranges, this might give a 33 bit product. If this product is
+ greater than the dividend, the tentative quotient was too large. */
+ movel d2, d1
+ mulu d0, d1 /* low part, 32 bits */
+ swap d2
+ mulu d0, d2 /* high part, at most 17 bits */
+ swap d2 /* align high part with low part */
+ tstw d2 /* high part 17 bits? */
+ jne L5 /* if 17 bits, quotient was too large */
+ addl d2, d1 /* add parts */
+ jcs L5 /* if sum is 33 bits, quotient was too large */
+ cmpl sp@(8), d1 /* compare the sum with the dividend */
+ jls L6 /* if sum > dividend, quotient was too large */
+L5: subql IMM (1), d0 /* adjust quotient */
+
+L6: movel sp@+, d2
+ rts
+
+#else /* __mcf5200__ || __mcoldfire__ */
+
+/* Coldfire implementation of non-restoring division algorithm from
+ Hennessy & Patterson, Appendix A. */
+ link a6,IMM (-12)
+ moveml d2-d4,sp@
+ movel a6@(8),d0
+ movel a6@(12),d1
+ clrl d2 | clear p
+ moveq IMM (31),d4
+L1: addl d0,d0 | shift reg pair (p,a) one bit left
+ addxl d2,d2
+ movl d2,d3 | subtract b from p, store in tmp.
+ subl d1,d3
+ jcs L2 | if no carry,
+ bset IMM (0),d0 | set the low order bit of a to 1,
+ movl d3,d2 | and store tmp in p.
+L2: subql IMM (1),d4
+ jcc L1
+ moveml sp@,d2-d4 | restore data registers
+ unlk a6 | and return
+ rts
+#endif /* __mcf5200__ || __mcoldfire__ */
+
git.openpandora.org / pandora-kernel.git / blobdiff