1###################################-
2#
3#  Copyright (C) 2009-2020 Free Software Foundation, Inc.
4#
5#  Contributed by Michael Eager <eager@eagercon.com>.
6#
7#  This file is free software; you can redistribute it and/or modify it
8#  under the terms of the GNU General Public License as published by the
9#  Free Software Foundation; either version 3, or (at your option) any
10#  later version.
11#
12#  GCC is distributed in the hope that it will be useful, but WITHOUT
13#  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
14#  or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
15#  License for more details.
16#
17#  Under Section 7 of GPL version 3, you are granted additional
18#  permissions described in the GCC Runtime Library Exception, version
19#  3.1, as published by the Free Software Foundation.
20#
21#  You should have received a copy of the GNU General Public License and
22#  a copy of the GCC Runtime Library Exception along with this program;
23#  see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
24#  <http://www.gnu.org/licenses/>.
25#
26#  divsi3.S
27#
28#  Divide operation for 32 bit integers.
29#	Input :	Dividend in Reg r5
30#		Divisor in Reg r6
31#	Output: Result in Reg r3
32#
33#######################################
34
35/* An executable stack is *not* required for these functions.  */
36#ifdef __linux__
37.section .note.GNU-stack,"",%progbits
38.previous
39#endif
40
41	.globl	__divsi3
42	.ent	__divsi3
43	.type	__divsi3,@function
44__divsi3:
45	.frame	r1,0,r15
46
47	ADDIK   r1,r1,-16
48	SWI     r28,r1,0
49	SWI     r29,r1,4
50	SWI     r30,r1,8
51	SWI     r31,r1,12
52
53	BEQI    r6,$LaDiv_By_Zero       # Div_by_Zero   # Division Error
54	BEQI    r5,$LaResult_Is_Zero    # Result is Zero
55	BGEID   r5,$LaR5_Pos
56	XOR     r28,r5,r6               # Get the sign of the result
57	RSUBI   r5,r5,0                 # Make r5 positive
58$LaR5_Pos:
59	BGEI    r6,$LaR6_Pos
60	RSUBI   r6,r6,0                 # Make r6 positive
61$LaR6_Pos:
62	ADDIK   r30,r0,0                # Clear mod
63	ADDIK   r3,r0,0                 # clear div
64	ADDIK   r29,r0,32               # Initialize the loop count
65
66        # First part try to find the first '1' in the r5
67$LaDIV0:
68        BLTI    r5,$LaDIV2              # This traps r5 == 0x80000000
69$LaDIV1:
70	ADD     r5,r5,r5                # left shift logical r5
71	BGTID   r5,$LaDIV1
72	ADDIK   r29,r29,-1
73$LaDIV2:
74	ADD     r5,r5,r5                # left shift logical  r5 get the '1' into the Carry
75	ADDC    r30,r30,r30             # Move that bit into the Mod register
76	RSUB    r31,r6,r30              # Try to subtract (r30 a r6)
77	BLTI    r31,$LaMOD_TOO_SMALL
78	OR      r30,r0,r31              # Move the r31 to mod since the result was positive
79	ADDIK   r3,r3,1
80$LaMOD_TOO_SMALL:
81	ADDIK   r29,r29,-1
82	BEQi    r29,$LaLOOP_END
83	ADD     r3,r3,r3                # Shift in the '1' into div
84	BRI     $LaDIV2                 # Div2
85$LaLOOP_END:
86	BGEI    r28,$LaRETURN_HERE
87	BRID    $LaRETURN_HERE
88	RSUBI   r3,r3,0                 # Negate the result
89$LaDiv_By_Zero:
90$LaResult_Is_Zero:
91	OR      r3,r0,r0 # set result to 0
92$LaRETURN_HERE:
93# Restore values of CSRs and that of r3 and the divisor and the dividend
94	LWI     r28,r1,0
95	LWI     r29,r1,4
96	LWI     r30,r1,8
97	LWI     r31,r1,12
98	RTSD    r15,8
99	ADDIK   r1,r1,16
100.end __divsi3
101	.size	__divsi3, . - __divsi3
102
103