1 ###################################-
3 # Copyright (C) 2009-2021 Free Software Foundation, Inc.
5 # Contributed by Michael Eager <eager@eagercon.com>.
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
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.
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.
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/>.
28 # Divide operation for 32 bit integers.
29 # Input : Dividend in Reg r5
31 # Output: Result in Reg r3
33 #######################################
35 /* An executable stack is *not* required for these functions. */
37 .section .note.GNU-stack,"",%progbits
43 .type __divsi3,@function
53 BEQI r6,$LaDiv_By_Zero # Div_by_Zero # Division Error
54 BEQI r5,$LaResult_Is_Zero # Result is Zero
56 XOR r28,r5,r6 # Get the sign of the result
57 RSUBI r5,r5,0 # Make r5 positive
60 RSUBI r6,r6,0 # Make r6 positive
62 ADDIK r30,r0,0 # Clear mod
63 ADDIK r3,r0,0 # clear div
64 ADDIK r29,r0,32 # Initialize the loop count
66 # First part try to find the first '1' in the r5
68 BLTI r5,$LaDIV2 # This traps r5 == 0x80000000
70 ADD r5,r5,r5 # left shift logical r5
74 ADD r5,r5,r5 # left shift logical r5 get the '1' into the Carry
75 ADDC r30,r30,r30 # Move that bit into the Mod register
76 RSUB r31,r6,r30 # Try to subtract (r30 a r6)
77 BLTI r31,$LaMOD_TOO_SMALL
78 OR r30,r0,r31 # Move the r31 to mod since the result was positive
83 ADD r3,r3,r3 # Shift in the '1' into div
86 BGEI r28,$LaRETURN_HERE
88 RSUBI r3,r3,0 # Negate the result
91 OR r3,r0,r0 # set result to 0
93 # Restore values of CSRs and that of r3 and the divisor and the dividend
101 .size __divsi3, . - __divsi3