1 ###################################
3 # Copyright (C) 2009-2024 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 # modulo operation for 64 bit integers.
30 #######################################
33 /* An executable stack is *not* required for these functions. */
35 .section .note.GNU-stack,"",%progbits
44 #Change the stack pointer value and Save callee saved regs
48 swi r27,r1,8 # used for sign
49 swi r28,r1,12 # used for loop count
50 swi r29,r1,16 # Used for div value High
51 swi r30,r1,20 # Used for div value Low
53 #Check for Zero Value in the divisor/dividend
54 OR r9,r5,r6 # Check for the op1 being zero
55 BEQID r9,$LaResult_Is_Zero # Result is zero
56 OR r9,r7,r8 # Check for the dividend being zero
57 BEQI r9,$LaDiv_By_Zero # Div_by_Zero # Division Error
59 XOR r27,r5,r7 # Get the sign of the result
60 RSUBI r6,r6,0 # Make dividend positive
61 RSUBIC r5,r5,0 # Make dividend positive
64 RSUBI r8,r8,0 # Make Divisor Positive
65 RSUBIC r9,r9,0 # Make Divisor Positive
67 ADDIK r4,r0,0 # Clear mod low
68 ADDIK r3,r0,0 # Clear mod high
69 ADDIK r29,r0,0 # clear div high
70 ADDIK r30,r0,0 # clear div low
71 ADDIK r28,r0,64 # Initialize the loop count
72 # First part try to find the first '1' in the r5/r6
75 ADDC r5,r5,r5 # left shift logical r5
80 ADDC r5,r5,r5 # left shift logical r5/r6 get the '1' into the Carry
81 ADDC r4,r4,r4 # Move that bit into the Mod register
82 ADDC r3,r3,r3 # Move carry into high mod register
83 rsub r18,r7,r3 # Compare the High Parts of Mod and Divisor
85 rsub r18,r6,r4 # Compare Low Parts only if Mod[h] == Divisor[h]
87 rSUB r26,r8,r4 # Subtract divisor[L] from Mod[L]
88 rsubc r25,r7,r3 # Subtract divisor[H] from Mod[H]
89 BLTi r25,$LaMOD_TOO_SMALL
90 OR r3,r0,r25 # move r25 to mod [h]
91 OR r4,r0,r26 # move r26 to mod [l]
97 ADD r30,r30,r30 # Shift in the '1' into div [low]
98 ADDC r29,r29,r29 # Move the carry generated into high
101 BGEI r27,$LaRETURN_HERE
107 or r29,r0,r0 # set result to 0 [High]
108 or r30,r0,r0 # set result to 0 [Low]
110 # Restore values of CSRs and that of r29 and the divisor and the dividend