1 ###################################
3 # Copyright (C) 2009-2015 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 32 bit integers.
29 # Input : op1 in Reg r5
31 # Output: op1 mod op2 in Reg r3
33 #######################################
37 .type __modsi3,@function
47 BEQI r6,$LaDiv_By_Zero # Div_by_Zero # Division Error
48 BEQI r5,$LaResult_Is_Zero # Result is Zero
50 ADD r28,r5,r0 # Get the sign of the result [ Depends only on the first arg]
51 RSUBI r5,r5,0 # Make r5 positive
54 RSUBI r6,r6,0 # Make r6 positive
56 ADDIK r3,r0,0 # Clear mod
57 ADDIK r30,r0,0 # clear div
58 BLTId r5,$LaDIV2 # If r5 is still negative (0x80000000), skip
59 # the first bit search.
60 ADDIK r29,r0,32 # Initialize the loop count
61 # First part try to find the first '1' in the r5
63 ADD r5,r5,r5 # left shift logical r5
67 ADD r5,r5,r5 # left shift logical r5 get the '1' into the Carry
68 ADDC r3,r3,r3 # Move that bit into the Mod register
69 rSUB r31,r6,r3 # Try to subtract (r30 a r6)
70 BLTi r31,$LaMOD_TOO_SMALL
71 OR r3,r0,r31 # Move the r31 to mod since the result was positive
76 ADD r30,r30,r30 # Shift in the '1' into div
79 BGEI r28,$LaRETURN_HERE
81 rsubi r3,r3,0 # Negate the result
84 or r3,r0,r0 # set result to 0 [Both mod as well as div are 0]
86 # Restore values of CSRs and that of r3 and the divisor and the dividend
94 .size __modsi3, . - __modsi3