| ################################### |
| # |
| # Copyright (C) 2009-2021 Free Software Foundation, Inc. |
| # |
| # Contributed by Michael Eager <eager@eagercon.com>. |
| # |
| # This file 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 3, or (at your option) any |
| # later version. |
| # |
| # GCC 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. |
| # |
| # Under Section 7 of GPL version 3, you are granted additional |
| # permissions described in the GCC Runtime Library Exception, version |
| # 3.1, as published by the Free Software Foundation. |
| # |
| # You should have received a copy of the GNU General Public License and |
| # a copy of the GCC Runtime Library Exception along with this program; |
| # see the files COPYING3 and COPYING.RUNTIME respectively. If not, see |
| # <http://www.gnu.org/licenses/>. |
| # |
| # modsi3.S |
| # |
| # modulo operation for 32 bit integers. |
| # Input : op1 in Reg r5 |
| # op2 in Reg r6 |
| # Output: op1 mod op2 in Reg r3 |
| # |
| ####################################### |
| |
| /* An executable stack is *not* required for these functions. */ |
| #ifdef __linux__ |
| .section .note.GNU-stack,"",%progbits |
| .previous |
| #endif |
| |
| .globl __modsi3 |
| .ent __modsi3 |
| .type __modsi3,@function |
| __modsi3: |
| .frame r1,0,r15 |
| |
| addik r1,r1,-16 |
| swi r28,r1,0 |
| swi r29,r1,4 |
| swi r30,r1,8 |
| swi r31,r1,12 |
| |
| BEQI r6,$LaDiv_By_Zero # Div_by_Zero # Division Error |
| BEQI r5,$LaResult_Is_Zero # Result is Zero |
| BGEId r5,$LaR5_Pos |
| ADD r28,r5,r0 # Get the sign of the result [ Depends only on the first arg] |
| RSUBI r5,r5,0 # Make r5 positive |
| $LaR5_Pos: |
| BGEI r6,$LaR6_Pos |
| RSUBI r6,r6,0 # Make r6 positive |
| $LaR6_Pos: |
| ADDIK r3,r0,0 # Clear mod |
| ADDIK r30,r0,0 # clear div |
| BLTId r5,$LaDIV2 # If r5 is still negative (0x80000000), skip |
| # the first bit search. |
| ADDIK r29,r0,32 # Initialize the loop count |
| # First part try to find the first '1' in the r5 |
| $LaDIV1: |
| ADD r5,r5,r5 # left shift logical r5 |
| BGEID r5,$LaDIV1 # |
| ADDIK r29,r29,-1 |
| $LaDIV2: |
| ADD r5,r5,r5 # left shift logical r5 get the '1' into the Carry |
| ADDC r3,r3,r3 # Move that bit into the Mod register |
| rSUB r31,r6,r3 # Try to subtract (r30 a r6) |
| BLTi r31,$LaMOD_TOO_SMALL |
| OR r3,r0,r31 # Move the r31 to mod since the result was positive |
| ADDIK r30,r30,1 |
| $LaMOD_TOO_SMALL: |
| ADDIK r29,r29,-1 |
| BEQi r29,$LaLOOP_END |
| ADD r30,r30,r30 # Shift in the '1' into div |
| BRI $LaDIV2 # Div2 |
| $LaLOOP_END: |
| BGEI r28,$LaRETURN_HERE |
| BRId $LaRETURN_HERE |
| rsubi r3,r3,0 # Negate the result |
| $LaDiv_By_Zero: |
| $LaResult_Is_Zero: |
| or r3,r0,r0 # set result to 0 [Both mod as well as div are 0] |
| $LaRETURN_HERE: |
| # Restore values of CSRs and that of r3 and the divisor and the dividend |
| lwi r28,r1,0 |
| lwi r29,r1,4 |
| lwi r30,r1,8 |
| lwi r31,r1,12 |
| rtsd r15,8 |
| addik r1,r1,16 |
| .end __modsi3 |
| .size __modsi3, . - __modsi3 |
| |
