| ###################################- |
| # |
| # 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/>. |
| # |
| # divsi3.S |
| # |
| # Divide operation for 32 bit integers. |
| # Input : Dividend in Reg r5 |
| # Divisor in Reg r6 |
| # Output: Result in Reg r3 |
| # |
| ####################################### |
| |
| /* An executable stack is *not* required for these functions. */ |
| #ifdef __linux__ |
| .section .note.GNU-stack,"",%progbits |
| .previous |
| #endif |
| |
| .globl __divsi3 |
| .ent __divsi3 |
| .type __divsi3,@function |
| __divsi3: |
| .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 |
| XOR r28,r5,r6 # Get the sign of the result |
| RSUBI r5,r5,0 # Make r5 positive |
| $LaR5_Pos: |
| BGEI r6,$LaR6_Pos |
| RSUBI r6,r6,0 # Make r6 positive |
| $LaR6_Pos: |
| ADDIK r30,r0,0 # Clear mod |
| ADDIK r3,r0,0 # clear div |
| ADDIK r29,r0,32 # Initialize the loop count |
| |
| # First part try to find the first '1' in the r5 |
| $LaDIV0: |
| BLTI r5,$LaDIV2 # This traps r5 == 0x80000000 |
| $LaDIV1: |
| ADD r5,r5,r5 # left shift logical r5 |
| BGTID r5,$LaDIV1 |
| ADDIK r29,r29,-1 |
| $LaDIV2: |
| ADD r5,r5,r5 # left shift logical r5 get the '1' into the Carry |
| ADDC r30,r30,r30 # Move that bit into the Mod register |
| RSUB r31,r6,r30 # Try to subtract (r30 a r6) |
| BLTI r31,$LaMOD_TOO_SMALL |
| OR r30,r0,r31 # Move the r31 to mod since the result was positive |
| ADDIK r3,r3,1 |
| $LaMOD_TOO_SMALL: |
| ADDIK r29,r29,-1 |
| BEQi r29,$LaLOOP_END |
| ADD r3,r3,r3 # 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 |
| $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 __divsi3 |
| .size __divsi3, . - __divsi3 |
| |
