###################################- # # Copyright (C) 2009-2014 Free Software Foundation, Inc. # # Contributed by Michael Eager . # # 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 # . # # divsi3.S # # Divide operation for 32 bit integers. # Input : Dividend in Reg r5 # Divisor in Reg r6 # Output: Result in Reg r3 # ####################################### .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