moddi3.S revision 1.1.1.8
1 ################################### 2 # 3 # Copyright (C) 2009-2019 Free Software Foundation, Inc. 4 # 5 # Contributed by Michael Eager <eager@eagercon.com>. 6 # 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 10 # later version. 11 # 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. 16 # 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. 20 # 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/>. 25 # 26 # modsi3.S 27 # 28 # modulo operation for 64 bit integers. 29 # 30 ####################################### 31 32 33 /* An executable stack is *not* required for these functions. */ 34 #ifdef __linux__ 35 .section .note.GNU-stack,"",%progbits 36 .previous 37 #endif 38 39 .globl __moddi3 40 .ent __moddi3 41 __moddi3: 42 .frame r1,0,r15 43 44 #Change the stack pointer value and Save callee saved regs 45 addik r1,r1,-24 46 swi r25,r1,0 47 swi r26,r1,4 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 52 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 58 BGEId r5,$La1_Pos 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 62 $La1_Pos: 63 BGEI r7,$La2_Pos 64 RSUBI r8,r8,0 # Make Divisor Positive 65 RSUBIC r9,r9,0 # Make Divisor Positive 66 $La2_Pos: 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 73 $LaDIV1: 74 ADD r6,r6,r6 75 ADDC r5,r5,r5 # left shift logical r5 76 BGEID r5,$LaDIV1 77 ADDIK r28,r28,-1 78 $LaDIV2: 79 ADD r6,r6,r6 80 ADDC r5,r5,r5 # left shift logical r5/r6 get the '1' into the Carry 81 ADDC r4,r4,r4 # Move that bit into the Mod register 82 ADDC r3,r3,r3 # Move carry into high mod register 83 rsub r18,r7,r3 # Compare the High Parts of Mod and Divisor 84 bnei r18,$L_High_EQ 85 rsub r18,r6,r4 # Compare Low Parts only if Mod[h] == Divisor[h] 86 $L_High_EQ: 87 rSUB r26,r8,r4 # Subtract divisor[L] from Mod[L] 88 rsubc r25,r7,r3 # Subtract divisor[H] from Mod[H] 89 BLTi r25,$LaMOD_TOO_SMALL 90 OR r3,r0,r25 # move r25 to mod [h] 91 OR r4,r0,r26 # move r26 to mod [l] 92 ADDI r30,r30,1 93 ADDC r29,r29,r0 94 $LaMOD_TOO_SMALL: 95 ADDIK r28,r28,-1 96 BEQi r28,$LaLOOP_END 97 ADD r30,r30,r30 # Shift in the '1' into div [low] 98 ADDC r29,r29,r29 # Move the carry generated into high 99 BRI $LaDIV2 # Div2 100 $LaLOOP_END: 101 BGEI r27,$LaRETURN_HERE 102 rsubi r30,r30,0 103 rsubc r29,r29,r0 104 BRI $LaRETURN_HERE 105 $LaDiv_By_Zero: 106 $LaResult_Is_Zero: 107 or r29,r0,r0 # set result to 0 [High] 108 or r30,r0,r0 # set result to 0 [Low] 109 $LaRETURN_HERE: 110 # Restore values of CSRs and that of r29 and the divisor and the dividend 111 112 lwi r25,r1,0 113 lwi r26,r1,4 114 lwi r27,r1,8 115 lwi r28,r1,12 116 lwi r29,r1,16 117 lwi r30,r1,20 118 rtsd r15,8 119 addik r1,r1,24 120 .end __moddi3 121 122
Indexes created Mon May 04 00:23:20 UTC 2026