Created
December 21, 2011 23:25
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Not working abs(x) routine for x = -2^31
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| ; Division routine | |
| 93c4: e3510000 cmp r1, #0 | |
| 93c8: 0a000014 beq 0x9420 | |
| 93cc: e1b02001 movs r2, r1 ; r2: divisor | |
| 93d0: e212c102 ands ip, r2, #-2147483648 ; 0x80000000 | |
| 93d4: 40225fc2 eormi r5, r2, r2, asr #31 | |
| 93d8: 40452fc2 submi r2, r5, r2, asr #31 | |
| 93dc: e1b01000 movs r1, r0 ; r1: dividend | |
| 93e0: e03cc041 eors ip, ip, r1, asr #32 | |
| 93e4: 40215fc1 eormi r5, r1, r1, asr #31 | |
| 93e8: 40451fc1 submi r1, r5, r1, asr #31 | |
| 93ec: e3a00000 mov r0, #0 | |
| 93f0: e3a03001 mov r3, #1 | |
| 93f4: e1520001 cmp r2, r1 | |
| 93f8: 91a02082 lslls r2, r2, #1 | |
| 93fc: 91a03083 lslls r3, r3, #1 | |
| 9400: 9afffffb bls 0x93f4 | |
| 9404: e1510002 cmp r1, r2 | |
| 9408: 20411002 subcs r1, r1, r2 | |
| 940c: 20800003 addcs r0, r0, r3 | |
| 9410: e1b030a3 lsrs r3, r3, #1 | |
| 9414: 31a020a2 lsrcc r2, r2, #1 | |
| 9418: 3afffff9 bcc 0x9404 | |
| 941c: e1b0c08c lsls ip, ip, #1 | |
| 9420: 22600000 rsbcs r0, r0, #0 | |
| 9424: 42611000 rsbmi r1, r1, #0 | |
| 9428: e3340000 teq r4, #0 | |
| 942c: 01a0f00e moveq pc, lr | |
| 9430: e1b00001 movs r0, r1 | |
| 9434: e3340002 teq r4, #2 | |
| 9438: 01a0f00e moveq pc, lr | |
| 943c: e3500000 cmp r0, #0 | |
| 9440: 51a0f00e movpl pc, lr | |
| 9444: e3520000 cmp r2, #0 | |
| 9448: 41e00000 mvnmi r0, r0 | |
| 944c: e0800002 add r0, r0, r2 | |
| 9450: e1a0f00e mov pc, lr | |
| ; Debugging session | |
| (gdb) br *0x93e0 | |
| Breakpoint 1 at 0x93e0 | |
| (gdb) r | |
| Starting program: /root/ARM/test-division | |
| Breakpoint 1, 0x000093e0 in ?? () | |
| (gdb) i r | |
| r0 0x80000000 2147483648 | |
| r1 0x80000000 2147483648 | |
| r2 0x10000 65536 | |
| r3 0x0 0 | |
| r4 0x0 0 | |
| r5 0x0 0 | |
| r6 0x81a4 33188 | |
| r7 0x0 0 | |
| r8 0x0 0 | |
| r9 0x0 0 | |
| r10 0x40025000 1073893376 | |
| r11 0x0 0 | |
| r12 0x0 0 | |
| sp 0xbea27d84 0xbea27d84 | |
| lr 0x848c 33932 | |
| pc 0x93e0 0x93e0 | |
| cpsr 0xa0000010 -1610612720 | |
| (gdb) display/i $pc | |
| 1: x/i $pc | |
| Disabling display 1 to avoid infinite recursion. | |
| Cannot access memory at address 0x0 | |
| => 0x93e0: eors r12, r12, r1, asr #32 | |
| (gdb) si | |
| Cannot access memory at address 0x0 | |
| Cannot access memory at address 0x0 | |
| 0x000093e4 in ?? () | |
| (gdb) i r | |
| r0 0x80000000 2147483648 | |
| r1 0x80000000 2147483648 | |
| r2 0x10000 65536 | |
| r3 0x0 0 | |
| r4 0x0 0 | |
| r5 0x0 0 | |
| r6 0x81a4 33188 | |
| r7 0x0 0 | |
| r8 0x0 0 | |
| r9 0x0 0 | |
| r10 0x40025000 1073893376 | |
| r11 0x0 0 | |
| r12 0xffffffff 4294967295 | |
| sp 0xbea27d84 0xbea27d84 | |
| lr 0x848c 33932 | |
| pc 0x93e4 0x93e4 | |
| cpsr 0xa0000010 -1610612720 | |
| (gdb) si | |
| Cannot access memory at address 0x0 | |
| Cannot access memory at address 0x0 | |
| 0x000093e8 in ?? () | |
| (gdb) i r | |
| r0 0x80000000 2147483648 | |
| r1 0x80000000 2147483648 | |
| r2 0x10000 65536 | |
| r3 0x0 0 | |
| r4 0x0 0 | |
| r5 0x7fffffff 2147483647 | |
| r6 0x81a4 33188 | |
| r7 0x0 0 | |
| r8 0x0 0 | |
| r9 0x0 0 | |
| r10 0x40025000 1073893376 | |
| r11 0x0 0 | |
| r12 0xffffffff 4294967295 | |
| sp 0xbea27d84 0xbea27d84 | |
| lr 0x848c 33932 | |
| pc 0x93e8 0x93e8 | |
| cpsr 0xa0000010 -1610612720 | |
| (gdb) display/i $pc | |
| 2: x/i $pc | |
| => 0x93e8: submi r1, r5, r1, asr #31 | |
| (gdb) si | |
| Cannot access memory at address 0x0 | |
| Cannot access memory at address 0x0 | |
| 0x000093ec in ?? () | |
| 2: x/i $pc | |
| => 0x93ec: mov r0, #0 | |
| (gdb) i r | |
| r0 0x80000000 2147483648 | |
| r1 0x80000000 2147483648 | |
| r2 0x10000 65536 | |
| r3 0x0 0 | |
| r4 0x0 0 | |
| r5 0x7fffffff 2147483647 | |
| r6 0x81a4 33188 | |
| r7 0x0 0 | |
| r8 0x0 0 | |
| r9 0x0 0 | |
| r10 0x40025000 1073893376 | |
| r11 0x0 0 | |
| r12 0xffffffff 4294967295 | |
| sp 0xbea27d84 0xbea27d84 | |
| lr 0x848c 33932 | |
| pc 0x93ec 0x93ec | |
| cpsr 0xa0000010 -1610612720 | |
| (gdb) |
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