mirror of
https://github.com/ioacademy-jikim/debugging
synced 2025-06-08 08:26:14 +00:00
83 lines
1.3 KiB
C
83 lines
1.3 KiB
C
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#include <stdio.h>
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long long int arg = 0;
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long long int res = 0;
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extern void loop_plain ( void );
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asm("\n"
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".text\n"
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".globl loop_plain\n"
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"loop_plain:\n"
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"\tpushq %rcx\n"
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"\tmovq $999, %rax\n"
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"\tmovq arg, %rcx\n"
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".Lmn123plain:\n"
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"\tdecq %rax\n"
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"\tdecq %rax\n"
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"\tdecq %rax\n"
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"\tloop .Lmn123plain\n"
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"\tmovq %rax, res\n"
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"\tpopq %rcx\n"
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"\tret\n"
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);
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extern void loop_ne ( void );
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asm("\n"
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".text\n"
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".globl loop_ne\n"
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"loop_ne:\n"
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"\tpushq %rcx\n"
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"\tmovq $999, %rax\n"
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"\tmovq arg, %rcx\n"
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".Lmn123ne:\n"
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"\tdecq %rax\n"
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"\tdecq %rax\n"
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"\tdecq %rax\n"
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"\tloopne .Lmn123ne\n"
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"\tmovq %rax, res\n"
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"\tpopq %rcx\n"
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"\tret\n"
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);
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extern void loop_e ( void );
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asm("\n"
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".text\n"
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".globl loop_e\n"
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"loop_e:\n"
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"\tpushq %rcx\n"
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"\tmovq $999, %rax\n"
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"\tmovq arg, %rcx\n"
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".Lmn123e:\n"
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"\tdecq %rax\n"
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"\tdecq %rax\n"
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"\tdecq %rax\n"
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/* invert the Z flag */
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"\tpushfq\n"
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"\txorq $64, 0(%rsp)\n"
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"\tpopfq\n"
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"\tloope .Lmn123e\n"
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"\tmovq %rax, res\n"
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"\tpopq %rcx\n"
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"\tret\n"
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);
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int main ( void )
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{
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res = 0; arg = 10; loop_plain(); printf("res = %lld\n", res);
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res = 0; arg = 10; loop_ne(); printf("res = %lld\n", res);
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res = 0; arg = 500; loop_ne(); printf("res = %lld\n", res);
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res = 0; arg = 10; loop_e(); printf("res = %lld\n", res);
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res = 0; arg = 500; loop_e(); printf("res = %lld\n", res);
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return 0;
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}
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