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24 lines
620 B
ArmAsm
24 lines
620 B
ArmAsm
/* https://cirosantilli.com/linux-kernel-module-cheat#x86-binary-arithmetic-instructions
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*
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* Subtract with Borrow. Like ADC is for ADD, but for subtraction.
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*/
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#include <lkmc.h>
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LKMC_PROLOGUE
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/* rax : rbx -= rcx : rdx
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* 1 : 0 -= 0 : 0x8000000000000000
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* 0 : 0x8000000000000000
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*/
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mov $0x1, %rax
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mov $0x0, %rbx
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mov $0x0, %rcx
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mov $0x8000000000000000, %rdx
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sub %rdx, %rbx
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sbb %rcx, %rax
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mov %rax, %r12
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mov %rbx, %r13
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LKMC_ASSERT_EQ(%r12, $0x0)
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LKMC_ASSERT_EQ(%r13, $0x8000000000000000)
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LKMC_EPILOGUE
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