27 lines
1.8 KiB
Markdown
Executable File
27 lines
1.8 KiB
Markdown
Executable File
# NEG — Two's Complement Negation
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## Description
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Replaces the value of operand (the destination operand) with its two's complement. This operation is equivalent to subtracting the operand
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from 0. The destination operand is located in a general-purpose register or a memory location.
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## Instruction
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| Opcode | Assembly | Op/En | Modern Mode | Legacy Mode | Description |
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|---------------|------------|-------|-------------|-------------|-----------------------------------------------------------------------------|
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| F6 /3 | NEG r/m8 | M | Valid | Valid | Two's complement negate r/m8. |
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| REX + F6 /3 | NEG r/m8* | M | Valid | N.E. | Two's complement negate r/m8. |
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| F7 /3 | NEG r/m16 | M | Valid | Valid | Two's complement negate r/m16. |
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| F7 /3 | NEG r/m32 | M | Valid | Valid | Two's complement negate r/m32. |
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| REX.W + F7 /3 | NEG r/m64 | M | Valid | N.E. | Two's complement negate r/m64. |
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- In 64-bit mode, r/m8 can not be encoded to access the following byte registers if a REX prefix is used: AH, BH, CH, DH.
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## Information
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This instruction can be used with a LOCK prefix to allow the instruction to be executed atomically.
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In 64-bit mode, the instruction’s default operation size is 32 bits. Using a REX prefix in the form of REX.R permits access to additional
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registers (R8-R15). Using a REX prefix in the form of REX.W promotes operation to 64 bits. See the summary chart at the beginning of this
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section for encoding data and limits.
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