bb72f7f111
Un-special-case "xchg rax,rax"; allow it to be encoded as 48 90 for orthogonality's sake. It's a no-op, to be sure, but so are many other instructions. "xchg eax,eax" is still special-cased in 64-bit mode since it is not a no-op; unadorned opcode 90 is now simply "nop" and nothing else. Make the disassembler detect unused REX.W and display them as an "o64" prefix.
14 lines
137 B
NASM
14 lines
137 B
NASM
bits 64
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nop
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o64 nop
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pause
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o64 pause
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xchg ax,ax
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xchg eax,eax
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xchg rax,rax
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rep xchg ax,ax
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rep xchg eax,eax
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rep xchg rax,rax
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