notebook/notes/x86-64/instructions.md

title	TARGET DECK	FILE TAGS	tags
Instructions	Obsidian::STEM	x86-64	x86-64

Overview

x86-64 instructions are designed so that commonly used instructions and those with fewer operands are encoded in a smaller number of bytes. Instructions range in length from 1 to 15 bytes.

x86-64 assembly comes in two flavors: ATT and Intel. ATT is most common in Linux systems so I focus on that. The most important distinction between the two is operand ordering: Intel syntax lists multiple operands in reverse order compared to ATT.

%%ANKI Basic x86-64 assembly comes in what two formats? Back: ATT and Intel. Reference: Bryant, Randal E., and David O'Hallaron. Computer Systems: A Programmer's Perspective. Third edition, Global edition. Always Learning. Pearson, 2016.

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%%ANKI Basic Which x86-64 assembly format does Linux use? Back: ATT. Reference: Bryant, Randal E., and David O'Hallaron. Computer Systems: A Programmer's Perspective. Third edition, Global edition. Always Learning. Pearson, 2016.

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%%ANKI Basic Which x86-64 assembly format does Microsoft use? Back: Intel. Reference: Bryant, Randal E., and David O'Hallaron. Computer Systems: A Programmer's Perspective. Third edition, Global edition. Always Learning. Pearson, 2016.

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%%ANKI Basic What is the "most confusing" difference between ATT and Intel assembly? Back: Multiple operands in one are listed in reverse order relative to the other. Reference: Bryant, Randal E., and David O'Hallaron. Computer Systems: A Programmer's Perspective. Third edition, Global edition. Always Learning. Pearson, 2016.

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%%ANKI Basic What term describes assembly lines with a leading .? Back: Directives. Reference: Bryant, Randal E., and David O'Hallaron. Computer Systems: A Programmer's Perspective. Third edition, Global edition. Always Learning. Pearson, 2016.

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%%ANKI Basic Assembly directives are important for what two programs? Back: The assembler and the linker. Reference: Bryant, Randal E., and David O'Hallaron. Computer Systems: A Programmer's Perspective. Third edition, Global edition. Always Learning. Pearson, 2016.

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References

• Bryant, Randal E., and David O'Hallaron. Computer Systems: A Programmer's Perspective. Third edition, Global edition. Always Learning. Pearson, 2016.