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x86-64 Assembly / Loops & Arrays

Indexed addressing

Learn Indexed addressing in x86-64 Assembly through a focused explanation, a dedicated construct-specific example, an engineering boundary, and a mastery check.

10 min read • Intermediate

Indexed addressing is an atomic x86-64 Assembly topic inside Loops & Arrays. This lesson focuses on how the Indexed addressing construct is written, what it changes, and when it is the right tool.

Trace the example line by line. Identify the exact syntax for Indexed addressing, the input state before it runs, and the resulting value, control flow, database state, hardware behavior, or runtime effect afterward. Neighboring lessons use different constructs rather than renamed copies of this one.

Topic-specific example

assembly-05-03-indexed-addressing.asm
assembly Try It Live 
mov rcx, 2
mov eax, [numbers + rcx*4]
section .data
numbers dd 10,20,30,40
Edge case / engineering note

For Indexed addressing, test the boundary that belongs to this exact feature rather than a generic failure case. Check invalid or empty input, NULL/unknown state, numeric limits, transaction or exception behavior, synthesis/runtime constraints, ownership/permission rules, or backtracking/control-flow effects where they apply.

Content source & attribution
Original Syntaxis Content · Original Syntaxis Content

Lesson quizzes

Indexed addressing Mastery Check →
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Pointer traversal
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Scaled index