[sean0407]

Summary

x86 formatted operands -> comparison key -> instruction diff

Preserve x86 operand punctuation and argument positions in instruction comparisons, so mov eax, [ebx] and mov [eax], ebx are no longer treated as equivalent. Fixes #416.

Evidence

• Before: reproducing the reported byte sequences (8b 03 and 89 18) produced matching decoded argument values, so the distinct memory/register operand layouts were treated as equal.
• After: added a regression test confirming the two x86 instructions produce distinct comparison keys; the diff path reports an argument mismatch when keys differ.
• Checks: cargo test --offline -p objdiff-core passed; cargo +nightly clippy --offline -p objdiff-core --all-targets --all-features -- -D warnings passed; Nightly rustfmt check and git diff --check passed.
• Files: objdiff-core/src/arch/mod.rs, objdiff-core/src/arch/x86.rs, objdiff-core/src/diff/code.rs.

Merge Danger

Door: Two-way

Blast Radius: Low

The comparison key is opt-in by architecture and overridden only for x86 in this change.

[chatgpt-codex-connector]

Codex Review Summary

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Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-10-19T19:06:44.063934Z	34038e5	PR opened

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Reviewed commit: 34038e58ce

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[chatgpt-codex-connector]

Import String for the no-std WASM build

The documented WASM build uses objdiff-wasm, whose Cargo.toml:29-32 disables objdiff-core's default features while enabling x86, so this module is compiled with the core prelude rather than the std prelude. Because x86.rs does not import alloc::string::String, this new Vec<String> signature fails with cannot find type String in this scope and blocks the web artifact; import String from alloc.

AGENTS.md reference: AGENTS.md:L23-L23

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