[hryhoriiK97]

Summary:

RawPropsParser::at finds a prop's value by walking the parser's keys in the order the Props constructor reads them. On that path every lookup compares the requested name with the expected key using std::string_view equality, which runs memcmp over the name.

Props constructors pass the same string literal for a prop on every parse (convertRawProp(context, rawProps, "opacity", ...)), and that literal is what the parser stored in keys_ when it was prepared. So the two views almost always point to the same characters. This change compares the pointers first and only compares the characters when they differ, so the result is the same as == in every case: same pointer → equal exactly when the lengths match; different pointers → the full comparison as before.

All keys in core come from string literals with static storage (convertRawProp and the direct rawProps.at("...") calls); the prefix/suffix overload of RawProps::at, which builds a temporary string, has no callers in ReactCommon.

Changelog:

[GENERAL] [CHANGED] - Props parsing compares prop name pointers before their characters

Test Plan:

• yarn fantom (full suite, tester rebuilt with this change): 3314 tests pass. The other failures are unrelated to props: snapshot printing in my checkout's Jest setup, and a flaky tester crash in TesterAppDelegate::loadScriptAndRunTests that also happens without this change (the one suite it hit passes on rerun).
• clang-format --dry-run --Werror passes.
• On a device. RNTester release builds from the same checkout without and with this change, iPhone 15 Pro, a JS-driven animation that recolors 30 texts (a props update every frame), Time Profiler for 20 s, three runs each, interleaved. JS thread:

	before	this PR	change
memcmp in RawPropsParser::at	40 / 45 / 37 ms	1 / 1 / 0 ms	gone
RawPropsParser::at	105 / 106 / 110 ms	71 / 72 / 63 ms	−36%
props parsing (cloneProps and below)	245 / 263 / 233 ms	187 / 195 / 185 ms	−24%
JS thread total	3981 / 3921 / 3875 ms	3805 / 3796 / 3809 ms	−3.1%

🤖 Generated with Claude Code

[meta-codesync]

@javache has imported this pull request. If you are a Meta employee, you can view this in D128573190.