The String rewrite of a few months ago necessitated changes to XMLParser16.cpp; this ended up making it about half as fast as it used to be. Performance needs to be restored to (at least) old levels.
Created attachment 394386 [details] [diff] [review] Patch #1 Lots of optimizations to XMLParser to regain lost performance: -- add String::intern_substring, which creates an interned substring in one step. This reduces the need to create an intermediate substring which is immediately thrown away. (As a result of this, added AvmCore::findStringLatin1). -- added String::equals() as a fast-path for comparing entire strings, avoiding extra work done by String::Compare(). -- split String::matchesLatin1() into caseless and case-sensitive versions, since we never make this decision at runtime, and optimized the case-sensitive version. -- added String::indexOfCharCode() to optimize indexOf() when len=1 -- inlined and optimized String::isSpace() -- inlined and optimized StringIndexer -- rewrote code in XMLObject and XMLList to avoid calling substring()/substr() just to do a comparision; calling matchesLatin1() or Compare() with appropriate offsets is much faster than creating a temporary string. -- re-added an optimization to XMLParser::unescape that had gotten lost: if the string has no "&", bail early. -- change the various String::hashCode variants to accumulate in a signed (vs unsigned) int; produces much better hash code.
Comment on attachment 394386 [details] [diff] [review] Patch #1 Some comments in the various cases in String::equals() would be helpful. StringObject.cpp: "must be signed" comment is nice, but why must it be signed?
(In reply to comment #3) > (From update of attachment 394386 [details] [diff] [review]) > StringObject.cpp: "must be signed" comment is nice, but why must it be signed? yeah, should read "must match signedness of the other hash functions", will update
(In reply to comment #2) > benchmark results? Best benchmark was a torture-test in Flash that went from ~4000ms to ~2300ms.
pushed to redux as changeset: 2377:26c273b026bc
Status: NEW → RESOLVED
Last Resolved: 9 years ago
Resolution: --- → FIXED
Resolved fixed engineering / work item that has been pushed. Setting status to verified.
Status: RESOLVED → VERIFIED
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