From a113d39fe87e098c5b19ca75002b6995a3f69e3e Mon Sep 17 00:00:00 2001 From: Alon Zakai Date: Wed, 10 Nov 2021 13:40:34 -0800 Subject: Add GlobalSubtyping pass (#4306) This specializes the fields of structs based on the types written to them. That is, if a field is of type A but in practice we always write some subtype B to it then we can change the type of the field to that. On j2wasm this manages to improve at least one field in 2% of types. Not a large amount, but this does lead to further benefits in later opts (e.g. about a third of the improvements are to turn a field non-nullable). --- src/ir/lubs.h | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'src/ir/lubs.h') diff --git a/src/ir/lubs.h b/src/ir/lubs.h index b75932091..a45b62c52 100644 --- a/src/ir/lubs.h +++ b/src/ir/lubs.h @@ -39,6 +39,14 @@ struct LUBFinder { // Returns the lub that we found. Type get() { return lub; } + + // Combines the information in another LUBFinder into this one, and returns + // whether we changed anything. + bool combine(const LUBFinder& other) { + auto old = lub; + note(other.lub); + return lub != old; + } }; } // namespace wasm -- cgit v1.2.3