diff options
Diffstat (limited to 'libyul/optimiser/Rematerialiser.h')
| -rw-r--r-- | libyul/optimiser/Rematerialiser.h | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/libyul/optimiser/Rematerialiser.h b/libyul/optimiser/Rematerialiser.h index b3841519..c34353de 100644 --- a/libyul/optimiser/Rematerialiser.h +++ b/libyul/optimiser/Rematerialiser.h @@ -26,16 +26,27 @@ namespace yul { /** - * Optimisation stage that replaces variables by their most recently assigned expressions. + * Optimisation stage that replaces variables by their most recently assigned expressions, + * but only if the expression is movable and one of the following holds: + * - the variable is referenced exactly once + * - the value is extremely cheap ("cost" of zero like ``caller()``) + * - the variable is referenced at most 5 times and the value is rather cheap + * ("cost" of at most 1 like a constant up to 0xff) * * Prerequisite: Disambiguator */ class Rematerialiser: public DataFlowAnalyzer { +public: + static void run(Block& _ast); + protected: + Rematerialiser(Block& _ast); + using ASTModifier::visit; void visit(Expression& _e) override; + std::map<YulString, size_t> m_referenceCounts; }; } |