diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/mir/optimise.cpp | 47 |
1 files changed, 42 insertions, 5 deletions
diff --git a/src/mir/optimise.cpp b/src/mir/optimise.cpp index 3867de2c..323bd253 100644 --- a/src/mir/optimise.cpp +++ b/src/mir/optimise.cpp @@ -1946,6 +1946,7 @@ bool MIR_Optimise_PropagateSingleAssignments(::MIR::TypeResolve& state, ::MIR::F bool MIR_Optimise_GarbageCollect(::MIR::TypeResolve& state, ::MIR::Function& fcn) { ::std::vector<bool> used_temps( fcn.temporaries.size() ); + ::std::vector<bool> used_dfs( fcn.drop_flags.size() ); ::std::vector<bool> visited( fcn.blocks.size() ); ::std::vector< ::MIR::BasicBlockId> to_visit; to_visit.push_back( 0 ); @@ -1965,6 +1966,16 @@ bool MIR_Optimise_GarbageCollect(::MIR::TypeResolve& state, ::MIR::Function& fcn TU_IFLET( ::MIR::Statement, stmt, Assign, e, assigned_lval(e.dst); ) + else if( const auto* e = stmt.opt_Drop() ) + { + if( e->flag_idx != ~0u ) + used_dfs.at(e->flag_idx) = true; + } + else if( const auto* e = stmt.opt_SetDropFlag() ) + { + if( e->other != ~0u ) + used_dfs.at(e->other) = true; + } } TU_MATCHA( (block.terminator), (e), @@ -2018,6 +2029,17 @@ bool MIR_Optimise_GarbageCollect(::MIR::TypeResolve& state, ::MIR::Function& fcn } temp_rewrite_table.push_back( used_temps[i] ? j ++ : ~0u ); } + ::std::vector<unsigned int> df_rewrite_table; + unsigned int n_df = fcn.drop_flags.size(); + for(unsigned int i = 0, j = 0; i < n_df; i ++) + { + if( !used_dfs[i] ) + { + DEBUG("GC df" << i); + fcn.drop_flags.erase(fcn.drop_flags.begin() + j); + } + df_rewrite_table.push_back( used_dfs[i] ? j ++ : ~0u ); + } auto it = fcn.blocks.begin(); for(unsigned int i = 0; i < visited.size(); i ++) @@ -2040,12 +2062,27 @@ bool MIR_Optimise_GarbageCollect(::MIR::TypeResolve& state, ::MIR::Function& fcn } return false; }; - unsigned int stmt_idx = 0; - for(auto& stmt : it->statements) + for(auto stmt_it = it->statements.begin(); stmt_it != it->statements.end(); ++ stmt_it) { - state.set_cur_stmt(i, stmt_idx); - visit_mir_lvalues_mut(stmt, lvalue_cb); - stmt_idx ++; + state.set_cur_stmt(i, stmt_it - it->statements.begin()); + visit_mir_lvalues_mut(*stmt_it, lvalue_cb); + if( auto* se = stmt_it->opt_Drop() ) + { + // Rewrite drop flag indexes + if( se->flag_idx != ~0u ) + se->flag_idx = df_rewrite_table[se->flag_idx]; + } + else if( auto* se = stmt_it->opt_SetDropFlag() ) + { + // Rewrite drop flag indexes OR delete + if( df_rewrite_table[se->idx] == ~0u ) { + stmt_it = it->statements.erase(stmt_it)-1; + continue ; + } + se->idx = df_rewrite_table[se->idx]; + if( se->other != ~0u ) + se->other = df_rewrite_table[se->other]; + } } state.set_cur_stmt_term(i); // Rewrite and advance |