diff options
Diffstat (limited to 'src/mir/optimise.cpp')
| -rw-r--r-- | src/mir/optimise.cpp | 104 |
1 files changed, 69 insertions, 35 deletions
diff --git a/src/mir/optimise.cpp b/src/mir/optimise.cpp index 4a976662..a349c5fb 100644 --- a/src/mir/optimise.cpp +++ b/src/mir/optimise.cpp @@ -159,6 +159,36 @@ namespace { return visit_mir_lvalues_mut(const_cast<::MIR::Statement&>(stmt), [&](auto& lv, bool im){ return cb(lv, im); }); } + void visit_mir_lvalues_mut(::MIR::Terminator& term, ::std::function<bool(::MIR::LValue& , bool)> cb) + { + TU_MATCHA( (term), (e), + (Incomplete, + ), + (Return, + ), + (Diverge, + ), + (Goto, + ), + (Panic, + ), + (If, + visit_mir_lvalue_mut(e.cond, false, cb); + ), + (Switch, + visit_mir_lvalue_mut(e.val, false, cb); + ), + (Call, + if( e.fcn.is_Value() ) { + visit_mir_lvalue_mut(e.fcn.as_Value(), false, cb); + } + for(auto& v : e.args) + visit_mir_lvalue_mut(v, false, cb); + visit_mir_lvalue_mut(e.ret_val, true, cb); + ) + ) + } + void visit_mir_lvalues_mut(::MIR::TypeResolve& state, ::MIR::Function& fcn, ::std::function<bool(::MIR::LValue& , bool)> cb) { for(unsigned int block_idx = 0; block_idx < fcn.blocks.size(); block_idx ++) @@ -172,32 +202,7 @@ namespace { visit_mir_lvalues_mut(stmt, cb); } state.set_cur_stmt_term(block_idx); - TU_MATCHA( (block.terminator), (e), - (Incomplete, - ), - (Return, - ), - (Diverge, - ), - (Goto, - ), - (Panic, - ), - (If, - visit_mir_lvalue_mut(e.cond, false, cb); - ), - (Switch, - visit_mir_lvalue_mut(e.val, false, cb); - ), - (Call, - if( e.fcn.is_Value() ) { - visit_mir_lvalue_mut(e.fcn.as_Value(), false, cb); - } - for(auto& v : e.args) - visit_mir_lvalue_mut(v, false, cb); - visit_mir_lvalue_mut(e.ret_val, true, cb); - ) - ) + visit_mir_lvalues_mut(block.terminator, cb); } } void visit_mir_lvalues(::MIR::TypeResolve& state, const ::MIR::Function& fcn, ::std::function<bool(const ::MIR::LValue& , bool)> cb) @@ -369,7 +374,7 @@ void MIR_Optimise(const StaticTraitResolve& resolve, const ::HIR::ItemPath& path // > This includes mutation, borrowing, or moving. { // 1. Assignments (forward propagate) - ::std::map< ::MIR::LValue, ::MIR::LValue> replacements; + ::std::map< ::MIR::LValue, ::MIR::RValue> replacements; for(const auto& block : fcn.blocks) { if( block.terminator.tag() == ::MIR::Terminator::TAGDEAD ) @@ -489,7 +494,7 @@ void MIR_Optimise(const StaticTraitResolve& resolve, const ::HIR::ItemPath& path if( found ) { DEBUG("> Replace " << e.dst << " with " << e.src.as_Use()); - replacements.insert( ::std::make_pair(e.dst.clone(), e.src.as_Use().clone()) ); + replacements.insert( ::std::make_pair(e.dst.clone(), e.src.clone()) ); } else { @@ -503,13 +508,13 @@ void MIR_Optimise(const StaticTraitResolve& resolve, const ::HIR::ItemPath& path unsigned int inner_replaced_count = 0; for(auto& r : replacements) { - visit_mir_lvalue_mut(r.second, false, [&](auto& lv, bool is_write) { + visit_mir_lvalues_mut(r.second, [&](auto& lv, bool is_write) { if( !is_write ) { auto it = replacements.find(lv); - if( it != replacements.end() ) + if( it != replacements.end() && it->second.is_Use() ) { - lv = it->second.clone(); + lv = it->second.as_Use().clone(); inner_replaced_count ++; } } @@ -525,19 +530,48 @@ void MIR_Optimise(const StaticTraitResolve& resolve, const ::HIR::ItemPath& path while( replaced < replacements.size() ) { auto old_replaced = replaced; - visit_mir_lvalues_mut(state, fcn, [&](auto& lv, bool is_write){ + auto cb = [&](auto& lv, bool is_write){ if( !is_write ) { auto it = replacements.find(lv); if( it != replacements.end() ) { - MIR_ASSERT(state, it->second.tag() != ::MIR::LValue::TAGDEAD, "Replacement of " << lv << " fired twice"); - lv = ::std::move(it->second); + MIR_ASSERT(state, it->second.tag() != ::MIR::RValue::TAGDEAD, "Replacement of " << lv << " fired twice"); + MIR_ASSERT(state, it->second.is_Use(), "Replacing a lvalue with a rvalue"); + auto rval = ::std::move(it->second); + lv = ::std::move(rval.as_Use()); replaced += 1; } } return false; - }); + }; + for(unsigned int block_idx = 0; block_idx < fcn.blocks.size(); block_idx ++) + { + auto& block = fcn.blocks[block_idx]; + if( block.terminator.tag() == ::MIR::Terminator::TAGDEAD ) + continue ; + for(auto& stmt : block.statements) + { + state.set_cur_stmt(block_idx, (&stmt - &block.statements.front())); + if( stmt.is_Assign() && stmt.as_Assign().src.is_Use() ) + { + auto& e = stmt.as_Assign(); + auto it = replacements.find(e.src.as_Use()); + if( it != replacements.end() ) + { + MIR_ASSERT(state, it->second.tag() != ::MIR::RValue::TAGDEAD, "Replacement of " << it->first << " fired twice"); + e.src = mv$(it->second); + replaced += 1; + } + } + else + { + visit_mir_lvalues_mut(stmt, cb); + } + } + state.set_cur_stmt_term(block_idx); + visit_mir_lvalues_mut(block.terminator, cb); + } MIR_ASSERT(state, replaced > old_replaced, "Temporary eliminations didn't advance"); } // Remove assignments of replaced values |