diff options
| -rw-r--r-- | src/mir/optimise.cpp | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/src/mir/optimise.cpp b/src/mir/optimise.cpp index a45b1c05..b1be20a4 100644 --- a/src/mir/optimise.cpp +++ b/src/mir/optimise.cpp @@ -1411,6 +1411,12 @@ bool MIR_Optimise_Inlining(::MIR::TypeResolve& state, ::MIR::Function& fcn, bool return inline_happened; } +// TODO: New pass that removes useless borrows +// ``` +// _$1 = & _$0; +// (*_$1).1 = 0x0; +// ``` + // -------------------------------------------------------------------- // Replaces uses of stack slots with what they were assigned with (when // possible) @@ -1424,6 +1430,7 @@ bool MIR_Optimise_DeTemporary(::MIR::TypeResolve& state, ::MIR::Function& fcn) { auto& bb = fcn.blocks[bb_idx]; ::std::map<unsigned,unsigned> local_assignments; // Local number -> statement index + // TODO: Keep track of what variables would invalidate a local (and compound on assignment) ::std::vector<unsigned> statements_to_remove; // List of statements that have to be removed // ----- Helper closures ----- @@ -1457,6 +1464,7 @@ bool MIR_Optimise_DeTemporary(::MIR::TypeResolve& state, ::MIR::Function& fcn) case ValUsage::Write: // Mutated? It's invalidated case ValUsage::Move: // Moved? Now invalid visit_mir_lvalues(src_rvalue, [&](const auto& s_lv, auto /*s_vu*/) { + //DEBUG(" " << s_lv << " ?= " << lv); if( s_lv == lv ) { DEBUG(state << "> Invalidates source of Local(" << it->first << ") - " << src_rvalue); @@ -1556,6 +1564,12 @@ bool MIR_Optimise_DeTemporary(::MIR::TypeResolve& state, ::MIR::Function& fcn) { DEBUG(state << "> Don't record, self-referrential"); } + else if( visit_mir_lvalue(stmt.as_Assign().src.as_Use(), ValUsage::Read, [&](const auto& lv, auto /*vu*/) { + return lv.is_Deref(); + }) ) + { + DEBUG(state << "> Don't record, dereference"); + } else { local_assignments.insert(::std::make_pair( stmt.as_Assign().dst.as_Local(), stmt_idx )); |