MIR Gen - Remove arguments that are just assigned from arguments

2 files changed, 15 insertions, 0 deletions

diff --git a/src/mir/from_hir.hpp b/src/mir/from_hir.hpp
index 2730631f..ce310945 100644
--- a/src/mir/from_hir.hpp
+++ b/src/mir/from_hir.hpp
@@ -135,6 +135,8 @@ class MirBuilder
     ::std::vector<VarState>   m_slot_states;
     size_t  m_first_temp_idx;
 
+    ::std::map<unsigned,unsigned>   m_var_arg_mappings;
+
     struct ScopeDef
     {
         const Span& span;
@@ -173,6 +175,9 @@ public:
 
     // - Values
     ::MIR::LValue get_variable(const Span& sp, unsigned idx) const {
+        auto it = m_var_arg_mappings.find(idx);
+        if(it != m_var_arg_mappings.end())
+            return ::MIR::LValue::make_Argument({ it->second });
         return ::MIR::LValue::make_Local( idx );
     }
     ::MIR::LValue new_temporary(const ::HIR::TypeRef& ty);
diff --git a/src/mir/mir_builder.cpp b/src/mir/mir_builder.cpp
index 7dee2003..1549d39a 100644
--- a/src/mir/mir_builder.cpp
+++ b/src/mir/mir_builder.cpp
@@ -40,6 +40,16 @@ MirBuilder::MirBuilder(const Span& sp, const StaticTraitResolve& resolve, const
     DEBUG("First temporary will be " << m_first_temp_idx);
 
     m_if_cond_lval = this->new_temporary(::HIR::CoreType::Bool);
+
+    // Determine which variables can be replaced by arguents
+    for(size_t i = 0; i < args.size(); i ++)
+    {
+        const auto& pat = args[i].first;
+        if( pat.m_binding.is_valid() && pat.m_binding.m_type == ::HIR::PatternBinding::Type::Move )
+        {
+            m_var_arg_mappings[pat.m_binding.m_slot] = i;
+        }
+    }
 }
 MirBuilder::~MirBuilder()
 {