MIR - Reduce size of LValue::Static by putting the HIR::Path behind a pointer

15 files changed, 77 insertions, 21 deletions

diff --git a/src/hir/deserialise.cpp b/src/hir/deserialise.cpp
index 9933255f..cd25a3cb 100644
--- a/src/hir/deserialise.cpp
+++ b/src/hir/deserialise.cpp
@@ -423,7 +423,7 @@
             _(Return, {})
             _(Argument, { static_cast<unsigned int>(m_in.read_count()) } )
             _(Local,   static_cast<unsigned int>(m_in.read_count()) )
-            _(Static,  deserialise_path() )
+            _(Static,  box$(deserialise_path()) )
             _(Field, {
                 box$( deserialise_mir_lvalue() ),
                 static_cast<unsigned int>(m_in.read_count())
diff --git a/src/hir/serialise.cpp b/src/hir/serialise.cpp
index dd81596f..e90cf995 100644
--- a/src/hir/serialise.cpp
+++ b/src/hir/serialise.cpp
@@ -689,7 +689,7 @@
                 m_out.write_count(e);
                 ),
             (Static,
-                serialise_path(e);
+                serialise_path(*e);
                 ),
             (Field,
                 serialise(e.val);
diff --git a/src/hir_conv/bind.cpp b/src/hir_conv/bind.cpp
index a3b0041b..940b2cab 100644
--- a/src/hir_conv/bind.cpp
+++ b/src/hir_conv/bind.cpp
@@ -712,7 +712,7 @@ namespace {
                         (Argument,
                             ),
                         (Static,
-                            upper_visitor.visit_path(e, ::HIR::Visitor::PathContext::VALUE);
+                            upper_visitor.visit_path(*e, ::HIR::Visitor::PathContext::VALUE);
                             ),
                         (Field,
                             H::visit_lvalue(upper_visitor, *e.val);
diff --git a/src/hir_conv/constant_evaluation.cpp b/src/hir_conv/constant_evaluation.cpp
index 6049056c..6838e186 100644
--- a/src/hir_conv/constant_evaluation.cpp
+++ b/src/hir_conv/constant_evaluation.cpp
@@ -319,7 +319,7 @@ namespace {
                     return args[e.idx];
                     ),
                 (Static,
-                    MIR_TODO(state, "LValue::Static - " << e);
+                    MIR_TODO(state, "LValue::Static - " << *e);
                     ),
                 (Field,
                     auto& val = get_lval(*e.val);
@@ -495,7 +495,7 @@ namespace {
                     }
                     else if( const auto* p = e.val.opt_Static() ) {
                         // Borrow of a static, emit BorrowPath with the same path
-                        val = ::HIR::Literal::make_BorrowPath( p->clone() );
+                        val = ::HIR::Literal::make_BorrowPath( (*p)->clone() );
                     }
                     else {
                         auto inner_val = local_state.read_lval(e.val);
diff --git a/src/mir/dump.cpp b/src/mir/dump.cpp
index 90b81d5d..ffce8abb 100644
--- a/src/mir/dump.cpp
+++ b/src/mir/dump.cpp
@@ -187,7 +187,7 @@ namespace {
                 os << "_$" << e;
                 ),
             (Static,
-                os << e;
+                os << *e;
                 ),
             (Field,
                 os << "(";
diff --git a/src/mir/from_hir.cpp b/src/mir/from_hir.cpp
index a2d0c790..912b8c78 100644
--- a/src/mir/from_hir.cpp
+++ b/src/mir/from_hir.cpp
@@ -2195,7 +2195,7 @@ namespace {
                     m_builder.set_result( node.span(), mv$(tmp) );
                     ),
                 (Static,
-                    m_builder.set_result( node.span(), ::MIR::LValue::make_Static(node.m_path.clone()) );
+                    m_builder.set_result( node.span(), ::MIR::LValue::make_Static(box$(node.m_path.clone())) );
                     ),
                 (StructConstant,
                     // TODO: Why is this still a PathValue?
diff --git a/src/mir/helpers.cpp b/src/mir/helpers.cpp
index 38380fed..38388aed 100644
--- a/src/mir/helpers.cpp
+++ b/src/mir/helpers.cpp
@@ -82,7 +82,7 @@ const ::HIR::TypeRef& ::MIR::TypeResolve::get_lvalue_type(::HIR::TypeRef& tmp, c
         return m_fcn.locals.at(e);
         ),
     (Static,
-        return get_static_type(tmp,  e);
+        return get_static_type(tmp,  *e);
         ),
     (Field,
         const auto& ty = this->get_lvalue_type(tmp, *e.val);
diff --git a/src/mir/mir.cpp b/src/mir/mir.cpp
index ee6c1a6c..657e695d 100644
--- a/src/mir/mir.cpp
+++ b/src/mir/mir.cpp
@@ -104,7 +104,7 @@ namespace MIR {
             os << "Local(" << e << ")";
             ),
         (Static,
-            os << "Static(" << e << ")";
+            os << "Static(" << *e << ")";
             ),
         (Field,
             os << "Field(" << e.field_index << ", " << *e.val << ")";
@@ -543,7 +543,7 @@ namespace MIR {
     (Return, return LValue(e); ),
     (Argument, return LValue(e); ),
     (Local,  return LValue(e); ),
-    (Static, return LValue(e.clone()); ),
+    (Static, return LValue(box$(e->clone())); ),
     (Field, return LValue::make_Field({
         box$( e.val->clone() ),
         e.field_index
diff --git a/src/mir/mir.hpp b/src/mir/mir.hpp
index 31eb9cd7..6969225d 100644
--- a/src/mir/mir.hpp
+++ b/src/mir/mir.hpp
@@ -17,6 +17,62 @@ namespace MIR {
 typedef unsigned int    RegionId;
 typedef unsigned int    BasicBlockId;
 
+#if 0
+// TODO: Store LValues as:
+// - A packed root value (one word, using the low bits as an enum descriminator)
+// - A list of (inner to outer) wrappers
+struct LValue
+{
+    class Storage
+    {
+        uintptr_t   val;
+    public:
+        ~Storage()
+        {
+            if( is_Static() ) {
+                delete reinterpret_cast<::HIR::Path*>(val & ~3u);
+                val = 0;
+            }
+        }
+        bool is_Argument() const { return val != (MAX_ARG << 2) && (val & 3) == 0; }
+        bool is_Return() const { return val == (MAX_ARG << 2); }
+        bool is_Local() const { return (val & 3) == 1; }
+        bool is_Static() const { return (val & 3) == 2; }
+
+        const ::HIR::Path& as_Static() const { assert(is_Static()); return *reinterpret_cast<const ::HIR::Path*>(val & ~3u); }
+    };
+    class Wrapper
+    {
+        uintptr_t   val;
+    public:
+        bool is_Deref() const { return (val & 3) == 0; }
+        // Stores the field index
+        bool is_Field() const { return (val & 3) == 1; }
+        // Stores the variant index
+        bool is_Downcast() const { return (val & 3) == 2; }
+        // Stores a Local index
+        bool is_Index() const { return (val & 3) == 3; }
+
+        const unsigned as_Field() const { assert(is_Field()); return (val >> 2); }
+        const unsigned as_Index() const { assert(is_Index()); return (val >> 2); }
+    };
+
+    Storage m_root;
+    ::std::vector<Wrapper>  m_wrappers;
+
+    LValue clone() const;
+
+    class Ref
+    {
+        LValue& r;
+        size_t wrapper_idx;
+    public::
+        LValue clone() const;
+        void replace(LValue x) const;
+    };
+};
+#endif
+
 // "LVALUE" - Assignable values
 TAGGED_UNION_EX(LValue, (), Return, (
     // Function return
@@ -26,7 +82,7 @@ TAGGED_UNION_EX(LValue, (), Return, (
     // Variable/Temporary
     (Local, unsigned int),
     // `static` or `static mut`
-    (Static, ::HIR::Path),
+    (Static, ::std::unique_ptr<::HIR::Path>),
     // Field access (tuple, struct, tuple struct, enum field, ...)
     // NOTE: Also used to index an array/slice by a compile-time known index (e.g. in destructuring)
     (Field, struct {
diff --git a/src/mir/mir_builder.cpp b/src/mir/mir_builder.cpp
index ac1b7650..81816535 100644
--- a/src/mir/mir_builder.cpp
+++ b/src/mir/mir_builder.cpp
@@ -1622,20 +1622,20 @@ void MirBuilder::with_val_type(const Span& sp, const ::MIR::LValue& val, ::std::
         cb( m_output.locals.at(e) );
         ),
     (Static,
-        TU_MATCHA( (e.m_data), (pe),
+        TU_MATCHA( (e->m_data), (pe),
         (Generic,
             ASSERT_BUG(sp, pe.m_params.m_types.empty(), "Path params on static");
             const auto& s = m_resolve.m_crate.get_static_by_path(sp, pe.m_path);
             cb( s.m_type );
             ),
         (UfcsKnown,
-            TODO(sp, "Static - UfcsKnown - " << e);
+            TODO(sp, "Static - UfcsKnown - " << *e);
             ),
         (UfcsUnknown,
-            BUG(sp, "Encountered UfcsUnknown in Static - " << e);
+            BUG(sp, "Encountered UfcsUnknown in Static - " << *e);
             ),
         (UfcsInherent,
-            TODO(sp, "Static - UfcsInherent - " << e);
+            TODO(sp, "Static - UfcsInherent - " << *e);
             )
         )
         ),
diff --git a/src/mir/optimise.cpp b/src/mir/optimise.cpp
index 67a5d4a4..b7e63deb 100644
--- a/src/mir/optimise.cpp
+++ b/src/mir/optimise.cpp
@@ -1159,7 +1159,7 @@ bool MIR_Optimise_Inlining(::MIR::TypeResolve& state, ::MIR::Function& fcn, bool
                 return ::MIR::LValue::make_Local(this->var_base + se);
                 ),
             (Static,
-                return this->monomorph( se );
+                return box$(this->monomorph( *se ));
                 ),
             (Deref,
                 return ::MIR::LValue::make_Deref({ box$(this->clone_lval(*se.val)) });
diff --git a/src/trans/codegen_c.cpp b/src/trans/codegen_c.cpp
index 98d0d3de..373a36a8 100644
--- a/src/trans/codegen_c.cpp
+++ b/src/trans/codegen_c.cpp
@@ -5522,7 +5522,7 @@ namespace {
                     m_of << "var" << e;
                 ),
             (Static,
-                m_of << Trans_Mangle(e);
+                m_of << Trans_Mangle(*e);
                 ),
             (Field,
                 ::HIR::TypeRef  tmp;
diff --git a/src/trans/codegen_mmir.cpp b/src/trans/codegen_mmir.cpp
index b2c5282a..4867cf6f 100644
--- a/src/trans/codegen_mmir.cpp
+++ b/src/trans/codegen_mmir.cpp
@@ -52,7 +52,7 @@ namespace
             os << "arg" << e.idx;
             break;
         TU_ARM(x.e, Static, e)
-            os << e;
+            os << *e;
             break;
         TU_ARM(x.e, Deref, e)
             os << "*" << fmt(*e.val);
diff --git a/src/trans/enumerate.cpp b/src/trans/enumerate.cpp
index afdbd626..da11386c 100644
--- a/src/trans/enumerate.cpp
+++ b/src/trans/enumerate.cpp
@@ -735,7 +735,7 @@ void Trans_Enumerate_Types(EnumState& state)
                                 ),
                             (Static,
                                 if( tmp_ty_ptr ) {
-                                    const auto& path = e;
+                                    const auto& path = *e;
                                     TU_MATCHA( (path.m_data), (pe),
                                     (Generic,
                                         ASSERT_BUG(Span(), pe.m_params.m_types.empty(), "Path params on static - " << path);
@@ -1495,7 +1495,7 @@ void Trans_Enumerate_FillFrom_MIR_LValue(EnumState& state, const ::MIR::LValue&
     (Local,
         ),
     (Static,
-        Trans_Enumerate_FillFrom_Path(state, e, pp);
+        Trans_Enumerate_FillFrom_Path(state, *e, pp);
         ),
     (Field,
         Trans_Enumerate_FillFrom_MIR_LValue(state, *e.val, pp);
diff --git a/src/trans/monomorphise.cpp b/src/trans/monomorphise.cpp
index 3b958fec..0a0b43b5 100644
--- a/src/trans/monomorphise.cpp
+++ b/src/trans/monomorphise.cpp
@@ -19,7 +19,7 @@ namespace {
         (Argument,  return e; ),
         (Local,  return e; ),
         (Static,
-            return params.monomorph(resolve, e);
+            return box$(params.monomorph(resolve, *e));
             ),
         (Field,
             return ::MIR::LValue::make_Field({