Commit 62d0d88b56

Andrew Kelley <superjoe30@gmail.com>
2016-11-17 10:00:02
IR: pointers to constants don't copy data
1 parent a55555c
src/all_types.hpp
@@ -51,17 +51,24 @@ struct ConstEnumValue {
 };
 
 struct ConstStructValue {
-    ConstExprValue **fields;
+    ConstExprValue *fields;
 };
 
 struct ConstArrayValue {
-    ConstExprValue **fields;
+    ConstExprValue *elements;
+    // This will be the same as `len` from the type, but we duplicate the information
+    // in the constant value so that pointers pointing to arrays can see this size.
+    size_t size;
 };
 
 struct ConstPtrValue {
-    ConstExprValue **ptr;
-    // len should almost always be 1. exceptions include C strings
-    uint64_t len;
+    ConstExprValue *base_ptr;
+    // If index is SIZE_MAX, then base_ptr points directly to child type.
+    // Otherwise base_ptr points to an array const val and index is offset
+    // in object units from base_ptr into the block of memory pointed to
+    size_t index;
+    // This flag helps us preserve the null byte when performing compile-time
+    // concatenation on C strings.
     bool is_c_str;
 };
 
@@ -71,15 +78,17 @@ struct ConstErrValue {
 };
 
 enum ConstValSpecial {
-    ConstValSpecialOther,
+    ConstValSpecialRuntime,
+    ConstValSpecialStatic,
     ConstValSpecialUndef,
     ConstValSpecialZeroes,
 };
 
 struct ConstExprValue {
-    bool ok;
-    bool depends_on_compile_var;
     ConstValSpecial special;
+    bool depends_on_compile_var;
+    LLVMValueRef llvm_value;
+    LLVMValueRef llvm_global;
 
     // populated if val_type == ConstValTypeOk
     union {
@@ -108,13 +117,9 @@ enum ReturnKnowledge {
 };
 
 struct Expr {
-    TypeTableEntry *type_entry;
+    IrInstruction *instruction;
     ReturnKnowledge return_knowledge;
     VariableTableEntry *variable;
-
-    LLVMValueRef const_llvm_val;
-    ConstExprValue const_val;
-    bool has_global_const;
 };
 
 struct StructValExprCodeGen {
@@ -1289,7 +1294,6 @@ struct CodeGen {
     // there will not be a corresponding fn_defs entry.
     ZigList<FnTableEntry *> fn_protos;
     ZigList<VariableTableEntry *> global_vars;
-    ZigList<AstNode *> global_const_list;
 
     OutType out_type;
     FnTableEntry *cur_fn;
@@ -1733,4 +1737,7 @@ enum LValPurpose {
     LValPurposeConstAddressOf,
 };
 
+static const size_t slice_ptr_index = 0;
+static const size_t slice_len_index = 1;
+
 #endif
src/analyze.cpp
@@ -882,7 +882,7 @@ static TypeTableEntry *analyze_type_expr_pointer_only(CodeGen *g, ImportTableEnt
     if (result->type_entry->id == TypeTableEntryIdInvalid)
         return g->builtin_types.entry_invalid;
 
-    assert(result->static_value.ok);
+    assert(result->static_value.special != ConstValSpecialRuntime);
     return result->static_value.data.x_type;
 }
 
@@ -1963,9 +1963,8 @@ static void resolve_var_decl(CodeGen *g, ImportTableEntry *import, AstNode *node
         }
         if (implicit_type->id != TypeTableEntryIdInvalid) {
             Expr *expr = get_resolved_expr(var_decl->expr);
-            assert(result->static_value.ok);
-            expr->const_val = result->static_value;
-            expr->type_entry = result->type_entry;
+            assert(result->static_value.special != ConstValSpecialRuntime);
+            expr->instruction = result;
         }
     } else if (!is_extern) {
         add_node_error(g, node, buf_sprintf("variables must be initialized"));
@@ -2132,8 +2131,8 @@ static bool num_lit_fits_in_other_type(CodeGen *g, AstNode *literal_node, TypeTa
     }
 
     Expr *expr = get_resolved_expr(literal_node);
-    ConstExprValue *const_val = &expr->const_val;
-    assert(const_val->ok);
+    ConstExprValue *const_val = &expr->instruction->static_value;
+    assert(const_val->special != ConstValSpecialRuntime);
     if (other_type_underlying->id == TypeTableEntryIdFloat) {
         return true;
     } else if (other_type_underlying->id == TypeTableEntryIdInt &&
@@ -2600,15 +2599,15 @@ static void add_symbols_from_import(CodeGen *g, AstNode *src_use_node, AstNode *
     AstNode *use_target_node = src_use_node->data.use.expr;
     Expr *expr = get_resolved_expr(use_target_node);
 
-    if (expr->type_entry->id == TypeTableEntryIdInvalid) {
+    if (expr->instruction->type_entry->id == TypeTableEntryIdInvalid) {
         tld->import->any_imports_failed = true;
         return;
     }
 
     tld->resolution = TldResolutionOk;
 
-    ConstExprValue *const_val = &expr->const_val;
-    assert(const_val->ok);
+    ConstExprValue *const_val = &expr->instruction->static_value;
+    assert(const_val->special != ConstValSpecialRuntime);
 
     ImportTableEntry *target_import = const_val->data.x_import;
     assert(target_import);
@@ -3031,10 +3030,11 @@ void find_libc_lib_path(CodeGen *g) {
 }
 
 static uint32_t hash_ptr(void *ptr) {
-    uint64_t x = (uint64_t)(uintptr_t)(ptr);
-    uint32_t a = x >> 32;
-    uint32_t b = x & 0xffffffff;
-    return a ^ b;
+    return ((uintptr_t)ptr) % UINT32_MAX;
+}
+
+static uint32_t hash_size(size_t x) {
+    return x % UINT32_MAX;
 }
 
 uint32_t fn_type_id_hash(FnTypeId *id) {
@@ -3090,7 +3090,7 @@ static uint32_t hash_const_val(TypeTableEntry *type, ConstExprValue *const_val)
         case TypeTableEntryIdNumLitFloat:
             return const_val->data.x_bignum.data.x_float * UINT32_MAX;
         case TypeTableEntryIdPointer:
-            return hash_ptr(const_val->data.x_ptr.ptr);
+            return hash_ptr(const_val->data.x_ptr.base_ptr) + hash_size(const_val->data.x_ptr.index);
         case TypeTableEntryIdUndefLit:
             return 162837799;
         case TypeTableEntryIdNullLit:
@@ -3143,8 +3143,8 @@ uint32_t generic_fn_type_id_hash(GenericFnTypeId *id) {
     for (size_t i = 0; i < id->generic_param_count; i += 1) {
         GenericParamValue *generic_param = &id->generic_params[i];
         if (generic_param->node) {
-            ConstExprValue *const_val = &get_resolved_expr(generic_param->node)->const_val;
-            assert(const_val->ok);
+            ConstExprValue *const_val = &get_resolved_expr(generic_param->node)->instruction->static_value;
+            assert(const_val->special != ConstValSpecialRuntime);
             result += hash_const_val(generic_param->type, const_val);
         }
         result += hash_ptr(generic_param->type);
@@ -3160,10 +3160,10 @@ bool generic_fn_type_id_eql(GenericFnTypeId *a, GenericFnTypeId *b) {
         GenericParamValue *b_val = &b->generic_params[i];
         if (a_val->type != b_val->type) return false;
         if (a_val->node && b_val->node) {
-            ConstExprValue *a_const_val = &get_resolved_expr(a_val->node)->const_val;
-            ConstExprValue *b_const_val = &get_resolved_expr(b_val->node)->const_val;
-            assert(a_const_val->ok);
-            assert(b_const_val->ok);
+            ConstExprValue *a_const_val = &get_resolved_expr(a_val->node)->instruction->static_value;
+            ConstExprValue *b_const_val = &get_resolved_expr(b_val->node)->instruction->static_value;
+            assert(a_const_val->special != ConstValSpecialRuntime);
+            assert(b_const_val->special != ConstValSpecialRuntime);
             if (!const_values_equal(a_const_val, b_const_val, a_val->type)) {
                 return false;
             }
@@ -3237,3 +3237,4 @@ uint64_t get_memcpy_align(CodeGen *g, TypeTableEntry *type_entry) {
     return LLVMABISizeOfType(g->target_data_ref, first_type_in_mem->type_ref);
 }
 
+
src/codegen.cpp
@@ -226,7 +226,8 @@ void codegen_set_rdynamic(CodeGen *g, bool rdynamic) {
     g->linker_rdynamic = rdynamic;
 }
 
-static LLVMValueRef gen_const_val(CodeGen *g, TypeTableEntry *type_entry, ConstExprValue *const_val);
+static void render_const_val(CodeGen *g, TypeTableEntry *type_entry, ConstExprValue *const_val);
+static void render_const_val_global(CodeGen *g, TypeTableEntry *type_entry, ConstExprValue *const_val);
 
 static void set_debug_source_node(CodeGen *g, AstNode *node) {
     assert(node->block_context);
@@ -862,11 +863,17 @@ static LLVMValueRef ir_llvm_value(CodeGen *g, IrInstruction *instruction) {
     if (!type_has_bits(instruction->type_entry))
         return nullptr;
     if (!instruction->llvm_value) {
-        assert(instruction->static_value.ok);
+        assert(instruction->static_value.special != ConstValSpecialRuntime);
         assert(instruction->type_entry);
-        instruction->llvm_value = gen_const_val(g, instruction->type_entry, &instruction->static_value);
+        render_const_val(g, instruction->type_entry, &instruction->static_value);
+        instruction->llvm_value = instruction->static_value.llvm_value;
         assert(instruction->llvm_value);
     }
+    if (instruction->static_value.special != ConstValSpecialRuntime) {
+        if (instruction->type_entry->id == TypeTableEntryIdPointer) {
+            return LLVMBuildLoad(g->builder, instruction->static_value.llvm_global, "");
+        }
+    }
     return instruction->llvm_value;
 }
 
@@ -1401,9 +1408,9 @@ static LLVMValueRef ir_render_decl_var(CodeGen *g, IrExecutable *executable,
     bool want_zeroes = false;
 
     ConstExprValue *const_val = &init_value->static_value;
-    if (!const_val->ok || const_val->special == ConstValSpecialOther)
+    if (const_val->special == ConstValSpecialRuntime || const_val->special == ConstValSpecialStatic)
         have_init_expr = true;
-    if (const_val->ok && const_val->special == ConstValSpecialZeroes)
+    if (const_val->special == ConstValSpecialZeroes)
         want_zeroes = true;
 
     if (have_init_expr) {
@@ -1740,14 +1747,14 @@ static void ir_render(CodeGen *g, FnTableEntry *fn_entry) {
 }
 
 static LLVMValueRef gen_const_val(CodeGen *g, TypeTableEntry *type_entry, ConstExprValue *const_val) {
-    assert(const_val->ok);
-
     switch (const_val->special) {
+        case ConstValSpecialRuntime:
+            zig_unreachable();
         case ConstValSpecialUndef:
             return LLVMGetUndef(type_entry->type_ref);
         case ConstValSpecialZeroes:
             return LLVMConstNull(type_entry->type_ref);
-        case ConstValSpecialOther:
+        case ConstValSpecialStatic:
             break;
 
     }
@@ -1814,7 +1821,7 @@ static LLVMValueRef gen_const_val(CodeGen *g, TypeTableEntry *type_entry, ConstE
                         continue;
                     }
                     fields[type_struct_field->gen_index] = gen_const_val(g, type_struct_field->type_entry,
-                            const_val->data.x_struct.fields[i]);
+                            &const_val->data.x_struct.fields[i]);
                 }
                 return LLVMConstNamedStruct(type_entry->type_ref, fields,
                         type_entry->data.structure.gen_field_count);
@@ -1829,8 +1836,8 @@ static LLVMValueRef gen_const_val(CodeGen *g, TypeTableEntry *type_entry, ConstE
                 uint64_t len = type_entry->data.array.len;
                 LLVMValueRef *values = allocate<LLVMValueRef>(len);
                 for (uint64_t i = 0; i < len; i += 1) {
-                    ConstExprValue *field_value = const_val->data.x_array.fields[i];
-                    values[i] = gen_const_val(g, child_type, field_value);
+                    ConstExprValue *elem_value = &const_val->data.x_array.elements[i];
+                    values[i] = gen_const_val(g, child_type, elem_value);
                 }
                 return LLVMConstArray(child_type->type_ref, values, len);
             }
@@ -1878,29 +1885,26 @@ static LLVMValueRef gen_const_val(CodeGen *g, TypeTableEntry *type_entry, ConstE
         case TypeTableEntryIdPointer:
             {
                 TypeTableEntry *child_type = type_entry->data.pointer.child_type;
-                size_t len = const_val->data.x_ptr.len;
-                LLVMValueRef target_val;
-                if (len == 1) {
-                    target_val = gen_const_val(g, child_type, const_val->data.x_ptr.ptr[0]);
-                } else if (len > 1) {
-                    LLVMValueRef *values = allocate<LLVMValueRef>(len);
-                    for (size_t i = 0; i < len; i += 1) {
-                        values[i] = gen_const_val(g, child_type, const_val->data.x_ptr.ptr[i]);
-                    }
-                    target_val = LLVMConstArray(child_type->type_ref, values, len);
-                } else {
-                    return LLVMGetUndef(type_entry->type_ref);
-                }
-                LLVMValueRef global_value = LLVMAddGlobal(g->module, LLVMTypeOf(target_val), "");
-                LLVMSetInitializer(global_value, target_val);
-                LLVMSetLinkage(global_value, LLVMPrivateLinkage);
-                LLVMSetGlobalConstant(global_value, type_entry->data.pointer.is_const);
-                LLVMSetUnnamedAddr(global_value, true);
-
-                if (len > 1) {
-                    return LLVMConstBitCast(global_value, type_entry->type_ref);
+
+                render_const_val_global(g, type_entry, const_val);
+                size_t index = const_val->data.x_ptr.index;
+                if (index == SIZE_MAX) {
+                    render_const_val(g, child_type, const_val->data.x_ptr.base_ptr);
+                    render_const_val_global(g, child_type, const_val->data.x_ptr.base_ptr);
+                    return const_val->data.x_ptr.base_ptr->llvm_global;
                 } else {
-                    return global_value;
+                    ConstExprValue *array_const_val = const_val->data.x_ptr.base_ptr;
+                    TypeTableEntry *array_type = get_array_type(g, child_type,
+                            array_const_val->data.x_array.size);
+                    render_const_val(g, array_type, array_const_val);
+                    render_const_val_global(g, array_type, array_const_val);
+                    TypeTableEntry *usize = g->builtin_types.entry_usize;
+                    LLVMValueRef indices[] = {
+                        LLVMConstNull(usize->type_ref),
+                        LLVMConstInt(usize->type_ref, index, false),
+                    };
+                    LLVMValueRef ptr_val = LLVMConstInBoundsGEP(array_const_val->llvm_global, indices, 2);
+                    return ptr_val;
                 }
             }
         case TypeTableEntryIdErrorUnion:
@@ -1945,27 +1949,26 @@ static LLVMValueRef gen_const_val(CodeGen *g, TypeTableEntry *type_entry, ConstE
     zig_unreachable();
 }
 
-static void gen_const_globals(CodeGen *g) {
-    for (size_t i = 0; i < g->global_const_list.length; i += 1) {
-        AstNode *expr_node = g->global_const_list.at(i);
-        Expr *expr = get_resolved_expr(expr_node);
-        ConstExprValue *const_val = &expr->const_val;
-        assert(const_val->ok);
-        TypeTableEntry *type_entry = expr->type_entry;
-
-        if (handle_is_ptr(type_entry)) {
-            LLVMValueRef init_val = gen_const_val(g, type_entry, const_val);
-            LLVMValueRef global_value = LLVMAddGlobal(g->module, LLVMTypeOf(init_val), "");
-            LLVMSetInitializer(global_value, init_val);
-            LLVMSetLinkage(global_value, LLVMPrivateLinkage);
-            LLVMSetGlobalConstant(global_value, true);
-            LLVMSetUnnamedAddr(global_value, true);
-            expr->const_llvm_val = global_value;
-        } else {
-            expr->const_llvm_val = gen_const_val(g, type_entry, const_val);
-        }
-        assert(expr->const_llvm_val);
+static void render_const_val(CodeGen *g, TypeTableEntry *type_entry, ConstExprValue *const_val) {
+    if (!const_val->llvm_value)
+        const_val->llvm_value = gen_const_val(g, type_entry, const_val);
+
+    if (const_val->llvm_global)
+        LLVMSetInitializer(const_val->llvm_global, const_val->llvm_value);
+}
+
+static void render_const_val_global(CodeGen *g, TypeTableEntry *type_entry, ConstExprValue *const_val) {
+    if (!const_val->llvm_global) {
+        LLVMValueRef global_value = LLVMAddGlobal(g->module, type_entry->type_ref, "");
+        LLVMSetLinkage(global_value, LLVMInternalLinkage);
+        LLVMSetGlobalConstant(global_value, true);
+        LLVMSetUnnamedAddr(global_value, true);
+
+        const_val->llvm_global = global_value;
     }
+
+    if (const_val->llvm_value)
+        LLVMSetInitializer(const_val->llvm_global, const_val->llvm_value);
 }
 
 static void delete_unused_builtin_fns(CodeGen *g) {
@@ -2096,9 +2099,6 @@ static void do_code_gen(CodeGen *g) {
     assert(!g->errors.length);
 
     delete_unused_builtin_fns(g);
-
-
-    gen_const_globals(g);
     generate_error_name_table(g);
 
     // Generate module level variables
@@ -2107,8 +2107,8 @@ static void do_code_gen(CodeGen *g) {
 
         if (var->type->id == TypeTableEntryIdNumLitFloat) {
             // Generate debug info for it but that's it.
-            ConstExprValue *const_val = &get_resolved_expr(var->val_node)->const_val;
-            assert(const_val->ok);
+            ConstExprValue *const_val = &get_resolved_expr(var->val_node)->instruction->static_value;
+            assert(const_val->special != ConstValSpecialRuntime);
             TypeTableEntry *var_type = g->builtin_types.entry_f64;
             LLVMValueRef init_val = LLVMConstReal(var_type->type_ref, const_val->data.x_bignum.data.x_float);
             gen_global_var(g, var, init_val, var_type);
@@ -2117,8 +2117,8 @@ static void do_code_gen(CodeGen *g) {
 
         if (var->type->id == TypeTableEntryIdNumLitInt) {
             // Generate debug info for it but that's it.
-            ConstExprValue *const_val = &get_resolved_expr(var->val_node)->const_val;
-            assert(const_val->ok);
+            ConstExprValue *const_val = &get_resolved_expr(var->val_node)->instruction->static_value;
+            assert(const_val->special != ConstValSpecialRuntime);
             TypeTableEntry *var_type = const_val->data.x_bignum.is_negative ?
                 g->builtin_types.entry_isize : g->builtin_types.entry_usize;
             LLVMValueRef init_val = LLVMConstInt(var_type->type_ref,
@@ -2143,25 +2143,13 @@ static void do_code_gen(CodeGen *g) {
             LLVMSetLinkage(global_value, LLVMExternalLinkage);
         } else {
             AstNode *expr_node = var->decl_node->data.variable_declaration.expr;
-            LLVMValueRef init_val;
-            if (expr_node) {
-                Expr *expr = get_resolved_expr(expr_node);
-                ConstExprValue *const_val = &expr->const_val;
-                assert(const_val->ok);
-                TypeTableEntry *type_entry = expr->type_entry;
-                init_val = gen_const_val(g, type_entry, const_val);
-            } else {
-                init_val = LLVMConstNull(var->type->type_ref);
-            }
-
-            global_value = LLVMAddGlobal(g->module, LLVMTypeOf(init_val), buf_ptr(&var->name));
-            LLVMSetInitializer(global_value, init_val);
-            LLVMSetLinkage(global_value, LLVMInternalLinkage);
-            LLVMSetUnnamedAddr(global_value, true);
-
+            IrInstruction *instruction = get_resolved_expr(expr_node)->instruction;
+            render_const_val(g, instruction->type_entry, &instruction->static_value);
+            render_const_val_global(g, instruction->type_entry, &instruction->static_value);
+            global_value = instruction->static_value.llvm_global;
             // TODO debug info for function pointers
             if (var->gen_is_const && var->type->id != TypeTableEntryIdFn) {
-                gen_global_var(g, var, init_val, var->type);
+                gen_global_var(g, var, instruction->static_value.llvm_value, var->type);
             }
         }
 
@@ -3282,11 +3270,11 @@ static void get_c_type(CodeGen *g, TypeTableEntry *type_entry, Buf *out_buf) {
 
 static void get_c_type_node(CodeGen *g, AstNode *type_node, Buf *out_buf) {
     Expr *expr = get_resolved_expr(type_node);
-    assert(expr->type_entry);
-    assert(expr->type_entry->id == TypeTableEntryIdMetaType);
+    assert(expr->instruction->type_entry);
+    assert(expr->instruction->type_entry->id == TypeTableEntryIdMetaType);
 
-    ConstExprValue *const_val = &expr->const_val;
-    assert(const_val->ok);
+    ConstExprValue *const_val = &expr->instruction->static_value;
+    assert(const_val->special != ConstValSpecialRuntime);
 
     TypeTableEntry *type_entry = const_val->data.x_type;
 
src/eval.cpp
@@ -147,7 +147,7 @@ static int eval_const_expr_bin_op_bignum(ConstExprValue *op1_val, ConstExprValue
         }
     }
 
-    out_val->ok = true;
+    out_val->special = ConstValSpecialStatic;
     out_val->depends_on_compile_var = op1_val->depends_on_compile_var || op2_val->depends_on_compile_var;
     return 0;
 }
@@ -155,8 +155,8 @@ static int eval_const_expr_bin_op_bignum(ConstExprValue *op1_val, ConstExprValue
 int eval_const_expr_bin_op(ConstExprValue *op1_val, TypeTableEntry *op1_type,
         BinOpType bin_op, ConstExprValue *op2_val, TypeTableEntry *op2_type, ConstExprValue *out_val)
 {
-    assert(op1_val->ok);
-    assert(op2_val->ok);
+    assert(op1_val->special != ConstValSpecialRuntime);
+    assert(op2_val->special != ConstValSpecialRuntime);
     assert(op1_type->id != TypeTableEntryIdInvalid);
     assert(op2_type->id != TypeTableEntryIdInvalid);
 
@@ -171,7 +171,7 @@ int eval_const_expr_bin_op(ConstExprValue *op1_val, TypeTableEntry *op1_type,
             assert(op1_type->id == TypeTableEntryIdBool);
             assert(op2_type->id == TypeTableEntryIdBool);
             out_val->data.x_bool = eval_bool_bin_op_bool(op1_val->data.x_bool, bin_op, op2_val->data.x_bool);
-            out_val->ok = true;
+            out_val->special = ConstValSpecialStatic;
             out_val->depends_on_compile_var = op1_val->depends_on_compile_var || op2_val->depends_on_compile_var;
             return 0;
         case BinOpTypeCmpEq:
@@ -219,7 +219,7 @@ int eval_const_expr_bin_op(ConstExprValue *op1_val, TypeTableEntry *op1_type,
                 out_val->depends_on_compile_var =
                     op1_val->depends_on_compile_var || op2_val->depends_on_compile_var;
                 out_val->data.x_bool = answer;
-                out_val->ok = true;
+                out_val->special = ConstValSpecialStatic;
                 return 0;
             }
         case BinOpTypeAdd:
@@ -309,67 +309,7 @@ void eval_const_expr_implicit_cast(CastOp cast_op,
             *const_val = *other_val;
             break;
         case CastOpPointerReinterpret:
-            if (other_type->id == TypeTableEntryIdPointer &&
-                new_type->id == TypeTableEntryIdPointer)
-            {
-                TypeTableEntry *other_child_type = other_type->data.pointer.child_type;
-                TypeTableEntry *new_child_type = new_type->data.pointer.child_type;
-
-                if ((other_child_type->id == TypeTableEntryIdInt ||
-                    other_child_type->id == TypeTableEntryIdFloat) &&
-                    (new_child_type->id == TypeTableEntryIdInt ||
-                    new_child_type->id == TypeTableEntryIdFloat))
-                {
-                    ConstExprValue **ptr_val = allocate<ConstExprValue*>(1);
-                    *ptr_val = other_val->data.x_ptr.ptr[0];
-                    const_val->data.x_ptr.ptr = ptr_val;
-                    const_val->data.x_ptr.len = 1;
-                    const_val->ok = true;
-                    const_val->special = other_val->special;
-                    const_val->depends_on_compile_var = other_val->depends_on_compile_var;
-                } else {
-                    zig_panic("TODO");
-                }
-            } else if (other_type->id == TypeTableEntryIdMaybe &&
-                       new_type->id == TypeTableEntryIdMaybe)
-            {
-                if (!other_val->data.x_maybe) {
-                    *const_val = *other_val;
-                    break;
-                }
-
-                TypeTableEntry *other_ptr_type = other_type->data.maybe.child_type;
-                TypeTableEntry *new_ptr_type = new_type->data.maybe.child_type;
-
-                if (other_ptr_type->id == TypeTableEntryIdPointer &&
-                    new_ptr_type->id == TypeTableEntryIdPointer) 
-                {
-                    TypeTableEntry *other_child_type = other_ptr_type->data.pointer.child_type;
-                    TypeTableEntry *new_child_type = new_ptr_type->data.pointer.child_type;
-
-                    if ((other_child_type->id == TypeTableEntryIdInt ||
-                        other_child_type->id == TypeTableEntryIdFloat) &&
-                        (new_child_type->id == TypeTableEntryIdInt ||
-                        new_child_type->id == TypeTableEntryIdFloat))
-                    {
-                        ConstExprValue *ptr_parent = allocate<ConstExprValue>(1);
-                        ConstExprValue **ptr_val = allocate<ConstExprValue*>(1);
-                        *ptr_val = other_val->data.x_maybe->data.x_ptr.ptr[0];
-                        ptr_parent->data.x_ptr.ptr = ptr_val;
-                        ptr_parent->data.x_ptr.len = 1;
-                        ptr_parent->ok = true;
-
-                        const_val->data.x_maybe = ptr_parent;
-                        const_val->ok = true;
-                        const_val->special = other_val->special;
-                        const_val->depends_on_compile_var = other_val->depends_on_compile_var;
-                    } else {
-                        zig_panic("TODO");
-                    }
-                } else {
-                    zig_panic("TODO");
-                }
-            }
+            zig_panic("TODO compile time pointer reinterpret");
             break;
         case CastOpPtrToInt:
         case CastOpIntToPtr:
@@ -378,62 +318,43 @@ void eval_const_expr_implicit_cast(CastOp cast_op,
             // can't do it
             break;
         case CastOpToUnknownSizeArray:
-            {
-                assert(other_type->id == TypeTableEntryIdArray);
-
-                ConstExprValue *all_fields = allocate<ConstExprValue>(2);
-                ConstExprValue *ptr_field = &all_fields[0];
-                ConstExprValue *len_field = &all_fields[1];
-
-                const_val->data.x_struct.fields = allocate<ConstExprValue*>(2);
-                const_val->data.x_struct.fields[0] = ptr_field;
-                const_val->data.x_struct.fields[1] = len_field;
-
-                ptr_field->ok = true;
-                ptr_field->data.x_ptr.ptr = other_val->data.x_array.fields;
-                ptr_field->data.x_ptr.len = other_type->data.array.len;
-
-                len_field->ok = true;
-                bignum_init_unsigned(&len_field->data.x_bignum, other_type->data.array.len);
-
-                const_val->ok = true;
-                break;
-            }
+            zig_panic("TODO compile time implicit to unknown size array");
+            break;
         case CastOpMaybeWrap:
             const_val->data.x_maybe = other_val;
-            const_val->ok = true;
+            const_val->special = ConstValSpecialStatic;
             break;
         case CastOpNullToMaybe:
             const_val->data.x_maybe = nullptr;
-            const_val->ok = true;
+            const_val->special = ConstValSpecialStatic;
             break;
         case CastOpErrorWrap:
             const_val->data.x_err.err = nullptr;
             const_val->data.x_err.payload = other_val;
-            const_val->ok = true;
+            const_val->special = ConstValSpecialStatic;
             break;
         case CastOpPureErrorWrap:
             const_val->data.x_err.err = other_val->data.x_err.err;
-            const_val->ok = true;
+            const_val->special = ConstValSpecialStatic;
             break;
         case CastOpErrToInt:
             {
                 uint64_t value = other_val->data.x_err.err ? other_val->data.x_err.err->value : 0;
                 bignum_init_unsigned(&const_val->data.x_bignum, value);
-                const_val->ok = true;
+                const_val->special = ConstValSpecialStatic;
                 break;
             }
         case CastOpIntToFloat:
             bignum_cast_to_float(&const_val->data.x_bignum, &other_val->data.x_bignum);
-            const_val->ok = true;
+            const_val->special = ConstValSpecialStatic;
             break;
         case CastOpFloatToInt:
             bignum_cast_to_int(&const_val->data.x_bignum, &other_val->data.x_bignum);
-            const_val->ok = true;
+            const_val->special = ConstValSpecialStatic;
             break;
         case CastOpBoolToInt:
             bignum_init_unsigned(&const_val->data.x_bignum, other_val->data.x_bool ? 1 : 0);
-            const_val->ok = true;
+            const_val->special = ConstValSpecialStatic;
             break;
         case CastOpIntToEnum:
             {
@@ -442,12 +363,12 @@ void eval_const_expr_implicit_cast(CastOp cast_op,
                 assert(value < new_type->data.enumeration.src_field_count);
                 const_val->data.x_enum.tag = value;
                 const_val->data.x_enum.payload = NULL;
-                const_val->ok = true;
+                const_val->special = ConstValSpecialStatic;
                 break;
             }
         case CastOpEnumToInt:
             bignum_init_unsigned(&const_val->data.x_bignum, other_val->data.x_enum.tag);
-            const_val->ok = true;
+            const_val->special = ConstValSpecialStatic;
             break;
     }
 }
@@ -465,7 +386,7 @@ static bool int_type_depends_on_compile_var(CodeGen *g, TypeTableEntry *int_type
 
 void eval_min_max_value(CodeGen *g, TypeTableEntry *type_entry, ConstExprValue *const_val, bool is_max) {
     if (type_entry->id == TypeTableEntryIdInt) {
-        const_val->ok = true;
+        const_val->special = ConstValSpecialStatic;
         const_val->depends_on_compile_var = int_type_depends_on_compile_var(g, type_entry);
         if (is_max) {
             if (type_entry->data.integral.is_signed) {
@@ -486,7 +407,7 @@ void eval_min_max_value(CodeGen *g, TypeTableEntry *type_entry, ConstExprValue *
     } else if (type_entry->id == TypeTableEntryIdFloat) {
         zig_panic("TODO analyze_min_max_value float");
     } else if (type_entry->id == TypeTableEntryIdBool) {
-        const_val->ok = true;
+        const_val->special = ConstValSpecialStatic;
         const_val->data.x_bool = is_max;
     } else {
         zig_unreachable();
src/ir.cpp
@@ -35,6 +35,18 @@ static IrInstruction *ir_gen_node_extra(IrBuilder *irb, AstNode *node, BlockCont
         LValPurpose lval);
 static TypeTableEntry *ir_analyze_instruction(IrAnalyze *ira, IrInstruction *instruction);
 
+ConstExprValue *const_ptr_pointee(ConstExprValue *const_val) {
+    ConstExprValue *base_ptr = const_val->data.x_ptr.base_ptr;
+    size_t index = const_val->data.x_ptr.index;
+
+    if (index == SIZE_MAX) {
+        return base_ptr;
+    } else {
+        assert(index < base_ptr->data.x_array.size);
+        return &base_ptr->data.x_array.elements[index];
+    }
+}
+
 static void ir_instruction_append(IrBasicBlock *basic_block, IrInstruction *instruction) {
     assert(basic_block);
     assert(instruction);
@@ -237,7 +249,7 @@ static IrInstruction *ir_build_cond_br(IrBuilder *irb, AstNode *source_node, IrI
 {
     IrInstructionCondBr *cond_br_instruction = ir_build_instruction<IrInstructionCondBr>(irb, source_node);
     cond_br_instruction->base.type_entry = irb->codegen->builtin_types.entry_unreachable;
-    cond_br_instruction->base.static_value.ok = true;
+    cond_br_instruction->base.static_value.special = ConstValSpecialStatic;
     cond_br_instruction->condition = condition;
     cond_br_instruction->then_block = then_block;
     cond_br_instruction->else_block = else_block;
@@ -262,7 +274,7 @@ static IrInstruction *ir_build_cond_br_from(IrBuilder *irb, IrInstruction *old_i
 static IrInstruction *ir_build_return(IrBuilder *irb, AstNode *source_node, IrInstruction *return_value) {
     IrInstructionReturn *return_instruction = ir_build_instruction<IrInstructionReturn>(irb, source_node);
     return_instruction->base.type_entry = irb->codegen->builtin_types.entry_unreachable;
-    return_instruction->base.static_value.ok = true;
+    return_instruction->base.static_value.special = ConstValSpecialStatic;
     return_instruction->value = return_value;
 
     ir_ref_instruction(return_value);
@@ -281,20 +293,19 @@ static IrInstruction *ir_build_return_from(IrBuilder *irb, IrInstruction *old_in
 static IrInstruction *ir_create_const(IrBuilder *irb, AstNode *source_node, TypeTableEntry *type_entry) {
     IrInstructionConst *const_instruction = ir_create_instruction<IrInstructionConst>(irb->exec, source_node);
     const_instruction->base.type_entry = type_entry;
-    const_instruction->base.static_value.ok = true;
+    const_instruction->base.static_value.special = ConstValSpecialStatic;
     return &const_instruction->base;
 }
 
 static IrInstruction *ir_build_const_void(IrBuilder *irb, AstNode *source_node) {
     IrInstructionConst *const_instruction = ir_build_instruction<IrInstructionConst>(irb, source_node);
     const_instruction->base.type_entry = irb->codegen->builtin_types.entry_void;
-    const_instruction->base.static_value.ok = true;
+    const_instruction->base.static_value.special = ConstValSpecialStatic;
     return &const_instruction->base;
 }
 
 static IrInstruction *ir_build_const_undefined(IrBuilder *irb, AstNode *source_node) {
     IrInstructionConst *const_instruction = ir_build_instruction<IrInstructionConst>(irb, source_node);
-    const_instruction->base.static_value.ok = true;
     const_instruction->base.static_value.special = ConstValSpecialUndef;
     const_instruction->base.type_entry = irb->codegen->builtin_types.entry_undef;
     return &const_instruction->base;
@@ -304,7 +315,7 @@ static IrInstruction *ir_build_const_bignum(IrBuilder *irb, AstNode *source_node
     IrInstructionConst *const_instruction = ir_build_instruction<IrInstructionConst>(irb, source_node);
     const_instruction->base.type_entry = (bignum->kind == BigNumKindInt) ?
         irb->codegen->builtin_types.entry_num_lit_int : irb->codegen->builtin_types.entry_num_lit_float;
-    const_instruction->base.static_value.ok = true;
+    const_instruction->base.static_value.special = ConstValSpecialStatic;
     const_instruction->base.static_value.data.x_bignum = *bignum;
     return &const_instruction->base;
 }
@@ -312,7 +323,7 @@ static IrInstruction *ir_build_const_bignum(IrBuilder *irb, AstNode *source_node
 static IrInstruction *ir_build_const_usize(IrBuilder *irb, AstNode *source_node, uint64_t value) {
     IrInstructionConst *const_instruction = ir_build_instruction<IrInstructionConst>(irb, source_node);
     const_instruction->base.type_entry = irb->codegen->builtin_types.entry_usize;
-    const_instruction->base.static_value.ok = true;
+    const_instruction->base.static_value.special = ConstValSpecialStatic;
     bignum_init_unsigned(&const_instruction->base.static_value.data.x_bignum, value);
     return &const_instruction->base;
 }
@@ -320,7 +331,7 @@ static IrInstruction *ir_build_const_usize(IrBuilder *irb, AstNode *source_node,
 static IrInstruction *ir_create_const_type(IrBuilder *irb, AstNode *source_node, TypeTableEntry *type_entry) {
     IrInstructionConst *const_instruction = ir_create_instruction<IrInstructionConst>(irb->exec, source_node);
     const_instruction->base.type_entry = irb->codegen->builtin_types.entry_type;
-    const_instruction->base.static_value.ok = true;
+    const_instruction->base.static_value.special = ConstValSpecialStatic;
     const_instruction->base.static_value.data.x_type = type_entry;
     return &const_instruction->base;
 }
@@ -334,7 +345,7 @@ static IrInstruction *ir_build_const_type(IrBuilder *irb, AstNode *source_node,
 static IrInstruction *ir_build_const_fn(IrBuilder *irb, AstNode *source_node, FnTableEntry *fn_entry) {
     IrInstructionConst *const_instruction = ir_build_instruction<IrInstructionConst>(irb, source_node);
     const_instruction->base.type_entry = fn_entry->type_entry;
-    const_instruction->base.static_value.ok = true;
+    const_instruction->base.static_value.special = ConstValSpecialStatic;
     const_instruction->base.static_value.data.x_fn = fn_entry;
     return &const_instruction->base;
 }
@@ -342,7 +353,7 @@ static IrInstruction *ir_build_const_fn(IrBuilder *irb, AstNode *source_node, Fn
 static IrInstruction *ir_build_const_generic_fn(IrBuilder *irb, AstNode *source_node, TypeTableEntry *fn_type) {
     IrInstructionConst *const_instruction = ir_build_instruction<IrInstructionConst>(irb, source_node);
     const_instruction->base.type_entry = fn_type;
-    const_instruction->base.static_value.ok = true;
+    const_instruction->base.static_value.special = ConstValSpecialStatic;
     const_instruction->base.static_value.data.x_type = fn_type;
     return &const_instruction->base;
 }
@@ -350,7 +361,7 @@ static IrInstruction *ir_build_const_generic_fn(IrBuilder *irb, AstNode *source_
 static IrInstruction *ir_build_const_import(IrBuilder *irb, AstNode *source_node, ImportTableEntry *import) {
     IrInstructionConst *const_instruction = ir_build_instruction<IrInstructionConst>(irb, source_node);
     const_instruction->base.type_entry = irb->codegen->builtin_types.entry_namespace;
-    const_instruction->base.static_value.ok = true;
+    const_instruction->base.static_value.special = ConstValSpecialStatic;
     const_instruction->base.static_value.data.x_import = import;
     return &const_instruction->base;
 }
@@ -358,7 +369,7 @@ static IrInstruction *ir_build_const_import(IrBuilder *irb, AstNode *source_node
 static IrInstruction *ir_build_const_scope(IrBuilder *irb, AstNode *source_node, BlockContext *scope) {
     IrInstructionConst *const_instruction = ir_build_instruction<IrInstructionConst>(irb, source_node);
     const_instruction->base.type_entry = irb->codegen->builtin_types.entry_block;
-    const_instruction->base.static_value.ok = true;
+    const_instruction->base.static_value.special = ConstValSpecialStatic;
     const_instruction->base.static_value.data.x_block = scope;
     return &const_instruction->base;
 }
@@ -366,7 +377,7 @@ static IrInstruction *ir_build_const_scope(IrBuilder *irb, AstNode *source_node,
 static IrInstruction *ir_build_const_bool(IrBuilder *irb, AstNode *source_node, bool value) {
     IrInstructionConst *const_instruction = ir_build_instruction<IrInstructionConst>(irb, source_node);
     const_instruction->base.type_entry = irb->codegen->builtin_types.entry_bool;
-    const_instruction->base.static_value.ok = true;
+    const_instruction->base.static_value.special = ConstValSpecialStatic;
     const_instruction->base.static_value.data.x_bool = value;
     return &const_instruction->base;
 }
@@ -377,45 +388,45 @@ static IrInstruction *ir_build_const_str_lit(IrBuilder *irb, AstNode *source_nod
     TypeTableEntry *type_entry = get_array_type(irb->codegen, u8_type, buf_len(str));
     const_instruction->base.type_entry = type_entry;
     ConstExprValue *const_val = &const_instruction->base.static_value;
-    const_val->ok = true;
-    const_val->data.x_array.fields = allocate<ConstExprValue*>(buf_len(str));
+    const_val->special = ConstValSpecialStatic;
+    const_val->data.x_array.elements = allocate<ConstExprValue>(buf_len(str));
+    const_val->data.x_array.size = buf_len(str);
 
-    ConstExprValue *all_chars = allocate<ConstExprValue>(buf_len(str));
     for (size_t i = 0; i < buf_len(str); i += 1) {
-        ConstExprValue *this_char = &all_chars[i];
-        this_char->ok = true;
+        ConstExprValue *this_char = &const_val->data.x_array.elements[i];
+        this_char->special = ConstValSpecialStatic;
         bignum_init_unsigned(&this_char->data.x_bignum, buf_ptr(str)[i]);
-        const_val->data.x_array.fields[i] = this_char;
     }
 
     return &const_instruction->base;
 }
 
 static IrInstruction *ir_build_const_c_str_lit(IrBuilder *irb, AstNode *source_node, Buf *str) {
-    IrInstructionConst *const_instruction = ir_build_instruction<IrInstructionConst>(irb, source_node);
-    TypeTableEntry *u8_type = irb->codegen->builtin_types.entry_u8;
-    TypeTableEntry *type_entry = get_pointer_to_type(irb->codegen, u8_type, true);
-    const_instruction->base.type_entry = type_entry;
-    ConstExprValue *const_val = &const_instruction->base.static_value;
-    const_val->ok = true;
-
+    // first we build the underlying array
     size_t len_with_null = buf_len(str) + 1;
-    const_val->data.x_ptr.ptr = allocate<ConstExprValue*>(len_with_null);
-    const_val->data.x_ptr.len = len_with_null;
-    const_val->data.x_ptr.is_c_str = true;
-
-    ConstExprValue *all_chars = allocate<ConstExprValue>(len_with_null);
+    ConstExprValue *array_val = allocate<ConstExprValue>(1);
+    array_val->special = ConstValSpecialStatic;
+    array_val->data.x_array.elements = allocate<ConstExprValue>(len_with_null);
+    array_val->data.x_array.size = len_with_null;
     for (size_t i = 0; i < buf_len(str); i += 1) {
-        ConstExprValue *this_char = &all_chars[i];
-        this_char->ok = true;
+        ConstExprValue *this_char = &array_val->data.x_array.elements[i];
+        this_char->special = ConstValSpecialStatic;
         bignum_init_unsigned(&this_char->data.x_bignum, buf_ptr(str)[i]);
-        const_val->data.x_ptr.ptr[i] = this_char;
     }
-
-    ConstExprValue *null_char = &all_chars[len_with_null - 1];
-    null_char->ok = true;
+    ConstExprValue *null_char = &array_val->data.x_array.elements[len_with_null - 1];
+    null_char->special = ConstValSpecialStatic;
     bignum_init_unsigned(&null_char->data.x_bignum, 0);
-    const_val->data.x_ptr.ptr[len_with_null - 1] = null_char;
+
+    // then make the pointer point to it
+    IrInstructionConst *const_instruction = ir_build_instruction<IrInstructionConst>(irb, source_node);
+    TypeTableEntry *u8_type = irb->codegen->builtin_types.entry_u8;
+    TypeTableEntry *type_entry = get_pointer_to_type(irb->codegen, u8_type, true);
+    const_instruction->base.type_entry = type_entry;
+    ConstExprValue *ptr_val = &const_instruction->base.static_value;
+    ptr_val->special = ConstValSpecialStatic;
+    ptr_val->data.x_ptr.base_ptr = array_val;
+    ptr_val->data.x_ptr.index = 0;
+    ptr_val->data.x_ptr.is_c_str = true;
 
     return &const_instruction->base;
 }
@@ -591,7 +602,7 @@ static IrInstruction *ir_build_phi_from(IrBuilder *irb, IrInstruction *old_instr
 static IrInstruction *ir_build_br(IrBuilder *irb, AstNode *source_node, IrBasicBlock *dest_block, bool is_inline) {
     IrInstructionBr *br_instruction = ir_build_instruction<IrInstructionBr>(irb, source_node);
     br_instruction->base.type_entry = irb->codegen->builtin_types.entry_unreachable;
-    br_instruction->base.static_value.ok = true;
+    br_instruction->base.static_value.special = ConstValSpecialStatic;
     br_instruction->dest_block = dest_block;
     br_instruction->is_inline = is_inline;
 
@@ -662,7 +673,7 @@ static IrInstruction *ir_build_container_init_fields(IrBuilder *irb, AstNode *so
 static IrInstruction *ir_build_unreachable(IrBuilder *irb, AstNode *source_node) {
     IrInstructionUnreachable *unreachable_instruction =
         ir_build_instruction<IrInstructionUnreachable>(irb, source_node);
-    unreachable_instruction->base.static_value.ok = true;
+    unreachable_instruction->base.static_value.special = ConstValSpecialStatic;
     unreachable_instruction->base.type_entry = irb->codegen->builtin_types.entry_unreachable;
     return &unreachable_instruction->base;
 }
@@ -677,7 +688,7 @@ static IrInstruction *ir_build_store_ptr(IrBuilder *irb, AstNode *source_node,
         IrInstruction *ptr, IrInstruction *value)
 {
     IrInstructionStorePtr *instruction = ir_build_instruction<IrInstructionStorePtr>(irb, source_node);
-    instruction->base.static_value.ok = true;
+    instruction->base.static_value.special = ConstValSpecialStatic;
     instruction->base.type_entry = irb->codegen->builtin_types.entry_void;
     instruction->ptr = ptr;
     instruction->value = value;
@@ -700,7 +711,7 @@ static IrInstruction *ir_build_var_decl(IrBuilder *irb, AstNode *source_node,
         VariableTableEntry *var, IrInstruction *var_type, IrInstruction *init_value)
 {
     IrInstructionDeclVar *decl_var_instruction = ir_build_instruction<IrInstructionDeclVar>(irb, source_node);
-    decl_var_instruction->base.static_value.ok = true;
+    decl_var_instruction->base.static_value.special = ConstValSpecialStatic;
     decl_var_instruction->base.type_entry = irb->codegen->builtin_types.entry_void;
     decl_var_instruction->var = var;
     decl_var_instruction->var_type = var_type;
@@ -1900,7 +1911,7 @@ static bool ir_num_lit_fits_in_other_type(IrAnalyze *ira, IrInstruction *instruc
     }
 
     ConstExprValue *const_val = &instruction->static_value;
-    assert(const_val->ok);
+    assert(const_val->special != ConstValSpecialRuntime);
     if (other_type_underlying->id == TypeTableEntryIdFloat) {
         return true;
     } else if (other_type_underlying->id == TypeTableEntryIdInt &&
@@ -2110,10 +2121,10 @@ static IrInstruction *ir_resolve_cast(IrAnalyze *ira, IrInstruction *source_inst
         IrInstruction *dest_type, CastOp cast_op, bool need_alloca)
 {
     assert(dest_type->type_entry->id == TypeTableEntryIdMetaType);
-    assert(dest_type->static_value.ok);
+    assert(dest_type->static_value.special != ConstValSpecialRuntime);
     TypeTableEntry *wanted_type = dest_type->static_value.data.x_type;
 
-    if (value->static_value.ok) {
+    if (value->static_value.special != ConstValSpecialRuntime) {
         IrInstruction *result = ir_create_const(&ira->new_irb, source_instr->source_node, wanted_type);
         eval_const_expr_implicit_cast(cast_op, &value->static_value, value->type_entry,
                 &result->static_value, wanted_type);
@@ -2194,7 +2205,7 @@ static ConstExprValue *ir_build_const_from(IrAnalyze *ira, IrInstruction *old_in
     }
     ir_link_new_instruction(new_instruction, old_instruction);
     ConstExprValue *const_val = &new_instruction->static_value;
-    const_val->ok = true;
+    const_val->special = ConstValSpecialStatic;
     const_val->depends_on_compile_var = depends_on_compile_var;
     return const_val;
 }
@@ -2226,7 +2237,7 @@ static TypeTableEntry *ir_resolve_type(IrAnalyze *ira, IrInstruction *type_value
     }
 
     ConstExprValue *const_val = &type_value->static_value;
-    if (!const_val->ok) {
+    if (const_val->special == ConstValSpecialRuntime) {
         add_node_error(ira->codegen, type_value->source_node,
                 buf_sprintf("unable to evaluate constant expression"));
         return ira->codegen->builtin_types.entry_invalid;
@@ -2249,7 +2260,7 @@ static bool ir_resolve_bool(IrAnalyze *ira, IrInstruction *bool_value, bool *out
     }
 
     ConstExprValue *const_val = &bool_value->static_value;
-    if (!const_val->ok) {
+    if (const_val->special == ConstValSpecialRuntime) {
         add_node_error(ira->codegen, bool_value->source_node,
                 buf_sprintf("unable to evaluate constant expression"));
         return false;
@@ -2273,7 +2284,7 @@ static FnTableEntry *ir_resolve_fn(IrAnalyze *ira, IrInstruction *fn_value) {
     }
 
     ConstExprValue *const_val = &fn_value->static_value;
-    if (!const_val->ok) {
+    if (const_val->special == ConstValSpecialRuntime) {
         add_node_error(ira->codegen, fn_value->source_node,
                 buf_sprintf("unable to evaluate constant expression"));
         return nullptr;
@@ -2286,7 +2297,7 @@ static IrInstruction *ir_analyze_cast(IrAnalyze *ira, IrInstruction *source_inst
     IrInstruction *dest_type, IrInstruction *value)
 {
     assert(dest_type->type_entry->id == TypeTableEntryIdMetaType);
-    assert(dest_type->static_value.ok);
+    assert(dest_type->static_value.special != ConstValSpecialRuntime);
 
     TypeTableEntry *wanted_type = dest_type->static_value.data.x_type;
     TypeTableEntry *actual_type = value->type_entry;
@@ -2618,7 +2629,7 @@ static TypeTableEntry *ir_analyze_bin_op_bool(IrAnalyze *ira, IrInstructionBinOp
 
     ConstExprValue *op1_val = &casted_op1->static_value;
     ConstExprValue *op2_val = &casted_op2->static_value;
-    if (op1_val->ok && op2_val->ok) {
+    if (op1_val->special != ConstValSpecialRuntime && op2_val->special != ConstValSpecialRuntime) {
         bool depends_on_compile_var = op1_val->depends_on_compile_var || op2_val->depends_on_compile_var;
         ConstExprValue *out_val = ir_build_const_from(ira, &bin_op_instruction->base, depends_on_compile_var);
 
@@ -2710,7 +2721,7 @@ static TypeTableEntry *ir_analyze_bin_op_cmp(IrAnalyze *ira, IrInstructionBinOp
 
     ConstExprValue *op1_val = &casted_op1->static_value;
     ConstExprValue *op2_val = &casted_op2->static_value;
-    if (op1_val->ok && op2_val->ok) {
+    if (op1_val->special != ConstValSpecialRuntime && op2_val->special != ConstValSpecialRuntime) {
         bool type_can_gt_lt_cmp = (resolved_type->id == TypeTableEntryIdNumLitFloat ||
                 resolved_type->id == TypeTableEntryIdNumLitInt ||
                 resolved_type->id == TypeTableEntryIdFloat ||
@@ -2799,7 +2810,7 @@ static int ir_eval_bignum(ConstExprValue *op1_val, ConstExprValue *op2_val,
         }
     }
 
-    out_val->ok = true;
+    out_val->special = ConstValSpecialStatic;
     out_val->depends_on_compile_var = op1_val->depends_on_compile_var || op2_val->depends_on_compile_var;
     return 0;
 }
@@ -2892,7 +2903,7 @@ static TypeTableEntry *ir_analyze_bin_op_math(IrAnalyze *ira, IrInstructionBinOp
         return ira->codegen->builtin_types.entry_invalid;
 
 
-    if (casted_op1->static_value.ok && casted_op2->static_value.ok) {
+    if (casted_op1->static_value.special != ConstValSpecialRuntime && casted_op2->static_value.special != ConstValSpecialRuntime) {
         ConstExprValue *op1_val = &casted_op1->static_value;
         ConstExprValue *op2_val = &casted_op2->static_value;
         ConstExprValue *out_val = &bin_op_instruction->base.static_value;
@@ -2992,7 +3003,7 @@ static TypeTableEntry *ir_analyze_instruction_decl_var(IrAnalyze *ira, IrInstruc
             break;
         case TypeTableEntryIdNumLitFloat:
         case TypeTableEntryIdNumLitInt:
-            if (is_export || is_extern || !casted_init_value->static_value.ok) {
+            if (is_export || is_extern || casted_init_value->static_value.special == ConstValSpecialRuntime) {
                 add_node_error(ira->codegen, var_type->source_node, buf_sprintf("unable to infer variable type"));
                 result_type = ira->codegen->builtin_types.entry_invalid;
             }
@@ -3006,7 +3017,7 @@ static TypeTableEntry *ir_analyze_instruction_decl_var(IrAnalyze *ira, IrInstruc
             break;
         case TypeTableEntryIdMetaType:
         case TypeTableEntryIdNamespace:
-            if (!casted_init_value->static_value.ok) {
+            if (casted_init_value->static_value.special == ConstValSpecialRuntime) {
                 add_node_error(ira->codegen, var_type->source_node,
                     buf_sprintf("variable of type '%s' must be constant", buf_ptr(&result_type->name)));
                 result_type = ira->codegen->builtin_types.entry_invalid;
@@ -3052,7 +3063,7 @@ static TypeTableEntry *ir_analyze_instruction_call(IrAnalyze *ira, IrInstruction
     if (fn_ref->type_entry->id == TypeTableEntryIdInvalid)
         return ira->codegen->builtin_types.entry_invalid;
 
-    if (fn_ref->static_value.ok) {
+    if (fn_ref->static_value.special != ConstValSpecialRuntime) {
         if (fn_ref->type_entry->id == TypeTableEntryIdMetaType) {
             size_t actual_param_count = call_instruction->arg_count;
 
@@ -3106,9 +3117,9 @@ static TypeTableEntry *ir_analyze_unary_bool_not(IrAnalyze *ira, IrInstructionUn
         return ira->codegen->builtin_types.entry_invalid;
 
     ConstExprValue *operand_val = &casted_value->static_value;
-    if (operand_val->ok) {
+    if (operand_val->special != ConstValSpecialRuntime) {
         ConstExprValue *result_val = &un_op_instruction->base.static_value;
-        result_val->ok = true;
+        result_val->special = ConstValSpecialStatic;
         result_val->depends_on_compile_var = operand_val->depends_on_compile_var;
         result_val->data.x_bool = !operand_val->data.x_bool;
         return bool_type;
@@ -3204,7 +3215,7 @@ static TypeTableEntry *ir_analyze_unary_address_of(IrAnalyze *ira, IrInstruction
             {
                 ConstExprValue *out_val = ir_build_const_from(ira, &un_op_instruction->base,
                         value->static_value.depends_on_compile_var);
-                assert(value->static_value.ok);
+                assert(value->static_value.special != ConstValSpecialRuntime);
                 TypeTableEntry *child_type = value->static_value.data.x_type;
                 out_val->data.x_type = get_pointer_to_type(ira->codegen, child_type, is_const);
                 return ira->codegen->builtin_types.entry_type;
@@ -3252,9 +3263,10 @@ static TypeTableEntry *ir_analyze_dereference(IrAnalyze *ira, IrInstructionUnOp
     // this dereference is always an rvalue because in the IR gen we identify lvalue and emit
     // one of the ptr instructions
 
-    if (value->static_value.ok) {
+    if (value->static_value.special != ConstValSpecialRuntime) {
         ConstExprValue *out_val = ir_build_const_from(ira, &un_op_instruction->base, false);
-        *out_val = *value->static_value.data.x_ptr.ptr[0];
+        ConstExprValue *pointee = const_ptr_pointee(&value->static_value);
+        *out_val = *pointee;
         return child_type;
     }
 
@@ -3428,7 +3440,7 @@ static TypeTableEntry *ir_analyze_instruction_cond_br(IrAnalyze *ira, IrInstruct
         return ir_finish_anal(ira, ira->codegen->builtin_types.entry_unreachable);
 
     // TODO detect backward jumps
-    if (condition->static_value.ok) {
+    if (condition->static_value.special != ConstValSpecialRuntime) {
         IrBasicBlock *old_dest_block = condition->static_value.data.x_bool ?
             cond_br_instruction->then_block : cond_br_instruction->else_block;
 
@@ -3463,7 +3475,7 @@ static TypeTableEntry *ir_analyze_instruction_phi(IrAnalyze *ira, IrInstructionP
                 continue;
             IrInstruction *value = phi_instruction->incoming_values[i]->other;
             assert(value->type_entry);
-            if (value->static_value.ok) {
+            if (value->static_value.special != ConstValSpecialRuntime) {
                 ConstExprValue *out_val = ir_build_const_from(ira, &phi_instruction->base,
                         value->static_value.depends_on_compile_var);
                 *out_val = value->static_value;
@@ -3523,17 +3535,16 @@ static TypeTableEntry *ir_analyze_instruction_var_ptr(IrAnalyze *ira, IrInstruct
     } else if (var->src_is_const) {
         AstNode *var_decl_node = var->decl_node;
         assert(var_decl_node->type == NodeTypeVariableDeclaration);
-        mem_slot = &get_resolved_expr(var_decl_node->data.variable_declaration.expr)->const_val;
-        assert(mem_slot->ok);
+        mem_slot = &get_resolved_expr(var_decl_node->data.variable_declaration.expr)->instruction->static_value;
+        assert(mem_slot->special != ConstValSpecialRuntime);
     }
 
-    if (mem_slot && mem_slot->ok) {
+    if (mem_slot && mem_slot->special != ConstValSpecialRuntime) {
         ConstExprValue *out_val = ir_build_const_from(ira, &var_ptr_instruction->base,
                 mem_slot->depends_on_compile_var);
 
-        out_val->data.x_ptr.len = 1;
-        out_val->data.x_ptr.ptr = allocate<ConstExprValue *>(1);
-        out_val->data.x_ptr.ptr[0] = mem_slot;
+        out_val->data.x_ptr.base_ptr = mem_slot;
+        out_val->data.x_ptr.index = SIZE_MAX;
         return ptr_type;
     } else {
         ir_build_var_ptr_from(&ira->new_irb, &var_ptr_instruction->base, var);
@@ -3577,7 +3588,7 @@ static TypeTableEntry *ir_analyze_instruction_elem_ptr(IrAnalyze *ira, IrInstruc
     if (casted_elem_index == ira->codegen->invalid_instruction)
         return ira->codegen->builtin_types.entry_invalid;
 
-    if (casted_elem_index->static_value.ok) {
+    if (casted_elem_index->static_value.special != ConstValSpecialRuntime) {
         uint64_t index = casted_elem_index->static_value.data.x_bignum.data.x_uint;
         if (array_type->id == TypeTableEntryIdArray) {
             uint64_t array_len = array_type->data.array.len;
@@ -3589,24 +3600,34 @@ static TypeTableEntry *ir_analyze_instruction_elem_ptr(IrAnalyze *ira, IrInstruc
             }
         }
 
-        if (array_ptr->static_value.ok) {
+        if (array_ptr->static_value.special != ConstValSpecialRuntime) {
             bool depends_on_compile_var = array_ptr->static_value.depends_on_compile_var ||
                 casted_elem_index->static_value.depends_on_compile_var;
             ConstExprValue *out_val = ir_build_const_from(ira, &elem_ptr_instruction->base, depends_on_compile_var);
-            out_val->data.x_ptr.len = 1;
-            out_val->data.x_ptr.ptr = allocate<ConstExprValue *>(1);
             if (array_type->id == TypeTableEntryIdPointer) {
-                uint64_t pointer_len = array_ptr->static_value.data.x_ptr.len;
-                if (index >= pointer_len) {
+                size_t offset = array_ptr->static_value.data.x_ptr.index;
+                size_t new_index;
+                size_t mem_size;
+                size_t old_size;
+                if (offset == SIZE_MAX) {
+                    new_index = SIZE_MAX;
+                    mem_size = 1;
+                    old_size = 1;
+                } else {
+                    new_index = offset + index;
+                    mem_size = array_ptr->static_value.data.x_ptr.base_ptr->data.x_array.size;
+                    old_size = mem_size - offset;
+                }
+                if (new_index >= mem_size) {
                     add_node_error(ira->codegen, elem_ptr_instruction->base.source_node,
-                        buf_sprintf("index %" PRIu64 " outside pointer of size %" PRIu64,
-                            index, pointer_len));
+                        buf_sprintf("index %" PRIu64 " outside pointer of size %" PRIu64, index, old_size));
                     return ira->codegen->builtin_types.entry_invalid;
                 }
-                out_val->data.x_ptr.ptr[0] = array_ptr->static_value.data.x_ptr.ptr[index];
+                out_val->data.x_ptr.base_ptr = array_ptr->static_value.data.x_ptr.base_ptr;
+                out_val->data.x_ptr.index = new_index;
             } else if (is_slice(array_type)) {
-                ConstExprValue *ptr_field = array_ptr->static_value.data.x_struct.fields[0];
-                ConstExprValue *len_field = array_ptr->static_value.data.x_struct.fields[1];
+                ConstExprValue *ptr_field = &array_ptr->static_value.data.x_struct.fields[slice_ptr_index];
+                ConstExprValue *len_field = &array_ptr->static_value.data.x_struct.fields[slice_len_index];
                 uint64_t slice_len = len_field->data.x_bignum.data.x_uint;
                 if (index >= slice_len) {
                     add_node_error(ira->codegen, elem_ptr_instruction->base.source_node,
@@ -3614,10 +3635,18 @@ static TypeTableEntry *ir_analyze_instruction_elem_ptr(IrAnalyze *ira, IrInstruc
                             index, slice_len));
                     return ira->codegen->builtin_types.entry_invalid;
                 }
-                assert(index < ptr_field->data.x_ptr.len);
-                out_val->data.x_ptr.ptr[0] = ptr_field->data.x_ptr.ptr[index];
+                out_val->data.x_ptr.base_ptr = ptr_field->data.x_ptr.base_ptr;
+                size_t offset = ptr_field->data.x_ptr.index;
+                if (offset == SIZE_MAX) {
+                    out_val->data.x_ptr.index = SIZE_MAX;
+                } else {
+                    uint64_t new_index = offset + index;
+                    assert(new_index < ptr_field->data.x_ptr.base_ptr->data.x_array.size);
+                    out_val->data.x_ptr.index = new_index;
+                }
             } else if (array_type->id == TypeTableEntryIdArray) {
-                out_val->data.x_ptr.ptr[0] = array_ptr->static_value.data.x_array.fields[index];
+                out_val->data.x_ptr.base_ptr = &array_ptr->static_value;
+                out_val->data.x_ptr.index = index;
             } else {
                 zig_unreachable();
             }
@@ -3790,9 +3819,9 @@ static TypeTableEntry *ir_analyze_instruction_load_ptr(IrAnalyze *ira, IrInstruc
         return type_entry;
     } else if (type_entry->id == TypeTableEntryIdPointer) {
         TypeTableEntry *child_type = type_entry->data.pointer.child_type;
-        if (ptr->static_value.ok) {
-            ConstExprValue *pointee = ptr->static_value.data.x_ptr.ptr[0];
-            if (pointee->ok) {
+        if (ptr->static_value.special != ConstValSpecialRuntime) {
+            ConstExprValue *pointee = const_ptr_pointee(&ptr->static_value);
+            if (pointee->special != ConstValSpecialRuntime) {
                 ConstExprValue *out_val = ir_build_const_from(ira, &load_ptr_instruction->base,
                         pointee->depends_on_compile_var);
                 *out_val = *pointee;
@@ -3823,18 +3852,20 @@ static TypeTableEntry *ir_analyze_instruction_store_ptr(IrAnalyze *ira, IrInstru
     if (casted_value == ira->codegen->invalid_instruction)
         return ira->codegen->builtin_types.entry_invalid;
 
-    if (ptr->static_value.ok && casted_value->static_value.ok) {
-        ConstExprValue *dest_val = ptr->static_value.data.x_ptr.ptr[0];
-        if (dest_val->ok) {
+    if (ptr->static_value.special != ConstValSpecialRuntime &&
+        casted_value->static_value.special != ConstValSpecialRuntime)
+    {
+        ConstExprValue *dest_val = const_ptr_pointee(&ptr->static_value);
+        if (dest_val->special != ConstValSpecialRuntime) {
             *dest_val = casted_value->static_value;
             return ir_analyze_void(ira, &store_ptr_instruction->base);
         }
     }
 
-    if (ptr->static_value.ok) {
+    if (ptr->static_value.special != ConstValSpecialRuntime) {
         // This memory location is transforming from known at compile time to known at runtime.
         // We must emit our own var ptr instruction.
-        ptr->static_value.ok = false;
+        ptr->static_value.special = ConstValSpecialRuntime;
         IrInstruction *new_ptr_inst;
         if (ptr->id == IrInstructionIdVarPtr) {
             IrInstructionVarPtr *var_ptr_inst = (IrInstructionVarPtr *)ptr;
@@ -3842,7 +3873,7 @@ static TypeTableEntry *ir_analyze_instruction_store_ptr(IrAnalyze *ira, IrInstru
             new_ptr_inst = ir_build_var_ptr(&ira->new_irb, store_ptr_instruction->base.source_node, var);
             assert(var->mem_slot_index != SIZE_MAX);
             ConstExprValue *mem_slot = &ira->exec_context.mem_slot_list[var->mem_slot_index];
-            mem_slot->ok = false;
+            mem_slot->special = ConstValSpecialRuntime;
         } else if (ptr->id == IrInstructionIdFieldPtr) {
             zig_panic("TODO");
         } else if (ptr->id == IrInstructionIdElemPtr) {
@@ -4236,7 +4267,7 @@ IrInstruction *ir_exec_const_result(IrExecutable *exec) {
 
     IrInstructionReturn *ret_inst = (IrInstructionReturn *)only_inst;
     IrInstruction *value = ret_inst->value;
-    assert(value->static_value.ok);
+    assert(value->static_value.special != ConstValSpecialRuntime);
     return value;
 }
 
src/ir.hpp
@@ -19,5 +19,6 @@ TypeTableEntry *ir_analyze(CodeGen *g, IrExecutable *old_executable, IrExecutabl
 IrInstruction *ir_exec_const_result(IrExecutable *exec);
 
 bool ir_has_side_effects(IrInstruction *instruction);
+ConstExprValue *const_ptr_pointee(ConstExprValue *const_val);
 
 #endif
src/ir_print.cpp
@@ -23,13 +23,15 @@ static void ir_print_prefix(IrPrint *irp, IrInstruction *instruction) {
 
 static void ir_print_const_value(IrPrint *irp, TypeTableEntry *type_entry, ConstExprValue *const_val) {
     switch (const_val->special) {
+        case ConstValSpecialRuntime:
+            zig_unreachable();
         case ConstValSpecialUndef:
             fprintf(irp->f, "undefined");
             return;
         case ConstValSpecialZeroes:
             fprintf(irp->f, "zeroes");
             return;
-        case ConstValSpecialOther:
+        case ConstValSpecialStatic:
             break;
     }
     switch (type_entry->id) {
@@ -70,7 +72,7 @@ static void ir_print_const_value(IrPrint *irp, TypeTableEntry *type_entry, Const
             }
         case TypeTableEntryIdPointer:
             fprintf(irp->f, "&");
-            ir_print_const_value(irp, type_entry->data.pointer.child_type, const_val->data.x_ptr.ptr[0]);
+            ir_print_const_value(irp, type_entry->data.pointer.child_type, const_ptr_pointee(const_val));
             break;
         case TypeTableEntryIdFn:
             {
@@ -91,7 +93,7 @@ static void ir_print_const_value(IrPrint *irp, TypeTableEntry *type_entry, Const
                 for (uint64_t i = 0; i < len; i += 1) {
                     if (i != 0)
                         fprintf(irp->f, ",");
-                    ConstExprValue *child_value = const_val->data.x_array.fields[i];
+                    ConstExprValue *child_value = &const_val->data.x_array.elements[i];
                     TypeTableEntry *child_type = type_entry->data.array.child_type;
                     ir_print_const_value(irp, child_type, child_value);
                 }
@@ -126,7 +128,7 @@ static void ir_print_var_instruction(IrPrint *irp, IrInstruction *instruction) {
 }
 
 static void ir_print_other_instruction(IrPrint *irp, IrInstruction *instruction) {
-    if (instruction->static_value.ok) {
+    if (instruction->static_value.special != ConstValSpecialRuntime) {
         ir_print_const_instruction(irp, instruction);
     } else {
         ir_print_var_instruction(irp, instruction);
src/parser.cpp
@@ -2763,7 +2763,6 @@ AstNode *ast_clone_subtree_special(AstNode *old_node, uint32_t *next_node_index,
                                  old_node->data.prefix_op_expr.primary_expr, next_node_index);
             break;
         case NodeTypeFnCallExpr:
-            assert(!old_node->data.fn_call_expr.resolved_expr.has_global_const);
             clone_subtree_field(&new_node->data.fn_call_expr.fn_ref_expr,
                                  old_node->data.fn_call_expr.fn_ref_expr, next_node_index);
             clone_subtree_list(&new_node->data.fn_call_expr.params,