Merge branch 'align'

1 files changed, 61 insertions, 34 deletions

diff --git a/src/analyze.cpp b/src/analyze.cpp
index 0b43f2d1e4..3b4b933081 100644
--- a/src/analyze.cpp
+++ b/src/analyze.cpp
@@ -1245,9 +1245,10 @@ static void resolve_enum_type(CodeGen *g, TypeTableEntry *enum_type) {
     uint32_t gen_field_count = enum_type->data.enumeration.gen_field_count;
     ZigLLVMDIType **union_inner_di_types = allocate<ZigLLVMDIType*>(gen_field_count);
 
-    TypeTableEntry *biggest_union_member = nullptr;
+    TypeTableEntry *most_aligned_union_member = nullptr;
+    uint64_t size_of_most_aligned_member_in_bits = 0;
     uint64_t biggest_align_in_bits = 0;
-    uint64_t biggest_union_member_size_in_bits = 0;
+    uint64_t biggest_size_in_bits = 0;
 
     Scope *scope = &enum_type->data.enumeration.decls_scope->base;
     ImportTableEntry *import = get_scope_import(scope);
@@ -1271,27 +1272,28 @@ static void resolve_enum_type(CodeGen *g, TypeTableEntry *enum_type) {
         if (!type_has_bits(field_type))
             continue;
 
-        uint64_t debug_size_in_bits = 8*LLVMStoreSizeOfType(g->target_data_ref, field_type->type_ref);
-        uint64_t debug_align_in_bits = 8*LLVMABISizeOfType(g->target_data_ref, field_type->type_ref);
+        uint64_t store_size_in_bits = 8*LLVMStoreSizeOfType(g->target_data_ref, field_type->type_ref);
+        uint64_t preferred_align_in_bits = 8*LLVMPreferredAlignmentOfType(g->target_data_ref, field_type->type_ref);
 
-        assert(debug_size_in_bits > 0);
-        assert(debug_align_in_bits > 0);
+        assert(store_size_in_bits > 0);
+        assert(preferred_align_in_bits > 0);
 
         union_inner_di_types[type_enum_field->gen_index] = ZigLLVMCreateDebugMemberType(g->dbuilder,
                 ZigLLVMTypeToScope(enum_type->di_type), buf_ptr(type_enum_field->name),
                 import->di_file, (unsigned)(field_node->line + 1),
-                debug_size_in_bits,
-                debug_align_in_bits,
+                store_size_in_bits,
+                preferred_align_in_bits,
                 0,
                 0, field_type->di_type);
 
-        biggest_align_in_bits = max(biggest_align_in_bits, debug_align_in_bits);
+        biggest_size_in_bits = max(biggest_size_in_bits, store_size_in_bits);
 
-        if (!biggest_union_member ||
-            debug_size_in_bits > biggest_union_member_size_in_bits)
+        if (!most_aligned_union_member ||
+            preferred_align_in_bits > biggest_align_in_bits)
         {
-            biggest_union_member = field_type;
-            biggest_union_member_size_in_bits = debug_size_in_bits;
+            most_aligned_union_member = field_type;
+            biggest_align_in_bits = preferred_align_in_bits;
+            size_of_most_aligned_member_in_bits = store_size_in_bits;
         }
     }
 
@@ -1300,27 +1302,52 @@ static void resolve_enum_type(CodeGen *g, TypeTableEntry *enum_type) {
     enum_type->data.enumeration.complete = true;
 
     if (!enum_type->data.enumeration.is_invalid) {
-        enum_type->data.enumeration.union_type = biggest_union_member;
-
         TypeTableEntry *tag_int_type = get_smallest_unsigned_int_type(g, field_count);
         TypeTableEntry *tag_type_entry = create_enum_tag_type(g, enum_type, tag_int_type);
         enum_type->data.enumeration.tag_type = tag_type_entry;
 
-        if (biggest_union_member) {
+        uint64_t align_of_tag_in_bits = 8*LLVMPreferredAlignmentOfType(g->target_data_ref, tag_int_type->type_ref);
+
+        if (most_aligned_union_member) {
             // create llvm type for union
-            LLVMTypeRef union_element_type = biggest_union_member->type_ref;
-            LLVMTypeRef union_type_ref = LLVMStructType(&union_element_type, 1, false);
+            uint64_t padding_in_bits = biggest_size_in_bits - size_of_most_aligned_member_in_bits;
+            LLVMTypeRef union_type_ref;
+            if (padding_in_bits > 0) {
+                TypeTableEntry *u8_type = get_int_type(g, false, 8);
+                TypeTableEntry *padding_array = get_array_type(g, u8_type, padding_in_bits / 8);
+                LLVMTypeRef union_element_types[] = {
+                    most_aligned_union_member->type_ref,
+                    padding_array->type_ref,
+                };
+                union_type_ref = LLVMStructType(union_element_types, 2, false);
+            } else {
+                LLVMTypeRef union_element_types[] = {
+                    most_aligned_union_member->type_ref,
+                };
+                union_type_ref = LLVMStructType(union_element_types, 1, false);
+            }
+            enum_type->data.enumeration.union_type_ref = union_type_ref;
+
+            assert(8*LLVMPreferredAlignmentOfType(g->target_data_ref, union_type_ref) >= biggest_align_in_bits);
+            assert(8*LLVMStoreSizeOfType(g->target_data_ref, union_type_ref) >= biggest_size_in_bits);
+
+            if (align_of_tag_in_bits >= biggest_align_in_bits) {
+                enum_type->data.enumeration.gen_tag_index = 0;
+                enum_type->data.enumeration.gen_union_index = 1;
+            } else {
+                enum_type->data.enumeration.gen_union_index = 0;
+                enum_type->data.enumeration.gen_tag_index = 1;
+            }
 
             // create llvm type for root struct
-            LLVMTypeRef root_struct_element_types[] = {
-                tag_type_entry->type_ref,
-                union_type_ref,
-            };
+            LLVMTypeRef root_struct_element_types[2];
+            root_struct_element_types[enum_type->data.enumeration.gen_tag_index] = tag_type_entry->type_ref;
+            root_struct_element_types[enum_type->data.enumeration.gen_union_index] = union_type_ref;
             LLVMStructSetBody(enum_type->type_ref, root_struct_element_types, 2, false);
 
             // create debug type for tag
             uint64_t tag_debug_size_in_bits = 8*LLVMStoreSizeOfType(g->target_data_ref, tag_type_entry->type_ref);
-            uint64_t tag_debug_align_in_bits = 8*LLVMABISizeOfType(g->target_data_ref, tag_type_entry->type_ref);
+            uint64_t tag_debug_align_in_bits = 8*LLVMPreferredAlignmentOfType(g->target_data_ref, tag_type_entry->type_ref);
             ZigLLVMDIType *tag_di_type = ZigLLVMCreateDebugEnumerationType(g->dbuilder,
                     ZigLLVMTypeToScope(enum_type->di_type), "AnonEnum",
                     import->di_file, (unsigned)(decl_node->line + 1),
@@ -1331,11 +1358,12 @@ static void resolve_enum_type(CodeGen *g, TypeTableEntry *enum_type) {
             ZigLLVMDIType *union_di_type = ZigLLVMCreateDebugUnionType(g->dbuilder,
                     ZigLLVMTypeToScope(enum_type->di_type), "AnonUnion",
                     import->di_file, (unsigned)(decl_node->line + 1),
-                    biggest_union_member_size_in_bits, biggest_align_in_bits, 0, union_inner_di_types,
+                    biggest_size_in_bits, biggest_align_in_bits, 0, union_inner_di_types,
                     gen_field_count, 0, "");
 
             // create debug types for members of root struct
-            uint64_t tag_offset_in_bits = 8*LLVMOffsetOfElement(g->target_data_ref, enum_type->type_ref, 0);
+            uint64_t tag_offset_in_bits = 8*LLVMOffsetOfElement(g->target_data_ref, enum_type->type_ref,
+                    enum_type->data.enumeration.gen_tag_index);
             ZigLLVMDIType *tag_member_di_type = ZigLLVMCreateDebugMemberType(g->dbuilder,
                     ZigLLVMTypeToScope(enum_type->di_type), "tag_field",
                     import->di_file, (unsigned)(decl_node->line + 1),
@@ -1344,21 +1372,20 @@ static void resolve_enum_type(CodeGen *g, TypeTableEntry *enum_type) {
                     tag_offset_in_bits,
                     0, tag_di_type);
 
-            uint64_t union_offset_in_bits = 8*LLVMOffsetOfElement(g->target_data_ref, enum_type->type_ref, 1);
+            uint64_t union_offset_in_bits = 8*LLVMOffsetOfElement(g->target_data_ref, enum_type->type_ref,
+                    enum_type->data.enumeration.gen_union_index);
             ZigLLVMDIType *union_member_di_type = ZigLLVMCreateDebugMemberType(g->dbuilder,
                     ZigLLVMTypeToScope(enum_type->di_type), "union_field",
                     import->di_file, (unsigned)(decl_node->line + 1),
-                    biggest_union_member_size_in_bits,
+                    biggest_size_in_bits,
                     biggest_align_in_bits,
                     union_offset_in_bits,
                     0, union_di_type);
 
             // create debug type for root struct
-            ZigLLVMDIType *di_root_members[] = {
-                tag_member_di_type,
-                union_member_di_type,
-            };
-
+            ZigLLVMDIType *di_root_members[2];
+            di_root_members[enum_type->data.enumeration.gen_tag_index] = tag_member_di_type;
+            di_root_members[enum_type->data.enumeration.gen_union_index] = union_member_di_type;
 
             uint64_t debug_size_in_bits = 8*LLVMStoreSizeOfType(g->target_data_ref, enum_type->type_ref);
             uint64_t debug_align_in_bits = 8*LLVMABISizeOfType(g->target_data_ref, enum_type->type_ref);
@@ -1378,7 +1405,7 @@ static void resolve_enum_type(CodeGen *g, TypeTableEntry *enum_type) {
 
             // create debug type for tag
             uint64_t tag_debug_size_in_bits = 8*LLVMStoreSizeOfType(g->target_data_ref, tag_type_entry->type_ref);
-            uint64_t tag_debug_align_in_bits = 8*LLVMABISizeOfType(g->target_data_ref, tag_type_entry->type_ref);
+            uint64_t tag_debug_align_in_bits = 8*LLVMPreferredAlignmentOfType(g->target_data_ref, tag_type_entry->type_ref);
             ZigLLVMDIType *tag_di_type = ZigLLVMCreateDebugEnumerationType(g->dbuilder,
                     ZigLLVMFileToScope(import->di_file), buf_ptr(&enum_type->name),
                     import->di_file, (unsigned)(decl_node->line + 1),
@@ -2541,7 +2568,7 @@ bool types_match_const_cast_only(TypeTableEntry *expected_type, TypeTableEntry *
         if (expected_type->data.fn.is_generic != actual_type->data.fn.is_generic) {
             return false;
         }
-        if (!expected_type->data.fn.is_generic && 
+        if (!expected_type->data.fn.is_generic &&
             actual_type->data.fn.fn_type_id.return_type->id != TypeTableEntryIdUnreachable &&
             !types_match_const_cast_only(
                 expected_type->data.fn.fn_type_id.return_type,