Browse Source

Tuple support in codegen

gingerBill 9 years ago
parent
commit
153c27c755
9 changed files with 244 additions and 112 deletions
  1. 0 5
      examples/basic.odin
  2. 105 80
      examples/main.ll
  3. 11 0
      examples/main.odin
  4. 1 0
      src/checker/expr.cpp
  5. 25 15
      src/checker/type.cpp
  6. 2 0
      src/codegen/codegen.cpp
  7. 7 0
      src/codegen/print_llvm.cpp
  8. 80 10
      src/codegen/ssa.cpp
  9. 13 2
      src/parser.cpp

+ 0 - 5
examples/basic.odin

@@ -31,11 +31,6 @@ encode_rune :: proc(buf : []u8, r : rune) -> int {
 	if i > 0x0010ffff ||
 	   (i >= 0xd800 && i <= 0xdfff) {
 		r = 0xfffd;
-
-		buf[0] = 0xe0 | cast(u8)(r>>12);
-		buf[1] = 0x80 | cast(u8)(r>>6)&mask;
-		buf[2] = 0x80 | cast(u8)(r)&mask;
-		return 3;
 	}
 
 	if i <= 1<<16-1 {

+ 105 - 80
examples/main.ll

@@ -2,8 +2,56 @@
 
 %.rawptr = type i8* ; Basic_rawptr
 
+define {i64, i64} @tuple() {
+"entry - 0":
+	%0 = alloca {i64, i64}, align 8 
+	store {i64, i64} zeroinitializer, {i64, i64}* %0
+	%1 = getelementptr inbounds {i64, i64}, {i64, i64}* %0, i64 0, i32 0
+	store i64 1, i64* %1
+	%2 = getelementptr inbounds {i64, i64}, {i64, i64}* %0, i64 0, i32 1
+	store i64 2, i64* %2
+	%3 = load {i64, i64}, {i64, i64}* %0
+	ret {i64, i64} %3
+}
+
 define void @main() {
 "entry - 0":
+	%0 = alloca i64, align 8 ; a
+	store i64 zeroinitializer, i64* %0
+	%1 = alloca i64, align 8 ; b
+	store i64 zeroinitializer, i64* %1
+	%2 = call {i64, i64} @tuple()
+	%3 = alloca {i64, i64}, align 8 
+	store {i64, i64} zeroinitializer, {i64, i64}* %3
+	store {i64, i64} %2, {i64, i64}* %3
+	%4 = getelementptr inbounds {i64, i64}, {i64, i64}* %3, i64 0, i32 0
+	%5 = load i64, i64* %4
+	%6 = getelementptr inbounds {i64, i64}, {i64, i64}* %3, i64 0, i32 1
+	%7 = load i64, i64* %6
+	store i64 %5, i64* %0
+	store i64 %7, i64* %1
+	%8 = load i64, i64* %0
+	call void @print_int(i64 %8, i64 10)
+	%9 = getelementptr inbounds [1 x i8], [1 x i8]* @.str0, i64 0, i64 0
+	%10 = alloca %.string, align 8 
+	store %.string zeroinitializer, %.string* %10
+	%11 = getelementptr inbounds %.string, %.string* %10, i64 0, i32 0
+	%12 = getelementptr inbounds %.string, %.string* %10, i64 0, i32 1
+	store i8* %9, i8** %11
+	store i64 1, i64* %12
+	%13 = load %.string, %.string* %10
+	call void @print_string(%.string %13)
+	%14 = load i64, i64* %1
+	call void @print_int(i64 %14, i64 10)
+	%15 = getelementptr inbounds [1 x i8], [1 x i8]* @.str1, i64 0, i64 0
+	%16 = alloca %.string, align 8 
+	store %.string zeroinitializer, %.string* %16
+	%17 = getelementptr inbounds %.string, %.string* %16, i64 0, i32 0
+	%18 = getelementptr inbounds %.string, %.string* %16, i64 0, i32 1
+	store i8* %15, i8** %17
+	store i64 1, i64* %18
+	%19 = load %.string, %.string* %16
+	call void @print_string(%.string %19)
 	ret void
 }
 
@@ -167,62 +215,65 @@ define i64 @encode_rune({i8*, i64, i64} %buf, i32 %r) {
 
 "if.then - 5":
 	store i32 65533, i32* %1
-	%29 = getelementptr inbounds {i8*, i64, i64}, {i8*, i64, i64}* %0, i64 0, i32 0
-	%30 = load i8*, i8** %29
-	%31 = getelementptr i8, i8* %30, i64 0
-	%32 = load i32, i32* %1
-	%33 = lshr i32 %32, 12
-	%34 = trunc i32 %33 to i8
-	%35 = or i8 224, %34
-	store i8 %35, i8* %31
-	%36 = getelementptr inbounds {i8*, i64, i64}, {i8*, i64, i64}* %0, i64 0, i32 0
-	%37 = load i8*, i8** %36
-	%38 = getelementptr i8, i8* %37, i64 1
-	%39 = load i32, i32* %1
-	%40 = lshr i32 %39, 6
-	%41 = trunc i32 %40 to i8
-	%42 = and i8 %41, 63
-	%43 = or i8 128, %42
-	store i8 %43, i8* %38
-	%44 = getelementptr inbounds {i8*, i64, i64}, {i8*, i64, i64}* %0, i64 0, i32 0
-	%45 = load i8*, i8** %44
-	%46 = getelementptr i8, i8* %45, i64 2
-	%47 = load i32, i32* %1
-	%48 = trunc i32 %47 to i8
-	%49 = and i8 %48, 63
-	%50 = or i8 128, %49
-	store i8 %50, i8* %46
-	ret i64 3
+	br label %"if.done - 8"
 
 "cmp-or - 6":
-	%51 = load i32, i32* %2
-	%52 = icmp uge i32 %51, 55296
-	br i1 %52, label %"cmp-and - 7", label %"if.done - 8"
+	%29 = load i32, i32* %2
+	%30 = icmp uge i32 %29, 55296
+	br i1 %30, label %"cmp-and - 7", label %"if.done - 8"
 
 "cmp-and - 7":
-	%53 = load i32, i32* %2
-	%54 = icmp ule i32 %53, 57343
-	br i1 %54, label %"if.then - 5", label %"if.done - 8"
+	%31 = load i32, i32* %2
+	%32 = icmp ule i32 %31, 57343
+	br i1 %32, label %"if.then - 5", label %"if.done - 8"
 
 "if.done - 8":
-	%55 = load i32, i32* %2
-	%56 = icmp ule i32 %55, 65535
-	br i1 %56, label %"if.then - 9", label %"if.done - 10"
+	%33 = load i32, i32* %2
+	%34 = icmp ule i32 %33, 65535
+	br i1 %34, label %"if.then - 9", label %"if.done - 10"
 
 "if.then - 9":
+	%35 = getelementptr inbounds {i8*, i64, i64}, {i8*, i64, i64}* %0, i64 0, i32 0
+	%36 = load i8*, i8** %35
+	%37 = getelementptr i8, i8* %36, i64 0
+	%38 = load i32, i32* %1
+	%39 = lshr i32 %38, 12
+	%40 = trunc i32 %39 to i8
+	%41 = or i8 224, %40
+	store i8 %41, i8* %37
+	%42 = getelementptr inbounds {i8*, i64, i64}, {i8*, i64, i64}* %0, i64 0, i32 0
+	%43 = load i8*, i8** %42
+	%44 = getelementptr i8, i8* %43, i64 1
+	%45 = load i32, i32* %1
+	%46 = lshr i32 %45, 6
+	%47 = trunc i32 %46 to i8
+	%48 = and i8 %47, 63
+	%49 = or i8 128, %48
+	store i8 %49, i8* %44
+	%50 = getelementptr inbounds {i8*, i64, i64}, {i8*, i64, i64}* %0, i64 0, i32 0
+	%51 = load i8*, i8** %50
+	%52 = getelementptr i8, i8* %51, i64 2
+	%53 = load i32, i32* %1
+	%54 = trunc i32 %53 to i8
+	%55 = and i8 %54, 63
+	%56 = or i8 128, %55
+	store i8 %56, i8* %52
+	ret i64 3
+
+"if.done - 10":
 	%57 = getelementptr inbounds {i8*, i64, i64}, {i8*, i64, i64}* %0, i64 0, i32 0
 	%58 = load i8*, i8** %57
 	%59 = getelementptr i8, i8* %58, i64 0
 	%60 = load i32, i32* %1
-	%61 = lshr i32 %60, 12
+	%61 = lshr i32 %60, 18
 	%62 = trunc i32 %61 to i8
-	%63 = or i8 224, %62
+	%63 = or i8 240, %62
 	store i8 %63, i8* %59
 	%64 = getelementptr inbounds {i8*, i64, i64}, {i8*, i64, i64}* %0, i64 0, i32 0
 	%65 = load i8*, i8** %64
 	%66 = getelementptr i8, i8* %65, i64 1
 	%67 = load i32, i32* %1
-	%68 = lshr i32 %67, 6
+	%68 = lshr i32 %67, 12
 	%69 = trunc i32 %68 to i8
 	%70 = and i8 %69, 63
 	%71 = or i8 128, %70
@@ -231,47 +282,19 @@ define i64 @encode_rune({i8*, i64, i64} %buf, i32 %r) {
 	%73 = load i8*, i8** %72
 	%74 = getelementptr i8, i8* %73, i64 2
 	%75 = load i32, i32* %1
-	%76 = trunc i32 %75 to i8
-	%77 = and i8 %76, 63
-	%78 = or i8 128, %77
-	store i8 %78, i8* %74
-	ret i64 3
-
-"if.done - 10":
-	%79 = getelementptr inbounds {i8*, i64, i64}, {i8*, i64, i64}* %0, i64 0, i32 0
-	%80 = load i8*, i8** %79
-	%81 = getelementptr i8, i8* %80, i64 0
-	%82 = load i32, i32* %1
-	%83 = lshr i32 %82, 18
+	%76 = lshr i32 %75, 6
+	%77 = trunc i32 %76 to i8
+	%78 = and i8 %77, 63
+	%79 = or i8 128, %78
+	store i8 %79, i8* %74
+	%80 = getelementptr inbounds {i8*, i64, i64}, {i8*, i64, i64}* %0, i64 0, i32 0
+	%81 = load i8*, i8** %80
+	%82 = getelementptr i8, i8* %81, i64 3
+	%83 = load i32, i32* %1
 	%84 = trunc i32 %83 to i8
-	%85 = or i8 240, %84
-	store i8 %85, i8* %81
-	%86 = getelementptr inbounds {i8*, i64, i64}, {i8*, i64, i64}* %0, i64 0, i32 0
-	%87 = load i8*, i8** %86
-	%88 = getelementptr i8, i8* %87, i64 1
-	%89 = load i32, i32* %1
-	%90 = lshr i32 %89, 12
-	%91 = trunc i32 %90 to i8
-	%92 = and i8 %91, 63
-	%93 = or i8 128, %92
-	store i8 %93, i8* %88
-	%94 = getelementptr inbounds {i8*, i64, i64}, {i8*, i64, i64}* %0, i64 0, i32 0
-	%95 = load i8*, i8** %94
-	%96 = getelementptr i8, i8* %95, i64 2
-	%97 = load i32, i32* %1
-	%98 = lshr i32 %97, 6
-	%99 = trunc i32 %98 to i8
-	%100 = and i8 %99, 63
-	%101 = or i8 128, %100
-	store i8 %101, i8* %96
-	%102 = getelementptr inbounds {i8*, i64, i64}, {i8*, i64, i64}* %0, i64 0, i32 0
-	%103 = load i8*, i8** %102
-	%104 = getelementptr i8, i8* %103, i64 3
-	%105 = load i32, i32* %1
-	%106 = trunc i32 %105 to i8
-	%107 = and i8 %106, 63
-	%108 = or i8 128, %107
-	store i8 %108, i8* %104
+	%85 = and i8 %84, 63
+	%86 = or i8 128, %85
+	store i8 %86, i8* %82
 	ret i64 4
 }
 
@@ -384,7 +407,7 @@ define void @print_int(i64 %i, i64 %base) {
 "for.body - 5":
 	%16 = alloca i8, align 1 ; c
 	store i8 zeroinitializer, i8* %16
-	%17 = getelementptr inbounds [64 x i8], [64 x i8]* @.str0, i64 0, i64 0
+	%17 = getelementptr inbounds [64 x i8], [64 x i8]* @.str2, i64 0, i64 0
 	%18 = load i64, i64* %1
 	%19 = load i64, i64* %0
 	%20 = srem i64 %19, %18
@@ -466,4 +489,6 @@ define void @print_int(i64 %i, i64 %base) {
 	ret void
 }
 
[email protected] = global [64 x i8] c"0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz\40$"
[email protected] = global [1 x i8] c"\0A"
[email protected] = global [1 x i8] c"\0A"
[email protected] = global [64 x i8] c"0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz\40$"

+ 11 - 0
examples/main.odin

@@ -2,7 +2,18 @@ import "basic"
 
 TWO_HEARTS :: '💕';
 
+tuple :: proc() -> (int, int) {
+	return 1, 2;
+}
+
 main :: proc() {
+	a, b : int = tuple();
+
+	print_int(a, 10);
+	print_string("\n");
+	print_int(b, 10);
+	print_string("\n");
+
 /*
 	print_string("Chinese    - 你好世界\n");
 	print_string("Dutch      - Hello wereld\n");

+ 1 - 0
src/checker/expr.cpp

@@ -58,6 +58,7 @@ void check_struct_type(Checker *c, Type *struct_type, AstNode *node) {
 	}
 	struct_type->structure.fields = fields;
 	struct_type->structure.field_count = field_count;
+	struct_type->structure.is_packed = st->is_packed;
 }
 
 Type *check_get_params(Checker *c, Scope *scope, AstNode *field_list, isize field_count) {

+ 25 - 15
src/checker/type.cpp

@@ -103,6 +103,7 @@ struct Type {
 			isize    field_count; // == offset_count
 			i64 *    offsets;
 			b32      are_offsets_set;
+			b32      is_packed;
 		} structure;
 		struct { Type *elem; } pointer;
 		struct {
@@ -563,37 +564,46 @@ i64 type_align_of(BaseTypeSizes s, gbAllocator allocator, Type *t) {
 	} break;
 
 	case Type_Structure: {
-		i64 max = 1;
-		for (isize i = 0; i < t->structure.field_count; i++) {
-			i64 align = type_align_of(s, allocator, t->structure.fields[i]->type);
-			if (max < align)
-				max = align;
+		if (!t->structure.is_packed) {
+			i64 max = 1;
+			for (isize i = 0; i < t->structure.field_count; i++) {
+				i64 align = type_align_of(s, allocator, t->structure.fields[i]->type);
+				if (max < align)
+					max = align;
+			}
+			return max;
 		}
-		return max;
 	} break;
 	}
 
-	return gb_clamp(type_size_of(s, allocator, t), 1, s.max_align);
+	return gb_clamp(next_pow2(type_size_of(s, allocator, t)), 1, s.max_align);
 }
 
-i64 *type_set_offsets_of(BaseTypeSizes s, gbAllocator allocator, Entity **fields, isize field_count) {
+i64 *type_set_offsets_of(BaseTypeSizes s, gbAllocator allocator, Entity **fields, isize field_count, b32 is_packed) {
 	// TODO(bill): use arena allocation
 	i64 *offsets = gb_alloc_array(allocator, i64, field_count);
 	i64 curr_offset = 0;
-	for (isize i = 0; i < field_count; i++) {
-		i64 align = type_align_of(s, allocator, fields[i]->type);
-		curr_offset = align_formula(curr_offset, align);
-		offsets[i] = curr_offset;
-		curr_offset += type_size_of(s, allocator, fields[i]->type);
-	}
+	if (is_packed) {
+		for (isize i = 0; i < field_count; i++) {
+			offsets[i] = curr_offset;
+			curr_offset += type_size_of(s, allocator, fields[i]->type);
+		}
 
+	} else {
+		for (isize i = 0; i < field_count; i++) {
+			i64 align = type_align_of(s, allocator, fields[i]->type);
+			curr_offset = align_formula(curr_offset, align);
+			offsets[i] = curr_offset;
+			curr_offset += type_size_of(s, allocator, fields[i]->type);
+		}
+	}
 	return offsets;
 }
 
 b32 type_set_offsets(BaseTypeSizes s, gbAllocator allocator, Type *t) {
 	GB_ASSERT(t->kind == Type_Structure);
 	if (!t->structure.are_offsets_set) {
-		t->structure.offsets = type_set_offsets_of(s, allocator, t->structure.fields, t->structure.field_count);
+		t->structure.offsets = type_set_offsets_of(s, allocator, t->structure.fields, t->structure.field_count, t->structure.is_packed);
 		t->structure.are_offsets_set = true;
 		return true;
 	}

+ 2 - 0
src/codegen/codegen.cpp

@@ -81,6 +81,8 @@ void ssa_gen_code(ssaGen *s) {
 			ssa_build_proc(v);
 	}
 
+	// m->layout = make_string("e-p:64:64:64");
+
 	ssa_print_llvm_ir(&s->output_file, &s->module);
 }
 

+ 7 - 0
src/codegen/print_llvm.cpp

@@ -129,6 +129,9 @@ void ssa_print_type(gbFile *f, BaseTypeSizes s, Type *t) {
 		ssa_fprintf(f, "*, i%lld, i%lld}", word_bits, word_bits);
 		break;
 	case Type_Structure:
+		if (t->structure.is_packed) {
+			ssa_fprintf(f, "<");
+		}
 		ssa_fprintf(f, "{");
 		for (isize i = 0; i < t->structure.field_count; i++) {
 			if (i > 0) {
@@ -137,6 +140,10 @@ void ssa_print_type(gbFile *f, BaseTypeSizes s, Type *t) {
 			ssa_print_type(f, s, t->structure.fields[i]->type);
 		}
 		ssa_fprintf(f, "}");
+		if (t->structure.is_packed) {
+			ssa_fprintf(f, ">");
+		}
+
 		break;
 	case Type_Pointer:
 		ssa_print_type(f, s, t->pointer.elem);

+ 80 - 10
src/codegen/ssa.cpp

@@ -1244,6 +1244,11 @@ ssaValue *ssa_build_single_expr(ssaProcedure *proc, AstNode *expr, TypeAndValue
 		GB_PANIC("TODO(bill): ssa_build_single_expr ProcLit");
 	case_end;
 
+
+	case_ast_node(pl, CompoundLit, expr);
+		GB_PANIC("TODO(bill): ssa_build_single_expr CompoundLit");
+	case_end;
+
 	case_ast_node(ce, CastExpr, expr);
 		return ssa_emit_conv(proc, ssa_build_expr(proc, ce->expr), tv->type);
 	case_end;
@@ -1305,19 +1310,20 @@ ssaValue *ssa_build_single_expr(ssaProcedure *proc, AstNode *expr, TypeAndValue
 			ssaValue *a = ssa_build_expr(proc, arg);
 			Type *at = ssa_value_type(a);
 			if (at->kind == Type_Tuple) {
-				GB_PANIC("TODO(bill): tuple call arguments");
+				ssaValue *tuple = ssa_add_local_generated(proc, at);
+				ssa_emit_store(proc, tuple, a);
+				for (isize i = 0; i < at->tuple.variable_count; i++) {
+					Entity *e = at->tuple.variables[i];
+					ssaValue *index = ssa_make_value_constant(proc->module->allocator, t_i32, make_exact_value_integer(i));
+					ssaValue *v = ssa_emit_struct_gep(proc, tuple, index, e->type);
+					v = ssa_emit_load(proc, v);
+					args[arg_index++] = v;
+				}
 			} else {
 				args[arg_index++] = a;
 			}
 		}
 
-#if 0
-		for (isize i = 0; i < arg_count; i++) {
-			Entity *e = type->params->tuple.variables[i];
-			args[i] = ssa_emit_conv(proc, args[i], e->type);
-		}
-#endif
-
 		ssaValue *call = ssa_make_instr_call(proc, value, args, arg_count, tv->type);
 		ssa_value_set_type(call, proc_type_);
 		return ssa_emit(proc, call);
@@ -1569,7 +1575,46 @@ void ssa_build_stmt(ssaProcedure *proc, AstNode *node) {
 					}
 				}
 			} else { // Tuple(s)
-				GB_PANIC("TODO(bill): tuple assignment variable declaration");
+				gbArray(ssaLvalue)  lvals;
+				gbArray(ssaValue *) inits;
+				gb_array_init_reserve(lvals, gb_heap_allocator(), vd->name_count);
+				gb_array_init_reserve(inits, gb_heap_allocator(), vd->name_count);
+				defer (gb_array_free(lvals));
+				defer (gb_array_free(inits));
+
+				for (AstNode *name = vd->name_list; name != NULL; name = name->next) {
+					ssaLvalue lval = {ssaLvalue_Blank};
+					if (!ssa_is_blank_ident(name)) {
+						ssa_add_local_for_identifier(proc, name);
+						lval = ssa_build_addr(proc, name);
+					}
+
+					gb_array_append(lvals, lval);
+				}
+
+				for (AstNode *value = vd->value_list; value != NULL; value = value->next) {
+					ssaValue *init = ssa_build_expr(proc, value);
+					Type *t = ssa_value_type(init);
+					if (t->kind == Type_Tuple) {
+						ssaValue *tuple = ssa_add_local_generated(proc, t);
+						ssa_emit_store(proc, tuple, init);
+						for (isize i = 0; i < t->tuple.variable_count; i++) {
+							Entity *e = t->tuple.variables[i];
+							ssaValue *index = ssa_make_value_constant(proc->module->allocator, t_i32, make_exact_value_integer(i));
+							ssaValue *v = ssa_emit_struct_gep(proc, tuple, index, e->type);
+							v = ssa_emit_load(proc, v);
+							gb_array_append(inits, v);
+						}
+					} else {
+						gb_array_append(inits, init);
+					}
+				}
+
+
+				gb_for_array(i, inits) {
+					ssaValue *v = ssa_emit_conv(proc, inits[i], ssa_lvalue_type(lvals[i]));
+					ssa_lvalue_store(lvals[i], proc, v);
+				}
 			}
 		}
 	case_end;
@@ -1624,7 +1669,32 @@ void ssa_build_stmt(ssaProcedure *proc, AstNode *node) {
 					}
 				}
 			} else {
-				GB_PANIC("TODO(bill): tuple assignment");
+				gbArray(ssaValue *) inits;
+				gb_array_init_reserve(inits, gb_heap_allocator(), gb_array_count(lvals));
+				defer (gb_array_free(inits));
+
+				for (AstNode *rhs = as->rhs_list; rhs != NULL; rhs = rhs->next) {
+					ssaValue *init = ssa_build_expr(proc, rhs);
+					Type *t = ssa_value_type(init);
+					// TODO(bill): refactor for code reuse as this is repeated a bit
+					if (t->kind == Type_Tuple) {
+						ssaValue *tuple = ssa_add_local_generated(proc, t);
+						ssa_emit_store(proc, tuple, init);
+						for (isize i = 0; i < t->tuple.variable_count; i++) {
+							Entity *e = t->tuple.variables[i];
+							ssaValue *index = ssa_make_value_constant(proc->module->allocator, t_i32, make_exact_value_integer(i));
+							ssaValue *v = ssa_emit_struct_gep(proc, tuple, index, e->type);
+							v = ssa_emit_load(proc, v);
+							gb_array_append(inits, v);
+						}
+					} else {
+						gb_array_append(inits, init);
+					}
+				}
+
+				gb_for_array(i, inits) {
+					ssa_lvalue_store(lvals[i], proc, inits[i]);
+				}
 			}
 
 		} break;

+ 13 - 2
src/parser.cpp

@@ -206,6 +206,7 @@ AST_NODE_KIND(_TypeBegin, struct{}) \
 		Token token; \
 		AstNode *field_list; \
 		isize field_count; \
+		b32 is_packed; \
 	}) \
 AST_NODE_KIND(_TypeEnd, struct{}) \
 	AST_NODE_KIND(Count, struct{})
@@ -740,11 +741,12 @@ gb_inline AstNode *make_vector_type(AstFile *f, Token token, AstNode *count, Ast
 	return result;
 }
 
-gb_inline AstNode *make_struct_type(AstFile *f, Token token, AstNode *field_list, isize field_count) {
+gb_inline AstNode *make_struct_type(AstFile *f, Token token, AstNode *field_list, isize field_count, b32 is_packed) {
 	AstNode *result = make_node(f, AstNode_StructType);
 	result->StructType.token = token;
 	result->StructType.field_list = field_list;
 	result->StructType.field_count = field_count;
+	result->StructType.is_packed = is_packed;
 	return result;
 }
 
@@ -1491,12 +1493,21 @@ AstNode *parse_identifier_or_type(AstFile *f) {
 		AstNode *params = NULL;
 		isize param_count = 0;
 		AstScope *scope = make_ast_scope(f, NULL); // NOTE(bill): The struct needs its own scope with NO parent
+		b32 is_packed = false;
+		if (allow_token(f, Token_Hash)) {
+			Token tag = expect_token(f, Token_Identifier);
+			if (are_strings_equal(tag.string, make_string("packed"))) {
+				is_packed = true;
+			} else {
+				ast_file_err(f, tag, "Expected a `#packed` tag");
+			}
+		}
 
 		open   = expect_token(f, Token_OpenBrace);
 		params = parse_parameter_list(f, scope, &param_count);
 		close  = expect_token(f, Token_CloseBrace);
 
-		return make_struct_type(f, token, params, param_count);
+		return make_struct_type(f, token, params, param_count, is_packed);
 	}
 
 	case Token_proc: