Builder: Implement StrtabString and use it for Global names

src/codegen/llvm.zig

@@ -1046,7 +1046,7 @@ pub const Object = struct {
 
     fn genCmpLtErrorsLenFunction(o: *Object) !void {
         // If there is no such function in the module, it means the source code does not need it.
-        const name = o.builder.stringIfExists(lt_errors_fn_name) orelse return;
+        const name = o.builder.strtabStringIfExists(lt_errors_fn_name) orelse return;
         const llvm_fn = o.builder.getGlobal(name) orelse return;
         const mod = o.module;
         const errors_len = mod.global_error_set.count();
@@ -1087,7 +1087,7 @@ pub const Object = struct {
         for (object.extern_collisions.keys()) |decl_index| {
             const global = object.decl_map.get(decl_index) orelse continue;
             // Same logic as below but for externs instead of exports.
-            const decl_name = object.builder.stringIfExists(mod.intern_pool.stringToSlice(mod.declPtr(decl_index).name)) orelse continue;
+            const decl_name = object.builder.strtabStringIfExists(mod.intern_pool.stringToSlice(mod.declPtr(decl_index).name)) orelse continue;
             const other_global = object.builder.getGlobal(decl_name) orelse continue;
             if (other_global.toConst().getBase(&object.builder) ==
                 global.toConst().getBase(&object.builder)) continue;
@@ -1117,7 +1117,7 @@ pub const Object = struct {
         for (export_list) |exp| {
             // Detect if the LLVM global has already been created as an extern. In such
             // case, we need to replace all uses of it with this exported global.
-            const exp_name = object.builder.stringIfExists(mod.intern_pool.stringToSlice(exp.opts.name)) orelse continue;
+            const exp_name = object.builder.strtabStringIfExists(mod.intern_pool.stringToSlice(exp.opts.name)) orelse continue;
 
             const other_global = object.builder.getGlobal(exp_name) orelse continue;
             if (other_global.toConst().getBase(&object.builder) == global_base) continue;
@@ -1662,7 +1662,7 @@ pub const Object = struct {
             const subprogram = try o.builder.debugSubprogram(
                 file,
                 try o.builder.metadataString(ip.stringToSlice(decl.name)),
-                try o.builder.metadataStringFromString(function_index.name(&o.builder)),
+                try o.builder.metadataStringFromStrtabString(function_index.name(&o.builder)),
                 line_number,
                 line_number + func.lbrace_line,
                 debug_decl_type,
@@ -1763,12 +1763,12 @@ pub const Object = struct {
                 if (mod.getTarget().isWasm() and try decl.isFunction(mod)) {
                     if (mod.intern_pool.stringToSliceUnwrap(decl.getOwnedExternFunc(mod).?.lib_name)) |lib_name| {
                         if (!std.mem.eql(u8, lib_name, "c")) {
-                            break :decl_name try self.builder.fmt("{s}|{s}", .{ decl_name, lib_name });
+                            break :decl_name try self.builder.strtabStringFmt("{s}|{s}", .{ decl_name, lib_name });
                         }
                     }
                 }
 
-                break :decl_name try self.builder.string(decl_name);
+                break :decl_name try self.builder.strtabString(decl_name);
             };
 
             if (self.builder.getGlobal(decl_name)) |other_global| {
@@ -1791,7 +1791,7 @@ pub const Object = struct {
                 if (decl_var.is_weak_linkage) global_index.setLinkage(.extern_weak, &self.builder);
             }
         } else if (exports.len != 0) {
-            const main_exp_name = try self.builder.string(
+            const main_exp_name = try self.builder.strtabString(
                 mod.intern_pool.stringToSlice(exports[0].opts.name),
             );
             try global_index.rename(main_exp_name, &self.builder);
@@ -1802,7 +1802,7 @@ pub const Object = struct {
 
             return updateExportedGlobal(self, mod, global_index, exports);
         } else {
-            const fqn = try self.builder.string(
+            const fqn = try self.builder.strtabString(
                 mod.intern_pool.stringToSlice(try decl.fullyQualifiedName(mod)),
             );
             try global_index.rename(fqn, &self.builder);
@@ -1831,7 +1831,7 @@ pub const Object = struct {
         exports: []const *Module.Export,
     ) link.File.UpdateExportsError!void {
         const gpa = mod.gpa;
-        const main_exp_name = try o.builder.string(
+        const main_exp_name = try o.builder.strtabString(
             mod.intern_pool.stringToSlice(exports[0].opts.name),
         );
         const global_index = i: {
@@ -1899,7 +1899,7 @@ pub const Object = struct {
         // Until then we iterate over existing aliases and make them point
         // to the correct decl, or otherwise add a new alias. Old aliases are leaked.
         for (exports[1..]) |exp| {
-            const exp_name = try o.builder.string(mod.intern_pool.stringToSlice(exp.opts.name));
+            const exp_name = try o.builder.strtabString(mod.intern_pool.stringToSlice(exp.opts.name));
             if (o.builder.getGlobal(exp_name)) |global| {
                 switch (global.ptrConst(&o.builder).kind) {
                     .alias => |alias| {
@@ -2887,7 +2887,7 @@ pub const Object = struct {
         const is_extern = decl.isExtern(zcu);
         const function_index = try o.builder.addFunction(
             try o.lowerType(zig_fn_type),
-            try o.builder.string(ip.stringToSlice(if (is_extern)
+            try o.builder.strtabString(ip.stringToSlice(if (is_extern)
                 decl.name
             else
                 try decl.fullyQualifiedName(zcu))),
@@ -3077,7 +3077,7 @@ pub const Object = struct {
         const decl_ty = mod.intern_pool.typeOf(decl_val);
 
         const variable_index = try o.builder.addVariable(
-            try o.builder.fmt("__anon_{d}", .{@intFromEnum(decl_val)}),
+            try o.builder.strtabStringFmt("__anon_{d}", .{@intFromEnum(decl_val)}),
             try o.lowerType(Type.fromInterned(decl_ty)),
             llvm_addr_space,
         );
@@ -3103,7 +3103,7 @@ pub const Object = struct {
         const is_extern = decl.isExtern(mod);
 
         const variable_index = try o.builder.addVariable(
-            try o.builder.string(mod.intern_pool.stringToSlice(
+            try o.builder.strtabString(mod.intern_pool.stringToSlice(
                 if (is_extern) decl.name else try decl.fullyQualifiedName(mod),
             )),
             try o.lowerType(decl.ty),
@@ -4570,7 +4570,7 @@ pub const Object = struct {
     }
 
     fn getCmpLtErrorsLenFunction(o: *Object) !Builder.Function.Index {
-        const name = try o.builder.string(lt_errors_fn_name);
+        const name = try o.builder.strtabString(lt_errors_fn_name);
         if (o.builder.getGlobal(name)) |llvm_fn| return llvm_fn.ptrConst(&o.builder).kind.function;
 
         const zcu = o.module;
@@ -4607,7 +4607,7 @@ pub const Object = struct {
         const target = zcu.root_mod.resolved_target.result;
         const function_index = try o.builder.addFunction(
             try o.builder.fnType(ret_ty, &.{try o.lowerType(Type.fromInterned(enum_type.tag_ty))}, .normal),
-            try o.builder.fmt("__zig_tag_name_{}", .{fqn.fmt(ip)}),
+            try o.builder.strtabStringFmt("__zig_tag_name_{}", .{fqn.fmt(ip)}),
             toLlvmAddressSpace(.generic, target),
         );
 
@@ -4730,7 +4730,7 @@ pub const DeclGen = struct {
 
             const debug_global_var = try o.builder.debugGlobalVar(
                 try o.builder.metadataString(zcu.intern_pool.stringToSlice(decl.name)), // Name
-                try o.builder.metadataStringFromString(variable_index.name(&o.builder)), // Linkage name
+                try o.builder.metadataStringFromStrtabString(variable_index.name(&o.builder)), // Linkage name
                 debug_file, // File
                 debug_file, // Scope
                 line_number,
@@ -6169,7 +6169,7 @@ pub const FuncGen = struct {
         const compiler_rt_operand_abbrev = compilerRtIntAbbrev(rt_int_bits);
         const compiler_rt_dest_abbrev = compilerRtFloatAbbrev(dest_bits);
         const sign_prefix = if (is_signed_int) "" else "un";
-        const fn_name = try o.builder.fmt("__float{s}{s}i{s}f", .{
+        const fn_name = try o.builder.strtabStringFmt("__float{s}{s}i{s}f", .{
             sign_prefix,
             compiler_rt_operand_abbrev,
             compiler_rt_dest_abbrev,
@@ -6239,7 +6239,7 @@ pub const FuncGen = struct {
         const compiler_rt_dest_abbrev = compilerRtIntAbbrev(rt_int_bits);
         const sign_prefix = if (dest_scalar_ty.isSignedInt(mod)) "" else "uns";
 
-        const fn_name = try o.builder.fmt("__fix{s}{s}f{s}i", .{
+        const fn_name = try o.builder.strtabStringFmt("__fix{s}{s}f{s}i", .{
             sign_prefix,
             compiler_rt_operand_abbrev,
             compiler_rt_dest_abbrev,
@@ -8117,7 +8117,7 @@ pub const FuncGen = struct {
 
     fn getLibcFunction(
         self: *FuncGen,
-        fn_name: Builder.String,
+        fn_name: Builder.StrtabString,
         param_types: []const Builder.Type,
         return_type: Builder.Type,
     ) Allocator.Error!Builder.Function.Index {
@@ -8171,7 +8171,7 @@ pub const FuncGen = struct {
             .gt => "gt",
             .gte => "ge",
         };
-        const fn_name = try o.builder.fmt("__{s}{s}f2", .{ fn_base_name, compiler_rt_float_abbrev });
+        const fn_name = try o.builder.strtabStringFmt("__{s}{s}f2", .{ fn_base_name, compiler_rt_float_abbrev });
 
         const libc_fn = try self.getLibcFunction(fn_name, &.{ scalar_llvm_ty, scalar_llvm_ty }, .i32);
 
@@ -8329,7 +8329,7 @@ pub const FuncGen = struct {
                 const result = try self.wip.bin(.xor, bitcasted_operand, sign_mask, "");
                 return self.wip.cast(.bitcast, result, llvm_ty, "");
             },
-            .add, .sub, .div, .mul => try o.builder.fmt("__{s}{s}f3", .{
+            .add, .sub, .div, .mul => try o.builder.strtabStringFmt("__{s}{s}f3", .{
                 @tagName(op), compilerRtFloatAbbrev(float_bits),
             }),
             .ceil,
@@ -8350,7 +8350,7 @@ pub const FuncGen = struct {
             .sqrt,
             .tan,
             .trunc,
-            => try o.builder.fmt("{s}{s}{s}", .{
+            => try o.builder.strtabStringFmt("{s}{s}{s}", .{
                 libcFloatPrefix(float_bits), @tagName(op), libcFloatSuffix(float_bits),
             }),
         };
@@ -8614,7 +8614,7 @@ pub const FuncGen = struct {
             const operand_llvm_ty = try o.lowerType(operand_ty);
             const dest_llvm_ty = try o.lowerType(dest_ty);
 
-            const fn_name = try o.builder.fmt("__trunc{s}f{s}f2", .{
+            const fn_name = try o.builder.strtabStringFmt("__trunc{s}f{s}f2", .{
                 compilerRtFloatAbbrev(src_bits), compilerRtFloatAbbrev(dest_bits),
             });
 
@@ -8648,7 +8648,7 @@ pub const FuncGen = struct {
 
             const dest_bits = dest_ty.scalarType(mod).floatBits(target);
             const src_bits = operand_ty.scalarType(mod).floatBits(target);
-            const fn_name = try o.builder.fmt("__extend{s}f{s}f2", .{
+            const fn_name = try o.builder.strtabStringFmt("__extend{s}f{s}f2", .{
                 compilerRtFloatAbbrev(src_bits), compilerRtFloatAbbrev(dest_bits),
             });
 
@@ -9644,7 +9644,7 @@ pub const FuncGen = struct {
         const target = zcu.root_mod.resolved_target.result;
         const function_index = try o.builder.addFunction(
             try o.builder.fnType(.i1, &.{try o.lowerType(Type.fromInterned(enum_type.tag_ty))}, .normal),
-            try o.builder.fmt("__zig_is_named_enum_value_{}", .{fqn.fmt(&zcu.intern_pool)}),
+            try o.builder.strtabStringFmt("__zig_is_named_enum_value_{}", .{fqn.fmt(&zcu.intern_pool)}),
             toLlvmAddressSpace(.generic, target),
         );
 
@@ -9909,16 +9909,16 @@ pub const FuncGen = struct {
         // Use a manual loop over a softfloat call instead.
         const float_bits = scalar_ty.floatBits(target);
         const fn_name = switch (reduce.operation) {
-            .Min => try o.builder.fmt("{s}fmin{s}", .{
+            .Min => try o.builder.strtabStringFmt("{s}fmin{s}", .{
                 libcFloatPrefix(float_bits), libcFloatSuffix(float_bits),
             }),
-            .Max => try o.builder.fmt("{s}fmax{s}", .{
+            .Max => try o.builder.strtabStringFmt("{s}fmax{s}", .{
                 libcFloatPrefix(float_bits), libcFloatSuffix(float_bits),
             }),
-            .Add => try o.builder.fmt("__add{s}f3", .{
+            .Add => try o.builder.strtabStringFmt("__add{s}f3", .{
                 compilerRtFloatAbbrev(float_bits),
             }),
-            .Mul => try o.builder.fmt("__mul{s}f3", .{
+            .Mul => try o.builder.strtabStringFmt("__mul{s}f3", .{
                 compilerRtFloatAbbrev(float_bits),
             }),
             else => unreachable,
@@ -10323,7 +10323,7 @@ pub const FuncGen = struct {
 
         // TODO: Address space
         const variable_index =
-            try o.builder.addVariable(try o.builder.string("__zig_err_name_table"), .ptr, .default);
+            try o.builder.addVariable(try o.builder.strtabString("__zig_err_name_table"), .ptr, .default);
         variable_index.setLinkage(.private, &o.builder);
         variable_index.setMutability(.constant, &o.builder);
         variable_index.setUnnamedAddr(.unnamed_addr, &o.builder);

src/codegen/llvm/Builder.zig

@@ -24,14 +24,18 @@ attributes_extra: std.ArrayListUnmanaged(u32),
 
 function_attributes_set: std.AutoArrayHashMapUnmanaged(FunctionAttributes, void),
 
-globals: std.AutoArrayHashMapUnmanaged(String, Global),
+globals: std.AutoArrayHashMapUnmanaged(StrtabString, Global),
-next_unnamed_global: String,
+next_unnamed_global: StrtabString,
-next_replaced_global: String,
+next_replaced_global: StrtabString,
-next_unique_global_id: std.AutoHashMapUnmanaged(String, u32),
+next_unique_global_id: std.AutoHashMapUnmanaged(StrtabString, u32),
 aliases: std.ArrayListUnmanaged(Alias),
 variables: std.ArrayListUnmanaged(Variable),
 functions: std.ArrayListUnmanaged(Function),
 
+strtab_string_map: std.AutoArrayHashMapUnmanaged(void, void),
+strtab_string_indices: std.ArrayListUnmanaged(u32),
+strtab_string_bytes: std.ArrayListUnmanaged(u8),
+
 constant_map: std.AutoArrayHashMapUnmanaged(void, void),
 constant_items: std.MultiArrayList(Constant.Item),
 constant_extra: std.ArrayListUnmanaged(u32),
@@ -194,11 +198,6 @@ pub const CmpPredicate = enum(u6) {
     icmp_sle = 41,
 };
 
-pub const StrtabString = struct {
-    offset: usize,
-    size: usize,
-};
-
 pub const Type = enum(u32) {
     void,
     half,
@@ -2136,6 +2135,122 @@ pub const CallConv = enum(u10) {
     }
 };
 
+pub const StrtabString = enum(u32) {
+    none = std.math.maxInt(u31),
+    empty,
+    _,
+
+    pub fn isAnon(self: StrtabString) bool {
+        assert(self != .none);
+        return self.toIndex() == null;
+    }
+
+    pub fn slice(self: StrtabString, builder: *const Builder) ?[]const u8 {
+        const index = self.toIndex() orelse return null;
+        const start = builder.strtab_string_indices.items[index];
+        const end = builder.strtab_string_indices.items[index + 1];
+        return builder.strtab_string_bytes.items[start..end];
+    }
+
+    const FormatData = struct {
+        string: StrtabString,
+        builder: *const Builder,
+    };
+    fn format(
+        data: FormatData,
+        comptime fmt_str: []const u8,
+        _: std.fmt.FormatOptions,
+        writer: anytype,
+    ) @TypeOf(writer).Error!void {
+        if (comptime std.mem.indexOfNone(u8, fmt_str, "\"r")) |_|
+            @compileError("invalid format string: '" ++ fmt_str ++ "'");
+        assert(data.string != .none);
+        const string_slice = data.string.slice(data.builder) orelse
+            return writer.print("{d}", .{@intFromEnum(data.string)});
+        if (comptime std.mem.indexOfScalar(u8, fmt_str, 'r')) |_|
+            return writer.writeAll(string_slice);
+        try printEscapedString(
+            string_slice,
+            if (comptime std.mem.indexOfScalar(u8, fmt_str, '"')) |_|
+                .always_quote
+            else
+                .quote_unless_valid_identifier,
+            writer,
+        );
+    }
+    pub fn fmt(self: StrtabString, builder: *const Builder) std.fmt.Formatter(format) {
+        return .{ .data = .{ .string = self, .builder = builder } };
+    }
+
+    fn fromIndex(index: ?usize) StrtabString {
+        return @enumFromInt(@as(u32, @intCast((index orelse return .none) +
+            @intFromEnum(StrtabString.empty))));
+    }
+
+    fn toIndex(self: StrtabString) ?usize {
+        return std.math.sub(u32, @intFromEnum(self), @intFromEnum(StrtabString.empty)) catch null;
+    }
+
+    const Adapter = struct {
+        builder: *const Builder,
+        pub fn hash(_: Adapter, key: []const u8) u32 {
+            return @truncate(std.hash.Wyhash.hash(0, key));
+        }
+        pub fn eql(ctx: Adapter, lhs_key: []const u8, _: void, rhs_index: usize) bool {
+            return std.mem.eql(u8, lhs_key, StrtabString.fromIndex(rhs_index).slice(ctx.builder).?);
+        }
+    };
+};
+
+pub fn strtabString(self: *Builder, bytes: []const u8) Allocator.Error!StrtabString {
+    try self.strtab_string_bytes.ensureUnusedCapacity(self.gpa, bytes.len);
+    try self.strtab_string_indices.ensureUnusedCapacity(self.gpa, 1);
+    try self.strtab_string_map.ensureUnusedCapacity(self.gpa, 1);
+
+    const gop = self.strtab_string_map.getOrPutAssumeCapacityAdapted(bytes, StrtabString.Adapter{ .builder = self });
+    if (!gop.found_existing) {
+        self.strtab_string_bytes.appendSliceAssumeCapacity(bytes);
+        self.strtab_string_indices.appendAssumeCapacity(@intCast(self.strtab_string_bytes.items.len));
+    }
+    return StrtabString.fromIndex(gop.index);
+}
+
+pub fn strtabStringIfExists(self: *const Builder, bytes: []const u8) ?StrtabString {
+    return StrtabString.fromIndex(
+        self.strtab_string_map.getIndexAdapted(bytes, StrtabString.Adapter{ .builder = self }) orelse return null,
+    );
+}
+
+pub fn strtabStringFmt(self: *Builder, comptime fmt_str: []const u8, fmt_args: anytype) Allocator.Error!StrtabString {
+    try self.strtab_string_map.ensureUnusedCapacity(self.gpa, 1);
+    try self.strtab_string_bytes.ensureUnusedCapacity(self.gpa, @intCast(std.fmt.count(fmt_str, fmt_args)));
+    try self.strtab_string_indices.ensureUnusedCapacity(self.gpa, 1);
+    return self.strtabStringFmtAssumeCapacity(fmt_str, fmt_args);
+}
+
+pub fn strtabStringFmtAssumeCapacity(self: *Builder, comptime fmt_str: []const u8, fmt_args: anytype) StrtabString {
+    self.strtab_string_bytes.writer(undefined).print(fmt_str, fmt_args) catch unreachable;
+    return self.trailingStrtabStringAssumeCapacity();
+}
+
+pub fn trailingStrtabString(self: *Builder) Allocator.Error!StrtabString {
+    try self.strtab_string_indices.ensureUnusedCapacity(self.gpa, 1);
+    try self.strtab_string_map.ensureUnusedCapacity(self.gpa, 1);
+    return self.trailingStrtabStringAssumeCapacity();
+}
+
+pub fn trailingStrtabStringAssumeCapacity(self: *Builder) StrtabString {
+    const start = self.strtab_string_indices.getLast();
+    const bytes: []const u8 = self.strtab_string_bytes.items[start..];
+    const gop = self.strtab_string_map.getOrPutAssumeCapacityAdapted(bytes, StrtabString.Adapter{ .builder = self });
+    if (gop.found_existing) {
+        self.strtab_string_bytes.shrinkRetainingCapacity(start);
+    } else {
+        self.strtab_string_indices.appendAssumeCapacity(@intCast(self.strtab_string_bytes.items.len));
+    }
+    return StrtabString.fromIndex(gop.index);
+}
+
 pub const Global = struct {
     linkage: Linkage = .external,
     preemption: Preemption = .dso_preemptable,
@@ -2179,19 +2294,23 @@ pub const Global = struct {
             return &builder.globals.values()[@intFromEnum(self.unwrap(builder))];
         }
 
-        pub fn name(self: Index, builder: *const Builder) String {
+        pub fn name(self: Index, builder: *const Builder) StrtabString {
             return builder.globals.keys()[@intFromEnum(self.unwrap(builder))];
         }
 
-        pub fn strtab(self: Index, builder: *const Builder) StrtabString {
+        pub fn strtab(self: Index, builder: *const Builder) struct {
+            offset: u32,
+            size: u32,
+        } {
             const name_index = self.name(builder).toIndex() orelse return .{
                 .offset = 0,
                 .size = 0,
             };
 
             return .{
-                .offset = builder.string_indices.items[name_index],
+                .offset = builder.strtab_string_indices.items[name_index],
-                .size = builder.string_indices.items[name_index + 1] - builder.string_indices.items[name_index],
+                .size = builder.strtab_string_indices.items[name_index + 1] -
+                    builder.strtab_string_indices.items[name_index],
             };
         }
 
@@ -2243,7 +2362,7 @@ pub const Global = struct {
             return .{ .data = .{ .global = self, .builder = builder } };
         }
 
-        pub fn rename(self: Index, new_name: String, builder: *Builder) Allocator.Error!void {
+        pub fn rename(self: Index, new_name: StrtabString, builder: *Builder) Allocator.Error!void {
             try builder.ensureUnusedGlobalCapacity(new_name);
             self.renameAssumeCapacity(new_name, builder);
         }
@@ -2282,7 +2401,7 @@ pub const Global = struct {
             }
         }
 
-        fn renameAssumeCapacity(self: Index, new_name: String, builder: *Builder) void {
+        fn renameAssumeCapacity(self: Index, new_name: StrtabString, builder: *Builder) void {
             const old_name = self.name(builder);
             if (new_name == old_name) return;
             const index = @intFromEnum(self.unwrap(builder));
@@ -2333,11 +2452,11 @@ pub const Alias = struct {
             return &builder.aliases.items[@intFromEnum(self)];
         }
 
-        pub fn name(self: Index, builder: *const Builder) String {
+        pub fn name(self: Index, builder: *const Builder) StrtabString {
             return self.ptrConst(builder).global.name(builder);
         }
 
-        pub fn rename(self: Index, new_name: String, builder: *Builder) Allocator.Error!void {
+        pub fn rename(self: Index, new_name: StrtabString, builder: *Builder) Allocator.Error!void {
             return self.ptrConst(builder).global.rename(new_name, builder);
         }
 
@@ -2385,11 +2504,11 @@ pub const Variable = struct {
             return &builder.variables.items[@intFromEnum(self)];
         }
 
-        pub fn name(self: Index, builder: *const Builder) String {
+        pub fn name(self: Index, builder: *const Builder) StrtabString {
             return self.ptrConst(builder).global.name(builder);
         }
 
-        pub fn rename(self: Index, new_name: String, builder: *Builder) Allocator.Error!void {
+        pub fn rename(self: Index, new_name: StrtabString, builder: *Builder) Allocator.Error!void {
             return self.ptrConst(builder).global.rename(new_name, builder);
         }
 
@@ -3814,11 +3933,11 @@ pub const Function = struct {
             return &builder.functions.items[@intFromEnum(self)];
         }
 
-        pub fn name(self: Index, builder: *const Builder) String {
+        pub fn name(self: Index, builder: *const Builder) StrtabString {
             return self.ptrConst(builder).global.name(builder);
         }
 
-        pub fn rename(self: Index, new_name: String, builder: *Builder) Allocator.Error!void {
+        pub fn rename(self: Index, new_name: StrtabString, builder: *Builder) Allocator.Error!void {
             return self.ptrConst(builder).global.rename(new_name, builder);
         }
 
@@ -8331,6 +8450,10 @@ pub fn init(options: Options) Allocator.Error!Builder {
         .variables = .{},
         .functions = .{},
 
+        .strtab_string_map = .{},
+        .strtab_string_indices = .{},
+        .strtab_string_bytes = .{},
+
         .constant_map = .{},
         .constant_items = .{},
         .constant_extra = .{},
@@ -8351,6 +8474,9 @@ pub fn init(options: Options) Allocator.Error!Builder {
     try self.string_indices.append(self.gpa, 0);
     assert(try self.string("") == .empty);
 
+    try self.strtab_string_indices.append(self.gpa, 0);
+    assert(try self.strtabString("") == .empty);
+
     if (options.name.len > 0) self.source_filename = try self.string(options.name);
 
     if (options.triple.len > 0) {
@@ -8423,6 +8549,10 @@ pub fn clearAndFree(self: *Builder) void {
     for (self.functions.items) |*function| function.deinit(self.gpa);
     self.functions.clearAndFree(self.gpa);
 
+    self.strtab_string_map.clearAndFree(self.gpa);
+    self.strtab_string_indices.clearAndFree(self.gpa);
+    self.strtab_string_bytes.clearAndFree(self.gpa);
+
     self.constant_map.clearAndFree(self.gpa);
     self.constant_items.shrinkAndFree(self.gpa, 0);
     self.constant_extra.clearAndFree(self.gpa);
@@ -8467,6 +8597,10 @@ pub fn deinit(self: *Builder) void {
     for (self.functions.items) |*function| function.deinit(self.gpa);
     self.functions.deinit(self.gpa);
 
+    self.strtab_string_map.deinit(self.gpa);
+    self.strtab_string_indices.deinit(self.gpa);
+    self.strtab_string_bytes.deinit(self.gpa);
+
     self.constant_map.deinit(self.gpa);
     self.constant_items.deinit(self.gpa);
     self.constant_extra.deinit(self.gpa);
@@ -8660,14 +8794,14 @@ pub fn fnAttrs(self: *Builder, fn_attributes: []const Attributes) Allocator.Erro
     return function_attributes;
 }
 
-pub fn addGlobal(self: *Builder, name: String, global: Global) Allocator.Error!Global.Index {
+pub fn addGlobal(self: *Builder, name: StrtabString, global: Global) Allocator.Error!Global.Index {
     assert(!name.isAnon());
     try self.ensureUnusedTypeCapacity(1, NoExtra, 0);
     try self.ensureUnusedGlobalCapacity(name);
     return self.addGlobalAssumeCapacity(name, global);
 }
 
-pub fn addGlobalAssumeCapacity(self: *Builder, name: String, global: Global) Global.Index {
+pub fn addGlobalAssumeCapacity(self: *Builder, name: StrtabString, global: Global) Global.Index {
     _ = self.ptrTypeAssumeCapacity(global.addr_space);
     var id = name;
     if (name == .empty) {
@@ -8686,18 +8820,18 @@ pub fn addGlobalAssumeCapacity(self: *Builder, name: String, global: Global) Glo
 
         const unique_gop = self.next_unique_global_id.getOrPutAssumeCapacity(name);
         if (!unique_gop.found_existing) unique_gop.value_ptr.* = 2;
-        id = self.fmtAssumeCapacity("{s}.{d}", .{ name.slice(self).?, unique_gop.value_ptr.* });
+        id = self.strtabStringFmtAssumeCapacity("{s}.{d}", .{ name.slice(self).?, unique_gop.value_ptr.* });
         unique_gop.value_ptr.* += 1;
     }
 }
 
-pub fn getGlobal(self: *const Builder, name: String) ?Global.Index {
+pub fn getGlobal(self: *const Builder, name: StrtabString) ?Global.Index {
     return @enumFromInt(self.globals.getIndex(name) orelse return null);
 }
 
 pub fn addAlias(
     self: *Builder,
-    name: String,
+    name: StrtabString,
     ty: Type,
     addr_space: AddrSpace,
     aliasee: Constant,
@@ -8711,7 +8845,7 @@ pub fn addAlias(
 
 pub fn addAliasAssumeCapacity(
     self: *Builder,
-    name: String,
+    name: StrtabString,
     ty: Type,
     addr_space: AddrSpace,
     aliasee: Constant,
@@ -8727,7 +8861,7 @@ pub fn addAliasAssumeCapacity(
 
 pub fn addVariable(
     self: *Builder,
-    name: String,
+    name: StrtabString,
     ty: Type,
     addr_space: AddrSpace,
 ) Allocator.Error!Variable.Index {
@@ -8741,7 +8875,7 @@ pub fn addVariable(
 pub fn addVariableAssumeCapacity(
     self: *Builder,
     ty: Type,
-    name: String,
+    name: StrtabString,
     addr_space: AddrSpace,
 ) Variable.Index {
     const variable_index: Variable.Index = @enumFromInt(self.variables.items.len);
@@ -8756,7 +8890,7 @@ pub fn addVariableAssumeCapacity(
 pub fn addFunction(
     self: *Builder,
     ty: Type,
-    name: String,
+    name: StrtabString,
     addr_space: AddrSpace,
 ) Allocator.Error!Function.Index {
     assert(!name.isAnon());
@@ -8769,7 +8903,7 @@ pub fn addFunction(
 pub fn addFunctionAssumeCapacity(
     self: *Builder,
     ty: Type,
-    name: String,
+    name: StrtabString,
     addr_space: AddrSpace,
 ) Function.Index {
     assert(ty.isFunction(self));
@@ -8803,10 +8937,10 @@ pub fn getIntrinsic(
     const allocator = stack.get();
 
     const name = name: {
-        const writer = self.string_bytes.writer(self.gpa);
+        const writer = self.strtab_string_bytes.writer(self.gpa);
         try writer.print("llvm.{s}", .{@tagName(id)});
         for (overload) |ty| try writer.print(".{m}", .{ty.fmt(self)});
-        break :name try self.trailingString();
+        break :name try self.trailingStrtabString();
     };
     if (self.getGlobal(name)) |global| return global.ptrConst(self).kind.function;
 
@@ -10366,13 +10500,13 @@ fn printEscapedString(
     if (need_quotes) try writer.writeByte('"');
 }
 
-fn ensureUnusedGlobalCapacity(self: *Builder, name: String) Allocator.Error!void {
+fn ensureUnusedGlobalCapacity(self: *Builder, name: StrtabString) Allocator.Error!void {
-    try self.string_map.ensureUnusedCapacity(self.gpa, 1);
+    try self.strtab_string_map.ensureUnusedCapacity(self.gpa, 1);
     if (name.slice(self)) |id| {
         const count: usize = comptime std.fmt.count("{d}", .{std.math.maxInt(u32)});
-        try self.string_bytes.ensureUnusedCapacity(self.gpa, id.len + count);
+        try self.strtab_string_bytes.ensureUnusedCapacity(self.gpa, id.len + count);
     }
-    try self.string_indices.ensureUnusedCapacity(self.gpa, 1);
+    try self.strtab_string_indices.ensureUnusedCapacity(self.gpa, 1);
     try self.globals.ensureUnusedCapacity(self.gpa, 1);
     try self.next_unique_global_id.ensureUnusedCapacity(self.gpa, 1);
 }
@@ -11893,7 +12027,7 @@ pub fn metadataString(self: *Builder, bytes: []const u8) Allocator.Error!Metadat
     return @enumFromInt(gop.index);
 }
 
-pub fn metadataStringFromString(self: *Builder, str: String) Allocator.Error!MetadataString {
+pub fn metadataStringFromStrtabString(self: *Builder, str: StrtabString) Allocator.Error!MetadataString {
     if (str == .none or str == .empty) return MetadataString.none;
     return try self.metadataString(str.slice(self).?);
 }
@@ -15059,7 +15193,7 @@ pub fn toBitcode(self: *Builder, allocator: Allocator) bitcode_writer.Error![]co
         const Strtab = ir.Strtab;
         var strtab_block = try bitcode.enterTopBlock(Strtab);
 
-        try strtab_block.writeAbbrev(Strtab.Blob{ .blob = self.string_bytes.items });
+        try strtab_block.writeAbbrev(Strtab.Blob{ .blob = self.strtab_string_bytes.items });
 
         try strtab_block.end();
     }