authorgravatar for andrew@ziglang.orgAndrew Kelley <andrew@ziglang.org> 2020-05-20 22:41:18-04:00
committergravatar for andrew@ziglang.orgAndrew Kelley <andrew@ziglang.org> 2020-05-20 22:41:18-04:00
log84df1d4f3d0312553f5a3857ed67042319c20846
tree78cdf050acb81fa642629bfad9b0a5593865036e
parent44aeb383289bc80644e3c6aef2b7b2494149c80b

stage2 parser: elide memcpy of large initialization lists

throughput: 71.4 MiB/s => 72.9 MiB/s

2 files changed, 56 insertions(+), 4 deletions(-)

lib/std/zig/ast.zig+6
...@@ -18,6 +18,8 @@ pub const Tree = struct {...@@ -18,6 +18,8 @@ pub const Tree = struct {
1818
19 arena: std.heap.ArenaAllocator.State,19 arena: std.heap.ArenaAllocator.State,
20 gpa: *mem.Allocator,20 gpa: *mem.Allocator,
21 /// This keeps track of slices of memory that must be freed on deinit.
22 owned_memory: [][]u8,
2123
22 /// translate-c uses this to avoid having to emit correct newlines24 /// translate-c uses this to avoid having to emit correct newlines
23 /// TODO get rid of this hack25 /// TODO get rid of this hack
...@@ -26,6 +28,10 @@ pub const Tree = struct {...@@ -26,6 +28,10 @@ pub const Tree = struct {
26 pub fn deinit(self: *Tree) void {28 pub fn deinit(self: *Tree) void {
27 self.gpa.free(self.tokens);29 self.gpa.free(self.tokens);
28 self.gpa.free(self.errors);30 self.gpa.free(self.errors);
31 for (self.owned_memory) |list| {
32 self.gpa.free(list);
33 }
34 self.gpa.free(self.owned_memory);
29 self.arena.promote(self.gpa).deinit();35 self.arena.promote(self.gpa).deinit();
30 }36 }
3137
lib/std/zig/parse.zig+50-4
...@@ -10,6 +10,13 @@ const Token = std.zig.Token;...@@ -10,6 +10,13 @@ const Token = std.zig.Token;
1010
11pub const Error = error{ParseError} || Allocator.Error;11pub const Error = error{ParseError} || Allocator.Error;
1212
13/// This is the maximum length of a list that will be copied into the ast.Tree
14/// arena when parsing. If the list is longer than this, the ast.Tree will have
15/// a reference to the memory allocated in the general purpose allocator, and
16/// will free it separately. Simply put, lists longer than this will elide the
17/// memcpy().
18const large_list_len = 512;
19
13/// Result should be freed with tree.deinit() when there are20/// Result should be freed with tree.deinit() when there are
14/// no more references to any of the tokens or nodes.21/// no more references to any of the tokens or nodes.
15pub fn parse(gpa: *Allocator, source: []const u8) Allocator.Error!*Tree {22pub fn parse(gpa: *Allocator, source: []const u8) Allocator.Error!*Tree {
...@@ -32,6 +39,11 @@ pub fn parse(gpa: *Allocator, source: []const u8) Allocator.Error!*Tree {...@@ -32,6 +39,11 @@ pub fn parse(gpa: *Allocator, source: []const u8) Allocator.Error!*Tree {
32 .tokens = tokens.items,39 .tokens = tokens.items,
33 .errors = .{},40 .errors = .{},
34 .tok_i = 0,41 .tok_i = 0,
42 .owned_memory = .{},
43 };
44 defer parser.owned_memory.deinit(gpa);
45 errdefer for (parser.owned_memory.items) |list| {
46 gpa.free(list);
35 };47 };
36 defer parser.errors.deinit(gpa);48 defer parser.errors.deinit(gpa);
37 errdefer parser.arena.deinit();49 errdefer parser.arena.deinit();
...@@ -46,6 +58,7 @@ pub fn parse(gpa: *Allocator, source: []const u8) Allocator.Error!*Tree {...@@ -46,6 +58,7 @@ pub fn parse(gpa: *Allocator, source: []const u8) Allocator.Error!*Tree {
46 .source = source,58 .source = source,
47 .tokens = tokens.toOwnedSlice(),59 .tokens = tokens.toOwnedSlice(),
48 .errors = parser.errors.toOwnedSlice(gpa),60 .errors = parser.errors.toOwnedSlice(gpa),
61 .owned_memory = parser.owned_memory.toOwnedSlice(gpa),
49 .root_node = root_node,62 .root_node = root_node,
50 .arena = parser.arena.state,63 .arena = parser.arena.state,
51 };64 };
...@@ -60,6 +73,7 @@ const Parser = struct {...@@ -60,6 +73,7 @@ const Parser = struct {
60 tokens: []const Token,73 tokens: []const Token,
61 tok_i: TokenIndex,74 tok_i: TokenIndex,
62 errors: std.ArrayListUnmanaged(AstError),75 errors: std.ArrayListUnmanaged(AstError),
76 owned_memory: std.ArrayListUnmanaged([]u8),
6377
64 /// Root <- skip ContainerMembers eof78 /// Root <- skip ContainerMembers eof
65 fn parseRoot(p: *Parser) Allocator.Error!*Node.Root {79 fn parseRoot(p: *Parser) Allocator.Error!*Node.Root {
...@@ -1307,11 +1321,19 @@ const Parser = struct {...@@ -1307,11 +1321,19 @@ const Parser = struct {
1307 const next = (try p.parseFieldInit()) orelse break;1321 const next = (try p.parseFieldInit()) orelse break;
1308 try init_list.append(next);1322 try init_list.append(next);
1309 }1323 }
1324
1325 const list = if (init_list.items.len > large_list_len) blk: {
1326 try p.owned_memory.ensureCapacity(p.gpa, p.owned_memory.items.len + 1);
1327 const list = init_list.toOwnedSlice();
1328 p.owned_memory.appendAssumeCapacity(std.mem.sliceAsBytes(list));
1329 break :blk list;
1330 } else try p.arena.allocator.dupe(*Node, init_list.items);
1331
1310 const node = try p.arena.allocator.create(Node.StructInitializer);1332 const node = try p.arena.allocator.create(Node.StructInitializer);
1311 node.* = .{1333 node.* = .{
1312 .lhs = lhs,1334 .lhs = lhs,
1313 .rtoken = try p.expectToken(.RBrace),1335 .rtoken = try p.expectToken(.RBrace),
1314 .list = try p.arena.allocator.dupe(*Node, init_list.items),1336 .list = list,
1315 };1337 };
1316 return &node.base;1338 return &node.base;
1317 }1339 }
...@@ -1322,11 +1344,19 @@ const Parser = struct {...@@ -1322,11 +1344,19 @@ const Parser = struct {
1322 const next = (try p.parseExpr()) orelse break;1344 const next = (try p.parseExpr()) orelse break;
1323 try init_list.append(next);1345 try init_list.append(next);
1324 }1346 }
1347
1348 const list = if (init_list.items.len > large_list_len) blk: {
1349 try p.owned_memory.ensureCapacity(p.gpa, p.owned_memory.items.len + 1);
1350 const list = init_list.toOwnedSlice();
1351 p.owned_memory.appendAssumeCapacity(std.mem.sliceAsBytes(list));
1352 break :blk list;
1353 } else try p.arena.allocator.dupe(*Node, init_list.items);
1354
1325 const node = try p.arena.allocator.create(Node.ArrayInitializer);1355 const node = try p.arena.allocator.create(Node.ArrayInitializer);
1326 node.* = .{1356 node.* = .{
1327 .lhs = lhs,1357 .lhs = lhs,
1328 .rtoken = try p.expectToken(.RBrace),1358 .rtoken = try p.expectToken(.RBrace),
1329 .list = try p.arena.allocator.dupe(*Node, init_list.items),1359 .list = list,
1330 };1360 };
1331 return &node.base;1361 return &node.base;
1332 }1362 }
...@@ -1355,11 +1385,19 @@ const Parser = struct {...@@ -1355,11 +1385,19 @@ const Parser = struct {
1355 const next = (try p.parseFieldInit()) orelse break;1385 const next = (try p.parseFieldInit()) orelse break;
1356 try init_list.append(next);1386 try init_list.append(next);
1357 }1387 }
1388
1389 const list = if (init_list.items.len > large_list_len) blk: {
1390 try p.owned_memory.ensureCapacity(p.gpa, p.owned_memory.items.len + 1);
1391 const list = init_list.toOwnedSlice();
1392 p.owned_memory.appendAssumeCapacity(std.mem.sliceAsBytes(list));
1393 break :blk list;
1394 } else try p.arena.allocator.dupe(*Node, init_list.items);
1395
1358 const node = try p.arena.allocator.create(Node.StructInitializerDot);1396 const node = try p.arena.allocator.create(Node.StructInitializerDot);
1359 node.* = .{1397 node.* = .{
1360 .dot = dot,1398 .dot = dot,
1361 .rtoken = try p.expectToken(.RBrace),1399 .rtoken = try p.expectToken(.RBrace),
1362 .list = try p.arena.allocator.dupe(*Node, init_list.items),1400 .list = list,
1363 };1401 };
1364 return &node.base;1402 return &node.base;
1365 }1403 }
...@@ -1370,11 +1408,19 @@ const Parser = struct {...@@ -1370,11 +1408,19 @@ const Parser = struct {
1370 const next = (try p.parseExpr()) orelse break;1408 const next = (try p.parseExpr()) orelse break;
1371 try init_list.append(next);1409 try init_list.append(next);
1372 }1410 }
1411
1412 const list = if (init_list.items.len > large_list_len) blk: {
1413 try p.owned_memory.ensureCapacity(p.gpa, p.owned_memory.items.len + 1);
1414 const list = init_list.toOwnedSlice();
1415 p.owned_memory.appendAssumeCapacity(std.mem.sliceAsBytes(list));
1416 break :blk list;
1417 } else try p.arena.allocator.dupe(*Node, init_list.items);
1418
1373 const node = try p.arena.allocator.create(Node.ArrayInitializerDot);1419 const node = try p.arena.allocator.create(Node.ArrayInitializerDot);
1374 node.* = .{1420 node.* = .{
1375 .dot = dot,1421 .dot = dot,
1376 .rtoken = try p.expectToken(.RBrace),1422 .rtoken = try p.expectToken(.RBrace),
1377 .list = try p.arena.allocator.dupe(*Node, init_list.items),1423 .list = list,
1378 };1424 };
1379 return &node.base;1425 return &node.base;
1380 }1426 }