| author |  Andrew Kelley <andrew@ziglang.org> 2022-03-15 19:21:58-07:00 |
| committer | Andrew Kelley <andrew@ziglang.org> 2022-03-15 19:21:58-07:00 |
| log | 9a6fa67cbc7e5771f3770c0cb7d6d2c6bafb6957 |
| tree | 4ee6f2f8ebf858321d970b2da9e7191475827c6e |
| parent | fd43434149658ee482428714e05722e5a12fdecc |
Sema: only do store_ptr tuple optimization for arrays
Check the big comment in the diff for more details.
Fixes default-initialization of structs from empty struct literals.3 files changed, 17 insertions(+), 4 deletions(-)
src- test
- behavior
src/Sema.zig+7-3
| ... | ... | @@ -17578,10 +17578,13 @@ fn storePtr2( |
| 17578 | 17578 | // To generate better code for tuples, we detect a tuple operand here, and |
| 17579 | 17579 | // analyze field loads and stores directly. This avoids an extra allocation + memcpy |
| 17580 | 17580 | // which would occur if we used `coerce`. |
| 17581 | // However, we avoid this mechanism if the destination element type is | |
| 17582 | // the same tuple as the source, because the regular store will be better for this case. | |
| 17581 | // However, we avoid this mechanism if the destination element type is a tuple, | |
| 17582 | // because the regular store will be better for this case. | |
| 17583 | // If the destination type is a struct we don't want this mechanism to trigger, because | |
| 17584 | // this code does not handle tuple-to-struct coercion which requires dealing with missing | |
| 17585 | // fields. | |
| 17583 | 17586 | const operand_ty = sema.typeOf(uncasted_operand); |
| 17584 | if (operand_ty.isTuple() and !elem_ty.eql(operand_ty)) { | |
| 17587 | if (operand_ty.isTuple() and elem_ty.zigTypeTag() == .Array) { | |
| 17585 | 17588 | const tuple = operand_ty.tupleFields(); |
| 17586 | 17589 | for (tuple.types) |_, i_usize| { |
| 17587 | 17590 | const i = @intCast(u32, i_usize); |
| ... | ... | @@ -17595,6 +17598,7 @@ fn storePtr2( |
| 17595 | 17598 | } |
| 17596 | 17599 | |
| 17597 | 17600 | // TODO do the same thing for anon structs as for tuples above. |
| 17601 | // However, beware of the need to handle missing/extra fields. | |
| 17598 | 17602 | |
| 17599 | 17603 | // Detect if we are storing an array operand to a bitcasted vector pointer. |
| 17600 | 17604 | // If so, we instead reach through the bitcasted pointer to the vector pointer, |
test/behavior/struct.zig+9
| ... | ... | @@ -1281,3 +1281,12 @@ test "typed init through error unions and optionals" { |
| 1281 | 1281 | try S.doTheTest(); |
| 1282 | 1282 | comptime try S.doTheTest(); |
| 1283 | 1283 | } |
| 1284 | ||
| 1285 | test "initialize struct with empty literal" { | |
| 1286 | if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO | |
| 1287 | if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO | |
| 1288 | ||
| 1289 | const S = struct { x: i32 = 1234 }; | |
| 1290 | var s: S = .{}; | |
| 1291 | try expect(s.x == 1234); | |
| 1292 | } |
test/behavior/union.zig+1-1
| ... | ... | @@ -1092,7 +1092,7 @@ test "@unionInit on union with tag but no fields" { |
| 1092 | 1092 | } |
| 1093 | 1093 | |
| 1094 | 1094 | fn doTheTest() !void { |
| 1095 | var data: Data = .{ .no_op = .{} }; | |
| 1095 | var data: Data = .{ .no_op = {} }; | |
| 1096 | 1096 | _ = data; |
| 1097 | 1097 | var o = Data.decode(&[_]u8{}); |
| 1098 | 1098 | try expectEqual(Type.no_op, o); |