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codegen: fix access to byte-aligned nested packed struct elems

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When acessing a packed struct member via a byte aligned ptr (from the optimisation in Sema.structFieldPtrByIndex())
the codegen must apply the parent ptr packed_offset in addition to the field offset itself.

resolves https://github.com/ziglang/zig/issues/16609
This commit is contained in:
Xavier Bouchoux
2023-07-29 11:50:25 +02:00
parent 46abf20454
commit 8c367ef99a
5 changed files with 115 additions and 12 deletions
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94
test/behavior/packed-struct.zig
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@@ -528,6 +528,100 @@ test "nested packed struct field access test" {
try std.testing.expect(arg.g.i == 8);
}
test "nested packed struct at non-zero offset" {
if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_spirv64) return error.SkipZigTest;
const Pair = packed struct(u24) {
a: u16 = 0,
b: u8 = 0,
};
const A = packed struct {
p1: Pair,
p2: Pair,
};
var k: u8 = 123;
var v: A = .{
.p1 = .{ .a = k + 1, .b = k },
.p2 = .{ .a = k + 1, .b = k },
};
try expect(v.p1.a == k + 1 and v.p1.b == k);
try expect(v.p2.a == k + 1 and v.p2.b == k);
v.p2.a -= v.p1.a;
v.p2.b -= v.p1.b;
try expect(v.p2.a == 0 and v.p2.b == 0);
try expect(v.p1.a == k + 1 and v.p1.b == k);
}
test "nested packed struct at non-zero offset 2" {
if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;
if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest;
if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_spirv64) return error.SkipZigTest;
if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_c) return error.SkipZigTest;
const S = struct {
const Pair = packed struct(u40) {
a: u32 = 0,
b: u8 = 0,
};
const A = packed struct {
p1: Pair,
p2: Pair,
c: C,
};
const C = packed struct {
p1: Pair,
pad1: u5,
p2: Pair,
pad2: u3,
last: i16,
};
fn doTheTest() !void {
var k: u8 = 123;
var v: A = .{
.p1 = .{ .a = k + 1, .b = k },
.p2 = .{ .a = k + 1, .b = k },
.c = .{
.pad1 = 11,
.pad2 = 2,
.p1 = .{ .a = k + 1, .b = k },
.p2 = .{ .a = k + 1, .b = k },
.last = -12345,
},
};
try expect(v.p1.a == k + 1 and v.p1.b == k);
try expect(v.p2.a == k + 1 and v.p2.b == k);
try expect(v.c.p2.a == k + 1 and v.c.p2.b == k);
try expect(v.c.p2.a == k + 1 and v.c.p2.b == k);
try expect(v.c.last == -12345);
try expect(v.c.pad1 == 11 and v.c.pad2 == 2);
v.p2.a -= v.p1.a;
v.p2.b -= v.p1.b;
v.c.p2.a -= v.c.p1.a;
v.c.p2.b -= v.c.p1.b;
v.c.last -|= 32000;
try expect(v.p2.a == 0 and v.p2.b == 0);
try expect(v.p1.a == k + 1 and v.p1.b == k);
try expect(v.c.p2.a == 0 and v.c.p2.b == 0);
try expect(v.c.p1.a == k + 1 and v.c.p1.b == k);
try expect(v.c.last == -32768);
try expect(v.c.pad1 == 11 and v.c.pad2 == 2);
}
};
try S.doTheTest();
try comptime S.doTheTest();
}
test "runtime init of unnamed packed struct type" {
if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;
if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest;