Commit 0681bf06ab
Changed files (5)
test
behavior
src/Air/Legalize.zig
@@ -2682,12 +2682,10 @@ const Block = struct {
},
.@"packed" => switch (agg_ty.zigTypeTag(zcu)) {
else => unreachable,
- .@"struct" => switch (agg_ty.packedStructFieldPtrInfo(agg_ptr_ty, @intCast(field_index), pt)) {
- .bit_ptr => |packed_offset| {
- field_ptr_info.packed_offset = packed_offset;
- break :field_ptr_align agg_ptr_align;
- },
- .byte_ptr => |ptr_info| ptr_info.alignment,
+ .@"struct" => {
+ const packed_offset = agg_ty.packedStructFieldPtrInfo(agg_ptr_ty, @intCast(field_index), pt);
+ field_ptr_info.packed_offset = packed_offset;
+ break :field_ptr_align agg_ptr_align;
},
.@"union" => {
field_ptr_info.packed_offset = .{
src/Sema.zig
@@ -27457,15 +27457,9 @@ fn structFieldPtrByIndex(
if (struct_type.layout == .@"packed") {
assert(!field_is_comptime);
- switch (struct_ty.packedStructFieldPtrInfo(struct_ptr_ty, field_index, pt)) {
- .bit_ptr => |packed_offset| {
- ptr_ty_data.flags.alignment = parent_align;
- ptr_ty_data.packed_offset = packed_offset;
- },
- .byte_ptr => |ptr_info| {
- ptr_ty_data.flags.alignment = ptr_info.alignment;
- },
- }
+ const packed_offset = struct_ty.packedStructFieldPtrInfo(struct_ptr_ty, field_index, pt);
+ ptr_ty_data.flags.alignment = parent_align;
+ ptr_ty_data.packed_offset = packed_offset;
} else if (struct_type.layout == .@"extern") {
assert(!field_is_comptime);
// For extern structs, field alignment might be bigger than type's
src/Type.zig
@@ -3514,22 +3514,17 @@ pub fn arrayBase(ty: Type, zcu: *const Zcu) struct { Type, u64 } {
return .{ cur_ty, cur_len };
}
-pub fn packedStructFieldPtrInfo(struct_ty: Type, parent_ptr_ty: Type, field_idx: u32, pt: Zcu.PerThread) union(enum) {
- /// The result is a bit-pointer with the same value and a new packed offset.
- bit_ptr: InternPool.Key.PtrType.PackedOffset,
- /// The result is a standard pointer.
- byte_ptr: struct {
- /// The byte offset of the field pointer from the parent pointer value.
- offset: u64,
- /// The alignment of the field pointer type.
- alignment: InternPool.Alignment,
- },
-} {
+/// Returns a bit-pointer with the same value and a new packed offset.
+pub fn packedStructFieldPtrInfo(
+ struct_ty: Type,
+ parent_ptr_ty: Type,
+ field_idx: u32,
+ pt: Zcu.PerThread,
+) InternPool.Key.PtrType.PackedOffset {
comptime assert(Type.packed_struct_layout_version == 2);
const zcu = pt.zcu;
const parent_ptr_info = parent_ptr_ty.ptrInfo(zcu);
- const field_ty = struct_ty.fieldType(field_idx, zcu);
var bit_offset: u16 = 0;
var running_bits: u16 = 0;
@@ -3552,28 +3547,10 @@ pub fn packedStructFieldPtrInfo(struct_ty: Type, parent_ptr_ty: Type, field_idx:
bit_offset,
};
- // If the field happens to be byte-aligned, simplify the pointer type.
- // We can only do this if the pointee's bit size matches its ABI byte size,
- // so that loads and stores do not interfere with surrounding packed bits.
- //
- // TODO: we do not attempt this with big-endian targets yet because of nested
- // structs and floats. I need to double-check the desired behavior for big endian
- // targets before adding the necessary complications to this code. This will not
- // cause miscompilations; it only means the field pointer uses bit masking when it
- // might not be strictly necessary.
- if (res_bit_offset % 8 == 0 and field_ty.bitSize(zcu) == field_ty.abiSize(zcu) * 8 and zcu.getTarget().cpu.arch.endian() == .little) {
- const byte_offset = res_bit_offset / 8;
- const new_align = Alignment.fromLog2Units(@ctz(byte_offset | parent_ptr_ty.ptrAlignment(zcu).toByteUnits().?));
- return .{ .byte_ptr = .{
- .offset = byte_offset,
- .alignment = new_align,
- } };
- }
-
- return .{ .bit_ptr = .{
+ return .{
.host_size = res_host_size,
.bit_offset = res_bit_offset,
- } };
+ };
}
pub fn resolveLayout(ty: Type, pt: Zcu.PerThread) SemaError!void {
src/Value.zig
@@ -2255,32 +2255,18 @@ pub fn ptrField(parent_ptr: Value, field_idx: u32, pt: Zcu.PerThread) !Value {
});
return parent_ptr.getOffsetPtr(byte_off, result_ty, pt);
},
- .@"packed" => switch (aggregate_ty.packedStructFieldPtrInfo(parent_ptr_ty, field_idx, pt)) {
- .bit_ptr => |packed_offset| {
- const result_ty = try pt.ptrType(info: {
- var new = parent_ptr_info;
- new.packed_offset = packed_offset;
- new.child = field_ty.toIntern();
- if (new.flags.alignment == .none) {
- new.flags.alignment = try aggregate_ty.abiAlignmentSema(pt);
- }
- break :info new;
- });
- return pt.getCoerced(parent_ptr, result_ty);
- },
- .byte_ptr => |ptr_info| {
- const result_ty = try pt.ptrTypeSema(info: {
- var new = parent_ptr_info;
- new.child = field_ty.toIntern();
- new.packed_offset = .{
- .host_size = 0,
- .bit_offset = 0,
- };
- new.flags.alignment = ptr_info.alignment;
- break :info new;
- });
- return parent_ptr.getOffsetPtr(ptr_info.offset, result_ty, pt);
- },
+ .@"packed" => {
+ const packed_offset = aggregate_ty.packedStructFieldPtrInfo(parent_ptr_ty, field_idx, pt);
+ const result_ty = try pt.ptrType(info: {
+ var new = parent_ptr_info;
+ new.packed_offset = packed_offset;
+ new.child = field_ty.toIntern();
+ if (new.flags.alignment == .none) {
+ new.flags.alignment = try aggregate_ty.abiAlignmentSema(pt);
+ }
+ break :info new;
+ });
+ return pt.getCoerced(parent_ptr, result_ty);
},
}
},
test/behavior/packed-struct.zig
@@ -3,7 +3,6 @@ const builtin = @import("builtin");
const assert = std.debug.assert;
const expect = std.testing.expect;
const expectEqual = std.testing.expectEqual;
-const native_endian = builtin.cpu.arch.endian();
test "flags in packed structs" {
if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
@@ -163,26 +162,24 @@ test "correct sizeOf and offsets in packed structs" {
try expectEqual(22, @bitOffsetOf(PStruct, "u10_b"));
try expectEqual(4, @sizeOf(PStruct));
- if (native_endian == .little) {
- const s1 = @as(PStruct, @bitCast(@as(u32, 0x12345678)));
- try expectEqual(false, s1.bool_a);
- try expectEqual(false, s1.bool_b);
- try expectEqual(false, s1.bool_c);
- try expectEqual(true, s1.bool_d);
- try expectEqual(true, s1.bool_e);
- try expectEqual(true, s1.bool_f);
- try expectEqual(1, s1.u1_a);
- try expectEqual(false, s1.bool_g);
- try expectEqual(0, s1.u1_b);
- try expectEqual(3, s1.u3_a);
- try expectEqual(0b1101000101, s1.u10_a);
- try expectEqual(0b0001001000, s1.u10_b);
-
- const s2 = @as(packed struct { x: u1, y: u7, z: u24 }, @bitCast(@as(u32, 0xd5c71ff4)));
- try expectEqual(0, s2.x);
- try expectEqual(0b1111010, s2.y);
- try expectEqual(0xd5c71f, s2.z);
- }
+ const s1 = @as(PStruct, @bitCast(@as(u32, 0x12345678)));
+ try expectEqual(false, s1.bool_a);
+ try expectEqual(false, s1.bool_b);
+ try expectEqual(false, s1.bool_c);
+ try expectEqual(true, s1.bool_d);
+ try expectEqual(true, s1.bool_e);
+ try expectEqual(true, s1.bool_f);
+ try expectEqual(1, s1.u1_a);
+ try expectEqual(false, s1.bool_g);
+ try expectEqual(0, s1.u1_b);
+ try expectEqual(3, s1.u3_a);
+ try expectEqual(0b1101000101, s1.u10_a);
+ try expectEqual(0b0001001000, s1.u10_b);
+
+ const s2 = @as(packed struct { x: u1, y: u7, z: u24 }, @bitCast(@as(u32, 0xd5c71ff4)));
+ try expectEqual(0, s2.x);
+ try expectEqual(0b1111010, s2.y);
+ try expectEqual(0xd5c71f, s2.z);
}
test "nested packed structs" {
@@ -202,15 +199,13 @@ test "nested packed structs" {
try expectEqual(3, @offsetOf(S3, "y"));
try expectEqual(24, @bitOffsetOf(S3, "y"));
- if (native_endian == .little) {
- const s3 = @as(S3Padded, @bitCast(@as(u64, 0xe952d5c71ff4))).s3;
- try expectEqual(0xf4, s3.x.a);
- try expectEqual(0x1f, s3.x.b);
- try expectEqual(0xc7, s3.x.c);
- try expectEqual(0xd5, s3.y.d);
- try expectEqual(0x52, s3.y.e);
- try expectEqual(0xe9, s3.y.f);
- }
+ const s3 = @as(S3Padded, @bitCast(@as(u64, 0xe952d5c71ff4))).s3;
+ try expectEqual(0xf4, s3.x.a);
+ try expectEqual(0x1f, s3.x.b);
+ try expectEqual(0xc7, s3.x.c);
+ try expectEqual(0xd5, s3.y.d);
+ try expectEqual(0x52, s3.y.e);
+ try expectEqual(0xe9, s3.y.f);
const S4 = packed struct { a: i32, b: i8 };
const S5 = packed struct { a: i32, b: i8, c: S4 };
@@ -252,7 +247,6 @@ test "nested packed struct unaligned" {
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 (native_endian != .little) return error.SkipZigTest; // Byte aligned packed struct field pointers have not been implemented yet
const S1 = packed struct {
a: u4,
@@ -344,21 +338,12 @@ test "byte-aligned field pointer offsets" {
.c = 3,
.d = 4,
};
- switch (comptime builtin.cpu.arch.endian()) {
- .little => {
- comptime assert(@TypeOf(&a.a) == *align(4) u8);
- comptime assert(@TypeOf(&a.b) == *u8);
- comptime assert(@TypeOf(&a.c) == *align(2) u8);
- comptime assert(@TypeOf(&a.d) == *u8);
- },
- .big => {
- // TODO re-evaluate packed struct endianness
- comptime assert(@TypeOf(&a.a) == *align(4:0:4) u8);
- comptime assert(@TypeOf(&a.b) == *align(4:8:4) u8);
- comptime assert(@TypeOf(&a.c) == *align(4:16:4) u8);
- comptime assert(@TypeOf(&a.d) == *align(4:24:4) u8);
- },
- }
+
+ comptime assert(@TypeOf(&a.a) == *align(4:0:4) u8);
+ comptime assert(@TypeOf(&a.b) == *align(4:8:4) u8);
+ comptime assert(@TypeOf(&a.c) == *align(4:16:4) u8);
+ comptime assert(@TypeOf(&a.d) == *align(4:24:4) u8);
+
try expect(a.a == 1);
try expect(a.b == 2);
try expect(a.c == 3);
@@ -392,16 +377,10 @@ test "byte-aligned field pointer offsets" {
.a = 1,
.b = 2,
};
- switch (comptime builtin.cpu.arch.endian()) {
- .little => {
- comptime assert(@TypeOf(&b.a) == *align(4) u16);
- comptime assert(@TypeOf(&b.b) == *u16);
- },
- .big => {
- comptime assert(@TypeOf(&b.a) == *align(4:0:4) u16);
- comptime assert(@TypeOf(&b.b) == *align(4:16:4) u16);
- },
- }
+
+ comptime assert(@TypeOf(&b.a) == *align(4:0:4) u16);
+ comptime assert(@TypeOf(&b.b) == *align(4:16:4) u16);
+
try expect(b.a == 1);
try expect(b.b == 2);
@@ -426,7 +405,6 @@ test "nested packed struct field pointers" {
if (builtin.zig_backend == .stage2_spirv) return error.SkipZigTest;
if (builtin.zig_backend == .stage2_c) return error.SkipZigTest; // ubsan unaligned pointer access
if (builtin.zig_backend == .stage2_riscv64) return error.SkipZigTest; // TODO
- if (native_endian != .little) return error.SkipZigTest; // Byte aligned packed struct field pointers have not been implemented yet
const S2 = packed struct {
base: u8,
@@ -483,7 +461,6 @@ test "@intFromPtr on a packed struct field" {
if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest;
if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_spirv) return error.SkipZigTest;
- if (native_endian != .little) return error.SkipZigTest;
const S = struct {
const P = packed struct {
@@ -498,14 +475,13 @@ test "@intFromPtr on a packed struct field" {
.z = 0,
};
};
- try expect(@intFromPtr(&S.p0.z) - @intFromPtr(&S.p0.x) == 2);
+ try expect(@intFromPtr(&S.p0.z) - @intFromPtr(&S.p0.x) == 0);
}
test "@intFromPtr on a packed struct field unaligned and nested" {
if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest;
if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_spirv) return error.SkipZigTest;
- if (native_endian != .little) return error.SkipZigTest; // Byte aligned packed struct field pointers have not been implemented yet
const S1 = packed struct {
a: u4,
@@ -565,16 +541,16 @@ test "@intFromPtr on a packed struct field unaligned and nested" {
else => {},
}
try expect(@intFromPtr(&S2.s.base) - @intFromPtr(&S2.s) == 0);
- try expect(@intFromPtr(&S2.s.p0.a) - @intFromPtr(&S2.s) == 1);
- try expect(@intFromPtr(&S2.s.p0.b) - @intFromPtr(&S2.s) == 1);
- try expect(@intFromPtr(&S2.s.p0.c) - @intFromPtr(&S2.s) == 2);
+ try expect(@intFromPtr(&S2.s.p0.a) - @intFromPtr(&S2.s) == 0);
+ try expect(@intFromPtr(&S2.s.p0.b) - @intFromPtr(&S2.s) == 0);
+ try expect(@intFromPtr(&S2.s.p0.c) - @intFromPtr(&S2.s) == 0);
try expect(@intFromPtr(&S2.s.bit0) - @intFromPtr(&S2.s) == 0);
try expect(@intFromPtr(&S2.s.p1.a) - @intFromPtr(&S2.s) == 0);
try expect(@intFromPtr(&S2.s.p2.a) - @intFromPtr(&S2.s) == 0);
- try expect(@intFromPtr(&S2.s.p2.b) - @intFromPtr(&S2.s) == 5);
- try expect(@intFromPtr(&S2.s.p3.a) - @intFromPtr(&S2.s) == 6);
- try expect(@intFromPtr(&S2.s.p3.b) - @intFromPtr(&S2.s) == 6);
- try expect(@intFromPtr(&S2.s.p3.c) - @intFromPtr(&S2.s) == 7);
+ try expect(@intFromPtr(&S2.s.p2.b) - @intFromPtr(&S2.s) == 0);
+ try expect(@intFromPtr(&S2.s.p3.a) - @intFromPtr(&S2.s) == 0);
+ try expect(@intFromPtr(&S2.s.p3.b) - @intFromPtr(&S2.s) == 0);
+ try expect(@intFromPtr(&S2.s.p3.c) - @intFromPtr(&S2.s) == 0);
const S3 = packed struct {
pad: u8,
@@ -597,7 +573,7 @@ test "@intFromPtr on a packed struct field unaligned and nested" {
comptime assert(@TypeOf(&S3.v0.s.v) == *align(4:10:4) u3);
comptime assert(@TypeOf(&S3.v0.s.s.v) == *align(4:13:4) u2);
comptime assert(@TypeOf(&S3.v0.s.s.s.bit0) == *align(4:15:4) u1);
- comptime assert(@TypeOf(&S3.v0.s.s.s.byte) == *align(2) u8);
+ comptime assert(@TypeOf(&S3.v0.s.s.s.byte) == *align(4:16:4) u8);
comptime assert(@TypeOf(&S3.v0.s.s.s.bit1) == *align(4:24:4) u1);
try expect(@intFromPtr(&S3.v0.v) - @intFromPtr(&S3.v0) == 0);
try expect(@intFromPtr(&S3.v0.s) - @intFromPtr(&S3.v0) == 0);
@@ -606,7 +582,7 @@ test "@intFromPtr on a packed struct field unaligned and nested" {
try expect(@intFromPtr(&S3.v0.s.s.v) - @intFromPtr(&S3.v0) == 0);
try expect(@intFromPtr(&S3.v0.s.s.s) - @intFromPtr(&S3.v0) == 0);
try expect(@intFromPtr(&S3.v0.s.s.s.bit0) - @intFromPtr(&S3.v0) == 0);
- try expect(@intFromPtr(&S3.v0.s.s.s.byte) - @intFromPtr(&S3.v0) == 2);
+ try expect(@intFromPtr(&S3.v0.s.s.s.byte) - @intFromPtr(&S3.v0) == 0);
try expect(@intFromPtr(&S3.v0.s.s.s.bit1) - @intFromPtr(&S3.v0) == 0);
}
@@ -915,17 +891,8 @@ test "overaligned pointer to packed struct" {
const S = packed struct { a: u32, b: u32 };
var foo: S align(4) = .{ .a = 123, .b = 456 };
const ptr: *align(4) S = &foo;
- switch (comptime builtin.cpu.arch.endian()) {
- .little => {
- const ptr_to_b: *u32 = &ptr.b;
- try expect(ptr_to_b.* == 456);
- },
- .big => {
- // Byte aligned packed struct field pointers have not been implemented yet.
- const ptr_to_a: *align(4:0:8) u32 = &ptr.a;
- try expect(ptr_to_a.* == 123);
- },
- }
+ const ptr_to_a: *align(4:0:8) u32 = &ptr.a;
+ try expect(ptr_to_a.* == 123);
}
test "packed struct initialized in bitcast" {