tiny.chant.ast.types.layout

1const std = @import("std");2const types = @import("types.zig");34const Type = types.Type;56pub fn byteSize(c_type: *const Type) ?u64 {7    return switch (c_type.kind) {8        .auto_type, .void_type, .struct_type => null,9        .nullptr_type => 8,10        .enum_type => byteSize(c_type.child orelse &types.int_type),11        .char_type => 1,12        .short_type => 2,13        .int_type => 4,14        .long_type => 8,15        .bitint_type => bitintByteSize(c_type.bit_width),16        .float_type => 4,17        .double_type => 8,18        .decimal32_type => 4,19        .decimal64_type => 8,20        .decimal128_type => 16,21        .pointer => 8,22        .array => if (c_type.array_len) |len| blk: {23            const child_size = byteSize(c_type.child orelse return null) orelse return null;24            break :blk len * child_size;25        } else null,26        .function => null,27    };28}2930pub fn byteAlign(c_type: *const Type) ?u64 {31    return switch (c_type.kind) {32        .auto_type, .void_type, .struct_type, .function => null,33        .nullptr_type => 8,34        .enum_type => byteAlign(c_type.child orelse &types.int_type),35        .char_type => 1,36        .short_type => 2,37        .int_type => 4,38        .long_type => 8,39        .bitint_type => bitintByteAlign(c_type.bit_width),40        .float_type => 4,41        .double_type => 8,42        .decimal32_type => 4,43        .decimal64_type => 8,44        .decimal128_type => 16,45        .pointer => 8,46        .array => byteAlign(c_type.child orelse return null),47    };48}4950fn bitintByteSize(width: u16) u64 {51    return (@as(u64, width) + 7) / 8;52}5354fn bitintByteAlign(width: u16) u64 {55    const size = bitintByteSize(width);56    if (size <= 1) return 1;57    if (size <= 2) return 2;58    if (size <= 4) return 4;59    return 8;60}6162test "byte sizes follow the lp64 model" {63    try std.testing.expectEqual(@as(u64, 4), byteSize(&types.int_type).?);64    try std.testing.expectEqual(@as(u64, 8), byteSize(&types.long_type).?);65    try std.testing.expectEqual(@as(u64, 8), byteSize(&types.double_type).?);66    try std.testing.expectEqual(@as(u64, 16), byteSize(&types.decimal128_type).?);6768    const pointer = Type{ .kind = .pointer, .child = &types.double_type };69    try std.testing.expectEqual(@as(u64, 8), byteSize(&pointer).?);7071    const bitint = Type{ .kind = .bitint_type, .bit_width = 17 };72    try std.testing.expectEqual(@as(u64, 3), byteSize(&bitint).?);7374    const fixed_enum = Type{ .kind = .enum_type, .child = &types.uchar_type };75    try std.testing.expectEqual(@as(u64, 1), byteSize(&fixed_enum).?);7677    const array = Type{ .kind = .array, .child = &types.double_type, .array_len = 10 };78    try std.testing.expectEqual(@as(u64, 80), byteSize(&array).?);79}8081test "byte alignments follow the lp64 model" {82    try std.testing.expectEqual(@as(u64, 1), byteAlign(&types.char_type).?);83    try std.testing.expectEqual(@as(u64, 4), byteAlign(&types.int_type).?);84    try std.testing.expectEqual(@as(u64, 8), byteAlign(&types.double_type).?);85    try std.testing.expectEqual(@as(u64, 16), byteAlign(&types.decimal128_type).?);8687    const pointer = Type{ .kind = .pointer, .child = &types.double_type };88    try std.testing.expectEqual(@as(u64, 8), byteAlign(&pointer).?);8990    const bitint = Type{ .kind = .bitint_type, .bit_width = 17 };91    try std.testing.expectEqual(@as(u64, 4), byteAlign(&bitint).?);9293    const fixed_enum = Type{ .kind = .enum_type, .child = &types.uchar_type };94    try std.testing.expectEqual(@as(u64, 1), byteAlign(&fixed_enum).?);9596    const array = Type{ .kind = .array, .child = &types.double_type, .array_len = 10 };97    try std.testing.expectEqual(@as(u64, 8), byteAlign(&array).?);98}

1pub const layout = layout_mod;