mirror of
https://github.com/ziglang/zig.git
synced 2025-12-08 23:33:07 +00:00
428 lines
14 KiB
Zig
428 lines
14 KiB
Zig
const std = @import("std");
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const expect = std.testing.expect;
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const builtin = @import("builtin");
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const native_arch = builtin.target.cpu.arch;
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var foo: u8 align(4) = 100;
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test "global variable alignment" {
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if (builtin.zig_backend != .stage1) return error.SkipZigTest; // TODO
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comptime try expect(@typeInfo(@TypeOf(&foo)).Pointer.alignment == 4);
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comptime try expect(@TypeOf(&foo) == *align(4) u8);
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{
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const slice = @as(*[1]u8, &foo)[0..];
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comptime try expect(@TypeOf(slice) == *align(4) [1]u8);
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}
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{
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var runtime_zero: usize = 0;
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const slice = @as(*[1]u8, &foo)[runtime_zero..];
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comptime try expect(@TypeOf(slice) == []align(4) u8);
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}
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}
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test "default alignment allows unspecified in type syntax" {
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try expect(*u32 == *align(@alignOf(u32)) u32);
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}
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test "implicitly decreasing pointer alignment" {
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const a: u32 align(4) = 3;
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const b: u32 align(8) = 4;
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try expect(addUnaligned(&a, &b) == 7);
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}
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fn addUnaligned(a: *align(1) const u32, b: *align(1) const u32) u32 {
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return a.* + b.*;
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}
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test "@alignCast pointers" {
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var x: u32 align(4) = 1;
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expectsOnly1(&x);
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try expect(x == 2);
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}
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fn expectsOnly1(x: *align(1) u32) void {
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expects4(@alignCast(4, x));
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}
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fn expects4(x: *align(4) u32) void {
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x.* += 1;
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}
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test "alignment of structs" {
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try expect(@alignOf(struct {
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a: i32,
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b: *i32,
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}) == @alignOf(usize));
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}
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test "alignment of >= 128-bit integer type" {
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try expect(@alignOf(u128) == 16);
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try expect(@alignOf(u129) == 16);
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}
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test "alignment of struct with 128-bit field" {
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try expect(@alignOf(struct {
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x: u128,
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}) == 16);
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comptime {
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try expect(@alignOf(struct {
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x: u128,
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}) == 16);
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}
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}
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test "size of extern struct with 128-bit field" {
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try expect(@sizeOf(extern struct {
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x: u128,
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y: u8,
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}) == 32);
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comptime {
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try expect(@sizeOf(extern struct {
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x: u128,
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y: u8,
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}) == 32);
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}
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}
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test "@ptrCast preserves alignment of bigger source" {
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if (builtin.zig_backend != .stage1) return error.SkipZigTest; // TODO
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var x: u32 align(16) = 1234;
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const ptr = @ptrCast(*u8, &x);
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try expect(@TypeOf(ptr) == *align(16) u8);
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}
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test "alignstack" {
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try expect(fnWithAlignedStack() == 1234);
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}
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fn fnWithAlignedStack() i32 {
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@setAlignStack(256);
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return 1234;
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}
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test "implicitly decreasing slice alignment" {
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if (builtin.zig_backend == .stage2_c) return error.SkipZigTest;
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if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;
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const a: u32 align(4) = 3;
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const b: u32 align(8) = 4;
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try expect(addUnalignedSlice(@as(*const [1]u32, &a)[0..], @as(*const [1]u32, &b)[0..]) == 7);
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}
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fn addUnalignedSlice(a: []align(1) const u32, b: []align(1) const u32) u32 {
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return a[0] + b[0];
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}
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test "specifying alignment allows pointer cast" {
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if (builtin.zig_backend == .stage2_c) return error.SkipZigTest;
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if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;
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if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest;
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try testBytesAlign(0x33);
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}
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fn testBytesAlign(b: u8) !void {
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var bytes align(4) = [_]u8{ b, b, b, b };
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const ptr = @ptrCast(*u32, &bytes[0]);
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try expect(ptr.* == 0x33333333);
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}
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test "@alignCast slices" {
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if (builtin.zig_backend == .stage2_c) return error.SkipZigTest;
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if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;
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if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest;
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var array align(4) = [_]u32{ 1, 1 };
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const slice = array[0..];
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sliceExpectsOnly1(slice);
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try expect(slice[0] == 2);
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}
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fn sliceExpectsOnly1(slice: []align(1) u32) void {
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sliceExpects4(@alignCast(4, slice));
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}
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fn sliceExpects4(slice: []align(4) u32) void {
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slice[0] += 1;
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}
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test "return error union with 128-bit integer" {
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if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;
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if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest;
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if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest;
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if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest;
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try expect(3 == try give());
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}
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fn give() anyerror!u128 {
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return 3;
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}
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test "page aligned array on stack" {
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if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;
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if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest;
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if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest;
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if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest;
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// Large alignment value to make it hard to accidentally pass.
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var array align(0x1000) = [_]u8{ 1, 2, 3, 4, 5, 6, 7, 8 };
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var number1: u8 align(16) = 42;
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var number2: u8 align(16) = 43;
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try expect(@ptrToInt(&array[0]) & 0xFFF == 0);
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try expect(array[3] == 4);
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try expect(@truncate(u4, @ptrToInt(&number1)) == 0);
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try expect(@truncate(u4, @ptrToInt(&number2)) == 0);
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try expect(number1 == 42);
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try expect(number2 == 43);
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}
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fn derp() align(@sizeOf(usize) * 2) i32 {
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return 1234;
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}
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fn noop1() align(1) void {}
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fn noop4() align(4) void {}
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test "function alignment" {
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if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;
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if (builtin.zig_backend == .stage2_c) return error.SkipZigTest;
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if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest;
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// function alignment is a compile error on wasm32/wasm64
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if (native_arch == .wasm32 or native_arch == .wasm64) return error.SkipZigTest;
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try expect(derp() == 1234);
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try expect(@TypeOf(noop1) == fn () align(1) void);
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try expect(@TypeOf(noop4) == fn () align(4) void);
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noop1();
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noop4();
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}
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test "implicitly decreasing fn alignment" {
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if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;
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if (builtin.zig_backend == .stage1) return error.SkipZigTest;
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if (builtin.zig_backend == .stage2_llvm) return error.SkipZigTest;
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if (builtin.zig_backend == .stage2_c) return error.SkipZigTest;
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if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest;
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if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest;
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// function alignment is a compile error on wasm32/wasm64
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if (native_arch == .wasm32 or native_arch == .wasm64) return error.SkipZigTest;
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try testImplicitlyDecreaseFnAlign(alignedSmall, 1234);
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try testImplicitlyDecreaseFnAlign(alignedBig, 5678);
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}
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// TODO make it a compile error to put align on the fn proto instead of on the ptr
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fn testImplicitlyDecreaseFnAlign(ptr: *align(1) const fn () i32, answer: i32) !void {
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try expect(ptr() == answer);
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}
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fn alignedSmall() align(8) i32 {
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return 1234;
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}
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fn alignedBig() align(16) i32 {
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return 5678;
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}
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test "@alignCast functions" {
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if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;
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if (builtin.zig_backend == .stage1) return error.SkipZigTest;
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if (builtin.zig_backend == .stage2_c) return error.SkipZigTest;
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if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest;
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// function alignment is a compile error on wasm32/wasm64
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if (native_arch == .wasm32 or native_arch == .wasm64) return error.SkipZigTest;
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if (native_arch == .thumb) return error.SkipZigTest;
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try expect(fnExpectsOnly1(simple4) == 0x19);
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}
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fn fnExpectsOnly1(ptr: *const fn () align(1) i32) i32 {
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return fnExpects4(@alignCast(4, ptr));
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}
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fn fnExpects4(ptr: *align(4) const fn () i32) i32 {
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return ptr();
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}
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fn simple4() align(4) i32 {
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return 0x19;
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}
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test "generic function with align param" {
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if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;
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if (builtin.zig_backend == .stage2_llvm) return error.SkipZigTest;
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if (builtin.zig_backend == .stage2_c) return error.SkipZigTest;
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if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest;
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if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest;
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// function alignment is a compile error on wasm32/wasm64
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if (native_arch == .wasm32 or native_arch == .wasm64) return error.SkipZigTest;
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if (native_arch == .thumb) return error.SkipZigTest;
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try expect(whyWouldYouEverDoThis(1) == 0x1);
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try expect(whyWouldYouEverDoThis(4) == 0x1);
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try expect(whyWouldYouEverDoThis(8) == 0x1);
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}
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fn whyWouldYouEverDoThis(comptime align_bytes: u8) align(align_bytes) u8 {
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_ = align_bytes;
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return 0x1;
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}
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test "runtime known array index has best alignment possible" {
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if (builtin.zig_backend != .stage1) return error.SkipZigTest; // TODO
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if (builtin.zig_backend == .stage2_c) return error.SkipZigTest; // TODO
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// take full advantage of over-alignment
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var array align(4) = [_]u8{ 1, 2, 3, 4 };
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try expect(@TypeOf(&array[0]) == *align(4) u8);
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try expect(@TypeOf(&array[1]) == *u8);
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try expect(@TypeOf(&array[2]) == *align(2) u8);
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try expect(@TypeOf(&array[3]) == *u8);
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// because align is too small but we still figure out to use 2
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var bigger align(2) = [_]u64{ 1, 2, 3, 4 };
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try expect(@TypeOf(&bigger[0]) == *align(2) u64);
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try expect(@TypeOf(&bigger[1]) == *align(2) u64);
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try expect(@TypeOf(&bigger[2]) == *align(2) u64);
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try expect(@TypeOf(&bigger[3]) == *align(2) u64);
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// because pointer is align 2 and u32 align % 2 == 0 we can assume align 2
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var smaller align(2) = [_]u32{ 1, 2, 3, 4 };
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var runtime_zero: usize = 0;
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comptime try expect(@TypeOf(smaller[runtime_zero..]) == []align(2) u32);
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comptime try expect(@TypeOf(smaller[runtime_zero..].ptr) == [*]align(2) u32);
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try testIndex(smaller[runtime_zero..].ptr, 0, *align(2) u32);
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try testIndex(smaller[runtime_zero..].ptr, 1, *align(2) u32);
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try testIndex(smaller[runtime_zero..].ptr, 2, *align(2) u32);
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try testIndex(smaller[runtime_zero..].ptr, 3, *align(2) u32);
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// has to use ABI alignment because index known at runtime only
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try testIndex2(array[runtime_zero..].ptr, 0, *u8);
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try testIndex2(array[runtime_zero..].ptr, 1, *u8);
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try testIndex2(array[runtime_zero..].ptr, 2, *u8);
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try testIndex2(array[runtime_zero..].ptr, 3, *u8);
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}
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fn testIndex(smaller: [*]align(2) u32, index: usize, comptime T: type) !void {
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comptime try expect(@TypeOf(&smaller[index]) == T);
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}
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fn testIndex2(ptr: [*]align(4) u8, index: usize, comptime T: type) !void {
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comptime try expect(@TypeOf(&ptr[index]) == T);
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}
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test "alignment of function with c calling convention" {
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if (builtin.zig_backend == .stage1) return error.SkipZigTest;
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var runtime_nothing = ¬hing;
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const casted1 = @ptrCast(*const u8, runtime_nothing);
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const casted2 = @ptrCast(*const fn () callconv(.C) void, casted1);
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casted2();
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}
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fn nothing() callconv(.C) void {}
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const DefaultAligned = struct {
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nevermind: u32,
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badguy: i128,
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};
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test "read 128-bit field from default aligned struct in stack memory" {
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if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;
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if (builtin.zig_backend == .stage2_llvm) return error.SkipZigTest;
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if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest;
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if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest;
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if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest;
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var default_aligned = DefaultAligned{
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.nevermind = 1,
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.badguy = 12,
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};
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try expect((@ptrToInt(&default_aligned.badguy) % 16) == 0);
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try expect(12 == default_aligned.badguy);
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}
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var default_aligned_global = DefaultAligned{
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.nevermind = 1,
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.badguy = 12,
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};
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test "read 128-bit field from default aligned struct in global memory" {
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if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;
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if (builtin.zig_backend == .stage2_llvm) return error.SkipZigTest;
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if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest;
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if (builtin.zig_backend == .stage2_c) return error.SkipZigTest;
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if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest;
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if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest;
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try expect((@ptrToInt(&default_aligned_global.badguy) % 16) == 0);
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try expect(12 == default_aligned_global.badguy);
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}
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test "struct field explicit alignment" {
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if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;
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if (builtin.zig_backend == .stage2_llvm) return error.SkipZigTest;
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if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest;
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if (builtin.zig_backend == .stage2_c) return error.SkipZigTest;
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if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest;
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if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest;
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const S = struct {
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const Node = struct {
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next: *Node,
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massive_byte: u8 align(64),
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};
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};
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var node: S.Node = undefined;
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node.massive_byte = 100;
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try expect(node.massive_byte == 100);
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comptime try expect(@TypeOf(&node.massive_byte) == *align(64) u8);
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try expect(@ptrToInt(&node.massive_byte) % 64 == 0);
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}
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test "align(@alignOf(T)) T does not force resolution of T" {
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if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;
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if (builtin.zig_backend == .stage2_llvm) return error.SkipZigTest;
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if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest;
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if (builtin.zig_backend == .stage2_c) return error.SkipZigTest;
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if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest;
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if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest;
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const S = struct {
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const A = struct {
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a: *align(@alignOf(A)) A,
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};
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fn doTheTest() void {
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suspend {
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resume @frame();
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}
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_ = bar(@Frame(doTheTest));
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}
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fn bar(comptime T: type) *align(@alignOf(T)) T {
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ok = true;
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return undefined;
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}
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var ok = false;
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};
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_ = async S.doTheTest();
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try expect(S.ok);
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}
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test "align(N) on functions" {
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if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;
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if (builtin.zig_backend == .stage1) return error.SkipZigTest;
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if (builtin.zig_backend == .stage2_llvm) return error.SkipZigTest;
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if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest;
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if (builtin.zig_backend == .stage2_c) return error.SkipZigTest;
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if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest;
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if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest;
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// function alignment is a compile error on wasm32/wasm64
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if (native_arch == .wasm32 or native_arch == .wasm64) return error.SkipZigTest;
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if (native_arch == .thumb) return error.SkipZigTest;
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try expect((@ptrToInt(&overaligned_fn) & (0x1000 - 1)) == 0);
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}
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fn overaligned_fn() align(0x1000) i32 {
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return 42;
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}
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