diff --git a/test/behavior.zig b/test/behavior.zig
index 6ec59fa22df7..249d3191e65d 100644
--- a/test/behavior.zig
+++ b/test/behavior.zig
@@ -149,6 +149,7 @@ test {
     _ = @import("behavior/byval_arg_var.zig");
     _ = @import("behavior/c_char_signedness.zig");
     _ = @import("behavior/call.zig");
+    _ = @import("behavior/call_tail.zig");
     _ = @import("behavior/cast.zig");
     _ = @import("behavior/cast_int.zig");
     _ = @import("behavior/comptime_memory.zig");
diff --git a/test/behavior/call_tail.zig b/test/behavior/call_tail.zig
new file mode 100644
index 000000000000..371bab812362
--- /dev/null
+++ b/test/behavior/call_tail.zig
@@ -0,0 +1,59 @@
+const builtin = @import("builtin");
+const std = @import("std");
+const expect = std.testing.expect;
+
+var base: usize = undefined;
+var result_off: [7]usize = undefined;
+var result_len: [7]usize = undefined;
+var result_index: usize = 0;
+
+noinline fn insertionSort(data: []u64) void {
+    result_off[result_index] = @intFromPtr(data.ptr) - base;
+    result_len[result_index] = data.len;
+    result_index += 1;
+    if (data.len > 1) {
+        var least_i: usize = 0;
+        var i: usize = 1;
+        while (i < data.len) : (i += 1) {
+            if (data[i] < data[least_i])
+                least_i = i;
+        }
+        std.mem.swap(u64, &data[0], &data[least_i]);
+
+        // there used to be a bug where
+        // `data[1..]` is created on the stack
+        // and pointed to by the first argument register
+        // then stack is invalidated by the tailcall and
+        // overwritten by callee
+        // https://github.com/ziglang/zig/issues/9703
+        return @call(.always_tail, insertionSort, .{data[1..]});
+    }
+}
+
+test "arguments pointed to on stack into tailcall" {
+    switch (builtin.cpu.arch) {
+        .wasm32, .mips, .mipsel, .powerpc, .powerpcle, .powerpc64le => return error.SkipZigTest,
+        else => {},
+    }
+    if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest;
+    if (builtin.zig_backend == .stage2_c) return error.SkipZigTest;
+
+    var data = [_]u64{ 1, 6, 2, 7, 1, 9, 3 };
+    base = @intFromPtr(&data);
+    insertionSort(data[0..]);
+    try expect(result_len[0] == 7);
+    try expect(result_len[1] == 6);
+    try expect(result_len[2] == 5);
+    try expect(result_len[3] == 4);
+    try expect(result_len[4] == 3);
+    try expect(result_len[5] == 2);
+    try expect(result_len[6] == 1);
+
+    try expect(result_off[0] == 0);
+    try expect(result_off[1] == 8);
+    try expect(result_off[2] == 16);
+    try expect(result_off[3] == 24);
+    try expect(result_off[4] == 32);
+    try expect(result_off[5] == 40);
+    try expect(result_off[6] == 48);
+}
diff --git a/test/behavior/defer.zig b/test/behavior/defer.zig
index db776e598e27..dd7ded911de9 100644
--- a/test/behavior/defer.zig
+++ b/test/behavior/defer.zig
@@ -189,3 +189,15 @@ test "errdefer used in function that doesn't return an error" {
     };
     try expect(S.foo() == 5);
 }
+
+// Originally reported at https://github.com/ziglang/zig/issues/10591
+const defer_assign = switch (block: {
+    var x = 0;
+    defer x = 1;
+    break :block x;
+}) {
+    else => |i| i,
+};
+comptime {
+    if (defer_assign != 0) @compileError("defer_assign failed!");
+}
diff --git a/test/behavior/eval.zig b/test/behavior/eval.zig
index 24af16fc931c..80eabeaf933b 100644
--- a/test/behavior/eval.zig
+++ b/test/behavior/eval.zig
@@ -1703,3 +1703,13 @@ test "@inComptime" {
     try expectEqual(false, S.inComptime());
     try expectEqual(true, comptime S.inComptime());
 }
+
+// comptime partial array assign
+comptime {
+    var foo = [3]u8{ 0x55, 0x55, 0x55 };
+    var bar = [2]u8{ 1, 2 };
+    foo[0..2].* = bar;
+    assert(foo[0] == 1);
+    assert(foo[1] == 2);
+    assert(foo[2] == 0x55);
+}
diff --git a/test/behavior/packed-struct.zig b/test/behavior/packed-struct.zig
index e2970c36035f..d3d761c3dbc4 100644
--- a/test/behavior/packed-struct.zig
+++ b/test/behavior/packed-struct.zig
@@ -640,3 +640,13 @@ test "store undefined to packed result location" {
     var s = packed struct { x: u4, y: u4 }{ .x = x, .y = if (x > 0) x else undefined };
     try expectEqual(x, s.x);
 }
+
+test "bitcast back and forth" {
+    // Originally reported at https://github.com/ziglang/zig/issues/9914
+    const S = packed struct { one: u6, two: u1 };
+    const s = S{ .one = 0b110101, .two = 0b1 };
+    const u: u7 = @bitCast(s);
+    const s2: S = @bitCast(u);
+    try expect(s.one == s2.one);
+    try expect(s.two == s2.two);
+}
diff --git a/test/behavior/ptrcast.zig b/test/behavior/ptrcast.zig
index 3a2ec9db190f..8837c42a864c 100644
--- a/test/behavior/ptrcast.zig
+++ b/test/behavior/ptrcast.zig
@@ -284,3 +284,12 @@ test "@ptrCast undefined value at comptime" {
         _ = x;
     }
 }
+
+test "comptime @ptrCast with packed struct leaves value unmodified" {
+    const S = packed struct { three: u3 };
+    const st: S = .{ .three = 6 };
+    try expect(st.three == 6);
+    const p: *const [1]u3 = @ptrCast(&st);
+    try expect(p.*[0] == 6);
+    try expect(st.three == 6);
+}
diff --git a/test/behavior/switch.zig b/test/behavior/switch.zig
index 0ae7c510ef0e..7d90247a30ef 100644
--- a/test/behavior/switch.zig
+++ b/test/behavior/switch.zig
@@ -797,3 +797,22 @@ test "inline switch range that includes the maximum value of the switched type"
         }
     }
 }
+
+test "nested break ignores switch conditions and breaks instead" {
+    const S = struct {
+        fn register_to_address(ident: []const u8) !u8 {
+            const reg: u8 = if (std.mem.eql(u8, ident, "zero")) 0x00 else blk: {
+                break :blk switch (ident[0]) {
+                    0x61 => (try std.fmt.parseInt(u8, ident[1..], 0)) + 1,
+                    0x66 => (try std.fmt.parseInt(u8, ident[1..], 0)) + 1,
+                    else => {
+                        break :blk 0xFF;
+                    },
+                };
+            };
+            return reg;
+        }
+    };
+    // Originally reported at https://github.com/ziglang/zig/issues/10196
+    try expect(0x01 == try S.register_to_address("a0"));
+}
diff --git a/test/behavior/union.zig b/test/behavior/union.zig
index f7a481e311ef..3ea6f17a264a 100644
--- a/test/behavior/union.zig
+++ b/test/behavior/union.zig
@@ -1692,3 +1692,24 @@ test "packed union field pointer has correct alignment" {
     try expectEqual(@as(u20, 456), bp.*);
     try expectEqual(@as(u20, 789), cp.*);
 }
+
+test "union with 128 bit integer" {
+    const ValueTag = enum { int, other };
+
+    const Value3 = union(ValueTag) {
+        int: i128,
+        other: bool,
+    };
+    var values: [2]Value3 = undefined;
+    values[0] = .{ .int = 3 };
+    values[1] = .{ .int = 4 };
+
+    var ok: usize = 0;
+
+    for (values) |val| {
+        switch (val) {
+            .int => ok += 1,
+            else => return error.TestFailed,
+        }
+    }
+}