llvm: handle pointers in packed structs in more places

Closes #12776

1 files changed, 42 insertions, 0 deletions

diff --git a/test/behavior/bugs/12776.zig b/test/behavior/bugs/12776.zig
new file mode 100644
index 0000000000..e8fe106ac7
--- /dev/null
+++ b/test/behavior/bugs/12776.zig
@@ -0,0 +1,42 @@
+const std = @import("std");
+const builtin = @import("builtin");
+
+const RAM = struct {
+    data: [0xFFFF + 1]u8,
+    fn new() !RAM {
+        return RAM{ .data = [_]u8{0} ** 0x10000 };
+    }
+    fn get(self: *RAM, addr: u16) u8 {
+        return self.data[addr];
+    }
+};
+
+const CPU = packed struct {
+    interrupts: bool,
+    ram: *RAM,
+    fn new(ram: *RAM) !CPU {
+        return CPU{
+            .ram = ram,
+            .interrupts = false,
+        };
+    }
+    fn tick(self: *CPU) !void {
+        var queued_interrupts = self.ram.get(0xFFFF) & self.ram.get(0xFF0F);
+        if (self.interrupts and queued_interrupts != 0) {
+            self.interrupts = false;
+        }
+    }
+};
+
+test {
+    if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;
+    if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest;
+    if (builtin.zig_backend == .stage2_c) return error.SkipZigTest;
+    if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest;
+    if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest;
+
+    var ram = try RAM.new();
+    var cpu = try CPU.new(&ram);
+    try cpu.tick();
+    try std.testing.expect(cpu.interrupts == false);
+}