Commit 852c820841

@@ -1901,6 +1901,10 @@ fn airOverflow(self: *Self, inst: Air.Inst.Index) !void {
                             }
                         };
 
+                        if (tag == .sub_with_overflow) {
+                            break :result MCValue{ .register_v_flag = dest.register };
+                        }
+
                         switch (int_info.signedness) {
                             .unsigned => break :result MCValue{ .register_c_flag = dest.register },
                             .signed => break :result MCValue{ .register_v_flag = dest.register },

@@ -621,24 +621,41 @@ test "128-bit multiplication" {
 test "@addWithOverflow" {
     if (builtin.zig_backend == .stage2_c) return error.SkipZigTest; // TODO
 
-    var result: u8 = undefined;
-    try expect(@addWithOverflow(u8, 250, 100, &result));
-    try expect(result == 94);
-    try expect(!@addWithOverflow(u8, 100, 150, &result));
-    try expect(result == 250);
-
-    var a: u8 = 200;
-    var b: u8 = 99;
-    try expect(@addWithOverflow(u8, a, b, &result));
-    try expect(result == 43);
-    b = 55;
-    try expect(!@addWithOverflow(u8, a, b, &result));
-    try expect(result == 255);
+    {
+        var result: u8 = undefined;
+        try expect(@addWithOverflow(u8, 250, 100, &result));
+        try expect(result == 94);
+        try expect(!@addWithOverflow(u8, 100, 150, &result));
+        try expect(result == 250);
+
+        var a: u8 = 200;
+        var b: u8 = 99;
+        try expect(@addWithOverflow(u8, a, b, &result));
+        try expect(result == 43);
+        b = 55;
+        try expect(!@addWithOverflow(u8, a, b, &result));
+        try expect(result == 255);
+    }
+
+    {
+        var a: usize = 6;
+        var b: usize = 6;
+        var res: usize = undefined;
+        try expect(!@addWithOverflow(usize, a, b, &res));
+        try expect(res == 12);
+    }
+
+    {
+        var a: isize = -6;
+        var b: isize = -6;
+        var res: isize = undefined;
+        try expect(!@addWithOverflow(isize, a, b, &res));
+        try expect(res == -12);
+    }
 }
 
 test "small int addition" {
     if (builtin.zig_backend == .stage2_c) return error.SkipZigTest; // TODO
-    if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
     if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
 
     var x: u2 = 0;
@@ -886,19 +903,37 @@ test "@mulWithOverflow bitsize > 32" {
 test "@subWithOverflow" {
     if (builtin.zig_backend == .stage2_c) return error.SkipZigTest; // TODO
 
-    var result: u8 = undefined;
-    try expect(@subWithOverflow(u8, 1, 2, &result));
-    try expect(result == 255);
-    try expect(!@subWithOverflow(u8, 1, 1, &result));
-    try expect(result == 0);
+    {
+        var result: u8 = undefined;
+        try expect(@subWithOverflow(u8, 1, 2, &result));
+        try expect(result == 255);
+        try expect(!@subWithOverflow(u8, 1, 1, &result));
+        try expect(result == 0);
 
-    var a: u8 = 1;
-    var b: u8 = 2;
-    try expect(@subWithOverflow(u8, a, b, &result));
-    try expect(result == 255);
-    b = 1;
-    try expect(!@subWithOverflow(u8, a, b, &result));
-    try expect(result == 0);
+        var a: u8 = 1;
+        var b: u8 = 2;
+        try expect(@subWithOverflow(u8, a, b, &result));
+        try expect(result == 255);
+        b = 1;
+        try expect(!@subWithOverflow(u8, a, b, &result));
+        try expect(result == 0);
+    }
+
+    {
+        var a: usize = 6;
+        var b: usize = 6;
+        var res: usize = undefined;
+        try expect(!@subWithOverflow(usize, a, b, &res));
+        try expect(res == 0);
+    }
+
+    {
+        var a: isize = -6;
+        var b: isize = -6;
+        var res: isize = undefined;
+        try expect(!@subWithOverflow(isize, a, b, &res));
+        try expect(res == 0);
+    }
 }
 
 test "@shlWithOverflow" {