Commit 1f4f8d34a1
Changed files (1)
lib
compiler_rt
lib/compiler_rt/memcmp.zig
@@ -5,27 +5,26 @@ comptime {
@export(memcmp, .{ .name = "memcmp", .linkage = common.linkage });
}
-pub fn memcmp(vl: ?[*]const u8, vr: ?[*]const u8, n: usize) callconv(.C) c_int {
- @setRuntimeSafety(false);
-
- var index: usize = 0;
- while (index != n) : (index += 1) {
- const compare_val = @bitCast(i8, vl.?[index] -% vr.?[index]);
- if (compare_val != 0) {
- return compare_val;
- }
+pub fn memcmp(vl: [*]const u8, vr: [*]const u8, n: usize) callconv(.C) c_int {
+ var i: usize = 0;
+ while (i < n) : (i += 1) {
+ const compared = @as(c_int, vl[i]) -% @as(c_int, vr[i]);
+ if (compared != 0) return compared;
}
-
return 0;
}
test "memcmp" {
- const base_arr = &[_]u8{ 1, 1, 1 };
+ const arr0 = &[_]u8{ 1, 1, 1 };
const arr1 = &[_]u8{ 1, 1, 1 };
const arr2 = &[_]u8{ 1, 0, 1 };
const arr3 = &[_]u8{ 1, 2, 1 };
+ const arr4 = &[_]u8{ 1, 0xff, 1 };
+
+ try std.testing.expect(memcmp(arr0, arr1, 3) == 0);
+ try std.testing.expect(memcmp(arr0, arr2, 3) > 0);
+ try std.testing.expect(memcmp(arr0, arr3, 3) < 0);
- try std.testing.expect(memcmp(base_arr[0..], arr1[0..], base_arr.len) == 0);
- try std.testing.expect(memcmp(base_arr[0..], arr2[0..], base_arr.len) > 0);
- try std.testing.expect(memcmp(base_arr[0..], arr3[0..], base_arr.len) < 0);
+ try std.testing.expect(memcmp(arr0, arr4, 3) < 0);
+ try std.testing.expect(memcmp(arr4, arr0, 3) > 0);
}