diff options
Diffstat (limited to 'std/math.zig')
| -rw-r--r-- | std/math.zig | 16 |
1 files changed, 11 insertions, 5 deletions
diff --git a/std/math.zig b/std/math.zig index 765df6280c..92b6065e3c 100644 --- a/std/math.zig +++ b/std/math.zig @@ -288,10 +288,8 @@ pub fn shl(comptime T: type, a: T, shift_amt: var) T { const abs_shift_amt = absCast(shift_amt); const casted_shift_amt = if (abs_shift_amt >= T.bit_count) return 0 else @intCast(Log2Int(T), abs_shift_amt); - if (@typeOf(shift_amt).is_signed) { - if (shift_amt >= 0) { - return a << casted_shift_amt; - } else { + if (@typeOf(shift_amt) == comptime_int or @typeOf(shift_amt).is_signed) { + if (shift_amt < 0) { return a >> casted_shift_amt; } } @@ -304,6 +302,10 @@ test "math.shl" { testing.expect(shl(u8, 0b11111111, usize(8)) == 0); testing.expect(shl(u8, 0b11111111, usize(9)) == 0); testing.expect(shl(u8, 0b11111111, isize(-2)) == 0b00111111); + testing.expect(shl(u8, 0b11111111, 3) == 0b11111000); + testing.expect(shl(u8, 0b11111111, 8) == 0); + testing.expect(shl(u8, 0b11111111, 9) == 0); + testing.expect(shl(u8, 0b11111111, -2) == 0b00111111); } /// Shifts right. Overflowed bits are truncated. @@ -312,7 +314,7 @@ pub fn shr(comptime T: type, a: T, shift_amt: var) T { const abs_shift_amt = absCast(shift_amt); const casted_shift_amt = if (abs_shift_amt >= T.bit_count) return 0 else @intCast(Log2Int(T), abs_shift_amt); - if (@typeOf(shift_amt).is_signed) { + if (@typeOf(shift_amt) == comptime_int or @typeOf(shift_amt).is_signed) { if (shift_amt >= 0) { return a >> casted_shift_amt; } else { @@ -328,6 +330,10 @@ test "math.shr" { testing.expect(shr(u8, 0b11111111, usize(8)) == 0); testing.expect(shr(u8, 0b11111111, usize(9)) == 0); testing.expect(shr(u8, 0b11111111, isize(-2)) == 0b11111100); + testing.expect(shr(u8, 0b11111111, 3) == 0b00011111); + testing.expect(shr(u8, 0b11111111, 8) == 0); + testing.expect(shr(u8, 0b11111111, 9) == 0); + testing.expect(shr(u8, 0b11111111, -2) == 0b11111100); } /// Rotates right. Only unsigned values can be rotated. |