authorgravatar for sahnvour@pm.meSahnvour <sahnvour@pm.me> 2019-06-09 14:44:41+02:00
committergravatar for sahnvour@pm.meSahnvour <sahnvour@pm.me> 2019-06-09 14:44:41+02:00
log8e0670198b249f44e789f4380fd17d6de918832c
tree421c6807f367cfa3c0ea25d892d0d0c2488031ce
parent10e33b35368735d1911a073bcb7cbbaebee671ee

allow comptime_int in math.shl and math.shr

1 files changed, 11 insertions(+), 5 deletions(-)

std/math.zig+11-5
...@@ -288,10 +288,8 @@ pub fn shl(comptime T: type, a: T, shift_amt: var) T {...@@ -288,10 +288,8 @@ pub fn shl(comptime T: type, a: T, shift_amt: var) T {
288 const abs_shift_amt = absCast(shift_amt);288 const abs_shift_amt = absCast(shift_amt);
289 const casted_shift_amt = if (abs_shift_amt >= T.bit_count) return 0 else @intCast(Log2Int(T), abs_shift_amt);289 const casted_shift_amt = if (abs_shift_amt >= T.bit_count) return 0 else @intCast(Log2Int(T), abs_shift_amt);
290290
291 if (@typeOf(shift_amt).is_signed) {291 if (@typeOf(shift_amt) == comptime_int or @typeOf(shift_amt).is_signed) {
292 if (shift_amt >= 0) {292 if (shift_amt < 0) {
293 return a << casted_shift_amt;
294 } else {
295 return a >> casted_shift_amt;293 return a >> casted_shift_amt;
296 }294 }
297 }295 }
...@@ -304,6 +302,10 @@ test "math.shl" {...@@ -304,6 +302,10 @@ test "math.shl" {
304 testing.expect(shl(u8, 0b11111111, usize(8)) == 0);302 testing.expect(shl(u8, 0b11111111, usize(8)) == 0);
305 testing.expect(shl(u8, 0b11111111, usize(9)) == 0);303 testing.expect(shl(u8, 0b11111111, usize(9)) == 0);
306 testing.expect(shl(u8, 0b11111111, isize(-2)) == 0b00111111);304 testing.expect(shl(u8, 0b11111111, isize(-2)) == 0b00111111);
305 testing.expect(shl(u8, 0b11111111, 3) == 0b11111000);
306 testing.expect(shl(u8, 0b11111111, 8) == 0);
307 testing.expect(shl(u8, 0b11111111, 9) == 0);
308 testing.expect(shl(u8, 0b11111111, -2) == 0b00111111);
307}309}
308310
309/// Shifts right. Overflowed bits are truncated.311/// Shifts right. Overflowed bits are truncated.
...@@ -312,7 +314,7 @@ pub fn shr(comptime T: type, a: T, shift_amt: var) T {...@@ -312,7 +314,7 @@ pub fn shr(comptime T: type, a: T, shift_amt: var) T {
312 const abs_shift_amt = absCast(shift_amt);314 const abs_shift_amt = absCast(shift_amt);
313 const casted_shift_amt = if (abs_shift_amt >= T.bit_count) return 0 else @intCast(Log2Int(T), abs_shift_amt);315 const casted_shift_amt = if (abs_shift_amt >= T.bit_count) return 0 else @intCast(Log2Int(T), abs_shift_amt);
314316
315 if (@typeOf(shift_amt).is_signed) {317 if (@typeOf(shift_amt) == comptime_int or @typeOf(shift_amt).is_signed) {
316 if (shift_amt >= 0) {318 if (shift_amt >= 0) {
317 return a >> casted_shift_amt;319 return a >> casted_shift_amt;
318 } else {320 } else {
...@@ -328,6 +330,10 @@ test "math.shr" {...@@ -328,6 +330,10 @@ test "math.shr" {
328 testing.expect(shr(u8, 0b11111111, usize(8)) == 0);330 testing.expect(shr(u8, 0b11111111, usize(8)) == 0);
329 testing.expect(shr(u8, 0b11111111, usize(9)) == 0);331 testing.expect(shr(u8, 0b11111111, usize(9)) == 0);
330 testing.expect(shr(u8, 0b11111111, isize(-2)) == 0b11111100);332 testing.expect(shr(u8, 0b11111111, isize(-2)) == 0b11111100);
333 testing.expect(shr(u8, 0b11111111, 3) == 0b00011111);
334 testing.expect(shr(u8, 0b11111111, 8) == 0);
335 testing.expect(shr(u8, 0b11111111, 9) == 0);
336 testing.expect(shr(u8, 0b11111111, -2) == 0b11111100);
331}337}
332338
333/// Rotates right. Only unsigned values can be rotated.339/// Rotates right. Only unsigned values can be rotated.