Commit d7b029995c8ac678598de39aa106076dca232902 | zig

2 files changed, 21 insertions(+), 6 deletions(-)

src/bigint.cpp+4-6

...	...	@@ -1259,12 +1259,11 @@ void bigint_and(BigInt dest, const BigInt op1, const BigInt *op2) {
1259	1259	bigint_normalize(dest);
1260	1260	return;
1261	1261	}
1262		// TODO this code path is untested
1263		uint64_t first_digit = dest->data.digit;
	1262
1264	1263	dest->digit_count = max(op1->digit_count, op2->digit_count);
1265	1264	dest->data.digits = allocate_nonzero<uint64_t>(dest->digit_count);
1266		dest->data.digits[0] = first_digit;
1267		size_t i = 1;
	1265
	1266	size_t i = 0;
1268	1267	for (; i < op1->digit_count && i < op2->digit_count; i += 1) {
1269	1268	dest->data.digits[i] = op1_digits[i] & op2_digits[i];
1270	1269	}
...	...	@@ -1412,7 +1411,6 @@ void bigint_shr(BigInt dest, const BigInt op1, const BigInt *op2) {
1412	1411	return;
1413	1412	}
1414	1413
1415		// TODO this code path is untested
1416	1414	size_t digit_shift_count = shift_amt / 64;
1417	1415	size_t leftover_shift_count = shift_amt % 64;
1418	1416
...	...	@@ -1427,7 +1425,7 @@ void bigint_shr(BigInt dest, const BigInt op1, const BigInt *op2) {
1427	1425	uint64_t digit = op1_digits[op_digit_index];
1428	1426	size_t dest_digit_index = op_digit_index - digit_shift_count;
1429	1427	dest->data.digits[dest_digit_index] = carry \| (digit >> leftover_shift_count);
1430		carry = (0xffffffffffffffffULL << leftover_shift_count) & digit;
	1428	carry = digit << leftover_shift_count;
1431	1429
1432	1430	if (dest_digit_index == 0) { break; }
1433	1431	op_digit_index -= 1;

test/cases/math.zig+17

...	...	@@ -349,6 +349,23 @@ test "big number shifting" {
349	349	}
350	350	}
351	351
	352	test "big number multi-limb shift and mask" {
	353	comptime {
	354	var a = 0xefffffffa0000001eeeeeeefaaaaaaab;
	355
	356	assert(u32(a & 0xffffffff) == 0xaaaaaaab);
	357	a >>= 32;
	358	assert(u32(a & 0xffffffff) == 0xeeeeeeef);
	359	a >>= 32;
	360	assert(u32(a & 0xffffffff) == 0xa0000001);
	361	a >>= 32;
	362	assert(u32(a & 0xffffffff) == 0xefffffff);
	363	a >>= 32;
	364
	365	assert(a == 0);
	366	}
	367	}
	368
352	369	test "xor" {
353	370	test_xor();
354	371	comptime test_xor();