By convention, a 0-len bitfield write is a no-op, and a 0-len read sets the value of the output to 0.
So we can "encode" the value 0 over a length of 0 bit. Cover this in the test-cases for signed types. It is already covered for the unsigned test-cases. Signed-off-by: Mathieu Desnoyers <mathieu.desnoy...@efficios.com> Change-Id: Ib6038b98167ef2cfa8c504d7ac29498e71827b38 --- tests/lib/test_bitfield.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/tests/lib/test_bitfield.c b/tests/lib/test_bitfield.c index 5188335b..05547c07 100644 --- a/tests/lib/test_bitfield.c +++ b/tests/lib/test_bitfield.c @@ -391,7 +391,9 @@ void run_test_signed_write(int src_i, long long src_ll) long long readval; unsigned int s, l; - if (src_i & 0x80000000U) + if (!src_i) + nrbits_i = 0; /* The number of bits needed to represent 0 is 0. */ + else if (src_i & 0x80000000U) nrbits_i = fls_u32(~src_i) + 1; /* Find least significant bit conveying sign */ else nrbits_i = fls_u32(src_i) + 1; /* Keep sign at 0 */ @@ -442,7 +444,9 @@ void run_test_signed_write(int src_i, long long src_ll) } pass(SIGNED_INT_WRITE_TEST_DESC_FMT_STR, src_i); - if (src_ll & 0x8000000000000000ULL) + if (!src_ll) + nrbits_ll = 0; /* The number of bits needed to represent 0 is 0. */ + else if (src_ll & 0x8000000000000000ULL) nrbits_ll = fls_u64(~src_ll) + 1; /* Find least significant bit conveying sign */ else nrbits_ll = fls_u64(src_ll) + 1; /* Keep sign at 0 */ @@ -507,7 +511,9 @@ void run_test_signed_read(int src_i, long long src_ll) long long readval_ll; unsigned int s, l; - if (src_i & 0x80000000U) + if (!src_i) + nrbits_i = 0; /* The number of bits needed to represent 0 is 0. */ + else if (src_i & 0x80000000U) nrbits_i = fls_u32(~src_i) + 1; /* Find least significant bit conveying sign */ else nrbits_i = fls_u32(src_i) + 1; /* Keep sign at 0 */ @@ -558,6 +564,8 @@ void run_test_signed_read(int src_i, long long src_ll) } pass(SIGNED_INT_READ_TEST_DESC_FMT_STR, src_i); + if (!src_ll) + nrbits_ll = 0; /* The number of bits needed to represent 0 is 0. */ if (src_ll & 0x8000000000000000ULL) nrbits_ll = fls_u64(~src_ll) + 1; /* Find least significant bit conveying sign */ else -- 2.11.0 _______________________________________________ lttng-dev mailing list lttng-dev@lists.lttng.org https://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev