From: Dragoslav Sicarov Subject: FTBFS: grib-api - tests fail for mips Date: Sun, 29 Dec 2013 15:13:16 +0000 Forwarded: https://software.ecmwf.int/issues/browse/SUP-1589 Last-Updated: 2023-03-23 https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=733510 FTBFS: 21 of 38 tests fail when trying to build package from source on mips. Part of build log has been attached. The root cause of failing tests for mips is in function grib_encode_unsigned_long() that is used for writing into grib message buffer (function is implemented differently for big-endian and little-endian architectures). On big-endian architectures, function uses shift operations, where in some corner-case situations left operand (which is of type unsigned long; size of long equals 4 bytes for 32bit system) is shifted right by 32 bits. According to C standard, if the value of the right operand of shift operation is negative, or is greater than or equal to the width of the left operand, the behaviour is undefined. On 32-bit mips architecture shift operations by a variable number of bits are translated to/use 'srlv' and 'sllv' instructions which shift left operand by (right_operand mod 32) bits. In case of shifting by 32 bits, this results in left operand being unchanged. However, in order for this package to function properly a result of 0 is expected. Proposed patch fixes these corner-cases by setting the result of shift operation to 0 if right operand is greater than or equal to size of long (actually, no shifting is performed, the result is set to zero).