If you are not sure whether you have found a bug, here are some guidelines:
asmstatement), that is a compiler bug, unless the compiler reports errors (not just warnings) which would ordinarily prevent the assembler from being run.
However, you must double-check to make sure, because you may have run into an incompatibility between GNU C and traditional C (see Incompatibilities). These incompatibilities might be considered bugs, but they are inescapable consequences of valuable features.
Or you may have a program whose behavior is undefined, which happened by chance to give the desired results with another C or C++ compiler.
For example, in many nonoptimizing compilers, you can write
at the end of a function instead of
return x;, with the same
results. But the value of the function is undefined if
is omitted; it is not a bug when GCC produces different results.
Problems often result from expressions with two increment operators,
f (*p++, *p++). Your previous compiler might have
interpreted that expression the way you intended; GCC might
interpret it another way. Neither compiler is wrong. The bug is
in your code.
After you have localized the error to a single source line, it should be easy to check for these things. If your program is correct and well defined, you have found a compiler bug.