[Bug middle-end/126084] ICE verify_gimple failed - _BitInt + ASAN, r14-3751

[aoliva at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=126084

Alexandre Oliva <aoliva at gcc dot gnu.org> changed:

           What    |Removed                     |Added
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                 CC|                            |aoliva at gcc dot gnu.org

--- Comment #9 from Alexandre Oliva <aoliva at gcc dot gnu.org> ---
There's an unfortunate side effect of this patch: it introduces
__asan_report_load_* calls in bitintlower1, before asan1.  They'd normally only
be introduced in sanopt, long after asan.  When asan1 sees these noreturn
calls, it introduces undesirable __asan_handle_no_return calls before them.

On targets that don't enable ASAN option detect_stack_use_after_return, that
__asan_handle_no_return call largely resets shadow memory and significantly
lowers the quality of the asan runtime error report issued by the subsequent
report_load call, to the point that the expected outputs for the added tests
don't match.

We should probably arrange for asan1 to not instrument asan builtins that this
change might expose to asan1.