https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103038
--- Comment #6 from qinzhao at gcc dot gnu.org ---
just wondering why the ICE after my fix to PR102281. and found the reason:
Before the fix to PR102281, the IR before expansion phase is:
void test ()
{
<<< Unknown tree: offset_type >>> PtrMem;
<bb 2> :
PtrMem = .DEFERRED_INIT (8, 1, 0);
GIMPLE_NOP
PtrMem ={v} {CLOBBER};
return;
}
After the fix to PR102281, the IR before expansion phase is:
void test ()
{
<<< Unknown tree: offset_type >>> PtrMem;
<bb 2> :
PtrMem_1 = .DEFERRED_INIT (8, 1, 0);
return;
}
the key difference is,
Before the PR102281 Fix, the LHS of the call to .DEFERRED_INIT is a
VAR_DECL(due to the additional call to __builtin_clear_padding (&PtrMem, ...),
and folded to GIMPLE_NOP later). as a result, the RTL expansion for this call
went through the MEMSET expansion and succeed.
After the PR102281 Fix, the LHS of the call is a SSA name. as a result, the RTL
expansion for this call went thought the ASSIGN expansion and exposed the
issues for OFFSET_TYPE.
