https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81629
Bug ID: 81629 Summary: redefined memcpy leads to segmentation fault Product: gcc Version: 7.1.1 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c Assignee: unassigned at gcc dot gnu.org Reporter: frederic.besson at inria dot fr Target Milestone: --- Hi, The simple code below crashes with internal compiler error: Segmentation fault. It seems gcc does not like the redefinition of memcpy. extern unsigned long long memcpy(unsigned long long, unsigned long long, unsigned long long); void foo(unsigned long long ctx, unsigned long long output) { memcpy(ctx + 2LLU, ctx, 1U); return; } Best regards,