/* Test to verify that the temporary doesn't trigger a bogus -Warray-bounds warning. Distilled from libat_exchange_large_inplace in libatomic/gexch.c. { dg-do compile } { dg-options "-O2 -Wall" } */ typedef typeof (sizeof 0) size_t; extern void *memcpy (void*, const void*, size_t); void libat_exchange_large_inplace (size_t n, void *mptr, void *vptr) { char temp[1024]; size_t i = 0; for (i = 0; n >= 1024; i += 1024, n -= 1024) { memcpy (temp, mptr + i, 1024); /* The memcpy call below results in the following: unsigned long ivtmp.7; ivtmp.7_4 = (unsigned long) mptr_9(D); ... # ivtmp.7_22 = PHI ... _1 = (void *) ivtmp.7_22; ... memcpy (_1, _2, 1024); Treating _1 as a pointer results in the bogus: warning: 'memcpy' offset 0 is out of the bounds [0, 8] of object 'ivtmp.7' with type 'long unsigned int' [-Warray-bounds] memcpy (mptr + i, vptr + i, 1024); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ */ memcpy (mptr + i, vptr + i, 1024); memcpy (vptr + i, temp, 1024); } }