http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59409
--- Comment #17 from H.J. Lu <hjl.tools at gmail dot com> --- Perl_my_bcopy (len=31, to=0xf7fd801d "\021q", from=0x8023f0 "\264\005q") is miscompiled when inlined: Old value = 19935280 New value = 808464432 Perl_my_bcopy (len=-1, to=0xf7fd803c "\260Vx", from=<optimized out>) at util.c:1559 1559 while (len--) The last write is to 4-bytes at 0xf7fd803b: 442dd7: 83 fe 0b cmp $0xb,%esi 442dda: 67 44 88 42 0b mov %r8b,0xb(%edx) 442ddf: 74 27 je 442e08 <Perl_pp_rv2av+0x898> (gdb) p/x $edx $300 = 0xf7fd8030 (gdb) p/x $edx + 0xb $301 = 0xf7fd803b (gdb) But the last byte should be written at 0xf7fd801d + 30 == 0xf7fd803b. There are 3 byte overflow for write. I will see if I can write a testcase.
