[Bug c++/60516] [4.9/4.8 regression]: cc1plus crashes compiling a method with a huge struct as argument

[ktietz at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60516

--- Comment #3 from Kai Tietz <ktietz at gcc dot gnu.org> ---
Issue is that copy_rtx gets feed with invalid insn.

As (gdb) fr 1
#1  0x007ce0bf in ix86_expand_epilogue (style=style@entry=1)
    at ../../gcc/gcc/config/i386/i386.c:11712
11712                           copy_rtx (XVECEXP (PATTERN (insn), 0, 1)));
(gdb) call debug_rtx(insn)
(insn 15 14 0 (set (reg:SI 2 cx)
        (mem:SI (post_inc:SI (reg/f:SI 7 sp)) [0  S4 A8])) -1
     (nil))
(gdb) print (insn->u.fld[4]).rt_rtx
$2 = (rtx) 0xffe25630
(gdb) call debug_rtx((insn->u.fld[4]).rt_rtx)
(set (reg:SI 2 cx)
    (mem:SI (post_inc:SI (reg/f:SI 7 sp)) [0  S4 A8]))
(gdb) print ((insn->u.fld[4]).rt_rtx->u.fld[0]).rt_rtvec->elem[1]
$3 = (rtx_def *) 0x2