------- Comment #4 from kazu at gcc dot gnu dot org 2006-05-19 19:36 -------
Infinite recursion is going on in CSE. Here is what happens.
At cse.c:4278 in fold_rtx, we have
(gdb) call debug_rtx(x)
(plus:SI (reg/v/f:SI 60 [ first ])
(const_int 4 [0x4]))
(gdb) call debug_rtx(y)
(plus:SI (reg/v/f:SI 60 [ first ])
(mem/s/j:SI (plus:SI (reg/v/f:SI 59 [ cur ])
(const_int 4 [0x4])) [0 <variable>.offset_next+0
S4 A32]))
(gdb)
Here we call fold_rtx (XEXP (y, 1), 0), where XEXP (y, 1) is
(mem/s/j:SI (plus:SI (reg/v/f:SI 59 [ cur ])
(const_int 4 [0x4])) [0 <variable>.offset_next+0 S4
A32])
fold_rtx delegates all processing of MEMs to fold_rtx_mem, so
fold_rtx_mem gets
(mem/s/j:SI (plus:SI (reg/v/f:SI 59 [ cur ])
(const_int 4 [0x4])) [0 <variable>.offset_next+0 S4
A32])
fold_rtx_mem in turn calls fold_rtx with the address inside the MEM,
which is:
(plus:SI (reg/v/f:SI 59 [ cur ])
(const_int 4 [0x4])) [0 <variable>.offset_next+0 S4 A32])
fold_rtx later calls lookup_as_function on (reg/v/f:SI 59 [ cur ]),
which returns
(plus:SI (reg/v/f:SI 60 [ first ])
(mem/s/j:SI (plus:SI (reg/v/f:SI 60 [ first ])
(const_int 4 [0x4])) [0 <variable>.offset_next+0 S4
A32]))
which is the same as what we started with.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27616
