[Bug rtl-optimization/49941] [4.7 Regression] segmentation fault in redirect_jump_2

[amodra at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49941

--- Comment #6 from Alan Modra <amodra at gmail dot com> 2011-08-03 02:43:18 
UTC ---
Bernd, with your patch applied, bootstrap dies here:

In file included from
/home/amodra/src/gcc-virgin/libgcc/../libdecnumber/decQuad.c:140:0:
/home/amodra/src/gcc-virgin/libgcc/../libdecnumber/decBasic.c: In function
'decNumCompare':
/home/amodra/src/gcc-virgin/libgcc/../libdecnumber/decBasic.c:3773:3: internal
compiler error: Segmentation fault

(gdb) bt
#0  active_insn_p (insn=0x1b0000) at
/home/amodra/src/gcc-virgin/gcc/emit-rtl.c:3258
#1  0x1026b114 in next_active_insn (insn=0x1b0000) at
/home/amodra/src/gcc-virgin/gcc/emit-rtl.c:3271
#2  0x104e3ba4 in tablejump_p (insn=<value optimized out>, labelp=0x0,
tablep=0x10dd9ca8) at /home/amodra/src/gcc-virgin/gcc/rtlanal.c:2667
#3  0x1022bb5c in scan_trace (trace=<value optimized out>) at
/home/amodra/src/gcc-virgin/gcc/dwarf2cfi.c:2586
#4  0x1022c374 in create_cfi_notes () at
/home/amodra/src/gcc-virgin/gcc/dwarf2cfi.c:2621
#5  execute_dwarf2_frame () at /home/amodra/src/gcc-virgin/gcc/dwarf2cfi.c:2953

(gdb) p debug_rtx(insn)
(jump_insn 1695 1694 1698 (parallel [
            (return)
            (use (reg:DI 65 lr))
        ]) /home/amodra/src/gcc-virgin/libgcc/../libdecnumber/decBasic.c:3773
708 {*return_internal_di}
     (nil)
 -> return)
$4 = void
(gdb) p default_target_rtl.x_global_rtl[2]
$5 = (rtx) 0xf70200c0
(gdb) down
#2  0x104e3ba4 in tablejump_p (insn=<value optimized out>, labelp=0x0,
tablep=0x10dd9ca8) at /home/amodra/src/gcc-virgin/gcc/rtlanal.c:2667
(gdb) p label
$6 = (struct rtx_def *) 0xf7029f40
(gdb) p debug_rtx(label)
(return)
$7 = void
(gdb) p debug_rtx(default_target_rtl.x_global_rtl[2])
(return)
$8 = void
(gdb) 

So it appears we have another problem lurking here.