[Bug target/50635] New: ICE on invalid code: segfault in vectorize_loops

[Greta.Yorsh at arm dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50635

             Bug #: 50635
           Summary: ICE on invalid code: segfault in vectorize_loops
    Classification: Unclassified
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: Greta.Yorsh@arm.com
            Target: arm-none-eabi


Created attachment 25431
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=25431
small_ice.c

arm-none-eabi/gcc2/gcc/cc1 small_ice.c -O3 -quiet -mcpu=cortex-a9
-mfloat-abi=softfp -mfpu=neon 

small_ice.c: In function 'f0a':
small_ice.c:5:6: internal compiler error: Segmentation fault

Trace:

#0  flow_bb_inside_loop_p (loop=0x7ffff7436f68, bb=0x0) at
/work/local-checkouts/main/gcc-fsf/gcc/cfgloop.c:776
#1  0x00000000009ef6ef in vect_is_simple_use (operand=0x7ffff74bfaa0,
loop_vinfo=<value optimised out>, bb_vinfo=0x0, def_stmt=0x7fffffffe008,
def=0x7fffffffe010, dt=0x7fffffffe01c) at
/work/local-checkouts/main/gcc-fsf/gcc/tree-vect-stmts.c:5595
#2  0x00000000009f93dc in process_use (stmt=0x7ffff74b7580, use=0x7ffff74bfaa0,
loop_vinfo=0x15077a0, live_p=<value optimised out>,
relevant=vect_used_in_scope, worklist=<value optimised out>) at
/work/local-checkouts/main/gcc-fsf/gcc/tree-vect-stmts.c:368
#3  0x00000000009f9e69 in vect_mark_stmts_to_be_vectorized
(loop_vinfo=0x15077a0) at
/work/local-checkouts/main/gcc-fsf/gcc/tree-vect-stmts.c:658
#4  0x0000000000a0bae1 in vect_analyze_loop_2 (loop=0x7ffff7436f68) at
/work/local-checkouts/main/gcc-fsf/gcc/tree-vect-loop.c:1504
#5  vect_analyze_loop (loop=0x7ffff7436f68) at
/work/local-checkouts/main/gcc-fsf/gcc/tree-vect-loop.c:1650
#6  0x0000000000a18e4e in vectorize_loops () at
/work/local-checkouts/main/gcc-fsf/gcc/tree-vectorizer.c:203
#7  0x00000000007d7859 in execute_one_pass (pass=0x129b760) at
/work/local-checkouts/main/gcc-fsf/gcc/passes.c:2064
#8  0x00000000007d7bd5 in execute_pass_list (pass=0x129b760) at
/work/local-checkouts/main/gcc-fsf/gcc/passes.c:2119
#9  0x00000000007d7be7 in execute_pass_list (pass=0x129b580) at
/work/local-checkouts/main/gcc-fsf/gcc/passes.c:2120
#10 0x00000000007d7be7 in execute_pass_list (pass=0x129ac80) at
/work/local-checkouts/main/gcc-fsf/gcc/passes.c:2120
#11 0x00000000008deca8 in tree_rest_of_compilation (fndecl=0x7ffff7437400) at
/work/local-checkouts/main/gcc-fsf/gcc/tree-optimize.c:420
#12 0x00000000005c09ce in cgraph_expand_function (node=0x7ffff75a4120) at
/work/local-checkouts/main/gcc-fsf/gcc/cgraphunit.c:1805
#13 0x00000000005c3fca in cgraph_expand_all_functions () at
/work/local-checkouts/main/gcc-fsf/gcc/cgraphunit.c:1864
#14 cgraph_optimize () at
/work/local-checkouts/main/gcc-fsf/gcc/cgraphunit.c:2141
#15 0x00000000005c44ea in cgraph_finalize_compilation_unit () at
/work/local-checkouts/main/gcc-fsf/gcc/cgraphunit.c:1312
#16 0x00000000004a6e08 in c_write_global_declarations () at
/work/local-checkouts/main/gcc-fsf/gcc/c-decl.c:9936
#17 0x000000000087bcca in compile_file (argc=7, argv=0x7fffffffe4b8) at
/work/local-checkouts/main/gcc-fsf/gcc/toplev.c:581
#18 do_compile (argc=7, argv=0x7fffffffe4b8) at
/work/local-checkouts/main/gcc-fsf/gcc/toplev.c:1925
#19 toplev_main (argc=7, argv=0x7fffffffe4b8) at
/work/local-checkouts/main/gcc-fsf/gcc/toplev.c:2001
#20 0x00007ffff7874c4d in __libc_start_main () from /lib/libc.so.6
#21 0x0000000000496da9 in _start ()

ICE does not occur without "-mfloat-abi=softfp -mfpu=neon".
This ICE happens with trunk version of end of August 2011 and perhaps earlier.
It does not appear in gcc4.6. 
The code is invalid because uninitialized variable temp_3 is used.