[Bug tree-optimization/28798] remove_phi_node attempts removal of a phi node resized by resize_phi_node

["hosking at cs dot purdue dot edu" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #4 from hosking at cs dot purdue dot edu  2006-08-23 13:40 -------
Here is a stack trace showing call to resize_phi_node from execute_pre.

#0  resize_phi_node (phi=0x42580028, len=9) at
../../gcc/gcc/tree-phinodes.c:271
#1  0x001415e8 in reserve_phi_args_for_new_edge (bb=0x42580000) at
../../gcc/gcc/tree-phinodes.c:325
#2  0x001fd8b0 in unchecked_make_edge (src=0x425885a0, dst=0x42580000,
flags=1113063428) at ../../gcc/gcc/cfg.c:272
#3  0x002414fc in tree_split_edge (edge_in=0x424a12d0) at
../../gcc/gcc/tree-cfg.c:3117
#4  0x00261bcc in split_edge (e=0x4257ebe0) at ../../gcc/gcc/cfghooks.c:407
#5  0x002445b8 in tree_find_edge_insert_loc (e=0x424a12d0, bsi=0xbfffeca8,
new_bb=0x0) at ../../gcc/gcc/tree-cfg.c:2975
#6  0x00244764 in bsi_commit_one_edge_insert (e=0x42580028, new_bb=0x9) at
../../gcc/gcc/tree-cfg.c:3016
#7  0x002466c8 in bsi_commit_edge_inserts () at ../../gcc/gcc/tree-cfg.c:2997
#8  0x00344098 in execute_pre (do_fre=0 '\0') at
../../gcc/gcc/tree-ssa-pre.c:2731
#9  0x002260b8 in execute_one_pass (pass=0x4ed660) at
../../gcc/gcc/passes.c:827
#10 0x00226188 in execute_pass_list (pass=0x4ed660) at
../../gcc/gcc/passes.c:859
#11 0x002261a0 in execute_pass_list (pass=0x4ec21c) at
../../gcc/gcc/passes.c:860
#12 0x00153fa4 in tree_rest_of_compilation (fndecl=0x42443580) at
../../gcc/gcc/tree-optimize.c:419
#13 0x0000497c in m3_expand_function (fndecl=0x42443580) at
../../gcc/gcc/m3cg/parse.c:848
#14 0x00052784 in cgraph_expand_function (node=0x424501c0) at
../../gcc/gcc/cgraphunit.c:1055
#15 0x00052fc8 in cgraph_optimize () at ../../gcc/gcc/cgraphunit.c:1121
#16 0x000130c0 in m3_parse_file (xx=0) at ../../gcc/gcc/m3cg/parse.c:4397
#17 0x00036674 in toplev_main (argc=1079409344, argv=0x40567bcc) at
../../gcc/gcc/toplev.c:991
#18 0x00001f24 in _start (argc=6, argv=0xbffff214, envp=0xbffff230) at
/SourceCache/Csu/Csu-58.1.1/crt.c:272
#19 0x00001dcc in start ()

The phi node that gets resized (and replaced in its bb) is later attempted to
be deleted, at the following point:

Program received signal EXC_BAD_ACCESS, Could not access memory.
Reason: KERN_PROTECTION_FAILURE at address: 0x00000000
0x00141ca8 in remove_phi_node (phi=0x42577800, prev=0x0) at
../../gcc/gcc/tree-phinodes.c:454
(gdb) where
#0  0x00141ca8 in remove_phi_node (phi=0x42577800, prev=0x0) at
../../gcc/gcc/tree-phinodes.c:454
#1  0x00341aac in remove_dead_inserted_code () at
../../gcc/gcc/tree-ssa-pre.c:2547
#2  0x003440a0 in execute_pre (do_fre=0 '\0') at
../../gcc/gcc/tree-ssa-pre.c:2733
#3  0x002260b8 in execute_one_pass (pass=0x4ed660) at
../../gcc/gcc/passes.c:827
#4  0x00226188 in execute_pass_list (pass=0x4ed660) at
../../gcc/gcc/passes.c:859
#5  0x002261a0 in execute_pass_list (pass=0x4ec21c) at
../../gcc/gcc/passes.c:860
#6  0x00153fa4 in tree_rest_of_compilation (fndecl=0x42443580) at
../../gcc/gcc/tree-optimize.c:419
#7  0x0000497c in m3_expand_function (fndecl=0x42443580) at
../../gcc/gcc/m3cg/parse.c:848
#8  0x00052784 in cgraph_expand_function (node=0x424501c0) at
../../gcc/gcc/cgraphunit.c:1055
#9  0x00052fc8 in cgraph_optimize () at ../../gcc/gcc/cgraphunit.c:1121
#10 0x000130c0 in m3_parse_file (xx=0) at ../../gcc/gcc/m3cg/parse.c:4397
#11 0x00036674 in toplev_main (argc=1079409344, argv=0x40567bcc) at
../../gcc/gcc/toplev.c:991
#12 0x00001f24 in _start (argc=6, argv=0xbffff214, envp=0xbffff230) at
/SourceCache/Csu/Csu-58.1.1/crt.c:272
#13 0x00001dcc in start ()


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28798