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| author | Jeff Law <law@redhat.com> | 2016-06-13 14:55:59 -0600 |
|---|---|---|
| committer | Jeff Law <law@gcc.gnu.org> | 2016-06-13 14:55:59 -0600 |
| commit | a73786e39ff86e8e1d186baaf802b99f8675bbeb (patch) | |
| tree | 6a2c8bbaf60c75e44945f7c6c198e3a2a1e8fa1d /gcc/tree-ssa-threadbackward.c | |
| parent | 79a2bc2dc96fb0c6efd4db45d6d8d333f676e8a5 (diff) | |
| download | gcc-a73786e39ff86e8e1d186baaf802b99f8675bbeb.zip gcc-a73786e39ff86e8e1d186baaf802b99f8675bbeb.tar.gz gcc-a73786e39ff86e8e1d186baaf802b99f8675bbeb.tar.bz2 | |
re PR tree-optimization/71403 (wrong code (segfault) at -O3 on x86_64-linux-gnu)
PR tree-optimization/71403
* tree-ssa-threadbackward.c
(convert_and_register_jump_thread_path): No longer accept reference
to path. Do not pop items off the path anymore.
(fsm_find_control_statement_thread_paths): Do not allow threading
to a deeper loop nest. Pop the last item off the path here rather
than in convert_and_register_jump_thread_path.
PR tree-optimization/71403
* c-c++-common/ubsan/pr71403-1.c: New test.
* c-c++-common/ubsan/pr71403-2.c: New test.
* c-c++-common/ubsan/pr71403-3.c: New test.
From-SVN: r237403
Diffstat (limited to 'gcc/tree-ssa-threadbackward.c')
| -rw-r--r-- | gcc/tree-ssa-threadbackward.c | 26 |
1 files changed, 19 insertions, 7 deletions
diff --git a/gcc/tree-ssa-threadbackward.c b/gcc/tree-ssa-threadbackward.c index 139d376..9dd37ad 100644 --- a/gcc/tree-ssa-threadbackward.c +++ b/gcc/tree-ssa-threadbackward.c @@ -378,7 +378,7 @@ profitable_jump_thread_path (vec<basic_block, va_gc> *&path, register the path. */ static void -convert_and_register_jump_thread_path (vec<basic_block, va_gc> *&path, +convert_and_register_jump_thread_path (vec<basic_block, va_gc> *path, edge taken_edge) { vec<jump_thread_edge *> *jump_thread_path = new vec<jump_thread_edge *> (); @@ -402,9 +402,6 @@ convert_and_register_jump_thread_path (vec<basic_block, va_gc> *&path, register_jump_thread (jump_thread_path); --max_threaded_paths; - - /* Remove BBI from the path. */ - path->pop (); } /* We trace the value of the SSA_NAME NAME back through any phi nodes looking @@ -459,6 +456,9 @@ fsm_find_control_statement_thread_paths (tree name, seen_loop_phi = true; } + if (bb_loop_depth (last_bb_in_path) > bb_loop_depth (var_bb)) + return; + /* Following the chain of SSA_NAME definitions, we jumped from a definition in LAST_BB_IN_PATH to a definition in VAR_BB. When these basic blocks are different, append to PATH the blocks from LAST_BB_IN_PATH to VAR_BB. */ @@ -505,7 +505,9 @@ fsm_find_control_statement_thread_paths (tree name, NEXT_PATH. Don't add them here to avoid pollution. */ for (unsigned int i = 0; i < next_path->length () - 1; i++) { - if (visited_bbs->contains ((*next_path)[i])) + if (visited_bbs->contains ((*next_path)[i]) + || (bb_loop_depth (last_bb_in_path) + > bb_loop_depth ((*next_path)[i]))) { vec_free (next_path); return; @@ -557,7 +559,12 @@ fsm_find_control_statement_thread_paths (tree name, into the canonical form and register it. */ edge taken_edge = profitable_jump_thread_path (path, bbi, name, arg); if (taken_edge) - convert_and_register_jump_thread_path (path, taken_edge); + { + if (bb_loop_depth (taken_edge->src) + >= bb_loop_depth (taken_edge->dest)) + convert_and_register_jump_thread_path (path, taken_edge); + path->pop (); + } } } else if (gimple_code (def_stmt) == GIMPLE_ASSIGN) @@ -578,7 +585,12 @@ fsm_find_control_statement_thread_paths (tree name, edge taken_edge = profitable_jump_thread_path (path, var_bb, name, arg); if (taken_edge) - convert_and_register_jump_thread_path (path, taken_edge); + { + if (bb_loop_depth (taken_edge->src) + >= bb_loop_depth (taken_edge->dest)) + convert_and_register_jump_thread_path (path, taken_edge); + path->pop (); + } /* And put the current block back onto the path so that the state of the stack is unchanged when we leave. */ |