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| author | Richard Biener <rguenther@suse.de> | 2023-06-19 09:52:45 +0200 |
|---|---|---|
| committer | Richard Biener <rguenther@suse.de> | 2023-06-19 12:59:47 +0200 |
| commit | 916add3bf6e46467e4391e358b11ecfbc4daa275 (patch) | |
| tree | 031ec98a8f614aedc58f8c9584420ee49c2a5838 | |
| parent | de2d3b69eefde005759279d6739d9a0dbd2a05cc (diff) | |
| download | gcc-916add3bf6e46467e4391e358b11ecfbc4daa275.zip gcc-916add3bf6e46467e4391e358b11ecfbc4daa275.tar.gz gcc-916add3bf6e46467e4391e358b11ecfbc4daa275.tar.bz2 | |
tree-optimization/110298 - CFG cleanup and stale nb_iterations
When unrolling we eventually kill nb_iterations info since it may
refer to removed SSA names. But we do this only after cleaning
up the CFG which in turn can end up accessing it. Fixed by
swapping the two.
PR tree-optimization/110298
* tree-ssa-loop-ivcanon.cc (tree_unroll_loops_completely):
Clear number of iterations info before cleaning up the CFG.
* gcc.dg/torture/pr110298.c: New testcase.
| -rw-r--r-- | gcc/testsuite/gcc.dg/torture/pr110298.c | 20 | ||||
| -rw-r--r-- | gcc/tree-ssa-loop-ivcanon.cc | 7 |
2 files changed, 24 insertions, 3 deletions
diff --git a/gcc/testsuite/gcc.dg/torture/pr110298.c b/gcc/testsuite/gcc.dg/torture/pr110298.c new file mode 100644 index 0000000..139f5c7 --- /dev/null +++ b/gcc/testsuite/gcc.dg/torture/pr110298.c @@ -0,0 +1,20 @@ +/* { dg-do compile } */ + +int a, b, c, d, e; +int f() { + c = 0; + for (; c >= 0; c--) { + d = 0; + for (; d <= 0; d++) { + e = 0; + for (; d + c + e >= 0; e--) + ; + a = 1; + b = 0; + for (; a; ++b) + a *= 2; + for (; b + d >= 0;) + return 0; + } + } +} diff --git a/gcc/tree-ssa-loop-ivcanon.cc b/gcc/tree-ssa-loop-ivcanon.cc index 6a962a9..491b57e 100644 --- a/gcc/tree-ssa-loop-ivcanon.cc +++ b/gcc/tree-ssa-loop-ivcanon.cc @@ -1520,15 +1520,16 @@ tree_unroll_loops_completely (bool may_increase_size, bool unroll_outer) } BITMAP_FREE (fathers); + /* Clean up the information about numbers of iterations, since + complete unrolling might have invalidated it. */ + scev_reset (); + /* This will take care of removing completely unrolled loops from the loop structures so we can continue unrolling now innermost loops. */ if (cleanup_tree_cfg ()) update_ssa (TODO_update_ssa_only_virtuals); - /* Clean up the information about numbers of iterations, since - complete unrolling might have invalidated it. */ - scev_reset (); if (flag_checking && loops_state_satisfies_p (LOOP_CLOSED_SSA)) verify_loop_closed_ssa (true); } |