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| author | Jeff Law <law@redhat.com> | 2006-02-10 12:22:58 -0700 |
|---|---|---|
| committer | Jeff Law <law@gcc.gnu.org> | 2006-02-10 12:22:58 -0700 |
| commit | 61864771af6d7a5834f9df225b4ddd5542d656b0 (patch) | |
| tree | 5d6054da917dffe6c192e92e66570bbe9eaddf9d /gcc | |
| parent | def661340610359e6eea3cdd4189089b3b9b7acd (diff) | |
| download | gcc-61864771af6d7a5834f9df225b4ddd5542d656b0.zip gcc-61864771af6d7a5834f9df225b4ddd5542d656b0.tar.gz gcc-61864771af6d7a5834f9df225b4ddd5542d656b0.tar.bz2 | |
re PR tree-optimization/26213 (new (within last few days) infinite loop with -O1)
PR tree-optimization/26213
* tree-ssa-threadedge.c (simplify_control_stmt_condition): Do not
loop trying to follow SSA_NAME_VALUE chains.
* gcc.c-torture/compile/pr26213.c: New test.
From-SVN: r110846
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ChangeLog | 6 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 4 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.c-torture/compile/pr26213.c | 15 | ||||
| -rw-r--r-- | gcc/tree-ssa-threadedge.c | 12 |
4 files changed, 33 insertions, 4 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 59f2670..e9225a4 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2006-02-10 Jeff Law <law@redhat.com> + + PR tree-optimization/26213 + * tree-ssa-threadedge.c (simplify_control_stmt_condition): Do not + loop trying to follow SSA_NAME_VALUE chains. + 2006-02-10 Richard Guenther <rguenther@suse.de> * tree-dfa.c (get_ref_base_and_extent): When computing maxsize diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 28b84e4..b158d4a 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,7 @@ +2006-02-10 Jeff Law <law@redhat.com> + + * gcc.c-torture/compile/pr26213.c: New test. + 2006-02-10 Steven G. Kargl <kargls@comcast.net> gfortran.dg/null_1.f90: New test. diff --git a/gcc/testsuite/gcc.c-torture/compile/pr26213.c b/gcc/testsuite/gcc.c-torture/compile/pr26213.c new file mode 100644 index 0000000..7a6600c --- /dev/null +++ b/gcc/testsuite/gcc.c-torture/compile/pr26213.c @@ -0,0 +1,15 @@ +void +xnanosleep (_Bool overflow) +{ + struct { int tv_nsec; } ts_sleep; + if (0 <= ts_sleep.tv_nsec) + overflow |= 1; + + for (;;) + { + if (overflow) + ts_sleep.tv_nsec = 0; + if (foo (ts_sleep)) + break; + } +} diff --git a/gcc/tree-ssa-threadedge.c b/gcc/tree-ssa-threadedge.c index b8d4b13..cc98867 100644 --- a/gcc/tree-ssa-threadedge.c +++ b/gcc/tree-ssa-threadedge.c @@ -441,10 +441,14 @@ simplify_control_stmt_condition (edge e, { cached_lhs = cond; - /* Get the variable's current value from the equivalency chains. */ - while (cached_lhs - && TREE_CODE (cached_lhs) == SSA_NAME - && SSA_NAME_VALUE (cached_lhs)) + /* Get the variable's current value from the equivalency chains. + + It is possible to get loops in the SSA_NAME_VALUE chains + (consider threading the backedge of a loop where we have + a loop invariant SSA_NAME used in the condition. */ + if (cached_lhs + && TREE_CODE (cached_lhs) == SSA_NAME + && SSA_NAME_VALUE (cached_lhs)) cached_lhs = SSA_NAME_VALUE (cached_lhs); /* If we're dominated by a suitable ASSERT_EXPR, then |