diff options
| author | Jeff Law <law@redhat.com> | 2019-07-07 12:42:45 -0600 |
|---|---|---|
| committer | Jeff Law <law@gcc.gnu.org> | 2019-07-07 12:42:45 -0600 |
| commit | 0411f1d6cb283b68e85d41fae7601d6a3e0a9954 (patch) | |
| tree | eb2940b2938ff792279d79c7f0fa5a600d41d174 /gcc/tree-ssa-dom.c | |
| parent | 6ce4dac81392bb6f144c34a06e9be157c20f31da (diff) | |
re PR tree-optimization/91090 (A suspicious code in tree-ssa-dom.c)
PR tree-optimization/91090
* tree-ssa-dom.c (simplify_stmt_for_jump_threading): Fix logic error
in handling of ranges to simplify switch statements.
From-SVN: r273184
Diffstat (limited to 'gcc/tree-ssa-dom.c')
| -rw-r--r-- | gcc/tree-ssa-dom.c | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/gcc/tree-ssa-dom.c b/gcc/tree-ssa-dom.c index b0d56fcf3e3..17c852d5299 100644 --- a/gcc/tree-ssa-dom.c +++ b/gcc/tree-ssa-dom.c @@ -913,21 +913,26 @@ simplify_stmt_for_jump_threading (gimple *stmt, find_case_label_range (switch_stmt, vr->min (), vr->max (), &i, &j); + /* Is there only one such label? */ if (i == j) { tree label = gimple_switch_label (switch_stmt, i); tree singleton; + /* The i'th label will only be taken if the value range of the + operand is entirely within the bounds of this label. */ if (CASE_HIGH (label) != NULL_TREE ? (tree_int_cst_compare (CASE_LOW (label), vr->min ()) <= 0 && tree_int_cst_compare (CASE_HIGH (label), vr->max ()) >= 0) : (vr->singleton_p (&singleton) && tree_int_cst_equal (CASE_LOW (label), singleton))) return label; - - if (i > j) - return gimple_switch_label (switch_stmt, 0); } + + /* If there are no such labels, then the default label + will be taken. */ + if (i > j) + return gimple_switch_label (switch_stmt, 0); } if (vr->kind () == VR_ANTI_RANGE) |