diff options
Diffstat (limited to 'gcc/tree-ssa-sccvn.c')
| -rw-r--r-- | gcc/tree-ssa-sccvn.c | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/gcc/tree-ssa-sccvn.c b/gcc/tree-ssa-sccvn.c index eb7e4be..76cad43 100644 --- a/gcc/tree-ssa-sccvn.c +++ b/gcc/tree-ssa-sccvn.c @@ -4312,8 +4312,12 @@ visit_nary_op (tree lhs, gassign *stmt) operation. */ if (INTEGRAL_TYPE_P (type) && TREE_CODE (rhs1) == SSA_NAME - /* We only handle sign-changes or zero-extension -> & mask. */ - && ((TYPE_UNSIGNED (TREE_TYPE (rhs1)) + /* We only handle sign-changes, zero-extension -> & mask or + sign-extension if we know the inner operation doesn't + overflow. */ + && (((TYPE_UNSIGNED (TREE_TYPE (rhs1)) + || (INTEGRAL_TYPE_P (TREE_TYPE (rhs1)) + && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (rhs1)))) && TYPE_PRECISION (type) > TYPE_PRECISION (TREE_TYPE (rhs1))) || TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (rhs1)))) { @@ -4347,7 +4351,9 @@ visit_nary_op (tree lhs, gassign *stmt) { unsigned lhs_prec = TYPE_PRECISION (type); unsigned rhs_prec = TYPE_PRECISION (TREE_TYPE (rhs1)); - if (lhs_prec == rhs_prec) + if (lhs_prec == rhs_prec + || (INTEGRAL_TYPE_P (TREE_TYPE (rhs1)) + && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (rhs1)))) { gimple_match_op match_op (gimple_match_cond::UNCOND, NOP_EXPR, type, ops[0]); |