diff options
Diffstat (limited to 'gcc/tree-if-conv.c')
| -rw-r--r-- | gcc/tree-if-conv.c | 28 |
1 files changed, 27 insertions, 1 deletions
diff --git a/gcc/tree-if-conv.c b/gcc/tree-if-conv.c index d7b7b30..6a67acf 100644 --- a/gcc/tree-if-conv.c +++ b/gcc/tree-if-conv.c @@ -132,6 +132,11 @@ along with GCC; see the file COPYING3. If not see predicate_statements for the kinds of predication we support. */ static bool need_to_predicate; +/* True if we have to rewrite stmts that may invoke undefined behavior + when a condition C was false so it doesn't if it is always executed. + See predicate_statements for the kinds of predication we support. */ +static bool need_to_rewrite_undefined; + /* Indicate if there are any complicated PHIs that need to be handled in if-conversion. Complicated PHI has more than two arguments and can't be degenerated to two arguments PHI. See more information in comment @@ -1042,6 +1047,12 @@ if_convertible_gimple_assign_stmt_p (gimple *stmt, fprintf (dump_file, "tree could trap...\n"); return false; } + else if (INTEGRAL_TYPE_P (TREE_TYPE (lhs)) + && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (lhs)) + && arith_code_with_undefined_signed_overflow + (gimple_assign_rhs_code (stmt))) + /* We have to rewrite stmts with undefined overflow. */ + need_to_rewrite_undefined = true; /* When if-converting stores force versioning, likewise if we ended up generating store data races. */ @@ -2563,6 +2574,20 @@ predicate_statements (loop_p loop) gsi_replace (&gsi, new_stmt, true); } + else if (INTEGRAL_TYPE_P (TREE_TYPE (gimple_assign_lhs (stmt))) + && TYPE_OVERFLOW_UNDEFINED + (TREE_TYPE (gimple_assign_lhs (stmt))) + && arith_code_with_undefined_signed_overflow + (gimple_assign_rhs_code (stmt))) + { + gsi_remove (&gsi, true); + gsi_insert_seq_before (&gsi, rewrite_to_defined_overflow (stmt), + GSI_SAME_STMT); + if (gsi_end_p (gsi)) + gsi = gsi_last_bb (gimple_bb (stmt)); + else + gsi_prev (&gsi); + } else if (gimple_vdef (stmt)) { tree lhs = gimple_assign_lhs (stmt); @@ -2647,7 +2672,7 @@ combine_blocks (class loop *loop) insert_gimplified_predicates (loop); predicate_all_scalar_phis (loop); - if (need_to_predicate) + if (need_to_predicate || need_to_rewrite_undefined) predicate_statements (loop); /* Merge basic blocks. */ @@ -3148,6 +3173,7 @@ tree_if_conversion (class loop *loop, vec<gimple *> *preds) rloop = NULL; ifc_bbs = NULL; need_to_predicate = false; + need_to_rewrite_undefined = false; any_complicated_phi = false; /* Apply more aggressive if-conversion when loop or its outer loop were |