diff options
| -rw-r--r-- | gcc/gimple-predicate-analysis.cc | 119 |
1 files changed, 55 insertions, 64 deletions
diff --git a/gcc/gimple-predicate-analysis.cc b/gcc/gimple-predicate-analysis.cc index 58eade4..eb1e11c 100644 --- a/gcc/gimple-predicate-analysis.cc +++ b/gcc/gimple-predicate-analysis.cc @@ -1671,7 +1671,6 @@ predicate::init_from_control_deps (const vec<edge> *dep_chains, { gcc_assert (is_empty ()); - bool has_valid_pred = false; if (num_chains == 0) return; @@ -1689,27 +1688,16 @@ predicate::init_from_control_deps (const vec<edge> *dep_chains, of the predicates. */ const vec<edge> &path = dep_chains[i]; - has_valid_pred = false; + bool has_valid_pred = false; /* The chain of predicates guarding the definition along this path. */ pred_chain t_chain{ }; for (unsigned j = 0; j < path.length (); j++) { edge e = path[j]; basic_block guard_bb = e->src; - /* Ignore empty forwarder blocks. */ - if (empty_block_p (guard_bb) && single_succ_p (guard_bb)) - continue; - /* An empty basic block here is likely a PHI, and is not one - of the cases we handle below. */ - gimple_stmt_iterator gsi = gsi_last_bb (guard_bb); - if (gsi_end_p (gsi)) - { - has_valid_pred = false; - break; - } - /* Get the conditional controlling the bb exit edge. */ - gimple *cond_stmt = gsi_stmt (gsi); + gcc_assert (!empty_block_p (guard_bb) && !single_succ_p (guard_bb)); + /* Skip this edge if it is bypassing an abort - when the condition is not satisfied we are neither reaching the definition nor the use so it isn't meaningful. Note if @@ -1730,8 +1718,13 @@ predicate::init_from_control_deps (const vec<edge> *dep_chains, } } if (skip) - continue; + { + has_valid_pred = true; + continue; + } } + /* Get the conditional controlling the bb exit edge. */ + gimple *cond_stmt = last_stmt (guard_bb); if (gimple_code (cond_stmt) == GIMPLE_COND) { /* The true edge corresponds to the uninteresting condition. @@ -1757,37 +1750,29 @@ predicate::init_from_control_deps (const vec<edge> *dep_chains, } else if (gswitch *gs = dyn_cast<gswitch *> (cond_stmt)) { - /* Avoid quadratic behavior. */ - if (gimple_switch_num_labels (gs) > MAX_SWITCH_CASES) - { - has_valid_pred = false; - break; - } - /* Find the case label. */ tree l = NULL_TREE; - unsigned idx; - for (idx = 0; idx < gimple_switch_num_labels (gs); ++idx) - { - tree tl = gimple_switch_label (gs, idx); - if (e->dest == label_to_block (cfun, CASE_LABEL (tl))) - { - if (!l) - l = tl; - else - { - l = NULL_TREE; - break; - } - } - } + /* Find the case label, but avoid quadratic behavior. */ + if (gimple_switch_num_labels (gs) <= MAX_SWITCH_CASES) + for (unsigned idx = 0; + idx < gimple_switch_num_labels (gs); ++idx) + { + tree tl = gimple_switch_label (gs, idx); + if (e->dest == label_to_block (cfun, CASE_LABEL (tl))) + { + if (!l) + l = tl; + else + { + l = NULL_TREE; + break; + } + } + } /* If more than one label reaches this block or the case label doesn't have a contiguous range of values (like the default one) fail. */ if (!l || !CASE_LOW (l)) - { - has_valid_pred = false; - break; - } + has_valid_pred = false; else if (!CASE_HIGH (l) || operand_equal_p (CASE_LOW (l), CASE_HIGH (l))) { @@ -1824,31 +1809,37 @@ predicate::init_from_control_deps (const vec<edge> *dep_chains, both the USE (valid) and DEF (questionable) case. */ has_valid_pred = true; else - { - has_valid_pred = false; - break; - } + has_valid_pred = false; + + /* For USE predicates we can drop components of the + AND chain. */ + if (!has_valid_pred && !is_use) + break; } - if (!has_valid_pred) - break; - else - m_preds.quick_push (t_chain); - } + /* For DEF predicates we have to drop components of the OR chain + on failure. */ + if (!has_valid_pred && !is_use) + { + t_chain.release (); + continue; + } - if (has_valid_pred) - { - gcc_assert (m_preds.length () != 0); - if (DEBUG_PREDICATE_ANALYZER && dump_file) - dump (NULL, ""); - } - else - { - if (DEBUG_PREDICATE_ANALYZER && dump_file) - fprintf (dump_file, "\tFAILED\n"); - /* Clear M_PREDS to indicate failure. */ - m_preds.release (); + /* When we add || 1 simply prune the chain and return. */ + if (t_chain.is_empty ()) + { + t_chain.release (); + for (auto chain : m_preds) + chain.release (); + m_preds.truncate (0); + break; + } + + m_preds.quick_push (t_chain); } + + if (DEBUG_PREDICATE_ANALYZER && dump_file) + dump (NULL, ""); } /* Store a PRED in *THIS. */ @@ -1877,7 +1868,7 @@ predicate::dump (gimple *stmt, const char *msg) const unsigned np = m_preds.length (); if (np == 0) { - fprintf (dump_file, "\t(empty)\n"); + fprintf (dump_file, "\tTRUE (empty)\n"); return; } |