Correct a function pre/postcondition [PR102403].

[thirdparty/gcc.git] / gcc / tree-ssa-tail-merge.c

diff --git a/gcc/tree-ssa-tail-merge.c b/gcc/tree-ssa-tail-merge.c
index fc94f5d83d2c926cd5186f81602618e15c78c25f..48f94217d16ede158d81ef2d3d556c6548a54e8c 100644 (file)
--- a/gcc/tree-ssa-tail-merge.c
+++ b/gcc/tree-ssa-tail-merge.c
@@ -1,5 +1,5 @@
 /* Tail merging for gimple.
-   Copyright (C) 2011-2017 Free Software Foundation, Inc.
+   Copyright (C) 2011-2021 Free Software Foundation, Inc.
    Contributed by Tom de Vries (tom@codesourcery.com)
 
 This file is part of GCC.
@@ -201,7 +201,6 @@ along with GCC; see the file COPYING3.  If not see
 #include "gimple-iterator.h"
 #include "tree-cfg.h"
 #include "tree-into-ssa.h"
-#include "params.h"
 #include "tree-ssa-sccvn.h"
 #include "cfgloop.h"
 #include "tree-eh.h"
@@ -286,6 +285,21 @@ struct aux_bb_info
 #define BB_VOP_AT_EXIT(bb) (((struct aux_bb_info *)bb->aux)->vop_at_exit)
 #define BB_DEP_BB(bb) (((struct aux_bb_info *)bb->aux)->dep_bb)
 
+/* Valueization helper querying the VN lattice.  */
+
+static tree
+tail_merge_valueize (tree name)
+{
+  if (TREE_CODE (name) == SSA_NAME
+      && has_VN_INFO (name))
+    {
+      tree tem = VN_INFO (name)->valnum;
+      if (tem != VN_TOP)
+       return tem;
+    }
+  return name;
+}
+
 /* Returns true if the only effect a statement STMT has, is to define locally
    used SSA_NAMEs.  */
 
@@ -301,7 +315,15 @@ stmt_local_def (gimple *stmt)
   if (gimple_vdef (stmt) != NULL_TREE
       || gimple_has_side_effects (stmt)
       || gimple_could_trap_p_1 (stmt, false, false)
-      || gimple_vuse (stmt) != NULL_TREE)
+      || gimple_vuse (stmt) != NULL_TREE
+      /* Copied from tree-ssa-ifcombine.c:bb_no_side_effects_p():
+        const calls don't match any of the above, yet they could
+        still have some side-effects - they could contain
+        gimple_could_trap_p statements, like floating point
+        exceptions or integer division by zero.  See PR70586.
+        FIXME: perhaps gimple_has_side_effects or gimple_could_trap_p
+        should handle this.  */
+      || is_gimple_call (stmt))
     return false;
 
   def_p = SINGLE_SSA_DEF_OPERAND (stmt, SSA_OP_DEF);
@@ -363,7 +385,7 @@ gvn_uses_equal (tree val1, tree val2)
   if (val1 == val2)
     return true;
 
-  if (vn_valueize (val1) != vn_valueize (val2))
+  if (tail_merge_valueize (val1) != tail_merge_valueize (val2))
     return false;
 
   return ((TREE_CODE (val1) == SSA_NAME || CONSTANT_CLASS_P (val1))
@@ -473,7 +495,7 @@ same_succ_hash (const same_succ *e)
       for (i = 0; i < gimple_call_num_args (stmt); i++)
        {
          arg = gimple_call_arg (stmt, i);
-         arg = vn_valueize (arg);
+         arg = tail_merge_valueize (arg);
          inchash::add_expr (arg, hstate);
        }
     }
@@ -1139,7 +1161,7 @@ gimple_equal_p (same_succ *same_succ, gimple *s1, gimple *s2)
       if (lhs1 == NULL_TREE || lhs2 == NULL_TREE)
        return false;
       if (TREE_CODE (lhs1) == SSA_NAME && TREE_CODE (lhs2) == SSA_NAME)
-       return vn_valueize (lhs1) == vn_valueize (lhs2);
+       return tail_merge_valueize (lhs1) == tail_merge_valueize (lhs2);
       return operand_equal_p (lhs1, lhs2, 0);
 
     case GIMPLE_ASSIGN:
@@ -1167,8 +1189,8 @@ gimple_equal_p (same_succ *same_succ, gimple *s1, gimple *s2)
       if (!gimple_operand_equal_value_p (t1, t2))
        return false;
 
-      code1 = gimple_expr_code (s1);
-      code2 = gimple_expr_code (s2);
+      code1 = gimple_cond_code (s1);
+      code2 = gimple_cond_code (s2);
       inv_cond = (bitmap_bit_p (same_succ->inverse, bb1->index)
                  != bitmap_bit_p (same_succ->inverse, bb2->index));
       if (inv_cond)
@@ -1446,7 +1468,7 @@ find_clusters_1 (same_succ *same_succ)
   unsigned int i, j;
   bitmap_iterator bi, bj;
   int nr_comparisons;
-  int max_comparisons = PARAM_VALUE (PARAM_MAX_TAIL_MERGE_COMPARISONS);
+  int max_comparisons = param_max_tail_merge_comparisons;
 
   EXECUTE_IF_SET_IN_BITMAP (same_succ->bbs, 0, i, bi)
     {
@@ -1455,7 +1477,8 @@ find_clusters_1 (same_succ *same_succ)
       /* TODO: handle blocks with phi-nodes.  We'll have to find corresponding
         phi-nodes in bb1 and bb2, with the same alternatives for the same
         preds.  */
-      if (bb_has_non_vop_phi (bb1) || bb_has_eh_pred (bb1))
+      if (bb_has_non_vop_phi (bb1) || bb_has_eh_pred (bb1)
+         || bb_has_abnormal_pred (bb1))
        continue;
 
       nr_comparisons = 0;
@@ -1463,7 +1486,8 @@ find_clusters_1 (same_succ *same_succ)
        {
          bb2 = BASIC_BLOCK_FOR_FN (cfun, j);
 
-         if (bb_has_non_vop_phi (bb2) || bb_has_eh_pred (bb2))
+         if (bb_has_non_vop_phi (bb2) || bb_has_eh_pred (bb2)
+             || bb_has_abnormal_pred (bb2))
            continue;
 
          if (BB_CLUSTER (bb1) != NULL && BB_CLUSTER (bb1) == BB_CLUSTER (bb2))
@@ -1570,17 +1594,8 @@ replace_block_by (basic_block bb1, basic_block bb2)
        /* If probabilities are same, we are done.
           If counts are nonzero we can distribute accordingly. In remaining
           cases just avreage the values and hope for the best.  */
-       if (e1->probability == e2->probability)
-         ;
-       else if (bb1->count.nonzero_p () || bb2->count.nonzero_p ())
-         e2->probability
-            = e2->probability
-                * bb2->count.probability_in (bb1->count + bb2->count)
-              + e1->probability
-                * bb1->count.probability_in (bb1->count + bb2->count);
-       else
-         e2->probability = e2->probability * profile_probability::even ()
-                           + e1->probability * profile_probability::even ();
+       e2->probability = e1->probability.combine_with_count
+                            (bb1->count, e2->probability, bb2->count);
       }
   bb2->count += bb1->count;
 
@@ -1715,7 +1730,7 @@ tail_merge_optimize (unsigned int todo)
   int nr_bbs_removed;
   bool loop_entered = false;
   int iteration_nr = 0;
-  int max_iterations = PARAM_VALUE (PARAM_MAX_TAIL_MERGE_ITERATIONS);
+  int max_iterations = param_max_tail_merge_iterations;
 
   if (!flag_tree_tail_merge
       || max_iterations == 0)
@@ -1730,7 +1745,7 @@ tail_merge_optimize (unsigned int todo)
     {
       cleanup_tree_cfg ();
       todo &= ~TODO_cleanup_cfg;
-      split_critical_edges ();
+      split_edges_for_insertion ();
     }
 
   if (!dom_info_available_p (CDI_DOMINATORS))