Check equivalencies when calculating range on entry.

When propagating on-entry values in the cache, checking if any equivalence
has a known value can improve results.  No new calculations are made.
Only queries via dominators which do not populate the cache are checked.

	PR tree-optimization/106474
	gcc/
	* gimple-range-cache.cc (ranger_cache::fill_block_cache): Query
	range of equivalences that may contribute to the range.

	gcc/testsuite/
	* g++.dg/pr106474.C: New.

diff --git a/gcc/gimple-range-cache.cc b/gcc/gimple-range-cache.cc
index d9e160c9a2a4e3e2317ed292f0ef59e17477b96d..4782d47265eb56157056ef1c01afb74ffd190b63 100644 (file)
--- a/gcc/gimple-range-cache.cc
+++ b/gcc/gimple-range-cache.cc
@@ -1211,13 +1211,56 @@ ranger_cache::fill_block_cache (tree name, basic_block bb, basic_block def_bb)
   // Check if a dominators can supply the range.
   if (range_from_dom (block_result, name, bb, RFD_FILL))
     {
-      m_on_entry.set_bb_range (name, bb, block_result);
       if (DEBUG_RANGE_CACHE)
        {
          fprintf (dump_file, "Filled from dominator! :  ");
          block_result.dump (dump_file);
          fprintf (dump_file, "\n");
        }
+      // See if any equivalences can refine it.
+      if (m_oracle)
+       {
+         unsigned i;
+         bitmap_iterator bi;
+         // Query equivalences in read-only mode.
+         const_bitmap equiv = m_oracle->equiv_set (name, bb);
+         EXECUTE_IF_SET_IN_BITMAP (equiv, 0, i, bi)
+           {
+             if (i == SSA_NAME_VERSION (name))
+               continue;
+             tree equiv_name = ssa_name (i);
+             basic_block equiv_bb = gimple_bb (SSA_NAME_DEF_STMT (equiv_name));
+
+             // Check if the equiv has any ranges calculated.
+             if (!m_gori.has_edge_range_p (equiv_name))
+               continue;
+
+             // Check if the equiv definition dominates this block
+             if (equiv_bb == bb ||
+                 (equiv_bb && !dominated_by_p (CDI_DOMINATORS, bb, equiv_bb)))
+               continue;
+
+             Value_Range equiv_range (TREE_TYPE (equiv_name));
+             if (range_from_dom (equiv_range, equiv_name, bb, RFD_READ_ONLY))
+               {
+                 if (block_result.intersect (equiv_range))
+                   {
+                     if (DEBUG_RANGE_CACHE)
+                       {
+                         fprintf (dump_file, "Equivalence update! :  ");
+                         print_generic_expr (dump_file, equiv_name, TDF_SLIM);
+                         fprintf (dump_file, "had range  :  ");
+                         equiv_range.dump (dump_file);
+                         fprintf (dump_file, " refining range to :");
+                         block_result.dump (dump_file);
+                         fprintf (dump_file, "\n");
+                       }
+                   }
+               }
+           }
+       }
+
+      m_on_entry.set_bb_range (name, bb, block_result);
       gcc_checking_assert (m_workback.length () == 0);
       return;
     }

diff --git a/gcc/testsuite/g++.dg/pr106474.C b/gcc/testsuite/g++.dg/pr106474.C
new file mode 100644 (file)
index 0000000..6cd37a2
--- /dev/null
+++ b/gcc/testsuite/g++.dg/pr106474.C
@@ -0,0 +1,16 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-evrp " } */
+
+void foo();
+static void __attribute__ ((noinline)) DCEMarker0_() {foo ();}
+
+void f(bool s, bool c) {
+    if ((!c == !s) && !c) {
+        if (s) {
+            DCEMarker0_();
+        }
+    }
+}
+
+// With equivalences, vrp should be able to remove all IFs.
+/* { dg-final { scan-tree-dump-not "goto" "evrp" } } */