PR middle-end/38981

	* tree-ssa-coalesce.c (add_coalesce): Cap the costs of coalesce pairs
	at MUST_COALESCE_COST-1 instead of MUST_COALESCE_COST.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@144032 138bc75d-0d04-0410-961f-82ee72b054a4

4 files changed, 77 insertions, 7 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index a6deff996a4..b1e2ae8b875 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2009-02-09  Eric Botcazou  <ebotcazou@adacore.com>
+
+	PR middle-end/38981
+	* tree-ssa-coalesce.c (add_coalesce): Cap the costs of coalesce pairs
+	at MUST_COALESCE_COST-1 instead of MUST_COALESCE_COST.
+
 2009-02-09  Richard Guenther  <rguenther@suse.de>
 
 	PR middle-end/35202
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 7cde83d6c5e..cd90ac8d78a 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2009-02-09  Eric Botcazou  <ebotcazou@adacore.com>
+
+	* gcc.c-torture/compile/20090209-1.c: New test.
+
 2009-02-06  Paolo Carlini  <paolo.carlini@oracle.com>
 
 	PR c++/35147
diff --git a/gcc/testsuite/gcc.c-torture/compile/20090209-1.c b/gcc/testsuite/gcc.c-torture/compile/20090209-1.c
new file mode 100644
index 00000000000..781a5e8fd0d
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/compile/20090209-1.c
@@ -0,0 +1,61 @@
+/* PR middle-end/38981 */
+/* Reporter: Kamaraju Kusumanchi <kamaraju@gmail.com> */
+
+struct d_info
+{
+  int **subs;
+};
+
+static int *
+d_substitution (struct d_info *di, int prefix)
+{
+  char c;
+
+	c='_';
+
+  if (c == '_')
+    {
+      unsigned int id;
+
+      if (c != '_')
+	{
+	  do
+	    {
+	      unsigned int new_id;
+
+	      if (new_id < id)
+		return 0;
+	      id = new_id;
+	    }
+	  while (c != '_');
+	}
+
+
+
+      return di->subs[id];
+    }
+  else
+    {
+      int verbose;
+      int code;
+      int simple_len;
+
+	code=0;
+	simple_len=0;
+	verbose=0;
+      if (! code && prefix)
+	{
+	  char peek;
+		peek='A';
+
+	  if (peek == 'C' || peek == 'D')
+	    verbose = 1;
+	}
+
+	      if (verbose)
+		{
+		  code = simple_len;
+		}
+
+    }
+}
diff --git a/gcc/tree-ssa-coalesce.c b/gcc/tree-ssa-coalesce.c
index 3af0c3285d8..8ac74f0c290 100644
--- a/gcc/tree-ssa-coalesce.c
+++ b/gcc/tree-ssa-coalesce.c
@@ -284,8 +284,7 @@ add_cost_one_coalesce (coalesce_list_p cl, int p1, int p2)
 /* Add a coalesce between P1 and P2 in list CL with a cost of VALUE.  */
 
 static inline void 
-add_coalesce (coalesce_list_p cl, int p1, int p2,
-	      int value)
+add_coalesce (coalesce_list_p cl, int p1, int p2, int value)
 {
   coalesce_pair_p node;
 
@@ -295,13 +294,13 @@ add_coalesce (coalesce_list_p cl, int p1, int p2,
 
   node = find_coalesce_pair (cl, p1, p2, true);
 
-  /* Once the value is MUST_COALESCE_COST, leave it that way.  */
-  if (node->cost != MUST_COALESCE_COST)
+  /* Once the value is at least MUST_COALESCE_COST - 1, leave it that way.  */
+  if (node->cost < MUST_COALESCE_COST - 1)
     {
-      if (value == MUST_COALESCE_COST)
-	node->cost = value;
-      else
+      if (value < MUST_COALESCE_COST - 1)
 	node->cost += value;
+      else
+	node->cost = value;
     }
 }