re PR tree-optimization/48186 (ICE: SIGFPE (division by zero) in…

re PR tree-optimization/48186 (ICE: SIGFPE (division by zero) in maybe_hot_frequency_p at predict.c:129 with --param hot-bb-frequency-fraction=0 on basic code)

        PR tree-optimization/48186
        * predict.c (maybe_hot_frequency_p): Return false if
        HOT_BB_FREQUENCY_FRACTION is 0.
        (cgraph_maybe_hot_edge_p): Likewise.

        * gcc.dg/pr48186.c: New test.

From-SVN: r197487

gcc/ChangeLog

+2013-04-04  Marek Polacek  <polacek@redhat.com>
+
+	PR tree-optimization/48186
+	* predict.c (maybe_hot_frequency_p): Return false if
+	HOT_BB_FREQUENCY_FRACTION is 0.
+	(cgraph_maybe_hot_edge_p): Likewise.
+
 2013-04-04  Richard Biener  <rguenther@suse.de>
 
 	PR tree-optimization/56826

gcc/predict.c

@@ -122,6 +122,8 @@ maybe_hot_frequency_p (struct function *fun, int freq)
   if (node->frequency == NODE_FREQUENCY_EXECUTED_ONCE
       && freq < (ENTRY_BLOCK_PTR_FOR_FUNCTION (fun)->frequency * 2 / 3))
     return false;
+  if (PARAM_VALUE (HOT_BB_FREQUENCY_FRACTION) == 0)
+    return false;
   if (freq < (ENTRY_BLOCK_PTR_FOR_FUNCTION (fun)->frequency
 	      / PARAM_VALUE (HOT_BB_FREQUENCY_FRACTION)))
     return false;
@@ -202,10 +204,13 @@ cgraph_maybe_hot_edge_p (struct cgraph_edge *edge)
   if (edge->caller->frequency == NODE_FREQUENCY_EXECUTED_ONCE
       && edge->frequency < CGRAPH_FREQ_BASE * 3 / 2)
     return false;
-  if (flag_guess_branch_prob
-      && edge->frequency <= (CGRAPH_FREQ_BASE
-      			     / PARAM_VALUE (HOT_BB_FREQUENCY_FRACTION)))
-    return false;
+  if (flag_guess_branch_prob)
+    {
+      if (PARAM_VALUE (HOT_BB_FREQUENCY_FRACTION) == 0
+	  || edge->frequency <= (CGRAPH_FREQ_BASE
+				 / PARAM_VALUE (HOT_BB_FREQUENCY_FRACTION)))
+        return false;
+    }
   return true;
 }
 

gcc/testsuite/ChangeLog

+2013-04-04  Marek Polacek  <polacek@redhat.com>
+
+	PR tree-optimization/48186
+	* gcc.dg/pr48186.c: New test.
+
 2013-04-04  Richard Biener  <rguenther@suse.de>
 
 	PR tree-optimization/56826

gcc/testsuite/gcc.dg/pr48186.c

+/* PR tree-optimization/48186 */
+/* { dg-do compile } */
+/* { dg-options "-O --param hot-bb-frequency-fraction=0" } */
+
+void foo (void) { }