Re: [PATCH] Fix PR48186

[Marek Polacek]

On Thu, Apr 04, 2013 at 04:20:36PM +0200, Marek Polacek wrote:
> On Thu, Apr 04, 2013 at 04:06:35PM +0200, Jakub Jelinek wrote:
> > In this second hunk the division is done only for flag_guess_branch_prob,
> > so shouldn't it be
> >   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;
> > instead?
> 
> Yeah, I guess so.  Thanks; fixed:

Now really.

2013-04-04  Marek Polacek  <pola...@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.

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

--- gcc/predict.c.mp    2013-04-04 16:16:16.396977123 +0200
+++ gcc/predict.c       2013-04-04 16:25:51.621794236 +0200
@@ -122,6 +122,8 @@ maybe_hot_frequency_p (struct function *
   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_e
   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/gcc.dg/pr48186.c.mp   2013-04-04 16:26:16.720871459 +0200
+++ gcc/testsuite/gcc.dg/pr48186.c      2013-04-04 16:26:55.809991847 +0200
@@ -0,0 +1,5 @@
+/* PR tree-optimization/48186 */
+/* { dg-do compile } */
+/* { dg-options "-O --param hot-bb-frequency-fraction=0" } */
+
+void foo (void) { }

        Marek