* loop-unswitch.c (unswitch_loop): Pass probabilities to loopify.

	* tree-ssa-loop-unswitch.c (tree_unswitch_loop): Pass probabilities
	to loop_version.
	* cfgloopmanip.c (scale_loop_frequencies): Export.
	(loopify): Scale the frequencies by prescribed coefficients.
	(set_zero_probability): New function.
	(duplicate_loop_to_header_edge): Improve updating of frequencies.
	(lv_adjust_loop_entry_edge, loop_version): Set probabilities
	and frequencies according to arguments.
	* tree-ssa-loop-manip.c (tree_unroll_loop): Set probabilities
	correctly.
	* cfg.c (scale_bbs_frequencies_int): Allow scaling the frequencies up.
	* modulo-sched.c (sms_schedule): Set probabilities for entering
	versioned loop correctly.
	* tree-vect-transform.c (vect_transform_loop): Ditto.
	* cfgloop.h (loopify, loop_version): Declaration changed.
	(scale_loop_frequencies): Declared.

	* gcc.dg/tree-ssa/update-unroll-1.c: New test.
	* gcc.dg/tree-ssa/update-unswitch-1.c: New test.



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@120378 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 17 insertions, 4 deletions

diff --git a/gcc/cfg.c b/gcc/cfg.c
index aa8eaca9eec..9f5da32bfe8 100644
--- a/gcc/cfg.c
+++ b/gcc/cfg.c
@@ -949,15 +949,28 @@ scale_bbs_frequencies_int (basic_block *bbs, int nbbs, int num, int den)
   edge e;
   if (num < 0)
     num = 0;
-  if (num > den)
+
+  /* Scale NUM and DEN to avoid overflows.  Frequencies are in order of
+     10^4, if we make DEN <= 10^3, we can afford to upscale by 100
+     and still safely fit in int during calculations.  */
+  if (den > 1000)
+    {
+      if (num > 1000000)
+	return;
+
+      num = RDIV (1000 * num, den);
+      den = 1000;
+    }
+  if (num > 100 * den)
     return;
-  /* Assume that the users are producing the fraction from frequencies
-     that never grow far enough to risk arithmetic overflow.  */
-  gcc_assert (num < 65536);
+
   for (i = 0; i < nbbs; i++)
     {
       edge_iterator ei;
       bbs[i]->frequency = RDIV (bbs[i]->frequency * num, den);
+      /* Make sure the frequencies do not grow over BB_FREQ_MAX.  */
+      if (bbs[i]->frequency > BB_FREQ_MAX)
+	bbs[i]->frequency = BB_FREQ_MAX;
       bbs[i]->count = RDIV (bbs[i]->count * num, den);
       FOR_EACH_EDGE (e, ei, bbs[i]->succs)
 	e->count = RDIV (e->count * num, den);