predict.c (estimate_bb_frequencies): Do frequency calculation with a volatile temporary.

* predict.c (estimate_bb_frequencies): Do frequency calculation with a volatile temporary. From-SVN: r51879

predict.c (estimate_bb_frequencies): Do frequency calculation with a volatile temporary.
* predict.c (estimate_bb_frequencies): Do frequency calculation with a volatile temporary. From-SVN: r51879
39002160 · Richard Henderson · Richard Henderson · 677b3ae3 · 39002160 · 39002160
Commit 39002160 authored Apr 04, 2002 by Richard Henderson Committed by Richard Henderson Apr 04, 2002
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Showing with 12 additions and 2 deletions

gcc/ChangeLog
+5 -0

gcc/predict.c
+7 -2

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--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
+2002-04-04  Richard Henderson  <rth@redhat.com>
+
+	* predict.c (estimate_bb_frequencies): Do frequency calculation
+	with a volatile temporary.
+
 2002-04-04  Ulrich Weigand  <uweigand@de.ibm.com>

 	* config/s390/linux.h (LOCAL_LABEL_PREFIX): Define.

--- a/gcc/predict.c
+++ b/gcc/predict.c
@@ -942,6 +942,7 @@ estimate_bb_frequencies (loops)
  for (i = -2; i < n_basic_blocks; i++)
    {
      basic_block bb;
+      volatile double tmp;

      if (i == -2)
 	bb = ENTRY_BLOCK_PTR;
@@ -949,8 +950,12 @@ estimate_bb_frequencies (loops)
 	bb = EXIT_BLOCK_PTR;
      else
 	bb = BASIC_BLOCK (i);
-      bb->frequency
-	= BLOCK_INFO (bb)->frequency * BB_FREQ_MAX / freq_max + 0.5;
+
+      /* ??? Prevent rounding differences due to optimization on x86.  */
+      tmp = BLOCK_INFO (bb)->frequency * BB_FREQ_MAX;
+      tmp /= freq_max;
+      tmp += 0.5;
+      bb->frequency = tmp;
    }

  free_aux_for_blocks ();