Patchwork [SMS] Fix calculation of issue_rate

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Submitter Revital Eres
Date May 19, 2011, 6:54 a.m.
Message ID <BANLkTim=4Ao0B1fFs8kBZuN5oqfvFGT+fA@mail.gmail.com>
Download mbox | patch
Permalink /patch/96317/
State New
Headers show

Comments

Revital Eres - May 19, 2011, 6:54 a.m.
Hello,

The issue rate is currently been set in SMS by calling
targetm.sched.issue_rate  function if it is defined.  For rs6000 the
issue_rate is 1 if !reload_completed && !flag_sched_pressure.
To bypass that, SMS sets reload_completed to 1 before calling
targetm.sched.issue_rate and restores it's original value after the call.
The problem is that the issue rate is changed again to 1 because of the
following chain of calls which occurs right after setting issue_rate
in targetm.sched.issue_rate  ():

sms_schedule -> haifa_sched_init -> sched_init () ->
targetm.sched.issue_rate () (in haifa-sched.c:3474)

This time, when calling targetm.sched.issue_rate the issue_rate is
set to 1 as reload_completed  contains it's original value (zero).
The attached patch tries to fix that.

Tested (bootstrap and regtest) on ppc64-redhat-linux.

OK for mainline?

Thanks,
Revital


Changelog:

* modulo-sched.c (sms_schedule): Fix stage_count calculation.
Revital Eres - May 19, 2011, 7 a.m.
Hello,

>
> * modulo-sched.c (sms_schedule): Fix stage_count calculation.
>

Sorry, just noticed that the changelog entry is wrong, here
a correction:

        * modulo-sched.c (sms_schedule): Fix issue_rate calculation.

Thanks,
Revital

Patch

Index: modulo-sched.c
===================================================================
--- modulo-sched.c      (revision 173786)
+++ modulo-sched.c      (working copy)
@@ -924,6 +924,7 @@  sms_schedule (void)
   basic_block condition_bb = NULL;
   edge latch_edge;
   gcov_type trip_count = 0;
+  int temp;

   loop_optimizer_init (LOOPS_HAVE_PREHEADERS
                       | LOOPS_HAVE_RECORDED_EXITS);
@@ -933,22 +934,19 @@  sms_schedule (void)
       return;  /* There are no loops to schedule.  */
     }

+  temp = reload_completed;
+  reload_completed = 1;
   /* Initialize issue_rate.  */
   if (targetm.sched.issue_rate)
-    {
-      int temp = reload_completed;
-
-      reload_completed = 1;
-      issue_rate = targetm.sched.issue_rate ();
-      reload_completed = temp;
-    }
+    issue_rate = targetm.sched.issue_rate ();
   else
     issue_rate = 1;
-
+
   /* Initialize the scheduler.  */
   setup_sched_infos ();
   haifa_sched_init ();
-
+  reload_completed = temp;
+
   /* Allocate memory to hold the DDG array one entry for each loop.
      We use loop->num as index into this array.  */
   g_arr = XCNEWVEC (ddg_ptr, number_of_loops ());