New flag to apply SMS when SC equals 1 (Second try)

Message ID BANLkTinQoE15T5tXYBE_AO1SO4N3Liy5tQ@mail.gmail.com
State New
Headers show

Commit Message

Revital Eres April 17, 2011, 11:41 a.m.
Hello,

>
> New params need documentation in doc/invoke.texi.  Please also change the
> maximum value to 2, not 1.  Ok with that changes.

When changing the max value to 2, any value that is greater than
2 is rejected due to the following comment in params.def:

     - The maximum acceptable value for the parameter (if greater than
     the minimum).

So I'll leave the maximum value to be 1 if that's OK.
I added the documentation in invoke.taxi.

Thanks,
Revital

        * params.def (sms-min-sc): New param flag.
        * modulo-sched.c (sms_schedule): Use it.
        * doc/invoke.texi (sms-min-sc): Document it.

Patch

=== modified file 'gcc/doc/invoke.texi'
--- gcc/doc/invoke.texi	2011-03-07 03:00:04 +0000
+++ gcc/doc/invoke.texi	2011-04-17 11:28:33 +0000
@@ -8718,6 +8718,10 @@  through which the instruction may be pip
 The maximum number of best instructions in the ready list that are considered
 for renaming in the selective scheduler.  The default value is 2.
 
+@item sms-min-sc
+The minimum value of stage count that swing modulo scheduler will
+generate.  The default value is 2.
+
 @item max-last-value-rtl
 The maximum size measured as number of RTLs that can be recorded in an expression
 in combiner for a pseudo register as last known value of that register.  The default

=== modified file 'gcc/modulo-sched.c'
--- gcc/modulo-sched.c	2011-03-27 07:11:08 +0000
+++ gcc/modulo-sched.c	2011-04-17 10:53:03 +0000
@@ -1222,9 +1222,10 @@  sms_schedule (void)
 	  PS_STAGE_COUNT(ps) = stage_count;
 	}
       
-      /* Stage count of 1 means that there is no interleaving between
-         iterations, let the scheduling passes do the job.  */
-      if (stage_count <= 1
+      /* The default value of PARAM_SMS_MIN_SC is 2 as stage count of
+	 1 means that there is no interleaving between iterations thus
+	 we let the scheduling passes do the job in this case.  */
+      if (stage_count < (unsigned) PARAM_VALUE (PARAM_SMS_MIN_SC)
 	  || (count_init && (loop_count <= stage_count))
 	  || (flag_branch_probabilities && (trip_count <= stage_count)))
 	{

=== modified file 'gcc/params.def'
--- gcc/params.def	2011-02-02 15:52:08 +0000
+++ gcc/params.def	2011-04-17 11:16:03 +0000
@@ -344,6 +344,11 @@  DEFPARAM(PARAM_SMS_MAX_II_FACTOR,
 	 "sms-max-ii-factor",
 	 "A factor for tuning the upper bound that swing modulo scheduler uses for scheduling a loop",
 	 100, 0, 0)
+/* The minimum value of stage count that swing modulo scheduler will generate.  */
+DEFPARAM(PARAM_SMS_MIN_SC,
+        "sms-min-sc",
+        "The minimum value of stage count that swing modulo scheduler will generate.",
+        2, 1, 1)
 DEFPARAM(PARAM_SMS_DFA_HISTORY,
 	 "sms-dfa-history",
 	 "The number of cycles the swing modulo scheduler considers when checking conflicts using DFA",