Scheduler cleanups, 3/N

Scheduler cleanups, 3/N

[Bernd Schmidt]

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This caches dependency costs. The target adjust_cost macro can be quite
expensive. This may not make much of a difference now, but in the final
backtracking scheduler patches (which I'm omitting for the moment) we
look at these costs a bit more often.


Bernd

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	gcc/
	* sched-int.h (struct _dep): New member COST.
	(DEP_COST): New macro.
	(UNKNOWN_DEP_COST): Define.
	* sched-deps.c (init_dep_1): Initialize cost member.
	* haifa-sched.c (dep_cost_1): Use precomputed cost if available,
	compute and set it otherwise.
	(sched_change_pattern): Reset costs of dependencies.


Index: gcc/haifa-sched.c
===================================================================
--- gcc/haifa-sched.c.orig
+++ gcc/haifa-sched.c
@@ -845,6 +845,9 @@ dep_cost_1 (dep_t link, dw_t dw)
   rtx used = DEP_CON (link);
   int cost;
 
+  if (DEP_COST (link) != UNKNOWN_DEP_COST)
+    return DEP_COST (link);
+
   /* A USE insn should never require the value used to be computed.
      This allows the computation of a function's result and parameter
      values to overlap the return and call.  We don't care about the
@@ -902,6 +905,7 @@ dep_cost_1 (dep_t link, dw_t dw)
 	cost = 0;
     }
 
+  DEP_COST (link) = cost;
   return cost;
 }
 
@@ -4854,11 +4858,20 @@ fix_recovery_deps (basic_block rec)
 void
 sched_change_pattern (rtx insn, rtx new_pat)
 {
+  sd_iterator_def sd_it;
+  dep_t dep;
   int t;
 
   t = validate_change (insn, &PATTERN (insn), new_pat, 0);
   gcc_assert (t);
   dfa_clear_single_insn_cache (insn);
+
+  for (sd_it = sd_iterator_start (insn, SD_LIST_FORW | SD_LIST_BACK);
+       sd_iterator_cond (&sd_it, &dep);)
+    {
+      DEP_COST (dep) = UNKNOWN_DEP_COST;
+      sd_iterator_next (&sd_it);
+    }
 }
 
 /* Change pattern of INSN to NEW_PAT.  Invalidate cached haifa
Index: gcc/sched-deps.c
===================================================================
--- gcc/sched-deps.c.orig
+++ gcc/sched-deps.c
@@ -106,6 +106,7 @@ init_dep_1 (dep_t dep, rtx pro, rtx con,
   DEP_CON (dep) = con;
   DEP_TYPE (dep) = type;
   DEP_STATUS (dep) = ds;
+  DEP_COST (dep) = UNKNOWN_DEP_COST;
 }
 
 /* Init DEP with the arguments.
Index: gcc/sched-int.h
===================================================================
--- gcc/sched-int.h.orig
+++ gcc/sched-int.h
@@ -239,6 +239,9 @@ struct _dep
   /* Dependency status.  This field holds all dependency types and additional
      information for speculative dependencies.  */
   ds_t status;
+
+  /* Cached cost of the dependency.  */
+  int cost;
 };
 
 typedef struct _dep dep_def;
@@ -248,6 +251,9 @@ typedef dep_def *dep_t;
 #define DEP_CON(D) ((D)->con)
 #define DEP_TYPE(D) ((D)->type)
 #define DEP_STATUS(D) ((D)->status)
+#define DEP_COST(D) ((D)->cost)
+
+#define UNKNOWN_DEP_COST INT_MIN
 
 /* Functions to work with dep.  */
 

Re: Scheduler cleanups, 3/N

[Jeff Law]

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On 03/24/11 07:11, Bernd Schmidt wrote:
> This caches dependency costs. The target adjust_cost macro can be quite
> expensive. This may not make much of a difference now, but in the final
> backtracking scheduler patches (which I'm omitting for the moment) we
> look at these costs a bit more often.
OK.
jeff

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