[PATCH 3/7] S/390: Change handling of long-running instructions.

[Robin Dapp <rdapp at linux dot ibm dot com>]

This patch makes the detection of long-running instructions
independent of their latency and checks the execution unit
instead.

---
 gcc/config/s390/s390.c | 73 +++++++++++++++++++++++++++++++-----------
 1 file changed, 55 insertions(+), 18 deletions(-)

diff --git a/gcc/config/s390/s390.c b/gcc/config/s390/s390.c
index 95a4460dcf5..15926ec88cd 100644
--- a/gcc/config/s390/s390.c
+++ b/gcc/config/s390/s390.c
@@ -349,12 +349,11 @@ static int last_scheduled_unit_distance[MAX_SCHED_UNITS];
 
 #define NUM_SIDES 2
 static int current_side = 1;
-#define LONGRUNNING_THRESHOLD 20
 
 /* Estimate of number of cycles a long-running insn occupies an
    execution unit.  */
-static unsigned fxd_longrunning[NUM_SIDES];
-static unsigned fpd_longrunning[NUM_SIDES];
+static int fxd_longrunning[NUM_SIDES];
+static int fpd_longrunning[NUM_SIDES];
 
 /* The maximum score added for an instruction whose unit hasn't been
    in use for MAX_SCHED_MIX_DISTANCE steps.  Increase this value to
@@ -14357,6 +14356,17 @@ s390_get_unit_mask (rtx_insn *insn, int *units)
   return mask;
 }
 
+/* Returns TRUE if INSN is a long-running instruction.  */
+static bool
+s390_is_longrunning (rtx_insn *insn)
+{
+  if (insn == NULL_RTX)
+    return false;
+
+  return get_attr_z13_unit_fxd (insn) || get_attr_z13_unit_fpd (insn)
+    || get_attr_z14_unit_fxd (insn) || get_attr_z14_unit_fpd (insn);
+}
+
 /* Return the scheduling score for INSN.  The higher the score the
    better.  The score is calculated from the OOO scheduling attributes
    of INSN and the scheduling state s390_sched_state.  */
@@ -14432,20 +14442,48 @@ s390_sched_score (rtx_insn *insn)
 	  score += (last_scheduled_unit_distance[i] * MAX_SCHED_MIX_SCORE /
 		    MAX_SCHED_MIX_DISTANCE);
 
-      unsigned latency = insn_default_latency (insn);
-
       int other_side = 1 - current_side;
 
       /* Try to delay long-running insns when side is busy.  */
-      if (latency > LONGRUNNING_THRESHOLD)
+      if (s390_is_longrunning (insn))
 	{
-	  if (get_attr_z13_unit_fxu (insn) && fxd_longrunning[current_side]
-	      && fxd_longrunning[other_side] <= fxd_longrunning[current_side])
-	    score = MAX (0, score - 10);
+	  if (s390_tune == PROCESSOR_2964_Z13)
+	    {
+	      if (get_attr_z13_unit_fxd (insn) && fxd_longrunning[current_side]
+		  && fxd_longrunning[other_side] <= fxd_longrunning[current_side])
+		score = MAX (0, score - 10);
 
-	  if (get_attr_z13_unit_vfu (insn) && fpd_longrunning[current_side]
-	      && fpd_longrunning[other_side] <= fpd_longrunning[current_side])
-	    score = MAX (0, score - 10);
+	      if (get_attr_z13_unit_fxd (insn)
+		  && fxd_longrunning[other_side] >= fxd_longrunning[current_side])
+		score += 10;
+
+	      if (get_attr_z13_unit_fpd (insn) && fpd_longrunning[current_side]
+		  && fpd_longrunning[other_side] <= fpd_longrunning[current_side])
+		score = MAX (0, score - 10);
+
+	      if (get_attr_z13_unit_fpd (insn)
+		  && fpd_longrunning[other_side] >= fpd_longrunning[current_side])
+		score += 10;
+	    }
+
+	  if (s390_tune == PROCESSOR_3906_Z14)
+	    {
+	      if (get_attr_z14_unit_fxd (insn) && fxd_longrunning[current_side]
+		  && fxd_longrunning[other_side] <= fxd_longrunning[current_side])
+		score = MAX (0, score - 10);
+
+	      if (get_attr_z14_unit_fxd (insn)
+		  && fxd_longrunning[other_side] >= fxd_longrunning[current_side])
+		score += 10;
+
+	      if (get_attr_z14_unit_fpd (insn) && fpd_longrunning[current_side]
+		  && fpd_longrunning[other_side] <= fpd_longrunning[current_side])
+		score = MAX (0, score - 10);
+
+	      if (get_attr_z14_unit_fpd (insn)
+		  && fpd_longrunning[other_side] >= fpd_longrunning[current_side])
+		score += 10;
+	    }
 	}
     }
 
@@ -14629,16 +14667,15 @@ s390_sched_variable_issue (FILE *file, int verbose, rtx_insn *insn, int more)
 
       for (int i = 0; i < 2; i++)
 	{
-	  if (fxd_longrunning[i] >= 1)
-	    fxd_longrunning[i] -= 1;
-	  if (fpd_longrunning[i] >= 1)
-	    fpd_longrunning[i] -= 1;
+	  fxd_longrunning[i] = MAX (0, fxd_longrunning[i] - 1);
+	  fpd_longrunning[i] = MAX (0, fpd_longrunning[i] - 1);
 	}
 
       unsigned latency = insn_default_latency (insn);
-      if (latency > LONGRUNNING_THRESHOLD)
+      if (s390_is_longrunning (insn))
 	{
-	  if (get_attr_z13_unit_fxu (insn))
+	  if (get_attr_z13_unit_fxd (insn)
+	      || get_attr_z14_unit_fxd (insn))
 	    fxd_longrunning[current_side] = latency;
 	  else
 	    fpd_longrunning[current_side] = latency;
-- 
2.17.0