2001-09-21 Hartmut Penner <hpenner@de.ibm.com>

        * s390.md: Changed attributes for scheduling.
        * s390.c: (s390_adjust_cost, s390_adjust_priority)
        Changed scheduling


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@45725 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 46 insertions, 13 deletions

diff --git a/gcc/config/s390/s390.c b/gcc/config/s390/s390.c
index 425c98e1781..e4bc735209e 100644
--- a/gcc/config/s390/s390.c
+++ b/gcc/config/s390/s390.c
@@ -46,6 +46,7 @@ Boston, MA 02111-1307, USA.  */
 
 
 static int s390_adjust_cost PARAMS ((rtx, rtx, rtx, int));
+static int s390_adjust_priority PARAMS ((rtx, int));
 
 #undef  TARGET_ASM_FUNCTION_PROLOGUE 
 #define TARGET_ASM_FUNCTION_PROLOGUE s390_function_prologue
@@ -62,6 +63,9 @@ static int s390_adjust_cost PARAMS ((rtx, rtx, rtx, int));
 #undef  TARGET_SCHED_ADJUST_COST
 #define TARGET_SCHED_ADJUST_COST s390_adjust_cost
 
+#undef  TARGET_SCHED_ADJUST_PRIORITY
+#define TARGET_SCHED_ADJUST_PRIORITY s390_adjust_priority
+
 struct gcc_target targetm = TARGET_INITIALIZER;
 
 extern int reload_completed;
@@ -1587,7 +1591,9 @@ addr_generation_dependency_p (dep_rtx, insn)
    Data dependencies are all handled without delay.  However, if a
    register is modified and subsequently used as base or index 
    register of a memory reference, at least 4 cycles need to pass
-   between setting and using the register to avoid pipeline stalls.  */
+   between setting and using the register to avoid pipeline stalls.  
+   A exception is the LA instruction. A address generated by LA can
+   be used by introducing only a one cycle stall on the pipeline.  */
 
 static int
 s390_adjust_cost (insn, link, dep_insn, cost)
@@ -1610,19 +1616,13 @@ s390_adjust_cost (insn, link, dep_insn, cost)
   if (recog_memoized (insn) < 0 || recog_memoized (dep_insn) < 0)
     return cost;
 
-  /* If cost equal 1 nothing needs to be checked. */
-
-  if (cost == 1)
-    {
-      return cost;
-    }
-
   dep_rtx = PATTERN (dep_insn);
 
   if (GET_CODE (dep_rtx) == SET)
     {
       if (addr_generation_dependency_p (dep_rtx, insn))
 	{
+	  cost += (get_attr_type (dep_insn) == TYPE_LA) ? 1 : 4;  
 	  if (DEBUG_SCHED)
 	    {
 	      fprintf (stderr, "\n\nAddress dependency detected: cost %d\n",
@@ -1630,10 +1630,8 @@ s390_adjust_cost (insn, link, dep_insn, cost)
 	      debug_rtx (dep_insn);
 	      debug_rtx (insn);
 	    }
-	  return cost;
 	}
     }
-
   else if (GET_CODE (dep_rtx) == PARALLEL)
     {
       for (i = 0; i < XVECLEN (dep_rtx, 0); i++)
@@ -1641,6 +1639,7 @@ s390_adjust_cost (insn, link, dep_insn, cost)
 	  if (addr_generation_dependency_p (XVECEXP (dep_rtx, 0, i),
 					    insn))
 	    {
+	      cost += (get_attr_type (dep_insn) == TYPE_LA) ? 1 : 4;  
 	      if (DEBUG_SCHED)
 		{
 		  fprintf (stderr, "\n\nAddress dependency detected: cost %d\n"
@@ -1648,15 +1647,49 @@ s390_adjust_cost (insn, link, dep_insn, cost)
 		  debug_rtx (dep_insn);
 		  debug_rtx (insn);
 		}
-	      return cost;
 	    }
 	}
     }
 
-  /* default cost.  */
-  return 1;
+  return cost;
+}
+
+
+/* A C statement (sans semicolon) to update the integer scheduling priority
+   INSN_PRIORITY (INSN).  Reduce the priority to execute the INSN earlier,
+   increase the priority to execute INSN later.  Do not define this macro if
+   you do not need to adjust the scheduling priorities of insns. 
+
+   A LA instruction maybe scheduled later, since the pipeline bypasses the
+   calculated value.  */
+
+static int
+s390_adjust_priority (insn, priority)
+     rtx insn ATTRIBUTE_UNUSED;
+     int priority;
+{
+  if (! INSN_P (insn))
+    return priority;
+
+  if (GET_CODE (PATTERN (insn)) == USE 
+      || GET_CODE (PATTERN (insn)) == CLOBBER)
+    return priority;
+  
+  switch (get_attr_type (insn))
+    {
+    default:
+      break;
+      
+    case TYPE_LA:
+      if (priority >= 0 && priority < 0x01000000)
+	priority <<= 3;
+      break;
+    }
+  
+  return priority;
 }
 
+
 /* Pool concept for Linux 390:
    - Function prologue saves used register 
    - literal pool is dumped in prologue and  jump across with bras