(pa_adjust_cost): New procudure.

From-SVN: r3597

diff --git a/gcc/config/pa/pa.c b/gcc/config/pa/pa.c
index e5cf74fefb9ecbc29a53a9d286f7de9c7173f2ce..1b3d5ddeaf426640a919998d5cef00ecbd4c15a1 100644 (file)
--- a/gcc/config/pa/pa.c
+++ b/gcc/config/pa/pa.c
@@ -2061,6 +2061,102 @@ gen_cmp_fp (code, operand0, operand1)
                  gen_rtx (code, CCFPmode, operand0, operand1));
 }
 
+/* Adjust the cost of a scheduling dependency.  Return the new cost of
+   a dependency LINK or INSN on DEP_INSN.  COST is the current cost.  */
+
+int
+pa_adjust_cost (insn, link, dep_insn, cost)
+     rtx insn;
+     rtx link;
+     rtx dep_insn;
+     int cost;
+{
+  /* If the dependence is an anti-dependence, there is no cost.  For an
+     output dependence, there is sometimes a cost, but it doesn't seem
+     worth handling those few cases.  */
+
+  if (REG_NOTE_KIND (link) == 0)
+    {
+      /* Data dependency; DEP_INSN writes a register that INSN reads some
+        cycles later.  */
+
+      if (get_attr_type (insn) == TYPE_FPSTORE)
+       {
+         if (GET_CODE (PATTERN (insn)) != SET
+             || GET_CODE (PATTERN (dep_insn)) != SET)
+           /* If this happens, we have to extend this to schedule
+              optimally.  */
+           abort();
+
+         if (rtx_equal_p (SET_DEST (PATTERN (dep_insn)), SET_SRC (PATTERN (insn))))
+           {
+             /* INSN is a fp store and DEP_INSN is writing to the register
+                being stored.  */
+             switch (get_attr_type (dep_insn))
+               {
+               case TYPE_FPLOAD:
+                 /* This cost 3 cycles, not 2 as the md says.  */
+                 return cost + 1;
+
+               case TYPE_FPALU:
+               case TYPE_FPMUL:
+               case TYPE_FPDIVSGL:
+               case TYPE_FPDIVDBL:
+               case TYPE_FPSQRTSGL:
+               case TYPE_FPSQRTDBL:
+                 /* In these important cases, we save one cycle compared to
+                    when flop instruction feed each other.  */
+                 return cost - 1;
+
+               default:
+                 return cost;
+               }
+           }
+       }
+
+      /* For other data dependencies, the default cost specified in the
+        md is correct.  */
+      return cost;
+    }
+  else if (REG_NOTE_KIND (link) == REG_DEP_ANTI)
+    {
+      /* Anti dependency; DEP_INSN reads a register that INSN writes some
+        cycles later.  */
+
+      if (get_attr_type (insn) == TYPE_FPLOAD)
+       {
+         if (GET_CODE (PATTERN (insn)) != SET
+             || GET_CODE (PATTERN (dep_insn)) != SET)
+           /* If this happens, we have to extend this to schedule
+              optimally.  */
+           abort();
+
+         if (rtx_equal_p (SET_SRC (PATTERN (dep_insn)), SET_DEST (PATTERN (insn))))
+           {
+             switch (get_attr_type (dep_insn))
+               {
+               case TYPE_FPALU:
+               case TYPE_FPMUL:
+               case TYPE_FPDIVSGL:
+               case TYPE_FPDIVDBL:
+               case TYPE_FPSQRTSGL:
+               case TYPE_FPSQRTDBL:
+                 return cost - 1;
+
+               default:
+                 return 0;
+               }
+           }
+       }
+
+      /* For other anti dependencies, the cost is 0.  */
+      return 0;
+    }
+
+  /* For all other cases of anti dependency and all cases of output
+     dependence the md is correct enough for the PA7000.  */
+  return cost;
+}
 
 /* Print operand X (an rtx) in assembler syntax to file FILE.
    CODE is a letter or dot (`z' in `%z0') or 0 if no letter was specified.