(CONST_COSTS): Revise all costs.

From-SVN: r7225

diff --git a/gcc/config/alpha/alpha.h b/gcc/config/alpha/alpha.h
index 2f2471611136bdc22467018df8d3486c69d39b9d..ba135336986c778a667dd0151542c4b72fc8be65 100644 (file)
--- a/gcc/config/alpha/alpha.h
+++ b/gcc/config/alpha/alpha.h
@@ -1312,17 +1312,28 @@ extern char *current_function_name;
    of a switch statement.  If the code is computed here,
    return it with a return statement.  Otherwise, break from the switch.
 
-   We only care about the cost if it is valid in an insn, so all constants
-   are cheap.  */
+   If this is an 8-bit constant, return zero since it can be used
+   nearly anywhere with no cost.  If it is a valid operand for an
+   ADD or AND, likewise return 0 if we know it will be used in that
+   context.  Otherwise, return 2 since it might be used there later.
+   All other constants take at least two insns.  */
 
 #define CONST_COSTS(RTX,CODE,OUTER_CODE) \
   case CONST_INT:                                              \
+    if (INTVAL (RTX) >= 0 && INTVAL (RTX) < 2546)              \
+      return 0;                                                        \
   case CONST_DOUBLE:                                           \
-    return 0;                                                  \
+    if (((OUTER_CODE) == PLUS && add_operand (RTX, VOIDmode))  \
+       || ((OUTER_CODE) == AND && and_operand (RTX, VOIDmode))) \
+      return 0;                                                        \
+    else if (add_operand (RTX, VOIDmode) || and_operand (RTX, VOIDmode)) \
+      return 2;                                                        \
+    else                                                       \
+      return COSTS_N_INSNS (2);                                        \
   case CONST:                                                  \
   case SYMBOL_REF:                                             \
   case LABEL_REF:                                              \
-    return 6;                                                  \
+    return COSTS_N_INSNS (3);
     
 /* Provide the costs of a rtl expression.  This is in the body of a
    switch on CODE.  */