m68hc11.h (CONST_COSTS): Make the cost of constants cheap after reload.

	* config/m68hc11/m68hc11.h (CONST_COSTS): Make the cost of
	constants cheap after reload.
	* config/m68hc11/m68hc11.c (m68hc11_shift_cost): Shift by 16 and 32
	are cheap.
	(m68hc11_rtx_costs): Cost of multiplication by 65536 is expensive
	so that gcc prefers a shift by 16.
	(m6811_cost, m6812_cost): Make the shift cheap compared to an add.

From-SVN: r41834

gcc/ChangeLog

+2001-05-04  Stephane Carrez  <Stephane.Carrez@worldnet.fr>
+
+	* config/m68hc11/m68hc11.h (CONST_COSTS): Make the cost of
+	constants cheap after reload.
+	* config/m68hc11/m68hc11.c (m68hc11_shift_cost): Shift by 16 and 32
+	are cheap.
+	(m68hc11_rtx_costs): Cost of multiplication by 65536 is expensive
+	so that gcc prefers a shift by 16.
+	(m6811_cost, m6812_cost): Make the shift cheap compared to an add.
+
 2001-05-04  Nick Clifton  <nickc@cambridge.redhat.com>
 
 	* config/arm/elf.h (ASM_OUTPUT_ALIGNED_COMMON): Define.

gcc/config/m68hc11/m68hc11.c

@@ -136,7 +136,7 @@ struct processor_costs m6811_cost = {
     COSTS_N_INSNS (2), COSTS_N_INSNS (1) },
 
   /* shiftHI const */
-  { COSTS_N_INSNS (0), COSTS_N_INSNS (2), COSTS_N_INSNS (4),
+  { COSTS_N_INSNS (0), COSTS_N_INSNS (1), COSTS_N_INSNS (4),
     COSTS_N_INSNS (6), COSTS_N_INSNS (8), COSTS_N_INSNS (6),
     COSTS_N_INSNS (4), COSTS_N_INSNS (2),
     COSTS_N_INSNS (2), COSTS_N_INSNS (4),
@@ -171,7 +171,7 @@ struct processor_costs m6812_cost = {
     COSTS_N_INSNS (2), COSTS_N_INSNS (1) },
 
   /* shiftHI const */
-  { COSTS_N_INSNS (0), COSTS_N_INSNS (2), COSTS_N_INSNS (4),
+  { COSTS_N_INSNS (0), COSTS_N_INSNS (1), COSTS_N_INSNS (4),
     COSTS_N_INSNS (6), COSTS_N_INSNS (8), COSTS_N_INSNS (6),
     COSTS_N_INSNS (4), COSTS_N_INSNS (2),
     COSTS_N_INSNS (2), COSTS_N_INSNS (4), COSTS_N_INSNS (6),
@@ -4975,7 +4975,7 @@ m68hc11_shift_cost (mode, x, shift)
     }
 
   /* For SI and others, the cost is higher.  */
-  if (GET_MODE_SIZE (mode) > 2)
+  if (GET_MODE_SIZE (mode) > 2 && (shift % 16) != 0)
     total *= GET_MODE_SIZE (mode) / 2;
 
   /* When optimizing for size, make shift more costly so that
@@ -5081,10 +5081,6 @@ m68hc11_rtx_costs (x, code, outer_code)
           break;
 
         case SImode:
-          if (GET_CODE (XEXP (x, 1)) == CONST_INT
-              && INTVAL (XEXP (x, 1)) == 65536)
-            break;
-
         default:
           total += m68hc11_cost->multSI;
           break;

gcc/config/m68hc11/m68hc11.h

@@ -1481,14 +1481,16 @@ extern unsigned char m68hc11_reg_valid_for_index[FIRST_PSEUDO_REGISTER];
      /* with two registers.  */					\
      /* 'clr' is slow */					\
    if ((OUTER_CODE) == SET && (RTX) == const0_rtx)		\
-     return 1;							\
+     /* After reload, the reload_cse pass checks the cost */    \
+     /* to change a SET into a PLUS.  Make const0 cheap.  */    \
+     return 1 - reload_completed;				\
    else								\
      return 0;							\
  case CONST:							\
  case LABEL_REF:						\
  case SYMBOL_REF:						\
    if ((OUTER_CODE) == SET)					\
-      return 1;							\
+      return 1 - reload_completed;				\
    return 0;							\
  case CONST_DOUBLE:						\
    return 0;