(RTX_COSTS): Add special cases for a plain 68000.

From-SVN: r8869

diff --git a/gcc/config/m68k/m68k.h b/gcc/config/m68k/m68k.h
index b68aa60c47ecd08b729fb2fdba632c9cd1bcd270..d7d45d1e564732b844f4769551eab3a4dcacc8b4 100644 (file)
--- a/gcc/config/m68k/m68k.h
+++ b/gcc/config/m68k/m68k.h
@@ -1371,8 +1371,10 @@ __transfer_from_trampoline ()                                    \
    work properly in synth_mult on the 68020,
    relative to an average of the time for add and the time for shift,
    taking away a little more because sometimes move insns are needed.  */
+/* div?.w is relatively cheaper on 68000 counted in COSTS_N_INSNS terms.  */
 #define MULL_COST (TARGET_68040 ? 5 : 13)
-#define MULW_COST (TARGET_68040 ? 3 : 8)
+#define MULW_COST (TARGET_68040 ? 3 : TARGET_68020 ? 8 : 5)
+#define DIVW_COST (TARGET_68020 ? 27 : 12)
 
 #define RTX_COSTS(X,CODE,OUTER_CODE)                           \
   case PLUS:                                                   \
@@ -1389,7 +1391,19 @@ __transfer_from_trampoline ()                                    \
     break;                                                     \
   case ASHIFT:                                                 \
   case ASHIFTRT:                                               \
-  case LSHIFTRT:                                               \
+  case LSHIFTRT:                                                       \
+    if (! TARGET_68020)                                                        \
+      {                                                                        \
+       if (GET_CODE (XEXP (X, 1)) == CONST_INT)                        \
+         {                                                             \
+           if (INTVAL (XEXP (X, 1)) < 16)                              \
+             return COSTS_N_INSNS (2) + INTVAL (XEXP (X, 1)) / 2;      \
+           else                                                        \
+             /* We're using clrw + swap for these cases.  */           \
+             return COSTS_N_INSNS (4) + (INTVAL (XEXP (X, 1)) - 16) / 2; \     
+         }                                                             \
+       return COSTS_N_INSNS (10); /* worst case */                     \
+      }                                                                        \
     /* A shift by a big integer takes an extra instruction.  */ \
     if (GET_CODE (XEXP (X, 1)) == CONST_INT                    \
        && (INTVAL (XEXP (X, 1)) == 16))                        \
@@ -1400,6 +1414,10 @@ __transfer_from_trampoline ()                                    \
       return COSTS_N_INSNS (3);         /* lsr #i,dn */                \
     break;                                                     \
   case MULT:                                                   \
+    if ((GET_CODE (XEXP (X, 0)) == ZERO_EXTEND                 \
+        || GET_CODE (XEXP (X, 0)) == SIGN_EXTEND)              \
+       && GET_MODE (X) == SImode)                              \
+      return COSTS_N_INSNS (MULW_COST);                                \
     if (GET_MODE (X) == QImode || GET_MODE (X) == HImode)      \
       return COSTS_N_INSNS (MULW_COST);                                \
     else                                                       \
@@ -1409,7 +1427,7 @@ __transfer_from_trampoline ()                                     \
   case MOD:                                                    \
   case UMOD:                                                   \
     if (GET_MODE (X) == QImode || GET_MODE (X) == HImode)      \
-      return COSTS_N_INSNS (27); /* div.w */                   \
+      return COSTS_N_INSNS (DIVW_COST); /* div.w */            \
     return COSTS_N_INSNS (43);  /* div.l */
 \f
 /* Tell final.c how to eliminate redundant test instructions.  */