Add cases for SIGN_EXTEND and ZERO_EXTEND to RTX_COSTS

From-SVN: r13073

diff --git a/gcc/config/mips/mips.h b/gcc/config/mips/mips.h
index 0c96e65b734a947514ede206e98cdd99852124cd..624fdf71fe6880ec2820d210583c979c2c928a45 100644 (file)
--- a/gcc/config/mips/mips.h
+++ b/gcc/config/mips/mips.h
@@ -3026,7 +3026,24 @@ while (0)
     else if (mips_cpu == PROCESSOR_R5000)                              \
       return COSTS_N_INSNS (36);                                       \
     else                                                               \
-      return COSTS_N_INSNS (69);
+      return COSTS_N_INSNS (69);                                       \
+                                                                       \
+  case SIGN_EXTEND:                                                    \
+    /* A sign extend from SImode to DImode in 64 bit mode is often     \
+       zero instructions, because the result can often be used         \
+       directly by another instruction; we'll call it one.  */         \
+    if (TARGET_64BIT && GET_MODE (X) == DImode                         \
+       && GET_MODE (XEXP (X, 0)) == SImode)                            \
+      return COSTS_N_INSNS (1);                                                \
+    else                                                               \
+      return COSTS_N_INSNS (2);                                                \
+                                                                       \
+  case ZERO_EXTEND:                                                    \
+    if (TARGET_64BIT && GET_MODE (X) == DImode                         \
+       && GET_MODE (XEXP (X, 0)) == SImode)                            \
+      return COSTS_N_INSNS (2);                                                \
+    else                                                               \
+      return COSTS_N_INSNS (1);
 
 /* An expression giving the cost of an addressing mode that
    contains ADDRESS.  If not defined, the cost is computed from the