m68k.h (CONST_COSTS): Lower cost of 0.0 when used inside a COMPARE operator.

        * m68k.h (CONST_COSTS): Lower cost of 0.0 when used inside a
        COMPARE operator.

From-SVN: r50372

gcc/ChangeLog

+Wed Mar  6 12:27:10 2002  Jeffrey A Law  (law@redhat.com)
+
+	* m68k.h (CONST_COSTS): Lower cost of 0.0 when used inside a
+	COMPARE operator.
+	
 2002-03-06  Phil Edwards  <pme@gcc.gnu.org>
 
 	* version.c:  Fix misplaced leading blanks on first line.

gcc/config/m68k/m68k.h

@@ -1555,6 +1555,12 @@ __transfer_from_trampoline ()					\
   case SYMBOL_REF:						\
     return 3;							\
   case CONST_DOUBLE:						\
+    /* Make 0.0 cheaper than other floating constants to	\
+       encourage creating tstsf and tstdf insns.  */		\
+    if ((OUTER_CODE) == COMPARE					\
+        && ((RTX) == CONST0_RTX (SFmode)			\
+	    || (RTX) == CONST0_RTX (DFmode)))			\
+      return 4;							\
     return 5;
 
 /* Compute the cost of various arithmetic operations.