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

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 778b934d2f36324d0134c1ad65d7e724e6091383..ff9a8dcc6a5a19524ba19bb75a795d6fbab1cc85 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+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.

diff --git a/gcc/config/m68k/m68k.h b/gcc/config/m68k/m68k.h
index 1f21ba96bac4bb31186543399e2ff6757406841d..9d89fe74d039a570577bc7f7d3ea1e9172db514d 100644 (file)
--- a/gcc/config/m68k/m68k.h
+++ b/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.