mips.c (override_options): Default to no generation of branch-likely operations when...

2004-05-04  Chris Demetriou  <cgd@broadcom.com>

        * config/mips/mips.c (override_options): Default to no
        generation of branch-likely operations when tuning for
        CPUs where they tend to have a negative performance impact
        (e.g., SB-1).

From-SVN: r81494

gcc/ChangeLog

+2004-05-04  Chris Demetriou  <cgd@broadcom.com>
+
+	* config/mips/mips.c (override_options): Default to no
+	generation of branch-likely operations when tuning for
+	CPUs where they tend to have a negative performance impact
+	(e.g., SB-1).
+
 2004-05-04  Richard Kenner  <kenner@vlsi1.ultra.nyu.edu>
 
 	* expr.c (store_constructor_field): Don't call store_constructor

gcc/config/mips/mips.c

@@ -4681,9 +4681,10 @@ override_options (void)
 	 architecture.
 
 	 By default, we enable use of Branch Likely instructions on
-	 all architectures which support them except for MIPS32 and MIPS64
-	 (i.e., the generic MIPS32 and MIPS64 ISAs, and processors which
-	 implement them).
+	 all architectures which support them with the following
+	 exceptions: when creating MIPS32 or MIPS64 code, and when
+	 tuning for architectures where their use tends to hurt
+	 performance.
 
 	 The MIPS32 and MIPS64 architecture specifications say "Software
 	 is strongly encouraged to avoid use of Branch Likely
@@ -4691,7 +4692,9 @@ override_options (void)
 	 of the [MIPS32 and MIPS64] architecture."  Therefore, we do not
 	 issue those instructions unless instructed to do so by
 	 -mbranch-likely.  */
-      if (ISA_HAS_BRANCHLIKELY && !(ISA_MIPS32 || ISA_MIPS32R2 || ISA_MIPS64))
+      if (ISA_HAS_BRANCHLIKELY
+	  && !(ISA_MIPS32 || ISA_MIPS32R2 || ISA_MIPS64)
+	  && !(TUNE_SB1))
 	target_flags |= MASK_BRANCHLIKELY;
       else
 	target_flags &= ~MASK_BRANCHLIKELY;