mips.c (mips_process_sync_loop): Emit cmp result only if it is used.

2012-06-19  Maxim Kuvyrkov  <maxim@codesourcery.com>

	* config/mips/mips.c (mips_process_sync_loop): Emit cmp result only if
	it is used.

From-SVN: r188805

gcc/ChangeLog

+2012-06-19  Maxim Kuvyrkov  <maxim@codesourcery.com>
+
+	* config/mips/mips.c (mips_process_sync_loop): Emit cmp result only if
+	it is used.
+
 2012-06-19  Tom de Vries  <vries@codesourcery.com>
             Maxim Kuvyrkov  <maxim@codesourcery.com>
 

gcc/config/mips/mips.c

@@ -12073,6 +12073,10 @@ mips_process_sync_loop (rtx insn, rtx *operands)
   insn1 = get_attr_sync_insn1 (insn);
   insn2 = get_attr_sync_insn2 (insn);
 
+  /* Don't bother setting CMP result that is never used.  */
+  if (cmp && find_reg_note (insn, REG_UNUSED, cmp))
+    cmp = 0;
+
   memmodel_attr = get_attr_sync_memmodel (insn);
   switch (memmodel_attr)
     {