[MIPS] Enable load/store bonding for I6400

gcc/
	* config/mips/mips.h (ENABLE_LD_ST_PAIRS): Enable load/store pairs for
	I6400.

From-SVN: r226860

gcc/ChangeLog

+2015-08-13  Robert Suchanek  <robert.suchanek@imgtec.com>
+
+	* config/mips/mips.h (ENABLE_LD_ST_PAIRS): Enable load/store pairs for
+	TUNE_I6400.
+
 2015-08-13  Matthew Wahab  <matthew.wahab@arm.com>
 
 	* config/aarch64/aarch64-protos.h

gcc/config/mips/mips.h

@@ -3177,5 +3177,5 @@ extern GTY(()) struct target_globals *micromips_globals;
    performance can be degraded for those targets.  Hence, do not bond for
    micromips or fix_24k.  */
 #define ENABLE_LD_ST_PAIRS \
-  (TARGET_LOAD_STORE_PAIRS && TUNE_P5600 \
+  (TARGET_LOAD_STORE_PAIRS && (TUNE_P5600 || TUNE_I6400) \
    && !TARGET_MICROMIPS && !TARGET_FIX_24K)