[AArch64] Tie operand 1 to operand 0 in AESMC pattern when AES/AESMC fusion is enabled

	* config/aarch64/aarch64.c (aarch64_fusion_enabled_p): New function.
	* config/aarch64/aarch64-protos.h (aarch64_fusion_enabled_p): Declare
	prototype.
	* config/aarch64/aarch64-simd.md (aarch64_crypto_aes<aesmc_op>v16qi):
	Add "=w,0" alternative.  Enable it when AES/AESMC fusion is enabled.

From-SVN: r236820

gcc/ChangeLog

+2016-05-27  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
+
+	* config/aarch64/aarch64.c (aarch64_fusion_enabled_p): New function.
+	* config/aarch64/aarch64-protos.h (aarch64_fusion_enabled_p): Declare
+	prototype.
+	* config/aarch64/aarch64-simd.md (aarch64_crypto_aes<aesmc_op>v16qi):
+	Add "=w,0" alternative.  Enable it when AES/AESMC fusion is enabled.
+
 2016-05-27  Jiong Wang  <jiong.wang@arm.com>
 
 	PR target/63596

gcc/config/aarch64/aarch64-protos.h

@@ -287,6 +287,7 @@ bool aarch64_constant_address_p (rtx);
 bool aarch64_expand_movmem (rtx *);
 bool aarch64_float_const_zero_rtx_p (rtx);
 bool aarch64_function_arg_regno_p (unsigned);
+bool aarch64_fusion_enabled_p (enum aarch64_fusion_pairs);
 bool aarch64_gen_movmemqi (rtx *);
 bool aarch64_gimple_fold_builtin (gimple_stmt_iterator *);
 bool aarch64_is_extend_from_extract (machine_mode, rtx, rtx);

gcc/config/aarch64/aarch64-simd.md

@@ -5401,13 +5401,25 @@
   [(set_attr "type" "crypto_aese")]
 )
 
+;; When AES/AESMC fusion is enabled we want the register allocation to
+;; look like:
+;;    AESE Vn, _
+;;    AESMC Vn, Vn
+;; So prefer to tie operand 1 to operand 0 when fusing.
+
 (define_insn "aarch64_crypto_aes<aesmc_op>v16qi"
-  [(set (match_operand:V16QI 0 "register_operand" "=w")
-	(unspec:V16QI [(match_operand:V16QI 1 "register_operand" "w")]
+  [(set (match_operand:V16QI 0 "register_operand" "=w,w")
+	(unspec:V16QI [(match_operand:V16QI 1 "register_operand" "0,w")]
 	 CRYPTO_AESMC))]
   "TARGET_SIMD && TARGET_CRYPTO"
   "aes<aesmc_op>\\t%0.16b, %1.16b"
-  [(set_attr "type" "crypto_aesmc")]
+  [(set_attr "type" "crypto_aesmc")
+   (set_attr_alternative "enabled"
+     [(if_then_else (match_test
+		       "aarch64_fusion_enabled_p (AARCH64_FUSE_AES_AESMC)")
+		     (const_string "yes" )
+		     (const_string "no"))
+      (const_string "yes")])]
 )
 
 ;; sha1

gcc/config/aarch64/aarch64.c

@@ -13181,6 +13181,14 @@ aarch_macro_fusion_pair_p (rtx_insn *prev, rtx_insn *curr)
   return false;
 }
 
+/* Return true iff the instruction fusion described by OP is enabled.  */
+
+bool
+aarch64_fusion_enabled_p (enum aarch64_fusion_pairs op)
+{
+  return (aarch64_tune_params.fusible_ops & op) != 0;
+}
+
 /* If MEM is in the form of [base+offset], extract the two parts
    of address and set to BASE and OFFSET, otherwise return false
    after clearing BASE and OFFSET.  */