[ARM][3/3] Recognise bitwise operations leading to SImode rev16

	* config/arm/arm.md (arm_rev16si2): New pattern.
	(arm_rev16si2_alt): Likewise.
	* config/arm/arm.c (arm_new_rtx_costs): Handle rev16 case.

	* gcc.target/arm/rev16.c: New test.

From-SVN: r209705

gcc/ChangeLog

 2014-04-23  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
 
+	* config/arm/arm.md (arm_rev16si2): New pattern.
+	(arm_rev16si2_alt): Likewise.
+	* config/arm/arm.c (arm_new_rtx_costs): Handle rev16 case.
+
+2014-04-23  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
+
        * config/aarch64/aarch64.md (rev16<mode>2): New pattern.
        (rev16<mode>2_alt): Likewise.
        * config/aarch64/aarch64.c (aarch64_rtx_costs): Handle rev16 case.

gcc/config/arm/arm.c

@@ -9899,8 +9899,17 @@ arm_new_rtx_costs (rtx x, enum rtx_code code, enum rtx_code outer_code,
       /* Vector mode?  */
       *cost = LIBCALL_COST (2);
       return false;
+    case IOR:
+      if (mode == SImode && arm_arch6 && aarch_rev16_p (x))
+        {
+          *cost = COSTS_N_INSNS (1);
+          if (speed_p)
+            *cost += extra_cost->alu.rev;
 
-    case AND: case XOR: case IOR:
+          return true;
+        }
+    /* Fall through.  */
+    case AND: case XOR:
       if (mode == SImode)
 	{
 	  enum rtx_code subcode = GET_CODE (XEXP (x, 0));

gcc/config/arm/arm.md

@@ -12690,6 +12690,44 @@
    (set_attr "type" "rev")]
 )
 
+;; There are no canonicalisation rules for the position of the lshiftrt, ashift
+;; operations within an IOR/AND RTX, therefore we have two patterns matching
+;; each valid permutation.
+
+(define_insn "arm_rev16si2"
+  [(set (match_operand:SI 0 "register_operand" "=l,l,r")
+        (ior:SI (and:SI (ashift:SI (match_operand:SI 1 "register_operand" "l,l,r")
+                                   (const_int 8))
+                        (match_operand:SI 3 "const_int_operand" "n,n,n"))
+                (and:SI (lshiftrt:SI (match_dup 1)
+                                     (const_int 8))
+                        (match_operand:SI 2 "const_int_operand" "n,n,n"))))]
+  "arm_arch6
+   && aarch_rev16_shleft_mask_imm_p (operands[3], SImode)
+   && aarch_rev16_shright_mask_imm_p (operands[2], SImode)"
+  "rev16\\t%0, %1"
+  [(set_attr "arch" "t1,t2,32")
+   (set_attr "length" "2,2,4")
+   (set_attr "type" "rev")]
+)
+
+(define_insn "arm_rev16si2_alt"
+  [(set (match_operand:SI 0 "register_operand" "=l,l,r")
+        (ior:SI (and:SI (lshiftrt:SI (match_operand:SI 1 "register_operand" "l,l,r")
+                                     (const_int 8))
+                        (match_operand:SI 2 "const_int_operand" "n,n,n"))
+                (and:SI (ashift:SI (match_dup 1)
+                                   (const_int 8))
+                        (match_operand:SI 3 "const_int_operand" "n,n,n"))))]
+  "arm_arch6
+   && aarch_rev16_shleft_mask_imm_p (operands[3], SImode)
+   && aarch_rev16_shright_mask_imm_p (operands[2], SImode)"
+  "rev16\\t%0, %1"
+  [(set_attr "arch" "t1,t2,32")
+   (set_attr "length" "2,2,4")
+   (set_attr "type" "rev")]
+)
+
 (define_expand "bswaphi2"
   [(set (match_operand:HI 0 "s_register_operand" "=r")
 	(bswap:HI (match_operand:HI 1 "s_register_operand" "r")))]

gcc/testsuite/ChangeLog

 2014-04-23  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
 
+	* gcc.target/arm/rev16.c: New test.
+
+2014-04-23  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
+
        * gcc.target/aarch64/rev16_1.c: New test.
 
 2014-04-23  Richard Biener  <rguenther@suse.de>

gcc/testsuite/gcc.target/arm/rev16.c

+/* { dg-options "-O2" } */
+/* { dg-do run } */
+
+extern void abort (void);
+
+typedef unsigned int __u32;
+
+__u32
+__rev16_32_alt (__u32 x)
+{
+  return (((__u32)(x) & (__u32)0xff00ff00UL) >> 8)
+         | (((__u32)(x) & (__u32)0x00ff00ffUL) << 8);
+}
+
+__u32
+__rev16_32 (__u32 x)
+{
+  return (((__u32)(x) & (__u32)0x00ff00ffUL) << 8)
+         | (((__u32)(x) & (__u32)0xff00ff00UL) >> 8);
+}
+
+int
+main (void)
+{
+  volatile __u32 in32 = 0x12345678;
+  volatile __u32 expected32 = 0x34127856;
+
+  if (__rev16_32 (in32) != expected32)
+    abort ();
+
+  if (__rev16_32_alt (in32) != expected32)
+    abort ();
+
+  return 0;
+}