[ARM] Fix length attribute for neon_mov<mode> of VSTRUCT

[Jie Zhang <jie at codesourcery dot com>]

I just found that the length attribute of neon_mov<mode> pattern for 
VSTRUCT is not calculated correctly. This patch should fix it. Testing 
on arm-none-eabi for NEON has no regressions. Is it OK to commit?


Regards,
--
Jie
CodeSourcery

	* config/arm/arm.c (arm_attr_length_move_neon): New.
	* config/arm/arm-protos.h (arm_attr_length_move_neon): Declare.
	* config/arm/neon.md (define_mode_attr V_slen): Remove.
	(neon_mov<mode> for VSTRUCT): Use arm_attr_length_move_neon
	to compute length attribute.

Index: config/arm/arm.c
===================================================================
--- config/arm/arm.c	(revision 161525)
+++ config/arm/arm.c	(working copy)
@@ -12698,6 +12698,57 @@ output_move_neon (rtx *operands)
   return "";
 }
 
+/* Compute and return the length of neon_mov<mode>, where <mode> is
+   one of VSTRUCT modes: EI, OI, CI or XI.  */
+int
+arm_attr_length_move_neon (rtx insn)
+{
+  rtx reg, mem, addr;
+  int regno, load;
+  enum machine_mode mode;
+
+  extract_insn_cached (insn);
+
+  if (REG_P (recog_data.operand[0]) && REG_P (recog_data.operand[1]))
+    {
+      mode = GET_MODE (recog_data.operand[0]);
+      switch (mode)
+	{
+	case EImode:
+	case OImode:
+	  return 8;
+	case CImode:
+	  return 12;
+	case XImode:
+	  return 16;
+	default:
+	  gcc_unreachable ();
+	}
+    }
+
+  load = REG_P (recog_data.operand[0]);
+  reg = recog_data.operand[!load];
+  mem = recog_data.operand[load];
+
+  gcc_assert (MEM_P (mem));
+
+  mode = GET_MODE (reg);
+  regno = REGNO (reg);
+  addr = XEXP (mem, 0);
+
+  /* Strip off const from addresses like (const (plus (...))).  */
+  if (GET_CODE (addr) == CONST && GET_CODE (XEXP (addr, 0)) == PLUS)
+    addr = XEXP (addr, 0);
+
+  if (GET_CODE (addr) == LABEL_REF || GET_CODE (addr) == PLUS)
+    {
+      int insns = HARD_REGNO_NREGS (REGNO (reg), mode) / 2;
+      return insns * 4;
+    }
+  else
+    return 4;
+}
+
 /* Output an ADD r, s, #n where n may be too big for one instruction.
    If adding zero to one register, output nothing.  */
 const char *
Index: config/arm/arm-protos.h
===================================================================
--- config/arm/arm-protos.h	(revision 161525)
+++ config/arm/arm-protos.h	(working copy)
@@ -131,6 +131,7 @@ extern const char *output_move_double (r
 extern const char *output_move_quad (rtx *);
 extern const char *output_move_vfp (rtx *operands);
 extern const char *output_move_neon (rtx *operands);
+extern int arm_attr_length_move_neon (rtx);
 extern const char *output_add_immediate (rtx *);
 extern const char *arithmetic_instr (rtx, int);
 extern void output_ascii_pseudo_op (FILE *, const unsigned char *, int);
Index: config/arm/neon.md
===================================================================
--- config/arm/neon.md	(revision 161525)
+++ config/arm/neon.md	(working copy)
@@ -185,9 +185,6 @@
 ;; Opaque structure types wider than TImode.
 (define_mode_iterator VSTRUCT [EI OI CI XI])
 
-;; Number of instructions needed to load/store struct elements. FIXME!
-(define_mode_attr V_slen [(EI "2") (OI "2") (CI "3") (XI "4")])
-
 ;; Opaque structure types used in table lookups (except vtbl1/vtbx1).
 (define_mode_iterator VTAB [TI EI OI])
 
@@ -587,7 +584,7 @@
     }
 }
   [(set_attr "neon_type" "neon_int_1,neon_stm_2,neon_ldm_2")
-   (set_attr "length" "<V_slen>,<V_slen>,<V_slen>")])
+   (set (attr "length") (symbol_ref "arm_attr_length_move_neon (insn)"))])
 
 (define_split
   [(set (match_operand:EI 0 "s_register_operand" "")