[AArch64] Handle AND+ASHIFT form of UBFIZ correctly in costs

	* config/aarch64/aarch64.c (aarch64_mask_and_shift_for_ubfiz_p):
	New function.
	(aarch64_rtx_costs): Use it.  Rewrite CONST_INT_P (op1) case to handle
	mask+shift version.
	* config/aarch64/aarch64-protos.h (aarch64_mask_and_shift_for_ubfiz_p):
	New prototype.
	* config/aarch64/aarch64.md (*andim_ashift<mode>_bfiz): Replace
	matching condition with aarch64_mask_and_shift_for_ubfiz_p.

From-SVN: r237440

4 files changed, 48 insertions, 11 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 9904443..6836663 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,14 @@
+2015-06-14  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
+
+	* config/aarch64/aarch64.c (aarch64_mask_and_shift_for_ubfiz_p):
+	New function.
+	(aarch64_rtx_costs): Use it.  Rewrite CONST_INT_P (op1) case to handle
+	mask+shift version.
+	* config/aarch64/aarch64-protos.h (aarch64_mask_and_shift_for_ubfiz_p):
+	New prototype.
+	* config/aarch64/aarch64.md (*andim_ashift<mode>_bfiz): Replace
+	matching condition with aarch64_mask_and_shift_for_ubfiz_p.
+
 2016-06-14  Richard Biener  <rguenther@suse.de>
 
 	PR tree-optimization/71522
diff --git a/gcc/config/aarch64/aarch64-protos.h b/gcc/config/aarch64/aarch64-protos.h
index 3e0a0a3..e8c2ac8 100644
--- a/gcc/config/aarch64/aarch64-protos.h
+++ b/gcc/config/aarch64/aarch64-protos.h
@@ -318,6 +318,7 @@ bool aarch64_is_noplt_call_p (rtx);
 bool aarch64_label_mentioned_p (rtx);
 void aarch64_declare_function_name (FILE *, const char*, tree);
 bool aarch64_legitimate_pic_operand_p (rtx);
+bool aarch64_mask_and_shift_for_ubfiz_p (machine_mode, rtx, rtx);
 bool aarch64_modes_tieable_p (machine_mode mode1,
 			      machine_mode mode2);
 bool aarch64_zero_extend_const_eq (machine_mode, rtx, machine_mode, rtx);
diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
index df7cb92..e91017b 100644
--- a/gcc/config/aarch64/aarch64.c
+++ b/gcc/config/aarch64/aarch64.c
@@ -6050,6 +6050,19 @@ aarch64_extend_bitfield_pattern_p (rtx x)
   return op;
 }
 
+/* Return true if the mask and a shift amount from an RTX of the form
+   (x << SHFT_AMNT) & MASK are valid to combine into a UBFIZ instruction of
+   mode MODE.  See the *andim_ashift<mode>_bfiz pattern.  */
+
+bool
+aarch64_mask_and_shift_for_ubfiz_p (machine_mode mode, rtx mask, rtx shft_amnt)
+{
+  return CONST_INT_P (mask) && CONST_INT_P (shft_amnt)
+	 && INTVAL (shft_amnt) < GET_MODE_BITSIZE (mode)
+	 && exact_log2 ((INTVAL (mask) >> INTVAL (shft_amnt)) + 1) >= 0
+	 && (INTVAL (mask) & ((1 << INTVAL (shft_amnt)) - 1)) == 0;
+}
+
 /* Calculate the cost of calculating X, storing it in *COST.  Result
    is true if the total cost of the operation has now been calculated.  */
 static bool
@@ -6624,17 +6637,31 @@ cost_plus:
 
       if (GET_MODE_CLASS (mode) == MODE_INT)
 	{
-	  /* We possibly get the immediate for free, this is not
-	     modelled.  */
-	  if (CONST_INT_P (op1)
-	      && aarch64_bitmask_imm (INTVAL (op1), mode))
+	  if (CONST_INT_P (op1))
 	    {
-	      *cost += rtx_cost (op0, mode, (enum rtx_code) code, 0, speed);
+	      /* We have a mask + shift version of a UBFIZ
+		 i.e. the *andim_ashift<mode>_bfiz pattern.  */
+	      if (GET_CODE (op0) == ASHIFT
+		  && aarch64_mask_and_shift_for_ubfiz_p (mode, op1,
+							  XEXP (op0, 1)))
+		{
+		  *cost += rtx_cost (XEXP (op0, 0), mode,
+				     (enum rtx_code) code, 0, speed);
+		  if (speed)
+		    *cost += extra_cost->alu.bfx;
 
-	      if (speed)
-		*cost += extra_cost->alu.logical;
+		  return true;
+		}
+	      else if (aarch64_bitmask_imm (INTVAL (op1), mode))
+		{
+		/* We possibly get the immediate for free, this is not
+		   modelled.  */
+		  *cost += rtx_cost (op0, mode, (enum rtx_code) code, 0, speed);
+		  if (speed)
+		    *cost += extra_cost->alu.logical;
 
-	      return true;
+		  return true;
+		}
 	    }
 	  else
 	    {
diff --git a/gcc/config/aarch64/aarch64.md b/gcc/config/aarch64/aarch64.md
index 704e855..b4e6ba0 100644
--- a/gcc/config/aarch64/aarch64.md
+++ b/gcc/config/aarch64/aarch64.md
@@ -4380,9 +4380,7 @@
 	(and:GPI (ashift:GPI (match_operand:GPI 1 "register_operand" "r")
 			     (match_operand 2 "const_int_operand" "n"))
 		 (match_operand 3 "const_int_operand" "n")))]
-  "(INTVAL (operands[2]) < (<GPI:sizen>))
-   && exact_log2 ((INTVAL (operands[3]) >> INTVAL (operands[2])) + 1) >= 0
-   && (INTVAL (operands[3]) & ((1 << INTVAL (operands[2])) - 1)) == 0"
+  "aarch64_mask_and_shift_for_ubfiz_p (<MODE>mode, operands[3], operands[2])"
   "ubfiz\\t%<w>0, %<w>1, %2, %P3"
   [(set_attr "type" "bfm")]
 )