From patchwork Sun Oct  3 13:07:26 2010
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Subject: [i386] : Improve <shift>_mask splitters
From: Uros Bizjak <ubizjak@gmail.com>
X-Patchwork-Id: 66598
Message-Id: <AANLkTimZxWm_XAT3m0nyEYGRa=a9qUiy_Xc7C2gVvssP@mail.gmail.com>
To: gcc-patches@gcc.gnu.org
Date: Sun, 3 Oct 2010 15:07:26 +0200

Hello!

Attached patch gives combine pass some more freedom when creating
shifts with implicit count mask.

2010-10-03  Uros Bizjak  <ubizjak@gmail.com>

	* config/i386/i386.md (*ashl<mode>3_mask): Change operand 2 preticate
	to nonimmediate_operand.  Force operand 2 to register when allowed.
	(*<shiftrt_insn><mode>3_mask): Ditto.
	(*<rotate_insn><mode>3_mask): Ditto.

Tested on x86_64-pc-linux-gnu {,-m32}, committed to mainline.

Uros.

Index: i386.md
===================================================================
--- i386.md	(revision 164905)
+++ i386.md	(working copy)
@@ -9152,14 +9152,13 @@
 })
 
 ;; Avoid useless masking of count operand.
-
 (define_insn_and_split "*ashl<mode>3_mask"
   [(set (match_operand:SWI48 0 "nonimmediate_operand" "=rm")
 	(ashift:SWI48
 	  (match_operand:SWI48 1 "nonimmediate_operand" "0")
 	  (subreg:QI
 	    (and:SI
-	      (match_operand:SI 2 "register_operand" "c")
+	      (match_operand:SI 2 "nonimmediate_operand" "c")
 	      (match_operand:SI 3 "const_int_operand" "n")) 0)))
    (clobber (reg:CC FLAGS_REG))]
   "ix86_binary_operator_ok (ASHIFT, <MODE>mode, operands)
@@ -9170,7 +9169,12 @@
   [(parallel [(set (match_dup 0)
 		   (ashift:SWI48 (match_dup 1) (match_dup 2)))
 	      (clobber (reg:CC FLAGS_REG))])]
-  "operands[2] = simplify_gen_subreg (QImode, operands[2], SImode, 0);"
+{
+  if (can_create_pseudo_p ())
+    operands [2] = force_reg (SImode, operands[2]);
+
+  operands[2] = simplify_gen_subreg (QImode, operands[2], SImode, 0);
+}
   [(set_attr "type" "ishift")
    (set_attr "mode" "<MODE>")])
 
@@ -9714,14 +9718,13 @@
   "ix86_expand_binary_operator (<CODE>, <MODE>mode, operands); DONE;")
 
 ;; Avoid useless masking of count operand.
-
 (define_insn_and_split "*<shiftrt_insn><mode>3_mask"
   [(set (match_operand:SWI48 0 "nonimmediate_operand" "=rm")
 	(any_shiftrt:SWI48
 	  (match_operand:SWI48 1 "nonimmediate_operand" "0")
 	  (subreg:QI
 	    (and:SI
-	      (match_operand:SI 2 "register_operand" "c")
+	      (match_operand:SI 2 "nonimmediate_operand" "c")
 	      (match_operand:SI 3 "const_int_operand" "n")) 0)))
    (clobber (reg:CC FLAGS_REG))]
   "ix86_binary_operator_ok (<CODE>, <MODE>mode, operands)
@@ -9732,7 +9735,12 @@
   [(parallel [(set (match_dup 0)
 		   (any_shiftrt:SWI48 (match_dup 1) (match_dup 2)))
 	      (clobber (reg:CC FLAGS_REG))])]
-  "operands[2] = simplify_gen_subreg (QImode, operands[2], SImode, 0);"
+{
+  if (can_create_pseudo_p ())
+    operands [2] = force_reg (SImode, operands[2]);
+
+  operands[2] = simplify_gen_subreg (QImode, operands[2], SImode, 0);
+}
   [(set_attr "type" "ishift")
    (set_attr "mode" "<MODE>")])
 
@@ -10089,14 +10097,13 @@
   "ix86_expand_binary_operator (<CODE>, <MODE>mode, operands); DONE;")
 
 ;; Avoid useless masking of count operand.
-
 (define_insn_and_split "*<rotate_insn><mode>3_mask"
   [(set (match_operand:SWI48 0 "nonimmediate_operand" "=rm")
 	(any_rotate:SWI48
 	  (match_operand:SWI48 1 "nonimmediate_operand" "0")
 	  (subreg:QI
 	    (and:SI
-	      (match_operand:SI 2 "register_operand" "c")
+	      (match_operand:SI 2 "nonimmediate_operand" "c")
 	      (match_operand:SI 3 "const_int_operand" "n")) 0)))
    (clobber (reg:CC FLAGS_REG))]
   "ix86_binary_operator_ok (<CODE>, <MODE>mode, operands)
@@ -10107,7 +10114,12 @@
   [(parallel [(set (match_dup 0)
 		   (any_rotate:SWI48 (match_dup 1) (match_dup 2)))
 	      (clobber (reg:CC FLAGS_REG))])]
-  "operands[2] = simplify_gen_subreg (QImode, operands[2], SImode, 0);"
+{
+  if (can_create_pseudo_p ())
+    operands [2] = force_reg (SImode, operands[2]);
+
+  operands[2] = simplify_gen_subreg (QImode, operands[2], SImode, 0);
+}
   [(set_attr "type" "rotate")
    (set_attr "mode" "<MODE>")])