re PR target/53568 (SH Target: Add support for bswap built-ins)

	PR target/53568
	* config/sh/sh.md: Add peephole for swapbsi2.
	(*swapbisi2_and_shl8, *swapbhisi2): New insns and splits.

From-SVN: r188632

2 files changed, 81 insertions, 0 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 1e6d89f..e9b0007 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2012-06-14  Oleg Endo  <olegendo@gcc.gnu.org>
+
+	PR target/53568
+	* config/sh/sh.md: Add peephole for swapbsi2.
+	(*swapbisi2_and_shl8, *swapbhisi2): New insns and splits.
+
 2012-06-14  Uros Bizjak  <ubizjak@gmail.com>
 
 	* config/i386/i386.md (*zero_extendsidi2): Mark movd alternatives
diff --git a/gcc/config/sh/sh.md b/gcc/config/sh/sh.md
index 05a4f38..852f9fd 100644
--- a/gcc/config/sh/sh.md
+++ b/gcc/config/sh/sh.md
@@ -4561,6 +4561,81 @@ label:
   "swap.b	%1,%0"
   [(set_attr "type" "arith")])
 
+;; The *swapbisi2_and_shl8 pattern helps the combine pass simplifying
+;; partial byte swap expressions such as...
+;;   ((x & 0xFF) << 8) | ((x >> 8) & 0xFF).
+;; ...which are currently not handled by the tree optimizers.
+;; The combine pass will not initially try to combine the full expression,
+;; but only some sub-expressions.  In such a case the *swapbisi2_and_shl8
+;; pattern acts as an intermediate pattern that will eventually lead combine
+;; to the swapbsi2 pattern above.
+;; As a side effect this also improves code that does (x & 0xFF) << 8
+;; or (x << 8) & 0xFF00.
+(define_insn_and_split "*swapbisi2_and_shl8"
+  [(set (match_operand:SI 0 "arith_reg_dest" "=r")
+	(ior:SI (and:SI (ashift:SI (match_operand:SI 1 "arith_reg_operand" "r")
+				   (const_int 8))
+			(const_int 65280))
+		(match_operand:SI 2 "arith_reg_operand" "r")))]
+  "TARGET_SH1 && ! reload_in_progress && ! reload_completed"
+  "#"
+  "&& can_create_pseudo_p ()"
+  [(const_int 0)]
+{
+  rtx tmp0 = gen_reg_rtx (SImode);
+  rtx tmp1 = gen_reg_rtx (SImode);
+
+  emit_insn (gen_zero_extendqisi2 (tmp0, gen_lowpart (QImode, operands[1])));
+  emit_insn (gen_swapbsi2 (tmp1, tmp0));
+  emit_insn (gen_iorsi3 (operands[0], tmp1, operands[2]));
+  DONE;
+})
+
+;; The *swapbhisi2 pattern is, like the *swapbisi2_and_shl8 pattern, another
+;; intermediate pattern that will help the combine pass arriving at swapbsi2.
+(define_insn_and_split "*swapbhisi2"
+  [(set (match_operand:SI 0 "arith_reg_dest" "=r")
+	(ior:SI (and:SI (ashift:SI (match_operand:SI 1 "arith_reg_operand" "r")
+				   (const_int 8))
+			(const_int 65280))
+		(zero_extract:SI (match_dup 1) (const_int 8) (const_int 8))))]
+  "TARGET_SH1 && ! reload_in_progress && ! reload_completed"
+  "#"
+  "&& can_create_pseudo_p ()"
+  [(const_int 0)]
+{
+  rtx tmp = gen_reg_rtx (SImode);
+
+  emit_insn (gen_zero_extendhisi2 (tmp, gen_lowpart (HImode, operands[1])));
+  emit_insn (gen_swapbsi2 (operands[0], tmp));
+  DONE;
+})
+
+;; In some cases the swapbsi2 pattern might leave a sequence such as...
+;;   swap.b  r4,r4
+;;   mov     r4,r0
+;;
+;; which can be simplified to...
+;;   swap.b  r4,r0
+(define_peephole2
+  [(set (match_operand:SI 0 "arith_reg_dest" "")
+	(ior:SI (and:SI (match_operand:SI 1 "arith_reg_operand" "")
+			(const_int 4294901760))
+		(ior:SI (and:SI (ashift:SI (match_dup 1) (const_int 8))
+				(const_int 65280))
+			(and:SI (ashiftrt:SI (match_dup 1) (const_int 8))
+				(const_int 255)))))
+   (set (match_operand:SI 2 "arith_reg_dest" "")
+	(match_dup 0))]
+  "TARGET_SH1 && peep2_reg_dead_p (2, operands[0])"
+  [(set (match_dup 2)
+	(ior:SI (and:SI (match_operand:SI 1 "arith_reg_operand" "")
+			(const_int 4294901760))
+		(ior:SI (and:SI (ashift:SI (match_dup 1) (const_int 8))
+				(const_int 65280))
+			(and:SI (ashiftrt:SI (match_dup 1) (const_int 8))
+				(const_int 255)))))])
+
 
 ;; -------------------------------------------------------------------------
 ;; Zero extension instructions