re PR target/50751 (SH Target: Displacement addressing does not work for QImode and HImode)

	PR target/50751
	* config/sh/sh.h (CONST_OK_FOR_K04, CONST_OK_FOR_K12, DISP_ADDR_P,
	DISP_ADDR_OFFSET): New macros.
	* config/sh/sh.c (sh_address_cost): Add SH2A special case.
	(sh_legitimate_index_p): Allow QImode displacements for non-SH2A.
	(sh_legitimize_address): Add QImode displacement handling.
	(sh_cannot_change_mode_class): Disallow GENERAL_REGS for SFmode 
	vector subregs.
	(sh_secondary_reload): Add QImode displacement handling.
	* config/sh/predicates.md (movsrc_no_disp_mem_operand): New predicate.
	* config/sh/constraints.md (K04, Snd, Sdd): New constraints.
	* config/sh/sh.md (extendqisi2): Remove constraints from expander.
	(*extendqisi2_compact): Rename to *extendqisi2_compact_reg, restrict
	to register operands only.
	(*extendqisi2_compact_mem_disp, *extendqisi2_compact_snd): New insns.
	(extendqihi2): Change insn to expander.
	(*extendqihi2_compact_reg): New insn.
	(movqi_i, movqi): Replace with ... 
	(movqi, *movqi_reg_reg, *movqi_store_mem_disp12,
	*movqi_load_mem_disp, *movqi_load_mem_disp): ... these.
	Add new peepholes for QImode displacement addressing.

From-SVN: r185534

6 files changed, 331 insertions, 59 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 050d379..0417c40 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,29 @@
+2012-03-19  Oleg Endo  <olegendo@gcc.gnu.org>
+
+	PR target/50751
+	* config/sh/sh.h (CONST_OK_FOR_K04, CONST_OK_FOR_K12, DISP_ADDR_P,
+	DISP_ADDR_OFFSET): New macros.
+	* config/sh/sh.c (sh_address_cost): Add SH2A special case.
+	(sh_legitimate_index_p): Allow QImode displacements for non-SH2A.
+	(sh_legitimize_address): Add QImode displacement handling.
+	(sh_cannot_change_mode_class): Disallow GENERAL_REGS for SFmode 
+	vector subregs.
+	(sh_secondary_reload): Add QImode displacement handling.
+	* config/sh/predicates.md (movsrc_no_disp_mem_operand): New predicate.
+        * config/sh/constraints.md (K04, Snd, Sdd): New constraints.
+        * config/sh/sh.md (extendqisi2): Remove constraints from 
+        expander.
+        (*extendqisi2_compact): Rename to *extendqisi2_compact_reg, 
+        restrict to register operands only.
+        (*extendqisi2_compact_mem_disp, *extendqisi2_compact_snd): New 
+        insns.
+        (extendqihi2): Change insn to expander.
+        (*extendqihi2_compact_reg): New insn.
+        (movqi_i, movqi): Replace with ... 
+        (movqi, *movqi_reg_reg, *movqi_store_mem_disp12,
+        *movqi_load_mem_disp, *movqi_load_mem_disp): ... these.
+        Add new peepholes for QImode displacement addressing.
+
 2012-03-19  Paolo Carlini  <paolo.carlini@oracle.com>
 
 	PR c++/14710
diff --git a/gcc/config/sh/constraints.md b/gcc/config/sh/constraints.md
index 12a4a99..1f2ccf9 100644
--- a/gcc/config/sh/constraints.md
+++ b/gcc/config/sh/constraints.md
@@ -123,6 +123,7 @@
        (match_test "ival >=  -134217728 && ival <= 134217727")
        (match_test "(ival & 255) == 0")
        (match_test "TARGET_SH2A")))
+
 (define_constraint "J16"
   "0xffffffff00000000 or 0x00000000ffffffff."
   (and (match_code "const_int")
@@ -133,6 +134,11 @@
   (and (match_code "const_int")
        (match_test "ival >= 0 && ival <= 7")))
 
+(define_constraint "K04"
+  "An unsigned 4-bit constant, as used in mov.b displacement addressing."
+  (and (match_code "const_int")
+       (match_test "ival >= 0 && ival <= 15")))
+
 (define_constraint "K08"
   "An unsigned 8-bit constant, as used in and, or, etc."
   (and (match_code "const_int")
@@ -266,3 +272,11 @@
        (match_test "GET_CODE (XEXP (op, 0)) == PLUS")
        (match_test "REG_P (XEXP (XEXP (op, 0), 0))")
        (match_test "satisfies_constraint_K12 (XEXP (XEXP (op, 0), 1))")))
+
+(define_memory_constraint "Snd"
+  "A memory reference that excludes displacement addressing."
+  (match_test "! DISP_ADDR_P (op)"))
+
+(define_memory_constraint "Sdd"
+  "A memory reference that uses displacement addressing."
+  (match_test "DISP_ADDR_P (op)"))
diff --git a/gcc/config/sh/predicates.md b/gcc/config/sh/predicates.md
index 9745d63..ebcff45 100644
--- a/gcc/config/sh/predicates.md
+++ b/gcc/config/sh/predicates.md
@@ -418,6 +418,30 @@
   return general_operand (op, mode);
 })
 
+;; Same as movsrc_operand, but rejects displacement addressing.
+
+(define_predicate "movsrc_no_disp_mem_operand"
+  (match_code "subreg,reg,const_int,const_double,mem,symbol_ref,label_ref,const,const_vector")
+{
+  if (!general_movsrc_operand (op, mode))
+    return 0;
+
+  if ((mode == QImode || mode == HImode)
+      && mode == GET_MODE (op)
+      && (MEM_P (op)
+	  || (GET_CODE (op) == SUBREG && MEM_P (SUBREG_REG (op)))))
+    {
+      rtx x = XEXP ((MEM_P (op) ? op : SUBREG_REG (op)), 0);
+
+      if (GET_CODE (x) == PLUS
+	  && REG_P (XEXP (x, 0))
+	  && CONST_INT_P (XEXP (x, 1)))
+	return 0;
+    }
+
+  return 1;
+})
+
 ;; Returns 1 if OP can be a destination of a move. Same as
 ;; general_operand, but no preinc allowed.
 
diff --git a/gcc/config/sh/sh.c b/gcc/config/sh/sh.c
index 4c2d710..4b5db67 100644
--- a/gcc/config/sh/sh.c
+++ b/gcc/config/sh/sh.c
@@ -3137,6 +3137,11 @@ static int
 sh_address_cost (rtx X,
 	         bool speed ATTRIBUTE_UNUSED)
 {
+  /*  SH2A supports 4 byte displacement mov insns with higher offsets.
+      Consider those as more expensive than 2 byte insns.  */
+  if (DISP_ADDR_P (X) && GET_MODE (X) == QImode)
+    return DISP_ADDR_OFFSET (X) < 16 ? 0 : 1;
+
   return (GET_CODE (X) == PLUS
 	  && ! CONSTANT_P (XEXP (X, 1))
 	  && ! TARGET_SHMEDIA ? 1 : 0);
@@ -9606,11 +9611,13 @@ sh_legitimate_index_p (enum machine_mode mode, rtx op)
 
       if (TARGET_SH2A)
 	{
-	  if (GET_MODE_SIZE (mode) == 1
-		&& (unsigned) INTVAL (op) < 4096)
+	  if (mode == QImode && (unsigned) INTVAL (op) < 4096)
 	    return true;
 	}
 
+      if (mode == QImode && (unsigned) INTVAL (op) < 16)
+	return true;
+
       if ((GET_MODE_SIZE (mode) == 4
 	   && (unsigned) INTVAL (op) < 64
 	   && !(INTVAL (op) & 3)
@@ -9816,6 +9823,25 @@ sh_legitimize_address (rtx x, rtx oldx, enum machine_mode mode)
 	}
     }
 
+  /* This could be generalized for SImode, HImode, QImode displacement
+     addressing.  */
+  if (mode == QImode && GET_CODE (x) == PLUS
+      && BASE_REGISTER_RTX_P (XEXP (x, 0)) && CONST_INT_P (XEXP (x, 1)))
+    {
+      rtx index_rtx = XEXP (x, 1);
+      HOST_WIDE_INT offset = INTVAL (index_rtx);
+      HOST_WIDE_INT offset_base = offset & ~15;
+    
+      if (offset - offset_base <= 16)
+	{
+	  rtx sum = expand_binop (Pmode, add_optab, XEXP (x, 0),
+			      GEN_INT (offset_base), NULL_RTX, 0,
+			      OPTAB_LIB_WIDEN);
+
+	  return gen_rtx_PLUS (Pmode, sum, GEN_INT (offset - offset_base));
+	}
+    }
+
   return x;
 }
 
@@ -11444,8 +11470,13 @@ sh_cannot_change_mode_class (enum machine_mode from, enum machine_mode to,
 {
   /* We want to enable the use of SUBREGs as a means to
      VEC_SELECT a single element of a vector.  */
+
+  /* This effectively disallows using GENERAL_REGS for SFmode vector subregs.
+     This can be problematic when SFmode vector subregs need to be accessed
+     on the stack with displacement addressing, as it happens with -O0.
+     Thus we disallow the mode change for -O0.  */
   if (to == SFmode && VECTOR_MODE_P (from) && GET_MODE_INNER (from) == SFmode)
-    return (reg_classes_intersect_p (GENERAL_REGS, rclass));
+    return optimize ? (reg_classes_intersect_p (GENERAL_REGS, rclass)) : false;
 
   if (GET_MODE_SIZE (from) != GET_MODE_SIZE (to))
     {
@@ -11460,7 +11491,7 @@ sh_cannot_change_mode_class (enum machine_mode from, enum machine_mode to,
 	    return reg_classes_intersect_p (DF_HI_REGS, rclass);
 	}
     }
-  return 0;
+  return false;
 }
 
 /* Return true if registers in machine mode MODE will likely be
@@ -12472,6 +12503,25 @@ sh_secondary_reload (bool in_p, rtx x, reg_class_t rclass_i,
   if (rclass == FPUL_REGS && true_regnum (x) == -1)
     return GENERAL_REGS;
 
+  /* Force mov.b displacement addressing insn to use R0 as the other operand.
+     On SH2A could also just leave it alone here, which would result in a
+     4 byte move insn being generated instead.  However, for this to work
+     the insns must have the appropriate alternatives.  */
+  if (mode == QImode && rclass != R0_REGS
+      && DISP_ADDR_P (x) && DISP_ADDR_OFFSET (x) < 16)
+    return R0_REGS;
+
+  /* When reload is trying to address a QImode or HImode subreg on the stack, 
+     force any subreg byte into R0_REGS, as this is going to become a
+     displacement address.
+     We could restrict this to SUBREG_BYTE (x) > 0, but if the actual reg
+     is on the stack, the memref to it might already require a displacement
+     and that has to be added to the final address.  At this point we don't
+     know the cumulative displacement so we assume the worst case.  */
+  if ((mode == QImode || mode == HImode) && rclass != R0_REGS 
+      && GET_CODE (x) == SUBREG && true_regnum (x) == -1)
+    return R0_REGS;
+
   return NO_REGS;
 }
 
diff --git a/gcc/config/sh/sh.h b/gcc/config/sh/sh.h
index 7a2af0a..008c6fa 100644
--- a/gcc/config/sh/sh.h
+++ b/gcc/config/sh/sh.h
@@ -1210,12 +1210,24 @@ extern enum reg_class regno_reg_class[FIRST_PSEUDO_REGISTER];
   ((HOST_BITS_PER_WIDE_INT >= 64 && (VALUE) == (HOST_WIDE_INT) 0xffffffff) \
    || (HOST_BITS_PER_WIDE_INT >= 64 && (VALUE) == (HOST_WIDE_INT) -1 << 32))
 
+#define CONST_OK_FOR_K04(VALUE) (((HOST_WIDE_INT)(VALUE))>= 0 \
+				 && ((HOST_WIDE_INT)(VALUE)) <= 15)
+
 #define CONST_OK_FOR_K08(VALUE) (((HOST_WIDE_INT)(VALUE))>= 0 \
 				 && ((HOST_WIDE_INT)(VALUE)) <= 255)
 
+#define CONST_OK_FOR_K12(VALUE) (((HOST_WIDE_INT)(VALUE))>= 0 \
+				 && ((HOST_WIDE_INT)(VALUE)) <= 4095)
+
 #define ZERO_EXTRACT_ANDMASK(EXTRACT_SZ_RTX, EXTRACT_POS_RTX)\
   (((1 << INTVAL (EXTRACT_SZ_RTX)) - 1) << INTVAL (EXTRACT_POS_RTX))
 
+#define DISP_ADDR_P(X) (MEM_P (X) && GET_CODE (XEXP (X, 0)) == PLUS \
+			 && REG_P (XEXP (XEXP (X, 0), 0)) \
+			 && CONST_INT_P (XEXP (XEXP (X, 0), 1)))
+
+#define DISP_ADDR_OFFSET(X) (INTVAL (XEXP (XEXP (X, 0), 1)))
+
 #if 0
 #define SECONDARY_INOUT_RELOAD_CLASS(CLASS,MODE,X,ELSE) \
   ((((REGCLASS_HAS_FP_REG (CLASS) 					\
diff --git a/gcc/config/sh/sh.md b/gcc/config/sh/sh.md
index 528a120..31160b0 100644
--- a/gcc/config/sh/sh.md
+++ b/gcc/config/sh/sh.md
@@ -4871,24 +4871,56 @@ label:
 }")
 
 (define_expand "extendqisi2"
-  [(set (match_operand:SI 0 "arith_reg_dest" "=r,r")
-	(sign_extend:SI (match_operand:QI 1 "general_extend_operand" "r,m")))]
+  [(set (match_operand:SI 0 "arith_reg_dest" "")
+	(sign_extend:SI (match_operand:QI 1 "general_extend_operand" "")))]
   ""
   "")
 
-(define_insn "*extendqisi2_compact"
+(define_insn "*extendqisi2_compact_reg"
   [(set (match_operand:SI 0 "arith_reg_dest" "=r,r")
-	(sign_extend:SI (match_operand:QI 1 "general_movsrc_operand" "r,m")))]
+	(sign_extend:SI (match_operand:QI 1 "register_operand" "r,t")))]
   "TARGET_SH1"
   "@
 	exts.b	%1,%0
-	mov.b	%1,%0"
-  [(set_attr "type" "arith,load")
-   (set_attr_alternative "length"
-     [(const_int 2)
-       (if_then_else
-	(match_test "TARGET_SH2A")
-	(const_int 4) (const_int 2))])])
+	movt	%0"
+  [(set_attr "type" "arith,arith")])
+
+;; FIXME: Fold non-SH2A and SH2A alternatives with "enabled" attribute.
+;; See movqi insns.
+(define_insn "*extendqisi2_compact_mem_disp"
+  [(set (match_operand:SI 0 "arith_reg_dest" "=z,r")
+	(sign_extend:SI
+	 (mem:QI (plus:SI (match_operand:SI 1 "arith_reg_operand" "%r,r")
+			  (match_operand:SI 2 "const_int_operand" "K04,N")))))]
+  "TARGET_SH1 && ! TARGET_SH2A && CONST_OK_FOR_K04 (INTVAL (operands[2]))"
+  "@
+	mov.b	@(%O2,%1),%0
+	mov.b	@%1,%0"
+  [(set_attr "type" "load")])
+
+(define_insn "*extendqisi2_compact_mem_disp"
+  [(set (match_operand:SI 0 "arith_reg_dest" "=z,r,r")
+	(sign_extend:SI
+	 (mem:QI (plus:SI (match_operand:SI 1 "arith_reg_operand" "%r,r,r")
+			  (match_operand:SI 2 "const_int_operand" "K04,N,K12")))))]
+  "TARGET_SH2A
+   && (CONST_OK_FOR_K04 (INTVAL (operands[2]))
+       || (CONST_OK_FOR_K12 (INTVAL (operands[2]))))"
+  "@
+	mov.b	@(%O2,%1),%0
+	mov.b	@%1,%0
+	mov.b	@(%O2,%1),%0"
+  [(set_attr "type" "load")
+   (set_attr "length" "2,2,4")])
+
+;; This will take care of other QImode addressing modes than displacement
+;; addressing.
+(define_insn "*extendqisi2_compact_snd"
+  [(set (match_operand:SI 0 "arith_reg_dest" "=r")
+	(sign_extend:SI (match_operand:QI 1 "movsrc_no_disp_mem_operand" "Snd")))]
+  "TARGET_SH1"
+  "mov.b	%1,%0"
+  [(set_attr "type" "load")])
 
 (define_insn "*extendqisi2_media"
   [(set (match_operand:SI 0 "register_operand" "=r,r")
@@ -4919,19 +4951,18 @@ label:
 			   subreg_lowpart_offset (SImode, GET_MODE (op1)));
 }")
 
-(define_insn "extendqihi2"
-  [(set (match_operand:HI 0 "arith_reg_dest" "=r,r")
-	(sign_extend:HI (match_operand:QI 1 "general_movsrc_operand" "r,m")))]
+(define_expand "extendqihi2"
+  [(set (match_operand:HI 0 "arith_reg_dest" "")
+	(sign_extend:HI (match_operand:QI 1 "arith_reg_operand" "")))]
+  ""
+  "")
+
+(define_insn "*extendqihi2_compact_reg"
+  [(set (match_operand:HI 0 "arith_reg_dest" "=r")
+	(sign_extend:HI (match_operand:QI 1 "arith_reg_operand" "r")))]
   "TARGET_SH1"
-  "@
-	exts.b	%1,%0
-	mov.b	%1,%0"
-  [(set_attr "type" "arith,load")
-   (set_attr_alternative "length"
-     [(const_int 2)
-       (if_then_else
-	(match_test "TARGET_SH2A")
-	(const_int 4) (const_int 2))])])
+  "exts.b	%1,%0"
+  [(set_attr "type" "arith")])
 
 /* It would seem useful to combine the truncXi patterns into the movXi
    patterns, but unary operators are ignored when matching constraints,
@@ -5475,33 +5506,90 @@ label:
   [(set_attr "type" "sfunc")
    (set_attr "needs_delay_slot" "yes")])
 
-(define_insn "movqi_i"
-  [(set (match_operand:QI 0 "general_movdst_operand" "=r,r,r,m,r,r,l")
-	(match_operand:QI 1 "general_movsrc_operand"  "r,i,m,r,t,l,r"))]
+(define_expand "movqi"
+  [(set (match_operand:QI 0 "general_operand" "")
+	(match_operand:QI 1 "general_operand" ""))]
+  ""
+  "{ if (prepare_move_operands (operands, QImode)) DONE; }")
+
+;; If movqi_reg_reg is specified as an alternative of movqi, movqi will be
+;; selected to copy QImode regs.  If one of them happens to be allocated
+;; on the stack, reload will stick to movqi insn and generate wrong
+;; displacement addressing because of the generic m alternatives.  
+;; With the movqi_reg_reg being specified before movqi it will be intially 
+;; picked to load/store regs.  If the regs regs are on the stack reload will
+;; try other insns and not stick to movqi_reg_reg.
+(define_insn "*movqi_reg_reg"
+  [(set (match_operand:QI 0 "arith_reg_dest"   "=r,r")
+	(match_operand:QI 1 "register_operand" "r,t"))]
+  "TARGET_SH1"
+  "@
+	mov	%1,%0
+	movt	%0"
+  [(set_attr "type" "move,arith")])
+
+;; FIXME: The non-SH2A and SH2A variants should be combined by adding
+;; "enabled" attribute as it is done in other targets.
+(define_insn "*movqi_store_mem_disp04"
+  [(set (mem:QI (plus:SI (match_operand:SI 0 "arith_reg_operand" "%r,r")
+			 (match_operand:SI 1 "const_int_operand" "K04,N")))
+	(match_operand:QI 2 "arith_reg_operand" "z,r"))]
+  "TARGET_SH1 && CONST_OK_FOR_K04 (INTVAL (operands[1]))"
+  "@
+	mov.b	%2,@(%O1,%0)
+	mov.b	%2,@%0"
+  [(set_attr "type" "store")])
+
+(define_insn "*movqi_store_mem_disp12"
+  [(set (mem:QI (plus:SI (match_operand:SI 0 "arith_reg_operand" "%r")
+			 (match_operand:SI 1 "const_int_operand" "K12")))
+	(match_operand:QI 2 "arith_reg_operand" "r"))]
+  "TARGET_SH2A && CONST_OK_FOR_K12 (INTVAL (operands[1]))"
+  "mov.b	%2,@(%O1,%0)"
+  [(set_attr "type" "store")
+   (set_attr "length" "4")])
+
+(define_insn "*movqi_load_mem_disp"
+  [(set (match_operand:QI 0 "arith_reg_dest" "=z,r")
+	(mem:QI (plus:SI (match_operand:SI 1 "arith_reg_operand" "%r,r")
+			 (match_operand:SI 2 "const_int_operand" "K04,N"))))]
+  "TARGET_SH1 && ! TARGET_SH2A && CONST_OK_FOR_K04 (INTVAL (operands[2]))"
+  "@
+	mov.b	@(%O2,%1),%0
+	mov.b	@%1,%0"
+  [(set_attr "type" "load")])
+
+(define_insn "*movqi_load_mem_disp"
+  [(set (match_operand:QI 0 "arith_reg_dest" "=z,r,r")
+	(mem:QI (plus:SI (match_operand:SI 1 "arith_reg_operand" "%r,r,r")
+			 (match_operand:SI 2 "const_int_operand" "K04,N,K12"))))]
+  "TARGET_SH2A
+   && (CONST_OK_FOR_K04 (INTVAL (operands[2]))
+       || CONST_OK_FOR_K12 (INTVAL (operands[2])))"
+  "@
+	mov.b	@(%O2,%1),%0
+	mov.b	@%1,%0
+	mov.b	@(%O2,%1),%0"
+  [(set_attr "type" "load")
+   (set_attr "length" "2,2,4")])
+
+;; The m constraints basically allow any kind of addresses to be used with any
+;; source/target register as the other operand.  This is not true for 
+;; displacement addressing modes on anything but SH2A.  That's why the
+;; specialized load/store insns are specified above.
+(define_insn "*movqi"
+  [(set (match_operand:QI 0 "general_movdst_operand" "=r,r,m,r,l")
+	(match_operand:QI 1 "general_movsrc_operand"  "i,m,r,l,r"))]
   "TARGET_SH1
    && (arith_reg_operand (operands[0], QImode)
        || arith_reg_operand (operands[1], QImode))"
   "@
 	mov	%1,%0
-	mov	%1,%0
 	mov.b	%1,%0
 	mov.b	%1,%0
-	movt	%0
 	sts	%1,%0
 	lds	%1,%0"
- [(set_attr "type" "move,movi8,load,store,arith,prget,prset")
-  (set_attr_alternative "length"
-     [(const_int 2)
-      (const_int 2)
-      (if_then_else
-	(match_test "TARGET_SH2A")
-	(const_int 4) (const_int 2))
-      (if_then_else
-	(match_test "TARGET_SH2A")
-	(const_int 4) (const_int 2))
-      (const_int 2)
-      (const_int 2)
-      (const_int 2)])])
+ [(set_attr "type" "movi8,load,store,prget,prset")])
 
 (define_insn "*movqi_media"
   [(set (match_operand:QI 0 "general_movdst_operand" "=r,r,r,m")
@@ -5520,12 +5608,6 @@ label:
 	       (const_string "user")]
 	      (const_string "ignore")))])
 
-(define_expand "movqi"
-  [(set (match_operand:QI 0 "general_operand" "")
-	(match_operand:QI 1 "general_operand"  ""))]
-  ""
-  "{ if (prepare_move_operands (operands, QImode)) DONE; }")
-
 (define_expand "reload_inqi"
   [(set (match_operand:SI 2 "" "=&r")
 	(match_operand:QI 1 "inqhi_operand" ""))
@@ -7036,14 +7118,6 @@ label:
   [(set (match_dup 2) (match_dup 1))
    (set (match_dup 0) (match_dup 2))]
   "")
-
-(define_split
-  [(set (match_operand:SI 0 "register_operand" "")
-	(match_operand:SI 1 "memory_operand" ""))
-   (clobber (reg:SI R0_REG))]
-  "TARGET_SH1"
-  [(set (match_dup 0) (match_dup 1))]
-  "")
 
 ;; ------------------------------------------------------------------------
 ;; Define the real conditional branch instructions.
@@ -11684,6 +11758,78 @@ mov.l\\t1f,r0\\n\\
   "TARGET_SH2"
   "dt	%0")
 
+;; The following peepholes fold load sequences for which reload was not
+;; able to generate a displacement addressing move insn.
+;; This can happen when reload has to transform a move insn 
+;; without displacement into one with displacement.  Or when reload can't
+;; fit a displacement into the insn's constraints.  In the latter case, the
+;; load destination reg remains at r0, which reload compensates by inserting
+;; another mov insn.
+
+;; Fold sequence:
+;;	mov #54,r0
+;;	mov.b @(r0,r15),r0
+;;	mov r0,r3
+;; into:
+;;	mov.b @(54,r15),r3
+;;
+(define_peephole2
+  [(set (match_operand:SI 0 "arith_reg_dest" "")
+	(match_operand:SI 1 "const_int_operand" ""))
+   (set (match_operand:SI 2 "arith_reg_dest" "")
+	(sign_extend:SI
+	 (mem:QI (plus:SI (match_dup 0)
+			  (match_operand:SI 3 "arith_reg_operand" "")))))
+   (set (match_operand:QI 4 "arith_reg_dest" "")
+	(match_operand:QI 5 "arith_reg_operand" ""))]
+  "TARGET_SH2A
+   && CONST_OK_FOR_K12 (INTVAL (operands[1]))
+   && REGNO (operands[2]) == REGNO (operands[5])
+   && peep2_reg_dead_p (3, operands[5])"
+  [(set (match_dup 4) (mem:QI (plus:SI (match_dup 3) (match_dup 1))))]
+  "")
+
+;; Fold sequence:
+;;	mov #54,r0
+;;	mov.b @(r0,r15),r1
+;; into:
+;;	mov.b @(54,r15),r1
+;;
+(define_peephole2
+  [(set (match_operand:SI 0 "arith_reg_dest" "")
+	(match_operand:SI 1 "const_int_operand" ""))
+   (set (match_operand:SI 2 "arith_reg_dest" "")
+	 (sign_extend:SI
+	 (mem:QI (plus:SI (match_dup 0)
+			  (match_operand:SI 3 "arith_reg_operand" "")))))]
+  "TARGET_SH2A
+   && CONST_OK_FOR_K12 (INTVAL (operands[1]))
+   && (peep2_reg_dead_p (2, operands[0])
+       || REGNO (operands[0]) == REGNO (operands[2]))"
+  [(set (match_dup 2)
+	(sign_extend:SI (mem:QI (plus:SI (match_dup 3) (match_dup 1)))))]
+  "")
+
+;; Fold sequence:
+;;	mov.b @(r0,r15),r0
+;;	mov r0,r3
+;; into:
+;;	mov.b @(r0,r15),r3
+;;
+(define_peephole2
+  [(set (match_operand:SI 0 "arith_reg_dest" "")
+	(sign_extend:SI
+	 (mem:QI (plus:SI (match_operand:SI 1 "arith_reg_operand" "")
+			  (match_operand:SI 2 "arith_reg_operand" "")))))
+   (set (match_operand:QI 3 "arith_reg_dest" "")
+	(match_operand:QI 4 "arith_reg_operand" ""))]
+  "TARGET_SH1
+   && REGNO (operands[0]) == REGNO (operands[4])
+   && peep2_reg_dead_p (2, operands[0])"
+  [(set (match_dup 3)
+	(mem:QI (plus:SI (match_dup 1) (match_dup 2))))]
+  "")
+
 ;; These convert sequences such as `mov #k,r0; add r15,r0; mov.l @r0,rn'
 ;; to `mov #k,r0; mov.l @(r0,r15),rn'.  These sequences are generated by
 ;; reload when the constant is too large for a reg+offset address.