Index: ChangeLog
===================================================================
--- ChangeLog	(revision 232903)
+++ ChangeLog	(working copy)
@@ -1,3 +1,37 @@
+2016-01-27  Vladimir Makarov  <vmakarov@redhat.com>
+
+	PR target/68990
+	* config/i386/constraints.md (Bm): Describe as special memory
+	constraint.
+	* doc/md.texi (DEFINE_SPECIAL_MEMORY_CONSTRAINT): Describe it.
+	* genoutput.c (main): Process DEFINE_SPECIAL_MEMORY_CONSTRAINT.
+	* genpreds.c (struct constraint_data): Add is_special_memory.
+	(have_special_memory_constraints, special_memory_start): New
+	static vars.
+	(special_memory_end): Ditto.
+	(add_constraint): Add new arg is_special_memory.  Add code to
+	process its true value.  Update have_special_memory_constraints.
+	(process_define_constraint): Pass the new arg.
+	(process_define_register_constraint): Ditto.
+	(choose_enum_order): Process special memory.
+	(write_tm_preds_h): Generate enum const CT_SPECIAL_MEMORY and
+	function insn_extra_special_memory_constraint.
+	(main): Process DEFINE_SPECIAL_MEMORY_CONSTRAINT.
+	* gensupport.c (process_rtx): Process
+	DEFINE_SPECIAL_MEMORY_CONSTRAINT.
+	* ira-costs.c (record_reg_classes): Process CT_SPECIAL_MEMORY.
+	* ira-lives.c (single_reg_class): Use
+	insn_extra_special_memory_constraint.
+	* ira.c (ira_setup_alts): Process CT_SPECIAL_MEMORY.
+	* lra-constraints.c (process_alt_operands): Ditto.
+	(curr_insn_transform): Use insn_extra_special_memory_constraint.
+	* recog.c (asm_operand_ok, preprocess_constraints): Process
+	CT_SPECIAL_MEMORY.
+	* reload.c (find_reloads): Ditto.
+	* rtl.def (DEFINE_SPECIFAL_MEMORY_CONSTRAINT): New.
+	* stmt.c (parse_input_constraint): Use
+	insn_extra_special_memory_constraint.
+
 2016-01-27  H.J. Lu  <hongjiu.lu@intel.com>
 
 	PR target/68986
Index: config/i386/constraints.md
===================================================================
--- config/i386/constraints.md	(revision 232571)
+++ config/i386/constraints.md	(working copy)
@@ -161,7 +161,7 @@
   "@internal GOT memory operand."
   (match_operand 0 "GOT_memory_operand"))
 
-(define_constraint "Bm"
+(define_special_memory_constraint "Bm"
   "@internal Vector memory operand."
   (match_operand 0 "vector_memory_operand"))
 
Index: doc/md.texi
===================================================================
--- doc/md.texi	(revision 232571)
+++ doc/md.texi	(working copy)
@@ -4424,6 +4424,20 @@ The syntax and semantics are otherwise i
 @code{define_constraint}.
 @end deffn
 
+@deffn {MD Expression} define_special_memory_constraint name docstring exp
+Use this expression for constraints that match a subset of all memory
+operands: that is, @code{reload} can not make them match by reloading
+the address as it is described for @code{define_memory_constraint} or
+such address reload is undesirable with the performance point of view.
+
+For example, @code{define_special_memory_constraint} can be useful if
+specifically aligned memory is necessary or desirable for some insn
+operand.
+
+The syntax and semantics are otherwise identical to
+@code{define_constraint}.
+@end deffn
+
 @deffn {MD Expression} define_address_constraint name docstring exp
 Use this expression for constraints that match a subset of all address
 operands: that is, @code{reload} can make the constraint match by
Index: genoutput.c
===================================================================
--- genoutput.c	(revision 232571)
+++ genoutput.c	(working copy)
@@ -1019,6 +1019,7 @@ main (int argc, char **argv)
       case DEFINE_REGISTER_CONSTRAINT:
       case DEFINE_ADDRESS_CONSTRAINT:
       case DEFINE_MEMORY_CONSTRAINT:
+      case DEFINE_SPECIAL_MEMORY_CONSTRAINT:
 	note_constraint (&info);
 	break;
 
Index: genpreds.c
===================================================================
--- genpreds.c	(revision 232571)
+++ genpreds.c	(working copy)
@@ -659,11 +659,11 @@ write_one_predicate_function (struct pre
 
 /* Constraints fall into two categories: register constraints
    (define_register_constraint), and others (define_constraint,
-   define_memory_constraint, define_address_constraint).  We
-   work out automatically which of the various old-style macros
-   they correspond to, and produce appropriate code.  They all
-   go in the same hash table so we can verify that there are no
-   duplicate names.  */
+   define_memory_constraint, define_special_memory_constraint,
+   define_address_constraint).  We work out automatically which of the
+   various old-style macros they correspond to, and produce
+   appropriate code.  They all go in the same hash table so we can
+   verify that there are no duplicate names.  */
 
 /* All data from one constraint definition.  */
 struct constraint_data
@@ -681,6 +681,7 @@ struct constraint_data
   unsigned int is_const_dbl	: 1;
   unsigned int is_extra		: 1;
   unsigned int is_memory	: 1;
+  unsigned int is_special_memory: 1;
   unsigned int is_address	: 1;
   unsigned int maybe_allows_reg : 1;
   unsigned int maybe_allows_mem : 1;
@@ -718,6 +719,7 @@ static const char const_dbl_constraints[
 static unsigned int constraint_max_namelen;
 static bool have_register_constraints;
 static bool have_memory_constraints;
+static bool have_special_memory_constraints;
 static bool have_address_constraints;
 static bool have_extra_constraints;
 static bool have_const_int_constraints;
@@ -728,6 +730,7 @@ static unsigned int register_start, regi
 static unsigned int satisfied_start;
 static unsigned int const_int_start, const_int_end;
 static unsigned int memory_start, memory_end;
+static unsigned int special_memory_start, special_memory_end;
 static unsigned int address_start, address_end;
 static unsigned int maybe_allows_none_start, maybe_allows_none_end;
 static unsigned int maybe_allows_reg_start, maybe_allows_reg_end;
@@ -754,20 +757,22 @@ mangle (const char *name)
 
 /* Add one constraint, of any sort, to the tables.  NAME is its name;
    REGCLASS is the register class, if any; EXP is the expression to
-   test, if any;  IS_MEMORY and IS_ADDRESS indicate memory and address
-   constraints, respectively; LOC is the .md file location.
-
-   Not all combinations of arguments are valid; most importantly, REGCLASS
-   is mutually exclusive with EXP, and IS_MEMORY/IS_ADDRESS are only
-   meaningful for constraints with EXP.
+   test, if any; IS_MEMORY, IS_SPECIAL_MEMORY and IS_ADDRESS indicate
+   memory, special memory, and address constraints, respectively; LOC
+   is the .md file location.
+
+   Not all combinations of arguments are valid; most importantly,
+   REGCLASS is mutually exclusive with EXP, and
+   IS_MEMORY/IS_SPECIAL_MEMORY/IS_ADDRESS are only meaningful for
+   constraints with EXP.
 
    This function enforces all syntactic and semantic rules about what
    constraints can be defined.  */
 
 static void
 add_constraint (const char *name, const char *regclass,
-		rtx exp, bool is_memory, bool is_address,
-		file_location loc)
+		rtx exp, bool is_memory, bool is_special_memory,
+		bool is_address, file_location loc)
 {
   struct constraint_data *c, **iter, **slot;
   const char *p;
@@ -878,6 +883,17 @@ add_constraint (const char *name, const
 		      name, name[0]);
 	  return;
 	}
+      else if (is_special_memory)
+	{
+	  if (name[1] == '\0')
+	    error_at (loc, "constraint letter '%c' cannot be a "
+		      "special memory constraint", name[0]);
+	  else
+	    error_at (loc, "constraint name '%s' begins with '%c', "
+		      "and therefore cannot be a special memory constraint",
+		      name, name[0]);
+	  return;
+	}
       else if (is_address)
 	{
 	  if (name[1] == '\0')
@@ -904,6 +920,7 @@ add_constraint (const char *name, const
   c->is_const_dbl = is_const_dbl;
   c->is_extra = !(regclass || is_const_int || is_const_dbl);
   c->is_memory = is_memory;
+  c->is_special_memory = is_special_memory;
   c->is_address = is_address;
   c->maybe_allows_reg = true;
   c->maybe_allows_mem = true;
@@ -930,17 +947,20 @@ add_constraint (const char *name, const
   have_const_int_constraints |= c->is_const_int;
   have_extra_constraints |= c->is_extra;
   have_memory_constraints |= c->is_memory;
+  have_special_memory_constraints |= c->is_special_memory;
   have_address_constraints |= c->is_address;
   num_constraints += 1;
 }
 
-/* Process a DEFINE_CONSTRAINT, DEFINE_MEMORY_CONSTRAINT, or
-   DEFINE_ADDRESS_CONSTRAINT expression, C.  */
+/* Process a DEFINE_CONSTRAINT, DEFINE_MEMORY_CONSTRAINT,
+   DEFINE_SPECIAL_MEMORY_CONSTRAINT, or DEFINE_ADDRESS_CONSTRAINT
+   expression, C.  */
 static void
 process_define_constraint (md_rtx_info *info)
 {
   add_constraint (XSTR (info->def, 0), 0, XEXP (info->def, 2),
 		  GET_CODE (info->def) == DEFINE_MEMORY_CONSTRAINT,
+		  GET_CODE (info->def) == DEFINE_SPECIAL_MEMORY_CONSTRAINT,
 		  GET_CODE (info->def) == DEFINE_ADDRESS_CONSTRAINT,
 		  info->loc);
 }
@@ -950,7 +970,7 @@ static void
 process_define_register_constraint (md_rtx_info *info)
 {
   add_constraint (XSTR (info->def, 0), XSTR (info->def, 1),
-		  0, false, false, info->loc);
+		  0, false, false, false, info->loc);
 }
 
 /* Put the constraints into enum order.  We want to keep constraints
@@ -984,6 +1004,12 @@ choose_enum_order (void)
       enum_order[next++] = c;
   memory_end = next;
 
+  special_memory_start = next;
+  FOR_ALL_CONSTRAINTS (c)
+    if (c->is_special_memory)
+      enum_order[next++] = c;
+  special_memory_end = next;
+
   address_start = next;
   FOR_ALL_CONSTRAINTS (c)
     if (c->is_address)
@@ -992,27 +1018,31 @@ choose_enum_order (void)
 
   maybe_allows_none_start = next;
   FOR_ALL_CONSTRAINTS (c)
-    if (!c->is_register && !c->is_const_int && !c->is_memory && !c->is_address
+    if (!c->is_register && !c->is_const_int && !c->is_memory
+	&& !c->is_special_memory && !c->is_address
 	&& !c->maybe_allows_reg && !c->maybe_allows_mem)
       enum_order[next++] = c;
   maybe_allows_none_end = next;
 
   maybe_allows_reg_start = next;
   FOR_ALL_CONSTRAINTS (c)
-    if (!c->is_register && !c->is_const_int && !c->is_memory && !c->is_address
+    if (!c->is_register && !c->is_const_int && !c->is_memory
+	&& !c->is_special_memory && !c->is_address
 	&& c->maybe_allows_reg && !c->maybe_allows_mem)
       enum_order[next++] = c;
   maybe_allows_reg_end = next;
 
   maybe_allows_mem_start = next;
   FOR_ALL_CONSTRAINTS (c)
-    if (!c->is_register && !c->is_const_int && !c->is_memory && !c->is_address
+    if (!c->is_register && !c->is_const_int && !c->is_memory
+	&& !c->is_special_memory && !c->is_address
 	&& !c->maybe_allows_reg && c->maybe_allows_mem)
       enum_order[next++] = c;
   maybe_allows_mem_end = next;
 
   FOR_ALL_CONSTRAINTS (c)
-    if (!c->is_register && !c->is_const_int && !c->is_memory && !c->is_address
+    if (!c->is_register && !c->is_const_int && !c->is_memory
+	&& !c->is_special_memory && !c->is_address
 	&& c->maybe_allows_reg && c->maybe_allows_mem)
       enum_order[next++] = c;
   gcc_assert (next == num_constraints);
@@ -1431,6 +1461,8 @@ write_tm_preds_h (void)
 			    register_start, register_end);
       write_range_function ("insn_extra_memory_constraint",
 			    memory_start, memory_end);
+      write_range_function ("insn_extra_special_memory_constraint",
+			    special_memory_start, special_memory_end);
       write_range_function ("insn_extra_address_constraint",
 			    address_start, address_end);
       write_allows_reg_mem_function ();
@@ -1479,6 +1511,7 @@ write_tm_preds_h (void)
 	    "  CT_REGISTER,\n"
 	    "  CT_CONST_INT,\n"
 	    "  CT_MEMORY,\n"
+	    "  CT_SPECIAL_MEMORY,\n"
 	    "  CT_ADDRESS,\n"
 	    "  CT_FIXED_FORM\n"
 	    "};\n"
@@ -1491,6 +1524,8 @@ write_tm_preds_h (void)
 	values.safe_push (std::make_pair (const_int_start, "CT_CONST_INT"));
       if (memory_start != memory_end)
 	values.safe_push (std::make_pair (memory_start, "CT_MEMORY"));
+      if (special_memory_start != special_memory_end)
+	values.safe_push (std::make_pair (special_memory_start, "CT_SPECIAL_MEMORY"));
       if (address_start != address_end)
 	values.safe_push (std::make_pair (address_start, "CT_ADDRESS"));
       if (address_end != num_constraints)
@@ -1602,6 +1637,7 @@ main (int argc, char **argv)
 
       case DEFINE_CONSTRAINT:
       case DEFINE_MEMORY_CONSTRAINT:
+      case DEFINE_SPECIAL_MEMORY_CONSTRAINT:
       case DEFINE_ADDRESS_CONSTRAINT:
 	process_define_constraint (&info);
 	break;
Index: gensupport.c
===================================================================
--- gensupport.c	(revision 232571)
+++ gensupport.c	(working copy)
@@ -521,6 +521,7 @@ process_rtx (rtx desc, file_location loc
     case DEFINE_CONSTRAINT:
     case DEFINE_REGISTER_CONSTRAINT:
     case DEFINE_MEMORY_CONSTRAINT:
+    case DEFINE_SPECIAL_MEMORY_CONSTRAINT:
     case DEFINE_ADDRESS_CONSTRAINT:
       queue_pattern (desc, &define_pred_tail, loc);
       break;
Index: ira-costs.c
===================================================================
--- ira-costs.c	(revision 232571)
+++ ira-costs.c	(working copy)
@@ -777,6 +777,7 @@ record_reg_classes (int n_alts, int n_op
 		      break;
 
 		    case CT_MEMORY:
+		    case CT_SPECIAL_MEMORY:
 		      /* Every MEM can be reloaded to fit.  */
 		      insn_allows_mem[i] = allows_mem[i] = 1;
 		      if (MEM_P (op))
Index: ira-lives.c
===================================================================
--- ira-lives.c	(revision 232571)
+++ ira-lives.c	(working copy)
@@ -774,6 +774,7 @@ single_reg_class (const char *constraint
 	  /* ??? Is this the best way to handle memory constraints?  */
 	  cn = lookup_constraint (constraints);
 	  if (insn_extra_memory_constraint (cn)
+	      || insn_extra_special_memory_constraint (cn)
 	      || insn_extra_address_constraint (cn))
 	    return NO_REGS;
 	  if (constraint_satisfied_p (op, cn)
Index: ira.c
===================================================================
--- ira.c	(revision 232571)
+++ ira.c	(working copy)
@@ -1868,6 +1868,7 @@ ira_setup_alts (rtx_insn *insn, HARD_REG
 
 			case CT_ADDRESS:
 			case CT_MEMORY:
+			case CT_SPECIAL_MEMORY:
 			  goto op_success;
 
 			case CT_FIXED_FORM:
Index: lra-constraints.c
===================================================================
--- lra-constraints.c	(revision 232571)
+++ lra-constraints.c	(working copy)
@@ -400,7 +400,7 @@ valid_address_p (struct address_info *ad
 }
 
 /* Return true if the eliminated form of memory reference OP satisfies
-   extra memory constraint CONSTRAINT.  */
+   extra (special) memory constraint CONSTRAINT.  */
 static bool
 satisfies_memory_constraint_p (rtx op, enum constraint_num constraint)
 {
@@ -2038,6 +2038,14 @@ process_alt_operands (int only_alternati
 		      if (constraint_satisfied_p (op, cn))
 			win = true;
 		      break;
+
+		    case CT_SPECIAL_MEMORY:
+		      if (MEM_P (op)
+			  && satisfies_memory_constraint_p (op, cn))
+			win = true;
+		      else if (spilled_pseudo_p (op))
+			win = true;
+		      break;
 		    }
 		  break;
 
@@ -3701,7 +3709,8 @@ curr_insn_transform (bool check_only_p)
 		 constraint += CONSTRAINT_LEN (c, constraint))
 	      {
 		enum constraint_num cn = lookup_constraint (constraint);
-		if (insn_extra_memory_constraint (cn)
+		if ((insn_extra_memory_constraint (cn)
+		     || insn_extra_special_memory_constraint (cn))
 		    && satisfies_memory_constraint_p (tem, cn))
 		  break;
 	      }
Index: recog.c
===================================================================
--- recog.c	(revision 232571)
+++ recog.c	(working copy)
@@ -1791,6 +1791,7 @@ asm_operand_ok (rtx op, const char *cons
 	      break;
 
 	    case CT_MEMORY:
+	    case CT_SPECIAL_MEMORY:
 	      /* Every memory operand can be reloaded to fit.  */
 	      result = result || memory_operand (op, VOIDmode);
 	      break;
@@ -2403,6 +2404,7 @@ preprocess_constraints (int n_operands,
 		      break;
 
 		    case CT_MEMORY:
+		    case CT_SPECIAL_MEMORY:
 		      op_alt[i].memory_ok = 1;
 		      break;
 
Index: reload.c
===================================================================
--- reload.c	(revision 232571)
+++ reload.c	(working copy)
@@ -3471,6 +3471,23 @@ find_reloads (rtx_insn *insn, int replac
 			offmemok = 1;
 			break;
 
+		      case CT_SPECIAL_MEMORY:
+			if (force_reload)
+			  break;
+			if (constraint_satisfied_p (operand, cn))
+			  win = 1;
+			/* Likewise if the address will be reloaded because
+			   reg_equiv_address is nonzero.  For reg_equiv_mem
+			   we have to check.  */
+			else if (REG_P (operand)
+				 && REGNO (operand) >= FIRST_PSEUDO_REGISTER
+				 && reg_renumber[REGNO (operand)] < 0
+				 && reg_equiv_mem (REGNO (operand)) != 0
+				 && (constraint_satisfied_p
+				     (reg_equiv_mem (REGNO (operand)), cn)))
+			  win = 1;
+			break;
+
 		      case CT_ADDRESS:
 			if (constraint_satisfied_p (operand, cn))
 			  win = 1;
Index: rtl.def
===================================================================
--- rtl.def	(revision 232571)
+++ rtl.def	(working copy)
@@ -1035,6 +1035,7 @@ DEF_RTL_EXPR(DEFINE_REGISTER_CONSTRAINT,
       RTL object.  */
 DEF_RTL_EXPR(DEFINE_CONSTRAINT, "define_constraint", "sse", RTX_EXTRA)
 DEF_RTL_EXPR(DEFINE_MEMORY_CONSTRAINT, "define_memory_constraint", "sse", RTX_EXTRA)
+DEF_RTL_EXPR(DEFINE_SPECIAL_MEMORY_CONSTRAINT, "define_special_memory_constraint", "sse", RTX_EXTRA)
 DEF_RTL_EXPR(DEFINE_ADDRESS_CONSTRAINT, "define_address_constraint", "sse", RTX_EXTRA)
 
 
Index: stmt.c
===================================================================
--- stmt.c	(revision 232571)
+++ stmt.c	(working copy)
@@ -434,7 +434,8 @@ parse_input_constraint (const char **con
 	if (reg_class_for_constraint (cn) != NO_REGS
 	    || insn_extra_address_constraint (cn))
 	  *allows_reg = true;
-	else if (insn_extra_memory_constraint (cn))
+	else if (insn_extra_memory_constraint (cn)
+		 || insn_extra_special_memory_constraint (cn))
 	  *allows_mem = true;
 	else
 	  insn_extra_constraint_allows_reg_mem (cn, allows_reg, allows_mem);
