Enable LRA register allocator for PDP11.

* config/pdp11/constraints.md (Q): Use define_memory_constraints.
    (R): Likewise.
    (D): Likewise.
    * config/pdp11/pdp11.c (pdp11_lra_p): New function.
    * config/pdp11/pdp11.opt (-mlra): New option.
    * doc/invoke.texi (PDP-11 Options): Document -mlra.

From-SVN: r264819

gcc/config/pdp11/constraints.md

@@ -70,19 +70,19 @@
   (and (match_code "const_double")
        (match_test "op == CONST0_RTX (GET_MODE (op))")))
 
-(define_constraint "Q"
+(define_memory_constraint "Q"
   "Memory reference that requires an additional word after the opcode"
   (and (match_code "mem")
        (match_test "memory_address_p (GET_MODE (op), XEXP (op, 0))
                     && !simple_memory_operand (op, GET_MODE (op))")))
 
-(define_constraint "R"
+(define_memory_constraint "R"
   "Memory reference that is encoded within the opcode"
   (and (match_code "mem")
        (match_test "memory_address_p (GET_MODE (op), XEXP (op, 0))
                     && simple_memory_operand (op, GET_MODE (op))")))
 
-(define_constraint "D"
+(define_memory_constraint "D"
   "Memory reference that is encoded within the opcode, and not push or pop"
   (and (match_code "mem")
        (match_test "memory_address_p (GET_MODE (op), XEXP (op, 0))

gcc/config/pdp11/pdp11.c

@@ -230,7 +230,7 @@ static bool pdp11_scalar_mode_supported_p (scalar_mode);
 #define TARGET_PREFERRED_OUTPUT_RELOAD_CLASS pdp11_preferred_output_reload_class
 
 #undef  TARGET_LRA_P
-#define TARGET_LRA_P hook_bool_void_false
+#define TARGET_LRA_P pdp11_lra_p
 
 #undef  TARGET_LEGITIMATE_ADDRESS_P
 #define TARGET_LEGITIMATE_ADDRESS_P pdp11_legitimate_address_p
@@ -991,6 +991,12 @@ pdp11_assemble_integer (rtx x, unsigned int size, int aligned_p)
 }
 
 
+static bool
+pdp11_lra_p (void)
+{
+  return TARGET_LRA;
+}
+
 /* Register to register moves are cheap if both are general
    registers.  */
 static int 

gcc/config/pdp11/pdp11.opt

@@ -73,3 +73,7 @@ Target has split I&D.
 munix-asm
 Target RejectNegative Report Mask(UNIX_ASM) Negative(mdec-asm)
 Use UNIX assembler syntax.
+
+mlra
+Target Report Mask(LRA)
+Use LRA register allocator

gcc/doc/invoke.texi

@@ -1007,7 +1007,7 @@ Objective-C and Objective-C++ Dialects}.
 @gccoptlist{-mfpu  -msoft-float  -mac0  -mno-ac0  -m40  -m45  -m10 @gol
 -mint32  -mno-int16 -mint16  -mno-int32 @gol
 -mfloat32  -mno-float64 -mfloat64  -mno-float32 @gol
--msplit -munix-asm  -mdec-asm -mgnu-asm}
+-msplit -munix-asm  -mdec-asm -mgnu-asm -mlra}
 
 @emph{picoChip Options}
 @gccoptlist{-mae=@var{ae_type}  -mvliw-lookahead=@var{N} @gol
@@ -22721,6 +22721,11 @@ Use DEC assembler syntax.
 @item -mgnu-asm
 @opindex mgnu-asm
 Use GNU assembler syntax.  This is the default.
+
+@item -mlra
+@opindex mlra
+Use the new LRA register allocator.  By default, the old ``reload''
+allocator is used.
 @end table
 
 @node picoChip Options