re PR target/50887 ([avr] Support ACCUMULATE_OUTGOING_ARGS)

	PR target/50887
	* config/avr/avr.opt (-maccumulate-args): New option.
	* config/avr/avr.h (STARTING_FRAME_OFFSET): Redefine to
	avr_starting_frame_offset.
	(ACCUMULATE_OUTGOING_ARGS): Define to avr_accumulate_outgoing_args.
	* config/avr/avr.md (UNSPECV_WRITE_SP_IRQ_ON): Remove.
	(UNSPECV_WRITE_SP_IRQ_OFF): Remove.
	(UNSPECV_WRITE_SP): New constant.
	(*addhi3_sp_R): Rewrite to...
	(*addhi3_sp): ...this new insn.
	(movhi_sp_r_irq_off, movhi_sp_r_irq_on): Combine to...
	(movhi_sp_r): ...this new insn.
	* config/avr/avr-protos.h (avr_accumulate_outgoing_args): New.
	(avr_starting_frame_offset): New.
	* config/avr/avr.c (avr_accumulate_outgoing_args): New function.
	(avr_starting_frame_offset): New function.
	(avr_outgoing_args_size): New static function.
	(avr_initial_elimination_offset): Use it.
	(avr_simple_epilogue): Use it.
	(avr_asm_function_end_prologue): Use it.
	(expand_epilogue): Use it.
	(expand_prologue): Use it.  Break out code to...
	(avr_prologue_setup_frame): ...this new static function.
	(avr_can_eliminate): Allow eliminating to frame pointer if there
	is one.
	(avr_frame_pointer_required_p): Use frame pointer if target has a
	nonlocal label.
	* config/avr/constraints.md (R): Remove.
	(Csp): New constraint.
	* config/avr/predicates.md (avr_sp_immediate_operand): Use it.

From-SVN: r180654

gcc/ChangeLog

+2011-10-29  Georg-Johann Lay  <avr@gjlay.de>
+
+	PR target/50887
+	* config/avr/avr.opt (-maccumulate-args): New option.
+	* config/avr/avr.h (STARTING_FRAME_OFFSET): Redefine to
+	avr_starting_frame_offset.
+	(ACCUMULATE_OUTGOING_ARGS): Define to avr_accumulate_outgoing_args.
+	* config/avr/avr.md (UNSPECV_WRITE_SP_IRQ_ON): Remove.
+	(UNSPECV_WRITE_SP_IRQ_OFF): Remove.
+	(UNSPECV_WRITE_SP): New constant.
+	(*addhi3_sp_R): Rewrite to...
+	(*addhi3_sp): ...this new insn.
+	(movhi_sp_r_irq_off, movhi_sp_r_irq_on): Combine to...
+	(movhi_sp_r): ...this new insn.
+	* config/avr/avr-protos.h (avr_accumulate_outgoing_args): New.
+	(avr_starting_frame_offset): New.
+	* config/avr/avr.c (avr_accumulate_outgoing_args): New function.
+	(avr_starting_frame_offset): New function.
+	(avr_outgoing_args_size): New static function.
+	(avr_initial_elimination_offset): Use it.
+	(avr_simple_epilogue): Use it.
+	(avr_asm_function_end_prologue): Use it.
+	(expand_epilogue): Use it.
+	(expand_prologue): Use it.  Break out code to...
+	(avr_prologue_setup_frame): ...this new static function.
+	(avr_can_eliminate): Allow eliminating to frame pointer if there
+	is one.
+	(avr_frame_pointer_required_p): Use frame pointer if target has a
+	nonlocal label.
+	* config/avr/constraints.md (R): Remove.
+	(Csp): New constraint.
+	* config/avr/predicates.md (avr_sp_immediate_operand): Use it.
+
 2011-10-29  Andi Kleen  <ak@linux.intel.com>
 
 	* gcc-ar.c (target_machine): Add.

gcc/config/avr/avr-protos.h

@@ -32,6 +32,7 @@ extern int avr_initial_elimination_offset (int from, int to);
 extern int avr_simple_epilogue (void);
 extern int avr_hard_regno_rename_ok (unsigned int, unsigned int);
 extern rtx avr_return_addr_rtx (int count, rtx tem);
+extern bool avr_accumulate_outgoing_args (void);
 
 #ifdef TREE_CODE
 extern void avr_asm_output_aligned_decl_common (FILE*, const_tree, const char*, unsigned HOST_WIDE_INT, unsigned int, bool);
@@ -77,6 +78,7 @@ extern bool avr_rotate_bytes (rtx operands[]);
 extern void expand_prologue (void);
 extern void expand_epilogue (bool);
 extern int avr_epilogue_uses (int regno);
+extern int avr_starting_frame_offset (void);
 
 extern void avr_output_bld (rtx operands[], int bit_nr);
 extern void avr_output_addr_vec_elt (FILE *stream, int value);

gcc/config/avr/avr.h

@@ -324,7 +324,7 @@ enum reg_class {
 
 #define STACK_GROWS_DOWNWARD
 
-#define STARTING_FRAME_OFFSET 1
+#define STARTING_FRAME_OFFSET avr_starting_frame_offset()
 
 #define STACK_POINTER_OFFSET 1
 
@@ -635,3 +635,5 @@ struct GTY(()) machine_function
 /* AVR does not round pushes, but the existance of this macro is
    required in order for pushes to be generated.  */
 #define PUSH_ROUNDING(X)	(X)
+
+#define ACCUMULATE_OUTGOING_ARGS avr_accumulate_outgoing_args()

gcc/config/avr/avr.md

@@ -62,8 +62,7 @@
 (define_c_enum "unspecv"
   [UNSPECV_PROLOGUE_SAVES
    UNSPECV_EPILOGUE_RESTORES
-   UNSPECV_WRITE_SP_IRQ_ON
-   UNSPECV_WRITE_SP_IRQ_OFF
+   UNSPECV_WRITE_SP
    UNSPECV_GOTO_RECEIVER
    UNSPECV_ENABLE_IRQS
    UNSPECV_NOP
@@ -380,26 +379,24 @@
     }
 }")
 
-(define_insn "movhi_sp_r_irq_off"
-  [(set (match_operand:HI 0 "stack_register_operand" "=q")
-        (unspec_volatile:HI [(match_operand:HI 1 "register_operand"  "r")] 
-			    UNSPECV_WRITE_SP_IRQ_OFF))]
-  ""
-  "out __SP_H__, %B1
-	out __SP_L__, %A1"
-  [(set_attr "length" "2")
-   (set_attr "cc" "none")])
 
-(define_insn "movhi_sp_r_irq_on"
-  [(set (match_operand:HI 0 "stack_register_operand" "=q")
-        (unspec_volatile:HI [(match_operand:HI 1 "register_operand"  "r")] 
-			    UNSPECV_WRITE_SP_IRQ_ON))]
+;; Move register $1 to the Stack Pointer register SP.
+;; This insn is emit during function prologue/epilogue generation.
+;;    $2 = 0: We know that IRQs are off
+;;    $2 = 1: We know that IRQs are on
+;; Remaining cases when the state of the I-Flag is unknown are
+;; handled by generic movhi insn.
+
+(define_insn "movhi_sp_r"
+  [(set (match_operand:HI 0 "stack_register_operand"                "=q,q")
+        (unspec_volatile:HI [(match_operand:HI 1 "register_operand"  "r,r")
+                             (match_operand:HI 2 "const_int_operand" "L,P")]
+                            UNSPECV_WRITE_SP))]
   ""
-  "cli
-        out __SP_H__, %B1
-	sei
-	out __SP_L__, %A1"
-  [(set_attr "length" "4")
+  "@
+	out __SP_H__,%B1\;out __SP_L__,%A1
+	cli\;out __SP_H__,%B1\;sei\;out __SP_L__,%A1"
+  [(set_attr "length" "2,4")
    (set_attr "cc" "none")])
 
 (define_peephole2
@@ -800,15 +797,15 @@
   [(set_attr "length" "2")
    (set_attr "cc" "set_n")])
 
-(define_insn "*addhi3_sp_R"
-  [(set (match_operand:HI 1 "stack_register_operand" "=q")
-        (plus:HI (match_operand:HI 2 "stack_register_operand" "q")
-                 (match_operand:HI 0 "avr_sp_immediate_operand" "R")))]
+(define_insn "*addhi3_sp"
+  [(set (match_operand:HI 1 "stack_register_operand"           "=q")
+        (plus:HI (match_operand:HI 2 "stack_register_operand"   "q")
+                 (match_operand:HI 0 "avr_sp_immediate_operand" "Csp")))]
   ""
   {
     return avr_out_addto_sp (operands, NULL);
   }
-  [(set_attr "length" "5")
+  [(set_attr "length" "6")
    (set_attr "adjust_len" "addto_sp")])
 
 (define_insn "*addhi3"

gcc/config/avr/avr.opt

@@ -62,6 +62,10 @@ mpmem-wrap-around
 Target Report
 Make the linker relaxation machine assume that a program counter wrap-around occurs.
 
+maccumulate-args
+Target Report Mask(ACCUMULATE_OUTGOING_ARGS)
+Accumulate outgoing function arguments and acquire/release the needed stack space for outpoing function arguments in function prologue/epilogue.  Without this option, outgoing arguments are pushed before calling a function and popped afterwards.  This option can lead to reduced code size for functions that call many functions that get their arguments on the stack like, for example printf.
+
 mstrict-X
 Target Report Var(avr_strict_X) Init(0)
 When accessing RAM, use X as imposed by the hardware, i.e. just use pre-decrement, post-increment and indirect addressing with the X register.  Without this option, the compiler may assume that there is an addressing mode X+const similar to Y+const and Z+const and emit instructions to emulate such an addressing mode for X.

gcc/config/avr/constraints.md

@@ -98,11 +98,6 @@
   (and (match_code "const_double")
        (match_test "op == CONST0_RTX (SFmode)")))
 
-(define_constraint "R"
-  "Integer constant in the range -6 @dots{} 5."
-  (and (match_code "const_int")
-       (match_test "ival >= -6 && ival <= 5")))
-       
 (define_memory_constraint "Q"
   "A memory address based on Y or Z pointer with displacement."
   (and (match_code "mem")
@@ -162,3 +157,8 @@
   "Constant 4-byte integer that allows XOR without clobber register."
   (and (match_code "const_int")
        (match_test "avr_popcount_each_byte (op, 4, (1<<0) | (1<<8))")))
+
+(define_constraint "Csp"
+  "Integer constant in the range -6 @dots{} 6."
+  (and (match_code "const_int")
+       (match_test "IN_RANGE (ival, -6, 6)")))

gcc/config/avr/predicates.md

@@ -135,7 +135,7 @@
 ;;
 (define_predicate "avr_sp_immediate_operand"
   (and (match_code "const_int")
-       (match_test "INTVAL (op) >= -6 && INTVAL (op) <= 5")))
+       (match_test "satisfies_constraint_Csp (op)")))
 
 ;; True for EQ & NE
 (define_predicate "eqne_operator"