2015年12月15日の日記

Arduino の digitalWrite をコンパイルタイムに解決する

tech | 23:29 |

digitalWrite(pin, state) の引数はほとんど固定で使うことが多い (と思いますがどうでしょうか？ http://lowreal.net/2015/12/14/1 こういうケースでは常に固定ですね) が、digitalWrite は実装上、実行時にいちいちテーブルを使って、ピン番号からどのポートのどのビットかをひいている。たいへん無駄である。

そして、digitalWrite() は1度の1つのビットしか設定できないという制約がある。これは大変こまる場合がある (同時に複数のビットを設定して出力を変化させようとしても、タイムラグができてしまう)

ということで、これらを解決できないかと思った結果 C++ のテンプレートメタプログラミングに手を出すことになった

前提

Arduino が使っている 8bit AVR では PORTB, PORTC, PORTD などと最大8bitのレジスタがあり、これら単位では同時に操作が可能になっている。

Arduino ではこれらのポート単位を隠蔽し、ピン番号という一連の番号によって区別するように抽象化されている。具体的には 0〜7 が PD, 8〜14 が PB というような感じ (standard なArduino の場合)

仕様

digitalWrite() とインターフェイス互換であること (静的であること以外)
複数ビットを同時に操作できること
指定したピン番号同士のポートが同一でない場合エラーとすること

// オリジナル。0ピンをLOWにする
digitalWrite(0, LOW);

// 作ったもの。0ピンをLOW, 1ピンをHIGH... とする (同時に)
WRITE_MULTI(
  0, LOW,	
  1, HIGH,
  2, LOW,	
  3, HIGH
);

コード

Gist

    //#!ano build -f="-std=c++11 -Os" && /Applications/Arduino.app/Contents/Java/hardware/tools/avr/bin/avr-objdump -d .build_ano/uno/firmware.elf ;: 
  #include <Arduino.h> 
    
  // ARDUINO_MAIN で ifdef されているので外からみえない 
  constexpr uint8_t PB = 2; 
  constexpr uint8_t PC = 3; 
  constexpr uint8_t PD = 4; 
    
  // template version of Arduino builtin functions 
    
  constexpr uint16_t port_to_mode[] = { 
  	NOT_A_PORT, 
  	NOT_A_PORT, 
  	(uint16_t) &DDRB, 
  	(uint16_t) &DDRC, 
  	(uint16_t) &DDRD, 
  }; 
    
  constexpr uint16_t port_to_output[] = { 
  	NOT_A_PORT, 
  	NOT_A_PORT, 
  	(uint16_t) &PORTB, 
  	(uint16_t) &PORTC, 
  	(uint16_t) &PORTD, 
  }; 
    
  constexpr uint16_t port_to_input[] = { 
  	NOT_A_PORT, 
  	NOT_A_PORT, 
  	(uint16_t) &PINB, 
  	(uint16_t) &PINC, 
  	(uint16_t) &PIND, 
  }; 
    
  constexpr uint8_t digital_pin_to_port[] = { 
  	PD, /* 0 */ 
  	PD, 
  	PD, 
  	PD, 
  	PD, 
  	PD, 
  	PD, 
  	PD, 
  	PB, /* 8 */ 
  	PB, 
  	PB, 
  	PB, 
  	PB, 
  	PB, 
  	PC, /* 14 */ 
  	PC, 
  	PC, 
  	PC, 
  	PC, 
  	PC, 
  }; 
    
  constexpr uint8_t digital_pin_to_bit_mask[] = { 
  	_BV(0), /* 0, port D */ 
  	_BV(1), 
  	_BV(2), 
  	_BV(3), 
  	_BV(4), 
  	_BV(5), 
  	_BV(6), 
  	_BV(7), 
  	_BV(0), /* 8, port B */ 
  	_BV(1), 
  	_BV(2), 
  	_BV(3), 
  	_BV(4), 
  	_BV(5), 
  	_BV(0), /* 14, port C */ 
  	_BV(1), 
  	_BV(2), 
  	_BV(3), 
  	_BV(4), 
  	_BV(5), 
  }; 
    
  template<uint8_t port> 
  constexpr volatile uint8_t* portModeRegisterX() { 
  	static_assert(port < sizeof(port_to_mode), "invalid port number"); 
  	static_assert(port_to_mode[port] != NOT_A_PORT, "invalid port number"); 
  	return (volatile uint8_t*)port_to_mode[port]; 
  } 
    
  template<uint8_t port> 
  constexpr volatile uint8_t* portOutputRegisterX() { 
  	static_assert(port < sizeof(port_to_output), "invalid port number"); 
  	static_assert(port_to_output[port] != NOT_A_PORT, "invalid port number"); 
  	return (volatile uint8_t*)port_to_output[port]; 
  } 
    
  template<uint8_t port> 
  constexpr volatile uint8_t* portInputRegisterX() { 
  	static_assert(port < sizeof(port_to_input), "invalid port number"); 
  	static_assert(port_to_input[port] != NOT_A_PORT, "invalid port number"); 
  	return (volatile uint8_t*)port_to_input[port]; 
  } 
    
  template <uint16_t pin> 
  constexpr uint8_t digitalPinToBitMaskX() { 
  	static_assert(pin < sizeof(digital_pin_to_bit_mask), "invalid pin number"); 
  	return digital_pin_to_bit_mask[pin]; 
  }; 
    
    
  template <uint16_t pin> 
  constexpr uint8_t digitalPinToPortX() { 
  	static_assert(pin < sizeof(digital_pin_to_port), "invalid pin number"); 
  	return digital_pin_to_port[pin]; 
  }; 
    
  // multiple bit set function with cheking port consistency 
    
  template<uint8_t port, uint8_t mask, uint8_t vals> 
  constexpr void digitalWriteMulti_() { 
  	volatile uint8_t *out = portOutputRegisterX<port>(); 
  	*out = (*out & ~mask) | vals; 
  } 
    
  template<uint8_t port, uint8_t mask, uint8_t vals, uint16_t pin, uint8_t val, uint16_t... Rest> 
  constexpr void digitalWriteMulti_() { 
  	static_assert(digitalPinToPortX<pin>() == port, "all port must be same"); 
  	constexpr uint8_t bit = digitalPinToBitMaskX<pin>(); 
  	digitalWriteMulti_< 
   port, 
   mask | bit, 
   vals | (val ? bit : 0), 
   Rest... 
  	>(); 
  } 
    
  template<uint16_t pin, uint8_t val, uint16_t... Rest> 
  constexpr void digitalWriteMulti() { 
  	constexpr uint8_t port = digitalPinToPortX<pin>(); 
  	return digitalWriteMulti_< 
   port, 
   0, 
   0, 
    
   pin, 
   val, 
   Rest... 
  	>(); 
  } 
    
  // hide template magic from surface 
  #define WRITE_MULTI(...) digitalWriteMulti<__VA_ARGS__>() 
    
  void setup() { 
  	PORTD = (PORTD & 0b11110000) | (0b1010); 
    
  	asm volatile ("nop");	// marker 
    
  	// same as above 
  	WRITE_MULTI( 
   0, LOW, 
   1, HIGH, 
   2, LOW, 
   3, HIGH 
  	); 
    
  	asm volatile ("nop"); 
    
  	// another port 
  	WRITE_MULTI( 
   8, LOW, 
   9, HIGH, 
   10, LOW, 
   11, HIGH 
  	); 
    
  	asm volatile ("nop"); 
    
  	/** following is invalid 
   * static_assert(digitalPinToPortX<pin>() == port, "all port must be same"); 
   * pin=0 -> PORTB, pin=8 -> PORTC error 
  	digitalWriteMulti< 
   0, LOW, 
   1, HIGH, 
   2, LOW, 
   8, HIGH 
  	>(); 
  	*/ 
    
  	asm volatile ("nop"); 
  	/** builtin dynamic method 
   * this is very slow 
   */ 
  	digitalWrite(0, LOW); 
  } 
    
  void loop() { 
  } 
 

view raw digitalWriteMulti.cpp hosted with ❤ by GitHub

      
  .build_ano/uno/firmware.elf: file format elf32-avr 
    
    
  Disassembly of section .text: 
    
  00000000 <__vectors>: 
   0:	0c 94 61 00 jmp	0xc2	; 0xc2 <__ctors_end> 
   4:	0c 94 73 00 jmp	0xe6	; 0xe6 <__bad_interrupt> 
   8:	0c 94 73 00 jmp	0xe6	; 0xe6 <__bad_interrupt> 
   c:	0c 94 73 00 jmp	0xe6	; 0xe6 <__bad_interrupt> 
   10:	0c 94 73 00 jmp	0xe6	; 0xe6 <__bad_interrupt> 
   14:	0c 94 73 00 jmp	0xe6	; 0xe6 <__bad_interrupt> 
   18:	0c 94 73 00 jmp	0xe6	; 0xe6 <__bad_interrupt> 
   1c:	0c 94 73 00 jmp	0xe6	; 0xe6 <__bad_interrupt> 
   20:	0c 94 73 00 jmp	0xe6	; 0xe6 <__bad_interrupt> 
   24:	0c 94 73 00 jmp	0xe6	; 0xe6 <__bad_interrupt> 
   28:	0c 94 73 00 jmp	0xe6	; 0xe6 <__bad_interrupt> 
   2c:	0c 94 73 00 jmp	0xe6	; 0xe6 <__bad_interrupt> 
   30:	0c 94 73 00 jmp	0xe6	; 0xe6 <__bad_interrupt> 
   34:	0c 94 73 00 jmp	0xe6	; 0xe6 <__bad_interrupt> 
   38:	0c 94 73 00 jmp	0xe6	; 0xe6 <__bad_interrupt> 
   3c:	0c 94 73 00 jmp	0xe6	; 0xe6 <__bad_interrupt> 
   40:	0c 94 71 01 jmp	0x2e2	; 0x2e2 <__vector_16> 
   44:	0c 94 73 00 jmp	0xe6	; 0xe6 <__bad_interrupt> 
   48:	0c 94 73 00 jmp	0xe6	; 0xe6 <__bad_interrupt> 
   4c:	0c 94 73 00 jmp	0xe6	; 0xe6 <__bad_interrupt> 
   50:	0c 94 73 00 jmp	0xe6	; 0xe6 <__bad_interrupt> 
   54:	0c 94 73 00 jmp	0xe6	; 0xe6 <__bad_interrupt> 
   58:	0c 94 73 00 jmp	0xe6	; 0xe6 <__bad_interrupt> 
   5c:	0c 94 73 00 jmp	0xe6	; 0xe6 <__bad_interrupt> 
   60:	0c 94 73 00 jmp	0xe6	; 0xe6 <__bad_interrupt> 
   64:	0c 94 73 00 jmp	0xe6	; 0xe6 <__bad_interrupt> 
    
  00000068 <__trampolines_end>: 
   68:	00 00 nop 
   6a:	00 08 sbc	r0, r0 
   6c:	00 02 muls	r16, r16 
   6e:	01 00 .word	0x0001	; ???? 
   70:	00 03 mulsu	r16, r16 
   72:	04 07 cpc	r16, r20 
  	... 
    
  0000007c <digital_pin_to_bit_mask_PGM>: 
   7c:	01 02 04 08 10 20 40 80 01 02 04 08 10 20 01 02 ..... @...... .. 
   8c:	04 08 10 20 ...  
    
  00000090 <digital_pin_to_port_PGM>: 
   90:	04 04 04 04 04 04 04 04 02 02 02 02 02 02 03 03 ................ 
   a0:	03 03 03 03 .... 
    
  000000a4 <port_to_input_PGM>: 
   a4:	00 00 00 00 23 00 26 00 29 00 ....#.&.). 
    
  000000ae <port_to_output_PGM>: 
   ae:	00 00 00 00 25 00 28 00 2b 00 ....%.(.+. 
    
  000000b8 <port_to_mode_PGM>: 
   b8:	00 00 00 00 24 00 27 00 2a 00 ....$.'.*. 
    
  000000c2 <__ctors_end>: 
   c2:	11 24 eor	r1, r1 
   c4:	1f be out	0x3f, r1	; 63 
   c6:	cf ef ldi	r28, 0xFF	; 255 
   c8:	d8 e0 ldi	r29, 0x08	; 8 
   ca:	de bf out	0x3e, r29	; 62 
   cc:	cd bf out	0x3d, r28	; 61 
    
  000000ce <__do_clear_bss>: 
   ce:	21 e0 ldi	r18, 0x01	; 1 
   d0:	a0 e0 ldi	r26, 0x00	; 0 
   d2:	b1 e0 ldi	r27, 0x01	; 1 
   d4:	01 c0 rjmp	.+2 ; 0xd8 <.do_clear_bss_start> 
    
  000000d6 <.do_clear_bss_loop>: 
   d6:	1d 92 st	X+, r1 
    
  000000d8 <.do_clear_bss_start>: 
   d8:	a9 30 cpi	r26, 0x09	; 9 
   da:	b2 07 cpc	r27, r18 
   dc:	e1 f7 brne	.-8 ; 0xd6 <.do_clear_bss_loop> 
   de:	0e 94 b8 02 call	0x570	; 0x570 <main> 
   e2:	0c 94 cc 02 jmp	0x598	; 0x598 <_exit> 
    
  000000e6 <__bad_interrupt>: 
   e6:	0c 94 00 00 jmp	0	; 0x0 <__vectors> 
    
  000000ea <setup>: 
   ea:	8b b1 in	r24, 0x0b	; 11 
   ec:	80 7f andi	r24, 0xF0	; 240 
   ee:	8a 60 ori	r24, 0x0A	; 10 
   f0:	8b b9 out	0x0b, r24	; 11 
   f2:	00 00 nop 
   f4:	8b b1 in	r24, 0x0b	; 11 
   f6:	80 7f andi	r24, 0xF0	; 240 
   f8:	8a 60 ori	r24, 0x0A	; 10 
   fa:	8b b9 out	0x0b, r24	; 11 
   fc:	00 00 nop 
   fe:	85 b1 in	r24, 0x05	; 5 
   100:	80 7f andi	r24, 0xF0	; 240 
   102:	8a 60 ori	r24, 0x0A	; 10 
   104:	85 b9 out	0x05, r24	; 5 
   106:	00 00 nop 
   108:	00 00 nop 
   10a:	60 e0 ldi	r22, 0x00	; 0 
   10c:	80 e0 ldi	r24, 0x00	; 0 
   10e:	0c 94 c8 00 jmp	0x190	; 0x190 <digitalWrite> 
    
  00000112 <loop>: 
   112:	08 95 ret 
    
  00000114 <pinMode>: 
   114:	cf 93 push	r28 
   116:	df 93 push	r29 
   118:	90 e0 ldi	r25, 0x00	; 0 
   11a:	fc 01 movw	r30, r24 
   11c:	e4 58 subi	r30, 0x84	; 132 
   11e:	ff 4f sbci	r31, 0xFF	; 255 
   120:	24 91 lpm	r18, Z 
   122:	fc 01 movw	r30, r24 
   124:	e0 57 subi	r30, 0x70	; 112 
   126:	ff 4f sbci	r31, 0xFF	; 255 
   128:	84 91 lpm	r24, Z 
   12a:	88 23 and	r24, r24 
   12c:	b9 f0 breq	.+46 ; 0x15c <pinMode+0x48> 
   12e:	90 e0 ldi	r25, 0x00	; 0 
   130:	88 0f add	r24, r24 
   132:	99 1f adc	r25, r25 
   134:	fc 01 movw	r30, r24 
   136:	e8 54 subi	r30, 0x48	; 72 
   138:	ff 4f sbci	r31, 0xFF	; 255 
   13a:	a5 91 lpm	r26, Z+ 
   13c:	b4 91 lpm	r27, Z 
   13e:	82 55 subi	r24, 0x52	; 82 
   140:	9f 4f sbci	r25, 0xFF	; 255 
   142:	fc 01 movw	r30, r24 
   144:	c5 91 lpm	r28, Z+ 
   146:	d4 91 lpm	r29, Z 
   148:	9f b7 in	r25, 0x3f	; 63 
   14a:	66 23 and	r22, r22 
   14c:	51 f0 breq	.+20 ; 0x162 <pinMode+0x4e> 
   14e:	62 30 cpi	r22, 0x02	; 2 
   150:	a1 f0 breq	.+40 ; 0x17a <pinMode+0x66> 
   152:	f8 94 cli 
   154:	8c 91 ld	r24, X 
   156:	82 2b or	r24, r18 
   158:	8c 93 st	X, r24 
   15a:	9f bf out	0x3f, r25	; 63 
   15c:	df 91 pop	r29 
   15e:	cf 91 pop	r28 
   160:	08 95 ret 
   162:	f8 94 cli 
   164:	8c 91 ld	r24, X 
   166:	20 95 com	r18 
   168:	82 23 and	r24, r18 
   16a:	8c 93 st	X, r24 
   16c:	88 81 ld	r24, Y 
   16e:	82 23 and	r24, r18 
   170:	88 83 st	Y, r24 
   172:	9f bf out	0x3f, r25	; 63 
   174:	df 91 pop	r29 
   176:	cf 91 pop	r28 
   178:	08 95 ret 
   17a:	f8 94 cli 
   17c:	8c 91 ld	r24, X 
   17e:	32 2f mov	r19, r18 
   180:	30 95 com	r19 
   182:	83 23 and	r24, r19 
   184:	8c 93 st	X, r24 
   186:	88 81 ld	r24, Y 
   188:	82 2b or	r24, r18 
   18a:	88 83 st	Y, r24 
   18c:	9f bf out	0x3f, r25	; 63 
   18e:	e6 cf rjmp	.-52 ; 0x15c <pinMode+0x48> 
    
  00000190 <digitalWrite>: 
   190:	90 e0 ldi	r25, 0x00	; 0 
   192:	fc 01 movw	r30, r24 
   194:	e8 59 subi	r30, 0x98	; 152 
   196:	ff 4f sbci	r31, 0xFF	; 255 
   198:	24 91 lpm	r18, Z 
   19a:	fc 01 movw	r30, r24 
   19c:	e4 58 subi	r30, 0x84	; 132 
   19e:	ff 4f sbci	r31, 0xFF	; 255 
   1a0:	34 91 lpm	r19, Z 
   1a2:	fc 01 movw	r30, r24 
   1a4:	e0 57 subi	r30, 0x70	; 112 
   1a6:	ff 4f sbci	r31, 0xFF	; 255 
   1a8:	84 91 lpm	r24, Z 
   1aa:	88 23 and	r24, r24 
   1ac:	99 f0 breq	.+38 ; 0x1d4 <digitalWrite+0x44> 
   1ae:	21 11 cpse	r18, r1 
   1b0:	16 c0 rjmp	.+44 ; 0x1de <digitalWrite+0x4e> 
   1b2:	e8 2f mov	r30, r24 
   1b4:	f0 e0 ldi	r31, 0x00	; 0 
   1b6:	ee 0f add	r30, r30 
   1b8:	ff 1f adc	r31, r31 
   1ba:	e2 55 subi	r30, 0x52	; 82 
   1bc:	ff 4f sbci	r31, 0xFF	; 255 
   1be:	a5 91 lpm	r26, Z+ 
   1c0:	b4 91 lpm	r27, Z 
   1c2:	8f b7 in	r24, 0x3f	; 63 
   1c4:	f8 94 cli 
   1c6:	9c 91 ld	r25, X 
   1c8:	61 11 cpse	r22, r1 
   1ca:	05 c0 rjmp	.+10 ; 0x1d6 <digitalWrite+0x46> 
   1cc:	30 95 com	r19 
   1ce:	93 23 and	r25, r19 
   1d0:	9c 93 st	X, r25 
   1d2:	8f bf out	0x3f, r24	; 63 
   1d4:	08 95 ret 
   1d6:	93 2b or	r25, r19 
   1d8:	9c 93 st	X, r25 
   1da:	8f bf out	0x3f, r24	; 63 
   1dc:	fb cf rjmp	.-10 ; 0x1d4 <digitalWrite+0x44> 
   1de:	23 30 cpi	r18, 0x03	; 3 
   1e0:	29 f1 breq	.+74 ; 0x22c <digitalWrite+0x9c> 
   1e2:	60 f0 brcs	.+24 ; 0x1fc <digitalWrite+0x6c> 
   1e4:	27 30 cpi	r18, 0x07	; 7 
   1e6:	e1 f0 breq	.+56 ; 0x220 <digitalWrite+0x90> 
   1e8:	28 30 cpi	r18, 0x08	; 8 
   1ea:	a1 f0 breq	.+40 ; 0x214 <digitalWrite+0x84> 
   1ec:	24 30 cpi	r18, 0x04	; 4 
   1ee:	09 f7 brne	.-62 ; 0x1b2 <digitalWrite+0x22> 
   1f0:	90 91 80 00 lds	r25, 0x0080 
   1f4:	9f 7d andi	r25, 0xDF	; 223 
   1f6:	90 93 80 00 sts	0x0080, r25 
   1fa:	db cf rjmp	.-74 ; 0x1b2 <digitalWrite+0x22> 
   1fc:	21 30 cpi	r18, 0x01	; 1 
   1fe:	31 f0 breq	.+12 ; 0x20c <digitalWrite+0x7c> 
   200:	22 30 cpi	r18, 0x02	; 2 
   202:	b9 f6 brne	.-82 ; 0x1b2 <digitalWrite+0x22> 
   204:	94 b5 in	r25, 0x24	; 36 
   206:	9f 7d andi	r25, 0xDF	; 223 
   208:	94 bd out	0x24, r25	; 36 
   20a:	d3 cf rjmp	.-90 ; 0x1b2 <digitalWrite+0x22> 
   20c:	94 b5 in	r25, 0x24	; 36 
   20e:	9f 77 andi	r25, 0x7F	; 127 
   210:	94 bd out	0x24, r25	; 36 
   212:	cf cf rjmp	.-98 ; 0x1b2 <digitalWrite+0x22> 
   214:	90 91 b0 00 lds	r25, 0x00B0 
   218:	9f 7d andi	r25, 0xDF	; 223 
   21a:	90 93 b0 00 sts	0x00B0, r25 
   21e:	c9 cf rjmp	.-110 ; 0x1b2 <digitalWrite+0x22> 
   220:	90 91 b0 00 lds	r25, 0x00B0 
   224:	9f 77 andi	r25, 0x7F	; 127 
   226:	90 93 b0 00 sts	0x00B0, r25 
   22a:	c3 cf rjmp	.-122 ; 0x1b2 <digitalWrite+0x22> 
   22c:	90 91 80 00 lds	r25, 0x0080 
   230:	9f 77 andi	r25, 0x7F	; 127 
   232:	90 93 80 00 sts	0x0080, r25 
   236:	bd cf rjmp	.-134 ; 0x1b2 <digitalWrite+0x22> 
    
  00000238 <digitalRead>: 
   238:	90 e0 ldi	r25, 0x00	; 0 
   23a:	fc 01 movw	r30, r24 
   23c:	e8 59 subi	r30, 0x98	; 152 
   23e:	ff 4f sbci	r31, 0xFF	; 255 
   240:	24 91 lpm	r18, Z 
   242:	fc 01 movw	r30, r24 
   244:	e4 58 subi	r30, 0x84	; 132 
   246:	ff 4f sbci	r31, 0xFF	; 255 
   248:	34 91 lpm	r19, Z 
   24a:	fc 01 movw	r30, r24 
   24c:	e0 57 subi	r30, 0x70	; 112 
   24e:	ff 4f sbci	r31, 0xFF	; 255 
   250:	84 91 lpm	r24, Z 
   252:	88 23 and	r24, r24 
   254:	91 f0 breq	.+36 ; 0x27a <digitalRead+0x42> 
   256:	21 11 cpse	r18, r1 
   258:	13 c0 rjmp	.+38 ; 0x280 <digitalRead+0x48> 
   25a:	e8 2f mov	r30, r24 
   25c:	f0 e0 ldi	r31, 0x00	; 0 
   25e:	ee 0f add	r30, r30 
   260:	ff 1f adc	r31, r31 
   262:	ec 55 subi	r30, 0x5C	; 92 
   264:	ff 4f sbci	r31, 0xFF	; 255 
   266:	a5 91 lpm	r26, Z+ 
   268:	b4 91 lpm	r27, Z 
   26a:	2c 91 ld	r18, X 
   26c:	23 23 and	r18, r19 
   26e:	81 e0 ldi	r24, 0x01	; 1 
   270:	90 e0 ldi	r25, 0x00	; 0 
   272:	09 f0 breq	.+2 ; 0x276 <digitalRead+0x3e> 
   274:	08 95 ret 
   276:	80 e0 ldi	r24, 0x00	; 0 
   278:	08 95 ret 
   27a:	80 e0 ldi	r24, 0x00	; 0 
   27c:	90 e0 ldi	r25, 0x00	; 0 
   27e:	08 95 ret 
   280:	23 30 cpi	r18, 0x03	; 3 
   282:	29 f1 breq	.+74 ; 0x2ce <digitalRead+0x96> 
   284:	60 f0 brcs	.+24 ; 0x29e <digitalRead+0x66> 
   286:	27 30 cpi	r18, 0x07	; 7 
   288:	e1 f0 breq	.+56 ; 0x2c2 <digitalRead+0x8a> 
   28a:	28 30 cpi	r18, 0x08	; 8 
   28c:	a1 f0 breq	.+40 ; 0x2b6 <digitalRead+0x7e> 
   28e:	24 30 cpi	r18, 0x04	; 4 
   290:	21 f7 brne	.-56 ; 0x25a <digitalRead+0x22> 
   292:	90 91 80 00 lds	r25, 0x0080 
   296:	9f 7d andi	r25, 0xDF	; 223 
   298:	90 93 80 00 sts	0x0080, r25 
   29c:	de cf rjmp	.-68 ; 0x25a <digitalRead+0x22> 
   29e:	21 30 cpi	r18, 0x01	; 1 
   2a0:	31 f0 breq	.+12 ; 0x2ae <digitalRead+0x76> 
   2a2:	22 30 cpi	r18, 0x02	; 2 
   2a4:	d1 f6 brne	.-76 ; 0x25a <digitalRead+0x22> 
   2a6:	94 b5 in	r25, 0x24	; 36 
   2a8:	9f 7d andi	r25, 0xDF	; 223 
   2aa:	94 bd out	0x24, r25	; 36 
   2ac:	d6 cf rjmp	.-84 ; 0x25a <digitalRead+0x22> 
   2ae:	94 b5 in	r25, 0x24	; 36 
   2b0:	9f 77 andi	r25, 0x7F	; 127 
   2b2:	94 bd out	0x24, r25	; 36 
   2b4:	d2 cf rjmp	.-92 ; 0x25a <digitalRead+0x22> 
   2b6:	90 91 b0 00 lds	r25, 0x00B0 
   2ba:	9f 7d andi	r25, 0xDF	; 223 
   2bc:	90 93 b0 00 sts	0x00B0, r25 
   2c0:	cc cf rjmp	.-104 ; 0x25a <digitalRead+0x22> 
   2c2:	90 91 b0 00 lds	r25, 0x00B0 
   2c6:	9f 77 andi	r25, 0x7F	; 127 
   2c8:	90 93 b0 00 sts	0x00B0, r25 
   2cc:	c6 cf rjmp	.-116 ; 0x25a <digitalRead+0x22> 
   2ce:	90 91 80 00 lds	r25, 0x0080 
   2d2:	9f 77 andi	r25, 0x7F	; 127 
   2d4:	90 93 80 00 sts	0x0080, r25 
   2d8:	c0 cf rjmp	.-128 ; 0x25a <digitalRead+0x22> 
    
  000002da <atexit>: 
   2da:	80 e0 ldi	r24, 0x00	; 0 
   2dc:	90 e0 ldi	r25, 0x00	; 0 
   2de:	08 95 ret 
    
  000002e0 <initVariant>: 
   2e0:	08 95 ret 
    
  000002e2 <__vector_16>: 
   2e2:	1f 92 push	r1 
   2e4:	0f 92 push	r0 
   2e6:	0f b6 in	r0, 0x3f	; 63 
   2e8:	0f 92 push	r0 
   2ea:	11 24 eor	r1, r1 
   2ec:	2f 93 push	r18 
   2ee:	3f 93 push	r19 
   2f0:	8f 93 push	r24 
   2f2:	9f 93 push	r25 
   2f4:	af 93 push	r26 
   2f6:	bf 93 push	r27 
   2f8:	80 91 00 01 lds	r24, 0x0100 
   2fc:	90 91 01 01 lds	r25, 0x0101 
   300:	a0 91 02 01 lds	r26, 0x0102 
   304:	b0 91 03 01 lds	r27, 0x0103 
   308:	30 91 08 01 lds	r19, 0x0108 
   30c:	23 e0 ldi	r18, 0x03	; 3 
   30e:	23 0f add	r18, r19 
   310:	2d 37 cpi	r18, 0x7D	; 125 
   312:	68 f1 brcs	.+90 ; 0x36e <__vector_16+0x8c> 
   314:	26 e8 ldi	r18, 0x86	; 134 
   316:	23 0f add	r18, r19 
   318:	02 96 adiw	r24, 0x02	; 2 
   31a:	a1 1d adc	r26, r1 
   31c:	b1 1d adc	r27, r1 
   31e:	20 93 08 01 sts	0x0108, r18 
   322:	80 93 00 01 sts	0x0100, r24 
   326:	90 93 01 01 sts	0x0101, r25 
   32a:	a0 93 02 01 sts	0x0102, r26 
   32e:	b0 93 03 01 sts	0x0103, r27 
   332:	80 91 04 01 lds	r24, 0x0104 
   336:	90 91 05 01 lds	r25, 0x0105 
   33a:	a0 91 06 01 lds	r26, 0x0106 
   33e:	b0 91 07 01 lds	r27, 0x0107 
   342:	01 96 adiw	r24, 0x01	; 1 
   344:	a1 1d adc	r26, r1 
   346:	b1 1d adc	r27, r1 
   348:	80 93 04 01 sts	0x0104, r24 
   34c:	90 93 05 01 sts	0x0105, r25 
   350:	a0 93 06 01 sts	0x0106, r26 
   354:	b0 93 07 01 sts	0x0107, r27 
   358:	bf 91 pop	r27 
   35a:	af 91 pop	r26 
   35c:	9f 91 pop	r25 
   35e:	8f 91 pop	r24 
   360:	3f 91 pop	r19 
   362:	2f 91 pop	r18 
   364:	0f 90 pop	r0 
   366:	0f be out	0x3f, r0	; 63 
   368:	0f 90 pop	r0 
   36a:	1f 90 pop	r1 
   36c:	18 95 reti 
   36e:	01 96 adiw	r24, 0x01	; 1 
   370:	a1 1d adc	r26, r1 
   372:	b1 1d adc	r27, r1 
   374:	d4 cf rjmp	.-88 ; 0x31e <__vector_16+0x3c> 
    
  00000376 <millis>: 
   376:	2f b7 in	r18, 0x3f	; 63 
   378:	f8 94 cli 
   37a:	60 91 00 01 lds	r22, 0x0100 
   37e:	70 91 01 01 lds	r23, 0x0101 
   382:	80 91 02 01 lds	r24, 0x0102 
   386:	90 91 03 01 lds	r25, 0x0103 
   38a:	2f bf out	0x3f, r18	; 63 
   38c:	08 95 ret 
    
  0000038e <micros>: 
   38e:	3f b7 in	r19, 0x3f	; 63 
   390:	f8 94 cli 
   392:	80 91 04 01 lds	r24, 0x0104 
   396:	90 91 05 01 lds	r25, 0x0105 
   39a:	a0 91 06 01 lds	r26, 0x0106 
   39e:	b0 91 07 01 lds	r27, 0x0107 
   3a2:	26 b5 in	r18, 0x26	; 38 
   3a4:	a8 9b sbis	0x15, 0	; 21 
   3a6:	05 c0 rjmp	.+10 ; 0x3b2 <micros+0x24> 
   3a8:	2f 3f cpi	r18, 0xFF	; 255 
   3aa:	19 f0 breq	.+6 ; 0x3b2 <micros+0x24> 
   3ac:	01 96 adiw	r24, 0x01	; 1 
   3ae:	a1 1d adc	r26, r1 
   3b0:	b1 1d adc	r27, r1 
   3b2:	3f bf out	0x3f, r19	; 63 
   3b4:	66 27 eor	r22, r22 
   3b6:	78 2f mov	r23, r24 
   3b8:	89 2f mov	r24, r25 
   3ba:	9a 2f mov	r25, r26 
   3bc:	62 0f add	r22, r18 
   3be:	71 1d adc	r23, r1 
   3c0:	81 1d adc	r24, r1 
   3c2:	91 1d adc	r25, r1 
   3c4:	66 0f add	r22, r22 
   3c6:	77 1f adc	r23, r23 
   3c8:	88 1f adc	r24, r24 
   3ca:	99 1f adc	r25, r25 
   3cc:	66 0f add	r22, r22 
   3ce:	77 1f adc	r23, r23 
   3d0:	88 1f adc	r24, r24 
   3d2:	99 1f adc	r25, r25 
   3d4:	08 95 ret 
    
  000003d6 <delay>: 
   3d6:	cf 92 push	r12 
   3d8:	df 92 push	r13 
   3da:	ef 92 push	r14 
   3dc:	ff 92 push	r15 
   3de:	0f 93 push	r16 
   3e0:	1f 93 push	r17 
   3e2:	cf 93 push	r28 
   3e4:	df 93 push	r29 
   3e6:	00 d0 rcall	.+0 ; 0x3e8 <delay+0x12> 
   3e8:	00 d0 rcall	.+0 ; 0x3ea <delay+0x14> 
   3ea:	cd b7 in	r28, 0x3d	; 61 
   3ec:	de b7 in	r29, 0x3e	; 62 
   3ee:	3f b7 in	r19, 0x3f	; 63 
   3f0:	f8 94 cli 
   3f2:	c0 90 04 01 lds	r12, 0x0104 
   3f6:	d0 90 05 01 lds	r13, 0x0105 
   3fa:	e0 90 06 01 lds	r14, 0x0106 
   3fe:	f0 90 07 01 lds	r15, 0x0107 
   402:	26 b5 in	r18, 0x26	; 38 
   404:	a8 9b sbis	0x15, 0	; 21 
   406:	07 c0 rjmp	.+14 ; 0x416 <delay+0x40> 
   408:	2f 3f cpi	r18, 0xFF	; 255 
   40a:	29 f0 breq	.+10 ; 0x416 <delay+0x40> 
   40c:	4f ef ldi	r20, 0xFF	; 255 
   40e:	c4 1a sub	r12, r20 
   410:	d4 0a sbc	r13, r20 
   412:	e4 0a sbc	r14, r20 
   414:	f4 0a sbc	r15, r20 
   416:	3f bf out	0x3f, r19	; 63 
   418:	fe 2c mov	r15, r14 
   41a:	ed 2c mov	r14, r13 
   41c:	dc 2c mov	r13, r12 
   41e:	cc 24 eor	r12, r12 
   420:	c2 0e add	r12, r18 
   422:	d1 1c adc	r13, r1 
   424:	e1 1c adc	r14, r1 
   426:	f1 1c adc	r15, r1 
   428:	cc 0c add	r12, r12 
   42a:	dd 1c adc	r13, r13 
   42c:	ee 1c adc	r14, r14 
   42e:	ff 1c adc	r15, r15 
   430:	cc 0c add	r12, r12 
   432:	dd 1c adc	r13, r13 
   434:	ee 1c adc	r14, r14 
   436:	ff 1c adc	r15, r15 
   438:	86 01 movw	r16, r12 
   43a:	61 15 cp	r22, r1 
   43c:	71 05 cpc	r23, r1 
   43e:	81 05 cpc	r24, r1 
   440:	91 05 cpc	r25, r1 
   442:	09 f4 brne	.+2 ; 0x446 <delay+0x70> 
   444:	41 c0 rjmp	.+130 ; 0x4c8 <delay+0xf2> 
   446:	69 83 std	Y+1, r22	; 0x01 
   448:	7a 83 std	Y+2, r23	; 0x02 
   44a:	8b 83 std	Y+3, r24	; 0x03 
   44c:	9c 83 std	Y+4, r25	; 0x04 
   44e:	0e 94 b7 02 call	0x56e	; 0x56e <yield> 
   452:	3f b7 in	r19, 0x3f	; 63 
   454:	f8 94 cli 
   456:	c0 90 04 01 lds	r12, 0x0104 
   45a:	d0 90 05 01 lds	r13, 0x0105 
   45e:	e0 90 06 01 lds	r14, 0x0106 
   462:	f0 90 07 01 lds	r15, 0x0107 
   466:	26 b5 in	r18, 0x26	; 38 
   468:	69 81 ldd	r22, Y+1	; 0x01 
   46a:	7a 81 ldd	r23, Y+2	; 0x02 
   46c:	8b 81 ldd	r24, Y+3	; 0x03 
   46e:	9c 81 ldd	r25, Y+4	; 0x04 
   470:	a8 9b sbis	0x15, 0	; 21 
   472:	07 c0 rjmp	.+14 ; 0x482 <delay+0xac> 
   474:	2f 3f cpi	r18, 0xFF	; 255 
   476:	29 f0 breq	.+10 ; 0x482 <delay+0xac> 
   478:	ef ef ldi	r30, 0xFF	; 255 
   47a:	ce 1a sub	r12, r30 
   47c:	de 0a sbc	r13, r30 
   47e:	ee 0a sbc	r14, r30 
   480:	fe 0a sbc	r15, r30 
   482:	3f bf out	0x3f, r19	; 63 
   484:	fe 2c mov	r15, r14 
   486:	ed 2c mov	r14, r13 
   488:	dc 2c mov	r13, r12 
   48a:	cc 24 eor	r12, r12 
   48c:	c2 0e add	r12, r18 
   48e:	d1 1c adc	r13, r1 
   490:	e1 1c adc	r14, r1 
   492:	f1 1c adc	r15, r1 
   494:	cc 0c add	r12, r12 
   496:	dd 1c adc	r13, r13 
   498:	ee 1c adc	r14, r14 
   49a:	ff 1c adc	r15, r15 
   49c:	cc 0c add	r12, r12 
   49e:	dd 1c adc	r13, r13 
   4a0:	ee 1c adc	r14, r14 
   4a2:	ff 1c adc	r15, r15 
   4a4:	96 01 movw	r18, r12 
   4a6:	20 1b sub	r18, r16 
   4a8:	31 0b sbc	r19, r17 
   4aa:	28 3e cpi	r18, 0xE8	; 232 
   4ac:	33 40 sbci	r19, 0x03	; 3 
   4ae:	28 f2 brcs	.-118 ; 0x43a <delay+0x64> 
   4b0:	61 50 subi	r22, 0x01	; 1 
   4b2:	71 09 sbc	r23, r1 
   4b4:	81 09 sbc	r24, r1 
   4b6:	91 09 sbc	r25, r1 
   4b8:	08 51 subi	r16, 0x18	; 24 
   4ba:	1c 4f sbci	r17, 0xFC	; 252 
   4bc:	61 15 cp	r22, r1 
   4be:	71 05 cpc	r23, r1 
   4c0:	81 05 cpc	r24, r1 
   4c2:	91 05 cpc	r25, r1 
   4c4:	09 f0 breq	.+2 ; 0x4c8 <delay+0xf2> 
   4c6:	bf cf rjmp	.-130 ; 0x446 <delay+0x70> 
   4c8:	0f 90 pop	r0 
   4ca:	0f 90 pop	r0 
   4cc:	0f 90 pop	r0 
   4ce:	0f 90 pop	r0 
   4d0:	df 91 pop	r29 
   4d2:	cf 91 pop	r28 
   4d4:	1f 91 pop	r17 
   4d6:	0f 91 pop	r16 
   4d8:	ff 90 pop	r15 
   4da:	ef 90 pop	r14 
   4dc:	df 90 pop	r13 
   4de:	cf 90 pop	r12 
   4e0:	08 95 ret 
    
  000004e2 <delayMicroseconds>: 
   4e2:	82 30 cpi	r24, 0x02	; 2 
   4e4:	91 05 cpc	r25, r1 
   4e6:	38 f0 brcs	.+14 ; 0x4f6 <delayMicroseconds+0x14> 
   4e8:	88 0f add	r24, r24 
   4ea:	99 1f adc	r25, r25 
   4ec:	88 0f add	r24, r24 
   4ee:	99 1f adc	r25, r25 
   4f0:	05 97 sbiw	r24, 0x05	; 5 
   4f2:	01 97 sbiw	r24, 0x01	; 1 
   4f4:	f1 f7 brne	.-4 ; 0x4f2 <delayMicroseconds+0x10> 
   4f6:	08 95 ret 
    
  000004f8 <init>: 
   4f8:	78 94 sei 
   4fa:	84 b5 in	r24, 0x24	; 36 
   4fc:	82 60 ori	r24, 0x02	; 2 
   4fe:	84 bd out	0x24, r24	; 36 
   500:	84 b5 in	r24, 0x24	; 36 
   502:	81 60 ori	r24, 0x01	; 1 
   504:	84 bd out	0x24, r24	; 36 
   506:	85 b5 in	r24, 0x25	; 37 
   508:	82 60 ori	r24, 0x02	; 2 
   50a:	85 bd out	0x25, r24	; 37 
   50c:	85 b5 in	r24, 0x25	; 37 
   50e:	81 60 ori	r24, 0x01	; 1 
   510:	85 bd out	0x25, r24	; 37 
   512:	ee e6 ldi	r30, 0x6E	; 110 
   514:	f0 e0 ldi	r31, 0x00	; 0 
   516:	80 81 ld	r24, Z 
   518:	81 60 ori	r24, 0x01	; 1 
   51a:	80 83 st	Z, r24 
   51c:	e1 e8 ldi	r30, 0x81	; 129 
   51e:	f0 e0 ldi	r31, 0x00	; 0 
   520:	10 82 st	Z, r1 
   522:	80 81 ld	r24, Z 
   524:	82 60 ori	r24, 0x02	; 2 
   526:	80 83 st	Z, r24 
   528:	80 81 ld	r24, Z 
   52a:	81 60 ori	r24, 0x01	; 1 
   52c:	80 83 st	Z, r24 
   52e:	e0 e8 ldi	r30, 0x80	; 128 
   530:	f0 e0 ldi	r31, 0x00	; 0 
   532:	80 81 ld	r24, Z 
   534:	81 60 ori	r24, 0x01	; 1 
   536:	80 83 st	Z, r24 
   538:	e1 eb ldi	r30, 0xB1	; 177 
   53a:	f0 e0 ldi	r31, 0x00	; 0 
   53c:	80 81 ld	r24, Z 
   53e:	84 60 ori	r24, 0x04	; 4 
   540:	80 83 st	Z, r24 
   542:	e0 eb ldi	r30, 0xB0	; 176 
   544:	f0 e0 ldi	r31, 0x00	; 0 
   546:	80 81 ld	r24, Z 
   548:	81 60 ori	r24, 0x01	; 1 
   54a:	80 83 st	Z, r24 
   54c:	ea e7 ldi	r30, 0x7A	; 122 
   54e:	f0 e0 ldi	r31, 0x00	; 0 
   550:	80 81 ld	r24, Z 
   552:	84 60 ori	r24, 0x04	; 4 
   554:	80 83 st	Z, r24 
   556:	80 81 ld	r24, Z 
   558:	82 60 ori	r24, 0x02	; 2 
   55a:	80 83 st	Z, r24 
   55c:	80 81 ld	r24, Z 
   55e:	81 60 ori	r24, 0x01	; 1 
   560:	80 83 st	Z, r24 
   562:	80 81 ld	r24, Z 
   564:	80 68 ori	r24, 0x80	; 128 
   566:	80 83 st	Z, r24 
   568:	10 92 c1 00 sts	0x00C1, r1 
   56c:	08 95 ret 
    
  0000056e <yield>: 
   56e:	08 95 ret 
    
  00000570 <main>: 
   570:	0e 94 7c 02 call	0x4f8	; 0x4f8 <init> 
   574:	0e 94 70 01 call	0x2e0	; 0x2e0 <initVariant> 
   578:	0e 94 75 00 call	0xea	; 0xea <setup> 
   57c:	80 e0 ldi	r24, 0x00	; 0 
   57e:	90 e0 ldi	r25, 0x00	; 0 
   580:	89 2b or	r24, r25 
   582:	29 f0 breq	.+10 ; 0x58e <main+0x1e> 
   584:	0e 94 89 00 call	0x112	; 0x112 <loop> 
   588:	0e 94 00 00 call	0	; 0x0 <__vectors> 
   58c:	fb cf rjmp	.-10 ; 0x584 <main+0x14> 
   58e:	0e 94 89 00 call	0x112	; 0x112 <loop> 
   592:	0e 94 89 00 call	0x112	; 0x112 <loop> 
   596:	fb cf rjmp	.-10 ; 0x58e <main+0x1e> 
    
  00000598 <_exit>: 
   598:	f8 94 cli 
    
  0000059a <__stop_program>: 
   59a:	ff cf rjmp	.-2 ; 0x59a <__stop_program> 
 

view raw obj-dump hosted with ❤ by GitHub

解説

C++11

コンパイラは Arduino.app に入っている avr-gcc を使っているが -std=c++11 を指定して C++11 の機能を有効にしている (constexpr 関数) なので素の Arduino.app からだとコンパイルできない。

Arduino ビルトイン関数の再実装

Arduino 側で portOutputRegister digitalPinToBitMask digitalPinToPort といった関数が定義されており、これらは PROGMEM からテーブルをひいてくる実装になっているので、まずこれをコンパイル時にできるように constexpr 関数で再実装した。

C++14 ならもっと簡単に書けるはずなんだけど、C++11 相当だと関数本体に return 以外書けないのでキモい実装になっている。

digitalWriteMulti

ここがキモで、まず digitalWriteMulti でうけて、digitalWriteMulti_ で再帰的に処理している。digitalWriteMulti_ の最初の3引数は、持ってまわっている状態で、残りは元の digitalWriteMulti に渡された引数。

C++ のテンプレートメタプログラミングではこのようにパターンマッチでしか可変長引数を扱えないみたい。だけど思ったより綺麗に実装できた気がする。

WRITE_MULTI() マクロ

これはプリプロセッサマクロで単に置換している。テンプレート引数として渡すのが気持ち悪かったので(慣れかもしれない)マクロでラップしている。

その他

C++ はほとんど書いたことがないので、きっともっといい方法がありそうだと思う。特にテンプレートメタプログラミングで可変長引数を処理するとき、状態を全てテンプレート引数の頭にフラットに渡しているのがダサい。うまくコンパイル時だけ使えるコンテナみたいなのを持ちまわしていければよかったが、おもいつかなかった。

pinMode にも応用できると思うが pinMode は PORTx もいじるのでとりあえず省略した。

大きなメリット

同じようなことはテンプレートを使わない場合(素のCとか)だとまずできない。

特に「指定しなかった部分のビットはかえない」を実現しようとすると、どうしてもビットマスクと実際に設定するビット値の2つを扱わないといけないので、かなりコードが煩雑になる。テンプレート化することで表面上の可読性がかなり上がる (テンプレート部分はアレだけど)

そしてコンパイル時にチェックができる点はおおきい。マイコンはどうしてもフィードバックがすくないので、実行時エラーというのは実際気付くのが難しい。

速度的にも当然メリットがある。これの場合はコンパイルしたあとは素で書く場合と完全に同じバイナリになる。

000000ea <setup>:
; PORTD = (PORTD & 0b11110000) | (0b1010);
  ea:	8b b1       	in	r24, 0x0b	; 11
  ec:	80 7f       	andi	r24, 0xF0	; 240
  ee:	8a 60       	ori	r24, 0x0A	; 10
  f0:	8b b9       	out	0x0b, r24	; 11
; asm volatile ("nop");	// marker
  f2:	00 00       	nop
; WRITE_MULTI(...)
  f4:	8b b1       	in	r24, 0x0b	; 11
  f6:	80 7f       	andi	r24, 0xF0	; 240
  f8:	8a 60       	ori	r24, 0x0A	; 10
  fa:	8b b9       	out	0x0b, r24	; 11

素の digitalWrite の場合

; digitalWrite(0, LOW);
 10a:	60 e0       	ldi	r22, 0x00	; 0
 10c:	80 e0       	ldi	r24, 0x00	; 0
 10e:	0c 94 c8 00 	jmp	0x190	; 0x190 <digitalWrite>

で関数コールして

00000190 <digitalWrite>:
 190:	90 e0       	ldi	r25, 0x00	; 0
 192:	fc 01       	movw	r30, r24
 194:	e8 59       	subi	r30, 0x98	; 152
 196:	ff 4f       	sbci	r31, 0xFF	; 255
 198:	24 91       	lpm	r18, Z
 19a:	fc 01       	movw	r30, r24
 19c:	e4 58       	subi	r30, 0x84	; 132
 19e:	ff 4f       	sbci	r31, 0xFF	; 255
 1a0:	34 91       	lpm	r19, Z
 1a2:	fc 01       	movw	r30, r24
 1a4:	e0 57       	subi	r30, 0x70	; 112
 1a6:	ff 4f       	sbci	r31, 0xFF	; 255
 1a8:	84 91       	lpm	r24, Z
 1aa:	88 23       	and	r24, r24
 1ac:	99 f0       	breq	.+38     	; 0x1d4 <digitalWrite+0x44>
 1ae:	21 11       	cpse	r18, r1
 1b0:	16 c0       	rjmp	.+44     	; 0x1de <digitalWrite+0x4e>
 1b2:	e8 2f       	mov	r30, r24
 1b4:	f0 e0       	ldi	r31, 0x00	; 0
 1b6:	ee 0f       	add	r30, r30
 1b8:	ff 1f       	adc	r31, r31
 1ba:	e2 55       	subi	r30, 0x52	; 82
 1bc:	ff 4f       	sbci	r31, 0xFF	; 255
 1be:	a5 91       	lpm	r26, Z+
 1c0:	b4 91       	lpm	r27, Z
 1c2:	8f b7       	in	r24, 0x3f	; 63
 1c4:	f8 94       	cli
 1c6:	9c 91       	ld	r25, X
 1c8:	61 11       	cpse	r22, r1
 1ca:	05 c0       	rjmp	.+10     	; 0x1d6 <digitalWrite+0x46>
 1cc:	30 95       	com	r19
 1ce:	93 23       	and	r25, r19
 1d0:	9c 93       	st	X, r25
 1d2:	8f bf       	out	0x3f, r24	; 63
 1d4:	08 95       	ret
 1d6:	93 2b       	or	r25, r19
 1d8:	9c 93       	st	X, r25
 1da:	8f bf       	out	0x3f, r24	; 63
 1dc:	fb cf       	rjmp	.-10     	; 0x1d4 <digitalWrite+0x44>
 1de:	23 30       	cpi	r18, 0x03	; 3
 1e0:	29 f1       	breq	.+74     	; 0x22c <digitalWrite+0x9c>
 1e2:	60 f0       	brcs	.+24     	; 0x1fc <digitalWrite+0x6c>
 1e4:	27 30       	cpi	r18, 0x07	; 7
 1e6:	e1 f0       	breq	.+56     	; 0x220 <digitalWrite+0x90>
 1e8:	28 30       	cpi	r18, 0x08	; 8
 1ea:	a1 f0       	breq	.+40     	; 0x214 <digitalWrite+0x84>
 1ec:	24 30       	cpi	r18, 0x04	; 4
 1ee:	09 f7       	brne	.-62     	; 0x1b2 <digitalWrite+0x22>
 1f0:	90 91 80 00 	lds	r25, 0x0080
 1f4:	9f 7d       	andi	r25, 0xDF	; 223
 1f6:	90 93 80 00 	sts	0x0080, r25
 1fa:	db cf       	rjmp	.-74     	; 0x1b2 <digitalWrite+0x22>
 1fc:	21 30       	cpi	r18, 0x01	; 1
 1fe:	31 f0       	breq	.+12     	; 0x20c <digitalWrite+0x7c>
 200:	22 30       	cpi	r18, 0x02	; 2
 202:	b9 f6       	brne	.-82     	; 0x1b2 <digitalWrite+0x22>
 204:	94 b5       	in	r25, 0x24	; 36
 206:	9f 7d       	andi	r25, 0xDF	; 223
 208:	94 bd       	out	0x24, r25	; 36
 20a:	d3 cf       	rjmp	.-90     	; 0x1b2 <digitalWrite+0x22>
 20c:	94 b5       	in	r25, 0x24	; 36
 20e:	9f 77       	andi	r25, 0x7F	; 127
 210:	94 bd       	out	0x24, r25	; 36
 212:	cf cf       	rjmp	.-98     	; 0x1b2 <digitalWrite+0x22>
 214:	90 91 b0 00 	lds	r25, 0x00B0
 218:	9f 7d       	andi	r25, 0xDF	; 223
 21a:	90 93 b0 00 	sts	0x00B0, r25
 21e:	c9 cf       	rjmp	.-110    	; 0x1b2 <digitalWrite+0x22>
 220:	90 91 b0 00 	lds	r25, 0x00B0
 224:	9f 77       	andi	r25, 0x7F	; 127
 226:	90 93 b0 00 	sts	0x00B0, r25
 22a:	c3 cf       	rjmp	.-122    	; 0x1b2 <digitalWrite+0x22>
 22c:	90 91 80 00 	lds	r25, 0x0080
 230:	9f 77       	andi	r25, 0x7F	; 127
 232:	90 93 80 00 	sts	0x0080, r25
 236:	bd cf       	rjmp	.-134    	; 0x1b2 <digitalWrite+0x22>

となっていて、1bit 書くだけでかなり大層なことをしていることがわかる。

	//#!ano build -f="-std=c++11 -Os" && /Applications/Arduino.app/Contents/Java/hardware/tools/avr/bin/avr-objdump -d .build_ano/uno/firmware.elf ;:
	#include <Arduino.h>

	// ARDUINO_MAIN で ifdef されているので外からみえない
	constexpr uint8_t PB = 2;
	constexpr uint8_t PC = 3;
	constexpr uint8_t PD = 4;

	// template version of Arduino builtin functions

	constexpr uint16_t port_to_mode[] = {
	NOT_A_PORT,
	NOT_A_PORT,
	(uint16_t) &DDRB,
	(uint16_t) &DDRC,
	(uint16_t) &DDRD,
	};

	constexpr uint16_t port_to_output[] = {
	NOT_A_PORT,
	NOT_A_PORT,
	(uint16_t) &PORTB,
	(uint16_t) &PORTC,
	(uint16_t) &PORTD,
	};

	constexpr uint16_t port_to_input[] = {
	NOT_A_PORT,
	NOT_A_PORT,
	(uint16_t) &PINB,
	(uint16_t) &PINC,
	(uint16_t) &PIND,
	};

	constexpr uint8_t digital_pin_to_port[] = {
	PD, /* 0 */
	PD,
	PD,
	PD,
	PD,
	PD,
	PD,
	PD,
	PB, /* 8 */
	PB,
	PB,
	PB,
	PB,
	PB,
	PC, /* 14 */
	PC,
	PC,
	PC,
	PC,
	PC,
	};

	constexpr uint8_t digital_pin_to_bit_mask[] = {
	_BV(0), /* 0, port D */
	_BV(1),
	_BV(2),
	_BV(3),
	_BV(4),
	_BV(5),
	_BV(6),
	_BV(7),
	_BV(0), /* 8, port B */
	_BV(1),
	_BV(2),
	_BV(3),
	_BV(4),
	_BV(5),
	_BV(0), /* 14, port C */
	_BV(1),
	_BV(2),
	_BV(3),
	_BV(4),
	_BV(5),
	};

	template<uint8_t port>
	constexpr volatile uint8_t* portModeRegisterX() {
	static_assert(port < sizeof(port_to_mode), "invalid port number");
	static_assert(port_to_mode[port] != NOT_A_PORT, "invalid port number");
	return (volatile uint8_t*)port_to_mode[port];
	}

	template<uint8_t port>
	constexpr volatile uint8_t* portOutputRegisterX() {
	static_assert(port < sizeof(port_to_output), "invalid port number");
	static_assert(port_to_output[port] != NOT_A_PORT, "invalid port number");
	return (volatile uint8_t*)port_to_output[port];
	}

	template<uint8_t port>
	constexpr volatile uint8_t* portInputRegisterX() {
	static_assert(port < sizeof(port_to_input), "invalid port number");
	static_assert(port_to_input[port] != NOT_A_PORT, "invalid port number");
	return (volatile uint8_t*)port_to_input[port];
	}

	template <uint16_t pin>
	constexpr uint8_t digitalPinToBitMaskX() {
	static_assert(pin < sizeof(digital_pin_to_bit_mask), "invalid pin number");
	return digital_pin_to_bit_mask[pin];
	};


	template <uint16_t pin>
	constexpr uint8_t digitalPinToPortX() {
	static_assert(pin < sizeof(digital_pin_to_port), "invalid pin number");
	return digital_pin_to_port[pin];
	};

	// multiple bit set function with cheking port consistency

	template<uint8_t port, uint8_t mask, uint8_t vals>
	constexpr void digitalWriteMulti_() {
	volatile uint8_t *out = portOutputRegisterX<port>();
	out = (out & ~mask) \| vals;
	}

	template<uint8_t port, uint8_t mask, uint8_t vals, uint16_t pin, uint8_t val, uint16_t... Rest>
	constexpr void digitalWriteMulti_() {
	static_assert(digitalPinToPortX<pin>() == port, "all port must be same");
	constexpr uint8_t bit = digitalPinToBitMaskX<pin>();
	digitalWriteMulti_<
	port,
	mask \| bit,
	vals \| (val ? bit : 0),
	Rest...
	>();
	}

	template<uint16_t pin, uint8_t val, uint16_t... Rest>
	constexpr void digitalWriteMulti() {
	constexpr uint8_t port = digitalPinToPortX<pin>();
	return digitalWriteMulti_<
	port,
	0,
	0,

	pin,
	val,
	Rest...
	>();
	}

	// hide template magic from surface
	#define WRITE_MULTI(...) digitalWriteMulti<__VA_ARGS__>()

	void setup() {
	PORTD = (PORTD & 0b11110000) \| (0b1010);

	asm volatile ("nop"); // marker

	// same as above
	WRITE_MULTI(
	0, LOW,
	1, HIGH,
	2, LOW,
	3, HIGH
	);

	asm volatile ("nop");

	// another port
	WRITE_MULTI(
	8, LOW,
	9, HIGH,
	10, LOW,
	11, HIGH
	);

	asm volatile ("nop");

	/** following is invalid
	* static_assert(digitalPinToPortX<pin>() == port, "all port must be same");
	* pin=0 -> PORTB, pin=8 -> PORTC error
	digitalWriteMulti<
	0, LOW,
	1, HIGH,
	2, LOW,
	8, HIGH
	>();
	*/

	asm volatile ("nop");
	/** builtin dynamic method
	* this is very slow
	*/
	digitalWrite(0, LOW);
	}

	void loop() {
	}


	.build_ano/uno/firmware.elf: file format elf32-avr


	Disassembly of section .text:

	00000000 <__vectors>:
	0: 0c 94 61 00 jmp 0xc2 ; 0xc2 <__ctors_end>
	4: 0c 94 73 00 jmp 0xe6 ; 0xe6 <__bad_interrupt>
	8: 0c 94 73 00 jmp 0xe6 ; 0xe6 <__bad_interrupt>
	c: 0c 94 73 00 jmp 0xe6 ; 0xe6 <__bad_interrupt>
	10: 0c 94 73 00 jmp 0xe6 ; 0xe6 <__bad_interrupt>
	14: 0c 94 73 00 jmp 0xe6 ; 0xe6 <__bad_interrupt>
	18: 0c 94 73 00 jmp 0xe6 ; 0xe6 <__bad_interrupt>
	1c: 0c 94 73 00 jmp 0xe6 ; 0xe6 <__bad_interrupt>
	20: 0c 94 73 00 jmp 0xe6 ; 0xe6 <__bad_interrupt>
	24: 0c 94 73 00 jmp 0xe6 ; 0xe6 <__bad_interrupt>
	28: 0c 94 73 00 jmp 0xe6 ; 0xe6 <__bad_interrupt>
	2c: 0c 94 73 00 jmp 0xe6 ; 0xe6 <__bad_interrupt>
	30: 0c 94 73 00 jmp 0xe6 ; 0xe6 <__bad_interrupt>
	34: 0c 94 73 00 jmp 0xe6 ; 0xe6 <__bad_interrupt>
	38: 0c 94 73 00 jmp 0xe6 ; 0xe6 <__bad_interrupt>
	3c: 0c 94 73 00 jmp 0xe6 ; 0xe6 <__bad_interrupt>
	40: 0c 94 71 01 jmp 0x2e2 ; 0x2e2 <__vector_16>
	44: 0c 94 73 00 jmp 0xe6 ; 0xe6 <__bad_interrupt>
	48: 0c 94 73 00 jmp 0xe6 ; 0xe6 <__bad_interrupt>
	4c: 0c 94 73 00 jmp 0xe6 ; 0xe6 <__bad_interrupt>
	50: 0c 94 73 00 jmp 0xe6 ; 0xe6 <__bad_interrupt>
	54: 0c 94 73 00 jmp 0xe6 ; 0xe6 <__bad_interrupt>
	58: 0c 94 73 00 jmp 0xe6 ; 0xe6 <__bad_interrupt>
	5c: 0c 94 73 00 jmp 0xe6 ; 0xe6 <__bad_interrupt>
	60: 0c 94 73 00 jmp 0xe6 ; 0xe6 <__bad_interrupt>
	64: 0c 94 73 00 jmp 0xe6 ; 0xe6 <__bad_interrupt>

	00000068 <__trampolines_end>:
	68: 00 00 nop
	6a: 00 08 sbc r0, r0
	6c: 00 02 muls r16, r16
	6e: 01 00 .word 0x0001 ; ????
	70: 00 03 mulsu r16, r16
	72: 04 07 cpc r16, r20
	...

	0000007c <digital_pin_to_bit_mask_PGM>:
	7c: 01 02 04 08 10 20 40 80 01 02 04 08 10 20 01 02 ..... @...... ..
	8c: 04 08 10 20 ...

	00000090 <digital_pin_to_port_PGM>:
	90: 04 04 04 04 04 04 04 04 02 02 02 02 02 02 03 03 ................
	a0: 03 03 03 03 ....

	000000a4 <port_to_input_PGM>:
	a4: 00 00 00 00 23 00 26 00 29 00 ....#.&.).

	000000ae <port_to_output_PGM>:
	ae: 00 00 00 00 25 00 28 00 2b 00 ....%.(.+.

	000000b8 <port_to_mode_PGM>:
	b8: 00 00 00 00 24 00 27 00 2a 00 ....$.'.*.

	000000c2 <__ctors_end>:
	c2: 11 24 eor r1, r1
	c4: 1f be out 0x3f, r1 ; 63
	c6: cf ef ldi r28, 0xFF ; 255
	c8: d8 e0 ldi r29, 0x08 ; 8
	ca: de bf out 0x3e, r29 ; 62
	cc: cd bf out 0x3d, r28 ; 61

	000000ce <__do_clear_bss>:
	ce: 21 e0 ldi r18, 0x01 ; 1
	d0: a0 e0 ldi r26, 0x00 ; 0
	d2: b1 e0 ldi r27, 0x01 ; 1
	d4: 01 c0 rjmp .+2 ; 0xd8 <.do_clear_bss_start>

	000000d6 <.do_clear_bss_loop>:
	d6: 1d 92 st X+, r1

	000000d8 <.do_clear_bss_start>:
	d8: a9 30 cpi r26, 0x09 ; 9
	da: b2 07 cpc r27, r18
	dc: e1 f7 brne .-8 ; 0xd6 <.do_clear_bss_loop>
	de: 0e 94 b8 02 call 0x570 ; 0x570 <main>
	e2: 0c 94 cc 02 jmp 0x598 ; 0x598 <_exit>

	000000e6 <__bad_interrupt>:
	e6: 0c 94 00 00 jmp 0 ; 0x0 <__vectors>

	000000ea <setup>:
	ea: 8b b1 in r24, 0x0b ; 11
	ec: 80 7f andi r24, 0xF0 ; 240
	ee: 8a 60 ori r24, 0x0A ; 10
	f0: 8b b9 out 0x0b, r24 ; 11
	f2: 00 00 nop
	f4: 8b b1 in r24, 0x0b ; 11
	f6: 80 7f andi r24, 0xF0 ; 240
	f8: 8a 60 ori r24, 0x0A ; 10
	fa: 8b b9 out 0x0b, r24 ; 11
	fc: 00 00 nop
	fe: 85 b1 in r24, 0x05 ; 5
	100: 80 7f andi r24, 0xF0 ; 240
	102: 8a 60 ori r24, 0x0A ; 10
	104: 85 b9 out 0x05, r24 ; 5
	106: 00 00 nop
	108: 00 00 nop
	10a: 60 e0 ldi r22, 0x00 ; 0
	10c: 80 e0 ldi r24, 0x00 ; 0
	10e: 0c 94 c8 00 jmp 0x190 ; 0x190 <digitalWrite>

	00000112 <loop>:
	112: 08 95 ret

	00000114 <pinMode>:
	114: cf 93 push r28
	116: df 93 push r29
	118: 90 e0 ldi r25, 0x00 ; 0
	11a: fc 01 movw r30, r24
	11c: e4 58 subi r30, 0x84 ; 132
	11e: ff 4f sbci r31, 0xFF ; 255
	120: 24 91 lpm r18, Z
	122: fc 01 movw r30, r24
	124: e0 57 subi r30, 0x70 ; 112
	126: ff 4f sbci r31, 0xFF ; 255
	128: 84 91 lpm r24, Z
	12a: 88 23 and r24, r24
	12c: b9 f0 breq .+46 ; 0x15c <pinMode+0x48>
	12e: 90 e0 ldi r25, 0x00 ; 0
	130: 88 0f add r24, r24
	132: 99 1f adc r25, r25
	134: fc 01 movw r30, r24
	136: e8 54 subi r30, 0x48 ; 72
	138: ff 4f sbci r31, 0xFF ; 255
	13a: a5 91 lpm r26, Z+
	13c: b4 91 lpm r27, Z
	13e: 82 55 subi r24, 0x52 ; 82
	140: 9f 4f sbci r25, 0xFF ; 255
	142: fc 01 movw r30, r24
	144: c5 91 lpm r28, Z+
	146: d4 91 lpm r29, Z
	148: 9f b7 in r25, 0x3f ; 63
	14a: 66 23 and r22, r22
	14c: 51 f0 breq .+20 ; 0x162 <pinMode+0x4e>
	14e: 62 30 cpi r22, 0x02 ; 2
	150: a1 f0 breq .+40 ; 0x17a <pinMode+0x66>
	152: f8 94 cli
	154: 8c 91 ld r24, X
	156: 82 2b or r24, r18
	158: 8c 93 st X, r24
	15a: 9f bf out 0x3f, r25 ; 63
	15c: df 91 pop r29
	15e: cf 91 pop r28
	160: 08 95 ret
	162: f8 94 cli
	164: 8c 91 ld r24, X
	166: 20 95 com r18
	168: 82 23 and r24, r18
	16a: 8c 93 st X, r24
	16c: 88 81 ld r24, Y
	16e: 82 23 and r24, r18
	170: 88 83 st Y, r24
	172: 9f bf out 0x3f, r25 ; 63
	174: df 91 pop r29
	176: cf 91 pop r28
	178: 08 95 ret
	17a: f8 94 cli
	17c: 8c 91 ld r24, X
	17e: 32 2f mov r19, r18
	180: 30 95 com r19
	182: 83 23 and r24, r19
	184: 8c 93 st X, r24
	186: 88 81 ld r24, Y
	188: 82 2b or r24, r18
	18a: 88 83 st Y, r24
	18c: 9f bf out 0x3f, r25 ; 63
	18e: e6 cf rjmp .-52 ; 0x15c <pinMode+0x48>

	00000190 <digitalWrite>:
	190: 90 e0 ldi r25, 0x00 ; 0
	192: fc 01 movw r30, r24
	194: e8 59 subi r30, 0x98 ; 152
	196: ff 4f sbci r31, 0xFF ; 255
	198: 24 91 lpm r18, Z
	19a: fc 01 movw r30, r24
	19c: e4 58 subi r30, 0x84 ; 132
	19e: ff 4f sbci r31, 0xFF ; 255
	1a0: 34 91 lpm r19, Z
	1a2: fc 01 movw r30, r24
	1a4: e0 57 subi r30, 0x70 ; 112
	1a6: ff 4f sbci r31, 0xFF ; 255
	1a8: 84 91 lpm r24, Z
	1aa: 88 23 and r24, r24
	1ac: 99 f0 breq .+38 ; 0x1d4 <digitalWrite+0x44>
	1ae: 21 11 cpse r18, r1
	1b0: 16 c0 rjmp .+44 ; 0x1de <digitalWrite+0x4e>
	1b2: e8 2f mov r30, r24
	1b4: f0 e0 ldi r31, 0x00 ; 0
	1b6: ee 0f add r30, r30
	1b8: ff 1f adc r31, r31
	1ba: e2 55 subi r30, 0x52 ; 82
	1bc: ff 4f sbci r31, 0xFF ; 255
	1be: a5 91 lpm r26, Z+
	1c0: b4 91 lpm r27, Z
	1c2: 8f b7 in r24, 0x3f ; 63
	1c4: f8 94 cli
	1c6: 9c 91 ld r25, X
	1c8: 61 11 cpse r22, r1
	1ca: 05 c0 rjmp .+10 ; 0x1d6 <digitalWrite+0x46>
	1cc: 30 95 com r19
	1ce: 93 23 and r25, r19
	1d0: 9c 93 st X, r25
	1d2: 8f bf out 0x3f, r24 ; 63
	1d4: 08 95 ret
	1d6: 93 2b or r25, r19
	1d8: 9c 93 st X, r25
	1da: 8f bf out 0x3f, r24 ; 63
	1dc: fb cf rjmp .-10 ; 0x1d4 <digitalWrite+0x44>
	1de: 23 30 cpi r18, 0x03 ; 3
	1e0: 29 f1 breq .+74 ; 0x22c <digitalWrite+0x9c>
	1e2: 60 f0 brcs .+24 ; 0x1fc <digitalWrite+0x6c>
	1e4: 27 30 cpi r18, 0x07 ; 7
	1e6: e1 f0 breq .+56 ; 0x220 <digitalWrite+0x90>
	1e8: 28 30 cpi r18, 0x08 ; 8
	1ea: a1 f0 breq .+40 ; 0x214 <digitalWrite+0x84>
	1ec: 24 30 cpi r18, 0x04 ; 4
	1ee: 09 f7 brne .-62 ; 0x1b2 <digitalWrite+0x22>
	1f0: 90 91 80 00 lds r25, 0x0080
	1f4: 9f 7d andi r25, 0xDF ; 223
	1f6: 90 93 80 00 sts 0x0080, r25
	1fa: db cf rjmp .-74 ; 0x1b2 <digitalWrite+0x22>
	1fc: 21 30 cpi r18, 0x01 ; 1
	1fe: 31 f0 breq .+12 ; 0x20c <digitalWrite+0x7c>
	200: 22 30 cpi r18, 0x02 ; 2
	202: b9 f6 brne .-82 ; 0x1b2 <digitalWrite+0x22>
	204: 94 b5 in r25, 0x24 ; 36
	206: 9f 7d andi r25, 0xDF ; 223
	208: 94 bd out 0x24, r25 ; 36
	20a: d3 cf rjmp .-90 ; 0x1b2 <digitalWrite+0x22>
	20c: 94 b5 in r25, 0x24 ; 36
	20e: 9f 77 andi r25, 0x7F ; 127
	210: 94 bd out 0x24, r25 ; 36
	212: cf cf rjmp .-98 ; 0x1b2 <digitalWrite+0x22>
	214: 90 91 b0 00 lds r25, 0x00B0
	218: 9f 7d andi r25, 0xDF ; 223
	21a: 90 93 b0 00 sts 0x00B0, r25
	21e: c9 cf rjmp .-110 ; 0x1b2 <digitalWrite+0x22>
	220: 90 91 b0 00 lds r25, 0x00B0
	224: 9f 77 andi r25, 0x7F ; 127
	226: 90 93 b0 00 sts 0x00B0, r25
	22a: c3 cf rjmp .-122 ; 0x1b2 <digitalWrite+0x22>
	22c: 90 91 80 00 lds r25, 0x0080
	230: 9f 77 andi r25, 0x7F ; 127
	232: 90 93 80 00 sts 0x0080, r25
	236: bd cf rjmp .-134 ; 0x1b2 <digitalWrite+0x22>

	00000238 <digitalRead>:
	238: 90 e0 ldi r25, 0x00 ; 0
	23a: fc 01 movw r30, r24
	23c: e8 59 subi r30, 0x98 ; 152
	23e: ff 4f sbci r31, 0xFF ; 255
	240: 24 91 lpm r18, Z
	242: fc 01 movw r30, r24
	244: e4 58 subi r30, 0x84 ; 132
	246: ff 4f sbci r31, 0xFF ; 255
	248: 34 91 lpm r19, Z
	24a: fc 01 movw r30, r24
	24c: e0 57 subi r30, 0x70 ; 112
	24e: ff 4f sbci r31, 0xFF ; 255
	250: 84 91 lpm r24, Z
	252: 88 23 and r24, r24
	254: 91 f0 breq .+36 ; 0x27a <digitalRead+0x42>
	256: 21 11 cpse r18, r1
	258: 13 c0 rjmp .+38 ; 0x280 <digitalRead+0x48>
	25a: e8 2f mov r30, r24
	25c: f0 e0 ldi r31, 0x00 ; 0
	25e: ee 0f add r30, r30
	260: ff 1f adc r31, r31
	262: ec 55 subi r30, 0x5C ; 92
	264: ff 4f sbci r31, 0xFF ; 255
	266: a5 91 lpm r26, Z+
	268: b4 91 lpm r27, Z
	26a: 2c 91 ld r18, X
	26c: 23 23 and r18, r19
	26e: 81 e0 ldi r24, 0x01 ; 1
	270: 90 e0 ldi r25, 0x00 ; 0
	272: 09 f0 breq .+2 ; 0x276 <digitalRead+0x3e>
	274: 08 95 ret
	276: 80 e0 ldi r24, 0x00 ; 0
	278: 08 95 ret
	27a: 80 e0 ldi r24, 0x00 ; 0
	27c: 90 e0 ldi r25, 0x00 ; 0
	27e: 08 95 ret
	280: 23 30 cpi r18, 0x03 ; 3
	282: 29 f1 breq .+74 ; 0x2ce <digitalRead+0x96>
	284: 60 f0 brcs .+24 ; 0x29e <digitalRead+0x66>
	286: 27 30 cpi r18, 0x07 ; 7
	288: e1 f0 breq .+56 ; 0x2c2 <digitalRead+0x8a>
	28a: 28 30 cpi r18, 0x08 ; 8
	28c: a1 f0 breq .+40 ; 0x2b6 <digitalRead+0x7e>
	28e: 24 30 cpi r18, 0x04 ; 4
	290: 21 f7 brne .-56 ; 0x25a <digitalRead+0x22>
	292: 90 91 80 00 lds r25, 0x0080
	296: 9f 7d andi r25, 0xDF ; 223
	298: 90 93 80 00 sts 0x0080, r25
	29c: de cf rjmp .-68 ; 0x25a <digitalRead+0x22>
	29e: 21 30 cpi r18, 0x01 ; 1
	2a0: 31 f0 breq .+12 ; 0x2ae <digitalRead+0x76>
	2a2: 22 30 cpi r18, 0x02 ; 2
	2a4: d1 f6 brne .-76 ; 0x25a <digitalRead+0x22>
	2a6: 94 b5 in r25, 0x24 ; 36
	2a8: 9f 7d andi r25, 0xDF ; 223
	2aa: 94 bd out 0x24, r25 ; 36
	2ac: d6 cf rjmp .-84 ; 0x25a <digitalRead+0x22>
	2ae: 94 b5 in r25, 0x24 ; 36
	2b0: 9f 77 andi r25, 0x7F ; 127
	2b2: 94 bd out 0x24, r25 ; 36
	2b4: d2 cf rjmp .-92 ; 0x25a <digitalRead+0x22>
	2b6: 90 91 b0 00 lds r25, 0x00B0
	2ba: 9f 7d andi r25, 0xDF ; 223
	2bc: 90 93 b0 00 sts 0x00B0, r25
	2c0: cc cf rjmp .-104 ; 0x25a <digitalRead+0x22>
	2c2: 90 91 b0 00 lds r25, 0x00B0
	2c6: 9f 77 andi r25, 0x7F ; 127
	2c8: 90 93 b0 00 sts 0x00B0, r25
	2cc: c6 cf rjmp .-116 ; 0x25a <digitalRead+0x22>
	2ce: 90 91 80 00 lds r25, 0x0080
	2d2: 9f 77 andi r25, 0x7F ; 127
	2d4: 90 93 80 00 sts 0x0080, r25
	2d8: c0 cf rjmp .-128 ; 0x25a <digitalRead+0x22>

	000002da <atexit>:
	2da: 80 e0 ldi r24, 0x00 ; 0
	2dc: 90 e0 ldi r25, 0x00 ; 0
	2de: 08 95 ret

	000002e0 <initVariant>:
	2e0: 08 95 ret

	000002e2 <__vector_16>:
	2e2: 1f 92 push r1
	2e4: 0f 92 push r0
	2e6: 0f b6 in r0, 0x3f ; 63
	2e8: 0f 92 push r0
	2ea: 11 24 eor r1, r1
	2ec: 2f 93 push r18
	2ee: 3f 93 push r19
	2f0: 8f 93 push r24
	2f2: 9f 93 push r25
	2f4: af 93 push r26
	2f6: bf 93 push r27
	2f8: 80 91 00 01 lds r24, 0x0100
	2fc: 90 91 01 01 lds r25, 0x0101
	300: a0 91 02 01 lds r26, 0x0102
	304: b0 91 03 01 lds r27, 0x0103
	308: 30 91 08 01 lds r19, 0x0108
	30c: 23 e0 ldi r18, 0x03 ; 3
	30e: 23 0f add r18, r19
	310: 2d 37 cpi r18, 0x7D ; 125
	312: 68 f1 brcs .+90 ; 0x36e <__vector_16+0x8c>
	314: 26 e8 ldi r18, 0x86 ; 134
	316: 23 0f add r18, r19
	318: 02 96 adiw r24, 0x02 ; 2
	31a: a1 1d adc r26, r1
	31c: b1 1d adc r27, r1
	31e: 20 93 08 01 sts 0x0108, r18
	322: 80 93 00 01 sts 0x0100, r24
	326: 90 93 01 01 sts 0x0101, r25
	32a: a0 93 02 01 sts 0x0102, r26
	32e: b0 93 03 01 sts 0x0103, r27
	332: 80 91 04 01 lds r24, 0x0104
	336: 90 91 05 01 lds r25, 0x0105
	33a: a0 91 06 01 lds r26, 0x0106
	33e: b0 91 07 01 lds r27, 0x0107
	342: 01 96 adiw r24, 0x01 ; 1
	344: a1 1d adc r26, r1
	346: b1 1d adc r27, r1
	348: 80 93 04 01 sts 0x0104, r24
	34c: 90 93 05 01 sts 0x0105, r25
	350: a0 93 06 01 sts 0x0106, r26
	354: b0 93 07 01 sts 0x0107, r27
	358: bf 91 pop r27
	35a: af 91 pop r26
	35c: 9f 91 pop r25
	35e: 8f 91 pop r24
	360: 3f 91 pop r19
	362: 2f 91 pop r18
	364: 0f 90 pop r0
	366: 0f be out 0x3f, r0 ; 63
	368: 0f 90 pop r0
	36a: 1f 90 pop r1
	36c: 18 95 reti
	36e: 01 96 adiw r24, 0x01 ; 1
	370: a1 1d adc r26, r1
	372: b1 1d adc r27, r1
	374: d4 cf rjmp .-88 ; 0x31e <__vector_16+0x3c>

	00000376 <millis>:
	376: 2f b7 in r18, 0x3f ; 63
	378: f8 94 cli
	37a: 60 91 00 01 lds r22, 0x0100
	37e: 70 91 01 01 lds r23, 0x0101
	382: 80 91 02 01 lds r24, 0x0102
	386: 90 91 03 01 lds r25, 0x0103
	38a: 2f bf out 0x3f, r18 ; 63
	38c: 08 95 ret

	0000038e <micros>:
	38e: 3f b7 in r19, 0x3f ; 63
	390: f8 94 cli
	392: 80 91 04 01 lds r24, 0x0104
	396: 90 91 05 01 lds r25, 0x0105
	39a: a0 91 06 01 lds r26, 0x0106
	39e: b0 91 07 01 lds r27, 0x0107
	3a2: 26 b5 in r18, 0x26 ; 38
	3a4: a8 9b sbis 0x15, 0 ; 21
	3a6: 05 c0 rjmp .+10 ; 0x3b2 <micros+0x24>
	3a8: 2f 3f cpi r18, 0xFF ; 255
	3aa: 19 f0 breq .+6 ; 0x3b2 <micros+0x24>
	3ac: 01 96 adiw r24, 0x01 ; 1
	3ae: a1 1d adc r26, r1
	3b0: b1 1d adc r27, r1
	3b2: 3f bf out 0x3f, r19 ; 63
	3b4: 66 27 eor r22, r22
	3b6: 78 2f mov r23, r24
	3b8: 89 2f mov r24, r25
	3ba: 9a 2f mov r25, r26
	3bc: 62 0f add r22, r18
	3be: 71 1d adc r23, r1
	3c0: 81 1d adc r24, r1
	3c2: 91 1d adc r25, r1
	3c4: 66 0f add r22, r22
	3c6: 77 1f adc r23, r23
	3c8: 88 1f adc r24, r24
	3ca: 99 1f adc r25, r25
	3cc: 66 0f add r22, r22
	3ce: 77 1f adc r23, r23
	3d0: 88 1f adc r24, r24
	3d2: 99 1f adc r25, r25
	3d4: 08 95 ret

	000003d6 <delay>:
	3d6: cf 92 push r12
	3d8: df 92 push r13
	3da: ef 92 push r14
	3dc: ff 92 push r15
	3de: 0f 93 push r16
	3e0: 1f 93 push r17
	3e2: cf 93 push r28
	3e4: df 93 push r29
	3e6: 00 d0 rcall .+0 ; 0x3e8 <delay+0x12>
	3e8: 00 d0 rcall .+0 ; 0x3ea <delay+0x14>
	3ea: cd b7 in r28, 0x3d ; 61
	3ec: de b7 in r29, 0x3e ; 62
	3ee: 3f b7 in r19, 0x3f ; 63
	3f0: f8 94 cli
	3f2: c0 90 04 01 lds r12, 0x0104
	3f6: d0 90 05 01 lds r13, 0x0105
	3fa: e0 90 06 01 lds r14, 0x0106
	3fe: f0 90 07 01 lds r15, 0x0107
	402: 26 b5 in r18, 0x26 ; 38
	404: a8 9b sbis 0x15, 0 ; 21
	406: 07 c0 rjmp .+14 ; 0x416 <delay+0x40>
	408: 2f 3f cpi r18, 0xFF ; 255
	40a: 29 f0 breq .+10 ; 0x416 <delay+0x40>
	40c: 4f ef ldi r20, 0xFF ; 255
	40e: c4 1a sub r12, r20
	410: d4 0a sbc r13, r20
	412: e4 0a sbc r14, r20
	414: f4 0a sbc r15, r20
	416: 3f bf out 0x3f, r19 ; 63
	418: fe 2c mov r15, r14
	41a: ed 2c mov r14, r13
	41c: dc 2c mov r13, r12
	41e: cc 24 eor r12, r12
	420: c2 0e add r12, r18
	422: d1 1c adc r13, r1
	424: e1 1c adc r14, r1
	426: f1 1c adc r15, r1
	428: cc 0c add r12, r12
	42a: dd 1c adc r13, r13
	42c: ee 1c adc r14, r14
	42e: ff 1c adc r15, r15
	430: cc 0c add r12, r12
	432: dd 1c adc r13, r13
	434: ee 1c adc r14, r14
	436: ff 1c adc r15, r15
	438: 86 01 movw r16, r12
	43a: 61 15 cp r22, r1
	43c: 71 05 cpc r23, r1
	43e: 81 05 cpc r24, r1
	440: 91 05 cpc r25, r1
	442: 09 f4 brne .+2 ; 0x446 <delay+0x70>
	444: 41 c0 rjmp .+130 ; 0x4c8 <delay+0xf2>
	446: 69 83 std Y+1, r22 ; 0x01
	448: 7a 83 std Y+2, r23 ; 0x02
	44a: 8b 83 std Y+3, r24 ; 0x03
	44c: 9c 83 std Y+4, r25 ; 0x04
	44e: 0e 94 b7 02 call 0x56e ; 0x56e <yield>
	452: 3f b7 in r19, 0x3f ; 63
	454: f8 94 cli
	456: c0 90 04 01 lds r12, 0x0104
	45a: d0 90 05 01 lds r13, 0x0105
	45e: e0 90 06 01 lds r14, 0x0106
	462: f0 90 07 01 lds r15, 0x0107
	466: 26 b5 in r18, 0x26 ; 38
	468: 69 81 ldd r22, Y+1 ; 0x01
	46a: 7a 81 ldd r23, Y+2 ; 0x02
	46c: 8b 81 ldd r24, Y+3 ; 0x03
	46e: 9c 81 ldd r25, Y+4 ; 0x04
	470: a8 9b sbis 0x15, 0 ; 21
	472: 07 c0 rjmp .+14 ; 0x482 <delay+0xac>
	474: 2f 3f cpi r18, 0xFF ; 255
	476: 29 f0 breq .+10 ; 0x482 <delay+0xac>
	478: ef ef ldi r30, 0xFF ; 255
	47a: ce 1a sub r12, r30
	47c: de 0a sbc r13, r30
	47e: ee 0a sbc r14, r30
	480: fe 0a sbc r15, r30
	482: 3f bf out 0x3f, r19 ; 63
	484: fe 2c mov r15, r14
	486: ed 2c mov r14, r13
	488: dc 2c mov r13, r12
	48a: cc 24 eor r12, r12
	48c: c2 0e add r12, r18
	48e: d1 1c adc r13, r1
	490: e1 1c adc r14, r1
	492: f1 1c adc r15, r1
	494: cc 0c add r12, r12
	496: dd 1c adc r13, r13
	498: ee 1c adc r14, r14
	49a: ff 1c adc r15, r15
	49c: cc 0c add r12, r12
	49e: dd 1c adc r13, r13
	4a0: ee 1c adc r14, r14
	4a2: ff 1c adc r15, r15
	4a4: 96 01 movw r18, r12
	4a6: 20 1b sub r18, r16
	4a8: 31 0b sbc r19, r17
	4aa: 28 3e cpi r18, 0xE8 ; 232
	4ac: 33 40 sbci r19, 0x03 ; 3
	4ae: 28 f2 brcs .-118 ; 0x43a <delay+0x64>
	4b0: 61 50 subi r22, 0x01 ; 1
	4b2: 71 09 sbc r23, r1
	4b4: 81 09 sbc r24, r1
	4b6: 91 09 sbc r25, r1
	4b8: 08 51 subi r16, 0x18 ; 24
	4ba: 1c 4f sbci r17, 0xFC ; 252
	4bc: 61 15 cp r22, r1
	4be: 71 05 cpc r23, r1
	4c0: 81 05 cpc r24, r1
	4c2: 91 05 cpc r25, r1
	4c4: 09 f0 breq .+2 ; 0x4c8 <delay+0xf2>
	4c6: bf cf rjmp .-130 ; 0x446 <delay+0x70>
	4c8: 0f 90 pop r0
	4ca: 0f 90 pop r0
	4cc: 0f 90 pop r0
	4ce: 0f 90 pop r0
	4d0: df 91 pop r29
	4d2: cf 91 pop r28
	4d4: 1f 91 pop r17
	4d6: 0f 91 pop r16
	4d8: ff 90 pop r15
	4da: ef 90 pop r14
	4dc: df 90 pop r13
	4de: cf 90 pop r12
	4e0: 08 95 ret

	000004e2 <delayMicroseconds>:
	4e2: 82 30 cpi r24, 0x02 ; 2
	4e4: 91 05 cpc r25, r1
	4e6: 38 f0 brcs .+14 ; 0x4f6 <delayMicroseconds+0x14>
	4e8: 88 0f add r24, r24
	4ea: 99 1f adc r25, r25
	4ec: 88 0f add r24, r24
	4ee: 99 1f adc r25, r25
	4f0: 05 97 sbiw r24, 0x05 ; 5
	4f2: 01 97 sbiw r24, 0x01 ; 1
	4f4: f1 f7 brne .-4 ; 0x4f2 <delayMicroseconds+0x10>
	4f6: 08 95 ret

	000004f8 <init>:
	4f8: 78 94 sei
	4fa: 84 b5 in r24, 0x24 ; 36
	4fc: 82 60 ori r24, 0x02 ; 2
	4fe: 84 bd out 0x24, r24 ; 36
	500: 84 b5 in r24, 0x24 ; 36
	502: 81 60 ori r24, 0x01 ; 1
	504: 84 bd out 0x24, r24 ; 36
	506: 85 b5 in r24, 0x25 ; 37
	508: 82 60 ori r24, 0x02 ; 2
	50a: 85 bd out 0x25, r24 ; 37
	50c: 85 b5 in r24, 0x25 ; 37
	50e: 81 60 ori r24, 0x01 ; 1
	510: 85 bd out 0x25, r24 ; 37
	512: ee e6 ldi r30, 0x6E ; 110
	514: f0 e0 ldi r31, 0x00 ; 0
	516: 80 81 ld r24, Z
	518: 81 60 ori r24, 0x01 ; 1
	51a: 80 83 st Z, r24
	51c: e1 e8 ldi r30, 0x81 ; 129
	51e: f0 e0 ldi r31, 0x00 ; 0
	520: 10 82 st Z, r1
	522: 80 81 ld r24, Z
	524: 82 60 ori r24, 0x02 ; 2
	526: 80 83 st Z, r24
	528: 80 81 ld r24, Z
	52a: 81 60 ori r24, 0x01 ; 1
	52c: 80 83 st Z, r24
	52e: e0 e8 ldi r30, 0x80 ; 128
	530: f0 e0 ldi r31, 0x00 ; 0
	532: 80 81 ld r24, Z
	534: 81 60 ori r24, 0x01 ; 1
	536: 80 83 st Z, r24
	538: e1 eb ldi r30, 0xB1 ; 177
	53a: f0 e0 ldi r31, 0x00 ; 0
	53c: 80 81 ld r24, Z
	53e: 84 60 ori r24, 0x04 ; 4
	540: 80 83 st Z, r24
	542: e0 eb ldi r30, 0xB0 ; 176
	544: f0 e0 ldi r31, 0x00 ; 0
	546: 80 81 ld r24, Z
	548: 81 60 ori r24, 0x01 ; 1
	54a: 80 83 st Z, r24
	54c: ea e7 ldi r30, 0x7A ; 122
	54e: f0 e0 ldi r31, 0x00 ; 0
	550: 80 81 ld r24, Z
	552: 84 60 ori r24, 0x04 ; 4
	554: 80 83 st Z, r24
	556: 80 81 ld r24, Z
	558: 82 60 ori r24, 0x02 ; 2
	55a: 80 83 st Z, r24
	55c: 80 81 ld r24, Z
	55e: 81 60 ori r24, 0x01 ; 1
	560: 80 83 st Z, r24
	562: 80 81 ld r24, Z
	564: 80 68 ori r24, 0x80 ; 128
	566: 80 83 st Z, r24
	568: 10 92 c1 00 sts 0x00C1, r1
	56c: 08 95 ret

	0000056e <yield>:
	56e: 08 95 ret

	00000570 <main>:
	570: 0e 94 7c 02 call 0x4f8 ; 0x4f8 <init>
	574: 0e 94 70 01 call 0x2e0 ; 0x2e0 <initVariant>
	578: 0e 94 75 00 call 0xea ; 0xea <setup>
	57c: 80 e0 ldi r24, 0x00 ; 0
	57e: 90 e0 ldi r25, 0x00 ; 0
	580: 89 2b or r24, r25
	582: 29 f0 breq .+10 ; 0x58e <main+0x1e>
	584: 0e 94 89 00 call 0x112 ; 0x112 <loop>
	588: 0e 94 00 00 call 0 ; 0x0 <__vectors>
	58c: fb cf rjmp .-10 ; 0x584 <main+0x14>
	58e: 0e 94 89 00 call 0x112 ; 0x112 <loop>
	592: 0e 94 89 00 call 0x112 ; 0x112 <loop>
	596: fb cf rjmp .-10 ; 0x58e <main+0x1e>

	00000598 <_exit>:
	598: f8 94 cli

	0000059a <__stop_program>:
	59a: ff cf rjmp .-2 ; 0x59a <__stop_program>