8.4  ATmega328p : détails de la chaîne de compilation (4/6)

• Génération de code pour un CPU virtuel.
• GCC utilise Register Transfer Language http://gcc.gnu.org/onlinedocs/gccint/RTL.html.
• Options pour obtenir le code RTL gcc --dump-rtl-xxx (e.g. --dump-rtl-expand) :

  ...
  ;; Function init_ports
  (note 1 0 3 NOTE_INSN_DELETED)
  (note 3 1 20 [bb 2] NOTE_INSN_BASIC_BLOCK)
  (note 20 3 2 NOTE_INSN_PROLOGUE_END)
  (note 2 20 6 NOTE_INSN_FUNCTION_BEG)
  (insn 6 2 7 (set (reg:QI 25 r25 [orig:42 D.1651 ] [42])
          (mem/v:QI (const_int 36 [0x24]) [0 MEM[(volatile uint8_t *)36B]+0 S1 A8])) timer.c:13 71 {movqi_insn}
       (nil))
  (note 7 6 8 NOTE_INSN_DELETED)
  (insn 8 7 9 (set (reg:QI 24 r24 [orig:51 led_bit ] [51])
          (mem/c:QI (symbol_ref:HI ("led_bit") [flags 0x2]  <var_decl 0x7f6d24cf8cf0 led_bit>) [1 led_bit+0 S1 A8])) timer.c:13 71 {movqi_insn}
       (nil))
  (insn 9 8 11 (set (reg:QI 24 r24 [orig:47 D.1651 ] [47])
          (ior:QI (reg:QI 24 r24 [orig:51 led_bit ] [51])
              (reg:QI 25 r25 [orig:42 D.1651 ] [42]))) timer.c:13 266 {iorqi3}
       (expr_list:REG_DEAD (reg:QI 25 r25 [orig:42 D.1651 ] [42])
          (nil)))
  (insn 11 9 13 (set (mem/v:QI (const_int 36 [0x24]) [0 MEM[(volatile uint8_t *)36B]+0 S1 A8])
          (reg:QI 24 r24 [orig:47 D.1651 ] [47])) timer.c:13 71 {movqi_insn}
       (expr_list:REG_DEAD (reg:QI 24 r24 [orig:47 D.1651 ] [47])
          (nil)))
  (insn 13 11 15 (set (reg:QI 24 r24 [orig:48 D.1651 ] [48])
          (mem/v:QI (const_int 37 [0x25]) [0 MEM[(volatile uint8_t *)37B]+0 S1 A8])) timer.c:14 71 {movqi_insn}
       (nil))
  (insn 15 13 22 (set (mem/v:QI (const_int 37 [0x25]) [0 MEM[(volatile uint8_t *)37B]+0 S1 A8])
          (reg:QI 24 r24 [orig:48 D.1651 ] [48])) timer.c:14 71 {movqi_insn}
       (expr_list:REG_DEAD (reg:QI 24 r24 [orig:48 D.1651 ] [48])
          (nil)))
  (jump_insn 22 15 21 (return) timer.c:14 453 {return}
       (nil)
   -> return)
  (barrier 21 22 18)
  (note 18 21 0 NOTE_INSN_DELETED)
  ...