@begin: scope:[]  from
  [0] phi()
  to:@1
@1: scope:[]  from @begin
  [1] phi()
  [2] call main 
  to:@end
@end: scope:[]  from @1
  [3] phi()
main: scope:[main]  from @1
  [4] *((const byte*) BGCOL#0) ← (const byte) BLACK#0
  [5] call memcpy 
  to:main::@2
main::@2: scope:[main]  from main
  [6] phi()
  [7] call memcpy 
  to:main::@1
main::@1: scope:[main]  from main::@1 main::@2
  [8] *((const byte*) SCREEN#0+(word) $3e7) ← *((const byte*) SCREEN#0+(word) $3e7) ^ (byte) $e
  to:main::@1
memcpy: scope:[memcpy]  from main main::@2
  [9] (void*) memcpy::destination#2 ← phi( main/(void*)(const byte*) SCREEN#0 main::@2/(void*)(const byte*) COLS#0 )
  [9] (void*) memcpy::source#2 ← phi( main/(void*)(const byte[$3e8]) MEDUSA_SCREEN#0 main::@2/(void*)(const byte[]) MEDUSA_COLORS#0 )
  [10] (byte*) memcpy::src_end#0 ← (byte*)(void*) memcpy::source#2 + (word) $3e8
  [11] (byte*~) memcpy::src#4 ← (byte*)(void*) memcpy::source#2
  [12] (byte*~) memcpy::dst#4 ← (byte*)(void*) memcpy::destination#2
  to:memcpy::@1
memcpy::@1: scope:[memcpy]  from memcpy memcpy::@2
  [13] (byte*) memcpy::dst#2 ← phi( memcpy/(byte*~) memcpy::dst#4 memcpy::@2/(byte*) memcpy::dst#1 )
  [13] (byte*) memcpy::src#2 ← phi( memcpy/(byte*~) memcpy::src#4 memcpy::@2/(byte*) memcpy::src#1 )
  [14] if((byte*) memcpy::src#2!=(byte*) memcpy::src_end#0) goto memcpy::@2
  to:memcpy::@return
memcpy::@return: scope:[memcpy]  from memcpy::@1
  [15] return 
  to:@return
memcpy::@2: scope:[memcpy]  from memcpy::@1
  [16] *((byte*) memcpy::dst#2) ← *((byte*) memcpy::src#2)
  [17] (byte*) memcpy::dst#1 ← ++ (byte*) memcpy::dst#2
  [18] (byte*) memcpy::src#1 ← ++ (byte*) memcpy::src#2
  to:memcpy::@1
