Update Doku aus Driversourcen
Change-Id: I455f0813b970151089b3dc1b8d9407eea323cdd1
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+This file contains a collection of non-configurable limits:
+
+Program properties
+==================
+* maximum program length: 1 MB (1048575 Bytes)
+ This is defined by FUNSTART_MASK in exec.h, which is the maximum offset
+ (address) of a functions code within the program block (relativ to the
+ beginning). Changing it involves changing funflag_t and probably other
+ stuff.
+
+* maximum number of programs: 2^32-1
+ The unique program ID number is a int32. It is incremented for each compiled
+ program. If it reaches zero (after wrapping to negative values) the
+ compiler or swapper calls renumber_programs(), which recycles numbers from
+ old programs.
+ (exec.h, prolang.y, swap.c, ...)
+
+* maximum number of functions in a program: 65534
+ The lookup table for function indexes holding the offsets of the function in
+ the functions tables is unsigned short.
+ The types of function arguments are stored in program_s.argument_types,
+ which is index by the unsigned short programs_s.type_start. 65535 has a
+ special meaning. Some code relies that this is unsigned short.
+ (exec.h, ...)
+ program_s.num_function_names and num_functions are unsigned short as well.
+
+* maximum length of switch: 256k (262143 Bytes)
+ Limited by BREAK_ADDRESS_MASK and CONTINUE_ADDRESS_MASK?
+
+* maximum offset for branches: 32765 (0x7ffd)
+ (prolang.y)
+
+* number of virtual variables: 256
+* number of global variables: 65536 (F_IDENTIFIER16)
+* number of local variables: 256 (F_PUSH_LOCAL_VARIABLE_LVALUE)
+* number of context variables: 256 (Should be consistent with local
+ variables, MAX_LOCAL applies to both. 16 bit opcodes are not used yet.)
+
+* max number of struct members: 255
+ (exec.h, ...)
+
+* max number of structs per program: usually 32767 (short)
+
+
+Hash tables
+===========
+* maximum size of the hash table for identifiers (ITABLE): 32768
+ The hashes of identifiers are signed short which are in most cases 16 bit
+ wide integers (lex.h, lex.c, ...)
+
+* maximum size of the hash table for objects (OTABLE): 65536
+* maximum size of the hash table for shared strings (HTABLE): 65536
+ The hashes are of type unsigned short which are in most cases 16 bit
+ wide integers.
+
+
+Objects
+=======
+* maximum clone ID number: 2^32-1
+ Not a real limitation, after that the driver starts checking if
+ blueprint name + #cloneid are unique.
+
+
+Memory management
+=================
+* max. size of single large block in slaballo.c and smalloc.c:
+ 0x07ffffff (134217727, defined by M_MASK)
+
+
+Language
+========
+* maximum number of simul-efuns: 2048
+ Only values 0xf800-0xffff in .x.closure_type of
+ a T_CLOSURE svalue are reserved for simul-efuns.
+ F_SIMUL_EFUN however takes a short int, so there 65536
+ simul-efuns would be possible.
+
+* maximum number of python efuns: 2048
+ Only values 0xe800-0xefff in .x.closure_type of
+ a T_CLOSURE svalue are reserved for python efuns.
+ F_PYTHON_EFUN however takes a short int, so there 65536
+ python efuns would be possible.