89 lines
3.2 KiB
Plaintext
89 lines
3.2 KiB
Plaintext
|
# $Header$
|
||
|
|
|
||
|
|
This directory contains two programs:
|
||
|
|
|
||
|
|
mkswitch:
|
||
|
|
C program, necessary for regenerating the giant switches
|
||
|
|
which are part of the INT project.
|
||
|
|
|
||
|
|
mkfuncs:
|
||
|
|
shell script that can be used to generate new function
|
||
|
|
files, if a new implementation is needed.
|
||
|
|
|
||
|
|
The first program reads an input file which holds the interpreter
|
||
|
|
opcode table (as shown in the [IR-81] report appendix B),
|
||
|
|
and creates an output file which contains an enormous switch
|
||
|
|
file. This switch has entries for each possible opcode. It's
|
||
|
|
possible to supply a third filename, which is the name of file
|
||
|
|
where all functions will be stored. This is necessary if a new
|
||
|
|
function implementation is needed.
|
||
|
|
|
||
|
|
The first argument to mkswitch is the prefix to be used in the
|
||
|
|
generated function names. For the interpreter proper this prefix
|
||
|
|
is Do.
|
||
|
|
|
||
|
|
The input file contains lines in the following format:
|
||
|
|
|
||
|
|
Mnemonic Flags Count First-number
|
||
|
|
|
||
|
|
The created switch file will contain a switch, with each case
|
||
|
|
having one of the following formats (? is the opcode):
|
||
|
|
|
||
|
|
1) case ?: DoAz();
|
||
|
|
2) case ?: DoBm(val);
|
||
|
|
3) case ?: DoCs(hob, wsize);
|
||
|
|
4) case ?: DoDXY(wsize);
|
||
|
|
|
||
|
|
Ad 1) This format shows that the corresponding opcode does not
|
||
|
|
have an argument. Often the operand is popped from the
|
||
|
|
stack.
|
||
|
|
|
||
|
|
e.g. DoNOPz(), this performs the NOP instruction.
|
||
|
|
|
||
|
|
Ad 2) This is the format for a mini. There is one implicit
|
||
|
|
argument (I) .
|
||
|
|
|
||
|
|
e.g. DoLOCm(1), this is the LOC 1 instruction.
|
||
|
|
|
||
|
|
Ad 3) This format corresponds with a shortie. There is an implicit
|
||
|
|
argument (high order byte), and a one byte text argument
|
||
|
|
(low order byte). W equals 'wsize' (if a word multiple),
|
||
|
|
otherwise it equals '1'. H is the value of the high
|
||
|
|
order byte.
|
||
|
|
|
||
|
|
e.g. DoLOEs(2, wsize), these are all LOE instructions,
|
||
|
|
with all addresses in the range:
|
||
|
|
(512 * wordsize) . . (767 * wordsize).
|
||
|
|
|
||
|
|
Ad 4) This format is used for opcodes with 2 or more text arguments,
|
||
|
|
and no implicit arguments. There are 6 types:
|
||
|
|
|
||
|
|
XY = l2: two byte negative or positive text argument.
|
||
|
|
XY = n2: two byte negative text argument.
|
||
|
|
XY = p2: two byte positive text argument.
|
||
|
|
XY = l4: four byte negative or positive text argument.
|
||
|
|
XY = n4: four byte negative text argument.
|
||
|
|
XY = p4: four byte positive text argument.
|
||
|
|
|
||
|
|
W equals 'wsize' (if a word multiple), otherwise it equals 1.
|
||
|
|
|
||
|
|
e.g. DoLDLp2(wsize), these are all LDL instructions, with
|
||
|
|
negative local offsets, which are word multiples.
|
||
|
|
|
||
|
|
|
||
|
|
When two file arguments are given to mkswitch (input file and output file),
|
||
|
|
only the switch is generated. If an additional third file name is
|
||
|
|
given (another output file), this file is filled with all function
|
||
|
|
calls in such a manner that mkfuncs will generate new function files.
|
||
|
|
|
||
|
|
Mkfuncs expects two arguments, an input file generated by
|
||
|
|
mkswitch and the name of a directory where the new function
|
||
|
|
files are stored. These files (15) each represent one group (as
|
||
|
|
proposed in [IR-81] sec 11.3) of instructions. Each file will
|
||
|
|
contain all functions needed to implement that specific group
|
||
|
|
of instructions. The functions will only contain a logging
|
||
|
|
message, and a call to newPC() which is necessary to skip the
|
||
|
|
arguments. The names of the generated files are: do_XXX.c, where
|
||
|
|
XXX is the name of the corresponding instruction group.
|
||
|
|
|