Vm Merge

wiki

Overview

This script is designed to take a Lua source file, run luac to generate the Lua VM code, and merge the two together.

eg. Using the following code :-

a = {}
b = a.x
print(b)

luac produces :-

main <0:@a.lua> (9 instructions/36 bytes at 002F29E8)
0 params, 2 stacks, 0 locals, 4 strings, 0 numbers, 0 functions, 5 lines
 1	[2]	CREATETABLE	0
 2	[2]	SETGLOBAL 	0	; a
 3	[3]	GETGLOBAL 	0	; a
 4	[3]	GETDOTTED 	2	; x
 5	[3]	SETGLOBAL 	1	; b
 6	[4]	GETGLOBAL 	3	; print
 7	[4]	GETGLOBAL 	1	; b
 8	[4]	CALL 	0 0
 9	[4]	END

The script will merge the source and VM code to produce :-

 a = {}
 	CREATETABLE	0
 	SETGLOBAL 	0	; a
 b = a.x
 	GETGLOBAL 	0	; a
 	GETDOTTED 	2	; x
 	SETGLOBAL 	1	; b
 print(b)
 	GETGLOBAL 	3	; print
 	GETGLOBAL 	1	; b
 	CALL 	0 0
 	END

It can also produce the above in HTML format to make it a bit easier on the eye (unfortunately no HTML preview facility is available on this site) :-

<html><pre>
<b>a = {}</b>
 CREATETABLE	0
 SETGLOBAL 	0	; a
<b>b = a.x</b>
 GETGLOBAL 	0	; a
 GETDOTTED 	2	; x
 SETGLOBAL 	1	; b
<b>print(b)</b>
 GETGLOBAL 	3	; print
 GETGLOBAL 	1	; b
 CALL 	0 0
 END</pre></html>

Note, the above example is without line numbers. You can find some more examples on OptimisationTips page.

Command line

Get the script (below).
Run the script using: lua -f vmmerge.lua ...options...
Make sure you have the lua and luac executables in your path. luac -p -l is used to generated the VM code.
--fmt merge|html chooses output format (see above).
--nol removes line numbers
Pipe the output into a file to save it. eg. "... > file.txt"
eg. lua -f vmmerge.lua --file my.lua --fmt html > my.html

Vm Merge

Overview

Command line

Download

See Also