MERCURY2  by Albert Ma

MERCURY2 is an extremely fast and small corewar interpreter without
graphical core display. I estimate it to be about 25 times faster than
C88v49. It requires a 386 or above and 160K of contiguous free memory.

There are two versions of the executable compiled from the same assembly
source (see below).  MERCURYD.EXE has debugging features; MERCURY2.EXE
is optimized for speed.

Limits: maximum size of redcode program: 16384 bytes
    maximum length of program: 1024 instructions
    maximum number of cells: 8192
    maximum number of processes: 16383
    maximum number of rounds: 65535
    maximum number of cycles: 2^32-1  i.e. a whole lot
    maximum number of labels and variables:  102 for average
                        length of 7
    maximum length of name: 63 characters
    maximum length of author: 63 characters

Compatabilty:
    Interprets warriors same as KotH
    requires comma between operands
    labels composed of A..Z _ 0..9  no limit to length of name
        all significant
    Uses in-register evaluation.

Instructions for MERCURY2:
    run MERCURY2 to see options
    press key after seeing first listing
    interpreter runs immediately after displaying second file
    press space to see status
    press escape to abort

The new -U option (coredump) displays all non-empty cells after the last
round has completed.

Additional instructions for the debugging version:
    press 's' to step through trace (if tracing)
    press 't' to step through trace (force tracing)
    press return to go back to full speed
    press 'n' to enable/disable debugging

Source-embedded debugging commands (debugging version only):
    ;debug          turn on debugging (MOV copies debug info)
    ;debug static   turn on debugging (MOV does not copy debug info)
    ;debug off      turn off debugging
    ;trace          turn on trace starting with next instruction
    ;trace off      turn off trace
    ;break          pause execution at next instruction
    ;break once     break once and then clear debug status
    (;debug and ;trace off are defaults)

Example:

;name Sucker 3
;strategy vampire
;debug  (copy debug info)
;break once (when opponent executes vampire fang)
jump    jmp clear-444,444
start   spl 0
loop    sub clear,jump
        mov jump,@jump
        djn loop,<4003
;trace (the next instruction)
clear   mov 34,<-34
;trace off
        spl clear
        jmp clear
        end start

Pressing 's' after the breakpoint displays the traced instruction
'clear'; pressing 't' steps through all following instructions as they
are executed. Traced instructions are displayed in this format:

<address> <instruction before execution> <warrior#> <instr. after exec.>

Compiling mercury2:
    You need TASM (a new version) unless you know assembly and
    can make minor modifications to the program.
    The commands
            TASM /m10 /ddebugging=0 mercury2
            TLINK mercury2
    create mercury2.exe without debugging features
    The commands
            TASM /m10 /ddebugging=1 mercury2
            TLINK mercury2.obj, mercuryd.exe
    create mercuryd.exe with debugging features

Credits:
    Stefan Strack for all his help and ideas for debugging.
    MAD for his validation suite which clearly explained in-register

Bugs:
    DO NOT run under DesqView
    Has not been tested in OS/2

Legal Stuff:
    This program is freeware.  I'd ask that you not try to
    sell it to anyone.  Provided as is, I am not responsible
    for damage caused by the proper or improper use of my
    program, *blah blah* expressed or implied *blah blah*.

    Seriously, I've crashed Stefan's computer hundreds of times
    during testing, be warned.  Feel free to modify the source
    code in any way you want (except putting viruses inside and
    distributing it).

Send comments or suggestions to ama@athena.mit.edu