nrj-oisc

commit 24eaaab70de07ebb79650892c11534563ff350f9
parent d712730bb499a777f41635b72e82953264c37cd7
Author: Luxferre <lux@ferre>
Date:   Sat,  3 Sep 2022 07:54:14 +0300

Optimized lookup table placement and trailing zero words stripping

Diffstat:
M
example.nrjasm
 | 
10
+++++-----
M
nrjasm.py
 | 
11
++++++++++-

2 files changed, 15 insertions(+), 6 deletions(-)
diff --git a/example.nrjasm b/example.nrjasm
@@ -12,9 +12,9 @@
 
 .inc stdlib.nrjasm
 
-.var x 12EF ; .var defines a label for a particular memory location
-.var y 12F0 ; define another variable at 0x12F0
-.set @x 33EE ; .set sets a memory location to a particular hex constant at the build time, @ dereferences a label into the address
+.var x 2EF ; .var defines a label for a particular memory location
+.var y 2F0 ; define another variable at 0x2F0
+.set @x 'm ; .set sets a memory location to a particular hex constant at the build time, @ dereferences a label into the address
 .set @y 'M ; ' dereferences a character into a whole word with its ASCII code
 
 ; we CANNOT use dereferencing operators with .var, only with .set or directly
@@ -28,13 +28,13 @@
 
 ; for the lookup table and CUR/NXT macros to work correctly, the code must start at an address divisible by 3
 ; note that FREE doesn't intelligently detect the available cells, it only takes the next one after the maximum address used
-; so in our case, the first FREE instance will be substituted with 12F1, the next with 12F2 and so on
-
+; so in our case, the first FREE instance will be substituted with 2F1, the next with 2F2 and so on
 
 ; now, lets output a character by transferring the y value to the output cell 1
 ; in an endless loop
 
 .lbl myloop
+MOV 1 @x 
 MOV 1 @y @myloop ; output the character and jump to the beginning
 ; we don't have to explicitly zero out the cell 1 as it is done by the I/O logic
 
diff --git a/nrjasm.py b/nrjasm.py
@@ -5,6 +5,7 @@
 import sys
 import array
 from os.path import realpath
+from numpy import trim_zeros
 
 # some constants to redefine more easily in case of major breaking changes
 
@@ -154,7 +155,11 @@ def start_assembly(srcfname, dstfname): # main assembly method
     # the NXT macro will be replaced with a cell in the lookup table that points to the next instruction
     # and the lookup table will also take some memory in the machine
 
-    ltoffset = memsize >> 1 # in the worst case scenario, the code will take half of all memory and lookup table will take the other half
+    # now, try to detect the optimal offset for our lookup table
+    if maxvar > 0: # we have some variables defined, so place the lookup table after them
+        ltoffset = maxvar + 1
+    else: # in the worst case scenario, the code will take half of all memory and lookup table will take the other half
+        ltoffset = memsize >> 1 
     targetmem[ltoffset] = haltaddr # the first lookup table entry is always the halting address
     codepos = 0
     ltpos = 1 
@@ -199,6 +204,10 @@ def start_assembly(srcfname, dstfname): # main assembly method
             for v in line:
                 codepos += 1
 
+    # looking for a more optimal solution than to import numpy just for this:
+
+    targetmem = trim_zeros(targetmem, 'b') # only strip trailing zero values
+
     # now, we have assembled our target memory snapshot, let's write the output file
 
     outf = open(dstfname, "wb")