add a D implementation of Nga (32-bit only)

FossilOrigin-Name: d5fe8aa2c40bfaef4110c9b07c9fb35671ca31a6bedeafd79ee5d273bfd8aa1a
This commit is contained in:
crc 2023-10-20 17:28:49 +00:00
parent 075fbd6500
commit 360c390300
2 changed files with 354 additions and 0 deletions

View file

@ -14,5 +14,6 @@
- err:notfound message no longer in C (C) (sevan)
- add -v for verbose mode (C)
- now skip execuion of NOP instructions (C)
- added an implementation of Nga in D (D)
================================================================

353
vm/nga-d/nga.d Normal file
View file

@ -0,0 +1,353 @@
/* nga.d, (c) charles childers */
import std.stdio;
import std.stdint;
import core.stdc.stdlib;
enum int_MIN = -2147483647;
enum int_MAX = 2147483646;
enum IMAGE_SIZE = 65536; /* Amount of RAM, in ints */
enum ADDRESSES = 256; /* Depth of address stack */
enum STACK_DEPTH = 256; /* Depth of data stack */
int sp, rp, ip; /* Stack and instruction pointers */
int[STACK_DEPTH] data; /* The data stack */
int[ADDRESSES] address; /* The address stack */
int[IMAGE_SIZE] memory; /* Image Memory */
void stack_push(int value)
{
sp += 1;
data[sp] = value;
}
int stack_pop()
{
sp -= 1;
return data[sp + 1];
}
void execute(int c)
{
int i;
ip = c;
while (ip < IMAGE_SIZE)
{
process_bundle(memory[ip]);
ip += 1;
}
}
void load_image()
{
FILE* fp;
long fileLen;
if ((fp = fopen("ngaImage", "rb")) !is null)
{
fseek(fp, 0, SEEK_END);
fileLen = ftell(fp);
rewind(fp);
fread(memory.ptr, 1, fileLen, fp);
fclose(fp);
}
}
void prepare_vm()
{
ip = sp = rp = 0;
foreach (i; 0 .. IMAGE_SIZE)
memory[i] = 0; /* NO - nop instruction */
foreach (i; 0 .. STACK_DEPTH)
data[i] = 0;
foreach (i; 0 .. ADDRESSES)
address[i] = 0;
}
void inst_no() {}
void inst_li()
{
ip += 1;
stack_push(memory[ip]);
}
void inst_du()
{
stack_push(data[sp]);
}
void inst_dr()
{
stack_pop();
}
void inst_sw()
{
int a = data[sp];
data[sp] = data[sp - 1];
data[sp - 1] = a;
}
void inst_pu()
{
rp += 1;
address[rp] = stack_pop();
}
void inst_po()
{
stack_push(address[rp]);
rp -= 1;
}
void inst_ju()
{
ip = stack_pop() - 1;
}
void inst_ca()
{
rp += 1;
address[rp] = ip;
ip = stack_pop() - 1;
}
void inst_cc()
{
int a, b;
a = stack_pop(); /* Target */
b = stack_pop(); /* Flag */
if (b != 0)
{
rp += 1;
address[rp] = ip;
ip = a - 1;
}
}
void inst_re()
{
ip = address[rp];
rp -= 1;
}
void inst_eq()
{
data[sp - 1] = (data[sp - 1] == data[sp]) ? -1 : 0;
inst_dr();
}
void inst_ne()
{
data[sp - 1] = (data[sp - 1] != data[sp]) ? -1 : 0;
inst_dr();
}
void inst_lt()
{
data[sp - 1] = (data[sp - 1] < data[sp]) ? -1 : 0;
inst_dr();
}
void inst_gt()
{
data[sp - 1] = (data[sp - 1] > data[sp]) ? -1 : 0;
inst_dr();
}
void inst_fe()
{
switch (data[sp])
{
case -1: data[sp] = sp - 1; break;
case -2: data[sp] = rp; break;
case -3: data[sp] = IMAGE_SIZE; break;
case -4: data[sp] = int_MIN; break;
case -5: data[sp] = int_MAX; break;
default: data[sp] = memory[data[sp]]; break;
}
}
void inst_st()
{
if (data[sp] <= IMAGE_SIZE && data[sp] >= 0)
{
memory[data[sp]] = data[sp - 1];
inst_dr();
inst_dr();
}
else
{
ip = IMAGE_SIZE;
}
}
void inst_ad()
{
data[sp - 1] += data[sp];
inst_dr();
}
void inst_su()
{
data[sp - 1] -= data[sp];
inst_dr();
}
void inst_mu()
{
data[sp - 1] *= data[sp];
inst_dr();
}
void inst_di()
{
int a = data[sp];
int b = data[sp - 1];
data[sp] = b / a;
data[sp - 1] = b % a;
}
void inst_an()
{
data[sp - 1] = data[sp] & data[sp - 1];
inst_dr();
}
void inst_or()
{
data[sp - 1] = data[sp] | data[sp - 1];
inst_dr();
}
void inst_xo()
{
data[sp - 1] = data[sp] ^ data[sp - 1];
inst_dr();
}
void inst_sh()
{
int y = data[sp];
int x = data[sp - 1];
if (data[sp] < 0)
data[sp - 1] = data[sp - 1] << (0 - data[sp]);
else
{
if (x < 0 && y > 0)
data[sp - 1] = x >> y | ~(~0U >> y);
else
data[sp - 1] = x >> y;
}
inst_dr();
}
void inst_zr()
{
if (data[sp] == 0)
{
inst_dr();
ip = address[rp];
rp -= 1;
}
}
void inst_ha()
{
ip = IMAGE_SIZE;
}
void inst_ie()
{
stack_push(2);
}
void inst_iq()
{
if (data[sp] == 0)
{
inst_dr();
stack_push(0);
stack_push(0);
}
else if (data[sp] == 1)
{
inst_dr();
stack_push(1);
stack_push(1);
}
}
void inst_ii()
{
int c;
if (data[sp] == 0)
{
inst_dr();
writef("%c", cast(char)stack_pop());
}
else if (data[sp] == 1)
{
c = getchar();
if (c < 0) exit(0);
inst_dr();
stack_push(c);
}
else
{
inst_dr();
}
}
void process(int opcode) {
switch (opcode) {
case 0: inst_no(); break;
case 1: inst_li(); break;
case 2: inst_du(); break;
case 3: inst_dr(); break;
case 4: inst_sw(); break;
case 5: inst_pu(); break;
case 6: inst_po(); break;
case 7: inst_ju(); break;
case 8: inst_ca(); break;
case 9: inst_cc(); break;
case 10: inst_re(); break;
case 11: inst_eq(); break;
case 12: inst_ne(); break;
case 13: inst_lt(); break;
case 14: inst_gt(); break;
case 15: inst_fe(); break;
case 16: inst_st(); break;
case 17: inst_ad(); break;
case 18: inst_su(); break;
case 19: inst_mu(); break;
case 20: inst_di(); break;
case 21: inst_an(); break;
case 22: inst_or(); break;
case 23: inst_xo(); break;
case 24: inst_sh(); break;
case 25: inst_zr(); break;
case 26: inst_ha(); break;
case 27: inst_ie(); break;
case 28: inst_iq(); break;
case 29: inst_ii(); break;
default: writef("\nERROR: %d\n", opcode); /* Handle unknown opcode */ exit(1); break;
}
}
void process_bundle(int opcode) {
process(opcode & 0xFF);
process((opcode >> 8) & 0xFF);
process((opcode >> 16) & 0xFF);
process((opcode >> 24) & 0xFF);
}
void main(string[] args)
{
prepare_vm();
load_image();
execute(0);
while (sp > 0) { writef("%d ", stack_pop()); } writef("\n");
exit(0);
}