undar-lang/vm/vm.c

539 lines
11 KiB
C

#include "vm.h"
#define FRAME_HEADER_SIZE 12
u32 pc; /* program counter */
u32 cp; /* code pointer */
u32 mp; /* memory pointer */
u32 fp; /* frame pointer */
u32 sp; /* frame pointer */
u8 status; /* status flag */
u8 interrupt; /* device interrupt */
u32 *stack; /* stack */
u8 *code; /* code */
u8 *mem; /* memory */
#define MAX_LEN_INT32 11
#define MAX_INT32 2147483647
#define MIN_INT32 -2147483648
const char radix_set[11] = "0123456789";
u32 str_alloc(char *str, u32 length) {
u32 str_addr = mp;
u8 *ptr = &mem[mp];
mcpy(ptr, &length, sizeof(u32));
ptr += 4;
mcpy(ptr, str, length);
ptr[length] = '\0';
mp += 4 + length;
return str_addr;
}
bool step_vm() {
u8 opcode = code[pc++];
u32 *locals = (u32*)(&mem[fp]);
u32 *globals = (u32*)(mem);
switch (opcode) {
case OP_HALT: {
/* no need to decode, all are zeros */
return false;
}
case OP_CALL: {
/* TODO: Fix this one so it makes sense with a stack based system */
/* function to jump to */
u32 fn_ptr = stack[--sp];
/* get mp in 'global indexing mode' */
u32 *header = &globals[mp / 4];
/* reset child locals counter */
lc = 0;
/* push parents frame value to reset the heap to */
(*header++) = fp;
/* increase the mp to new size */
mp += FRAME_HEADER_SIZE;
/* now set the frame pointer, where the locals start */
fp = mp;
/* move mp forward by count many locals */
mp += stack[--sp];
/* jump to dest_ptr */
pc = fn_ptr;
return true;
}
case OP_RETURN: {
/* TODO: Fix this one so it makes sense with a stack based system */
u32 i, size = 0;
u32 return_value = stack[--sp];
bool is_ptr = (((u32)(1)) << 15) & return_value;
/* reset mp to saved mp, use header size to get "real" start of frame */
u32 *frame_start = &globals[(fp / 4) - 3];
u32 parent_fp = *frame_start++;
u32 return_address = *frame_start++;
u32 parent_local_return_address = *frame_start++;
/* reset memory to parents end of memory */
mp = fp - FRAME_HEADER_SIZE;
/* reset the frame pointer */
fp = parent_fp;
if (is_ptr) {
/* copy value to end of mp if it is a pointer */
globals[parent_local_return_address/4] = mp;
size = globals[return_value/4];
globals[mp/4] = size;
mp += 4;
mcpy(&mem[mp], &mem[return_value], size);
mp += size;
} else {
/* otherwise just write the return value to its location */
mcpy(&mem[parent_local_return_address], &return_value, sizeof(u32));
}
/* jump to parent frame */
pc = return_address;
return true;
}
case OP_SYSCALL: {
u32 id = stack[--sp]; /* syscall id */
u32 size = stack[--sp]; /* size of heap at that pointer */
u32 rd = stack[--sp]; /* the pointer */
status = syscall(id, size, rd);
return true;
}
case OP_PUSH: {
return false;
}
case OP_POP: {
--sp;
return true;
}
case OP_SET: {
return false;
}
case OP_MEM_ALLOC: {
u32 size = stack[--sp];
stack[sp++] = mp;
WRITE_U32(mp, size);
mp += (size + 4);
return true;
}
case OP_MEM_CPY_8: {
u32 i = 0;
u32 count = stack[--sp];
u32 msrc = stack[--sp];
u32 mdest = stack[--sp];
if (mdest + count >= mp) {
status = 1;
return true;
}
for (i = 0; i < count; i++) {
mem[msrc + i] = mem[mdest + i];
}
status = 0;
return true;
}
case OP_MEM_CPY_16: {
u32 i = 0;
u32 count = stack[--sp];
u32 msrc = stack[--sp];
u32 mdest = stack[--sp];
if (mdest + count >= mp) {
status = 1;
return true;
}
for (i = 0; i < count; i++) {
u16 value = READ_U16(mdest + i);
WRITE_U16(msrc + i, value);
}
status = 0;
return true;
}
case OP_MEM_CPY_32: {
u32 i = 0;
u32 count = stack[--sp];
u32 msrc = stack[--sp];
u32 mdest = stack[--sp];
if (mdest + count >= mp) {
status = 1;
return true;
}
for (i = 0; i < count; i++) {
globals[msrc + i] = globals[mdest + i];
}
status = 0;
return true;
}
case OP_MEM_SET_8: {
u32 i, start, end;
u8 value = (u8)stack[--sp];
u32 count = stack[--sp];
start = stack[--sp];
end = start + count;
if (start >= mp || end > mp) {
status = 1;
return true;
}
for (i = start; i < end; i++) {
mem[i] = value;
}
status = 0;
return true;
}
case OP_MEM_SET_16: {
u32 i, start, end;
u8 value = (u8)stack[--sp];
u32 count = stack[--sp];
start = stack[--sp];
end = start + count;
if (start >= mp || end > mp) {
status = 1;
return true;
}
for (i = start; i < end; i += 2) {
WRITE_U16(i, value);
}
status = 0;
return true;
}
case OP_MEM_SET_32: {
u32 i, start, end;
u8 value = (u8)stack[--sp];
u32 count = stack[--sp];
start = stack[--sp];
end = start + count;
if (start >= mp || end > mp) {
status = 1;
return true;
}
for (i = start; i < end; i += 4) {
WRITE_U32(i, value);
}
status = 0;
return true;
}
case OP_DUP: {
u32 a = stack[--sp];
stack[sp++] = a;
stack[sp++] = a;
return true;
}
case OP_EXCH: {
u32 a = stack[--sp];
u32 b = stack[--sp];
stack[sp++] = b;
stack[sp++] = a;
return true;
}
case OP_OVER: {
u32 a = stack[sp - 1];
stack[sp++] = a;
return true;
}
case OP_PICK: {
u32 n = stack[--sp];
u32 b = stack[sp - n];
stack[sp++] = b;
return true;
}
case OP_ROT: {
return false;
}
case OP_DEPTH: {
u32 a = sp;
stack[sp++] = a;
return true;
}
case OP_ADD_INT: {
MATH_OP(i32, +);
}
case OP_SUB_INT: {
MATH_OP(i32, -);
}
case OP_MUL_INT: {
MATH_OP(i32, *);
}
case OP_DIV_INT: {
MATH_OP(i32, /);
}
case OP_ADD_NAT: {
MATH_OP(u32, +);
}
case OP_SUB_NAT: {
MATH_OP(u32, -);
}
case OP_MUL_NAT: {
MATH_OP(u32, *);
}
case OP_DIV_NAT: {
MATH_OP(u32, /);
}
case OP_ADD_REAL: {
MATH_OP(i32, +);
}
case OP_SUB_REAL: {
MATH_OP(i32, -);
}
case OP_MUL_REAL: {
i32 src1 = (i32)stack[--sp];
i32 src2 = (i32)stack[--sp];
i32 src1_whole = src1 >> 16;
i32 src2_whole = src2 >> 16;
i32 src1_decimal = src1 & 16;
i32 src2_decimal = src2 & 16;
i32 result = 0;
result += (src1_whole * src2_whole) << 16;
result += (src1_whole * src2_decimal);
result += (src1_decimal * src2_whole);
result += ((src1_decimal * src2_decimal) >> 16) & 16;
stack[sp++] = result;
return true;
}
case OP_DIV_REAL: {
i32 result;
i32 src1_val = (i32)stack[--sp];
i32 src2_val = (i32)stack[--sp];
u32 src2_reciprocal = 1;
src2_reciprocal <<= 31;
src2_reciprocal = (u32)(src2_reciprocal / src2_val);
result = src1_val * src2_reciprocal;
result <<= 1;
stack[sp++] = result;
return true;
}
case OP_INT_TO_REAL: {
i32 result = (i32)stack[--sp] << 16;
stack[sp++] = result;
return true;
}
case OP_INT_TO_NAT: {
u32 result = (u32)stack[--sp];
stack[sp++] = result;
return true;
}
case OP_NAT_TO_REAL: {
i32 result = (i32)stack[--sp] << 16;
stack[sp++] = result;
return true;
}
case OP_NAT_TO_INT: {
i32 result = (i32)stack[--sp];
stack[sp++] = result;
return true;
}
case OP_REAL_TO_INT: {
i32 result = (i32)stack[--sp] >> 16;
stack[sp++] = result;
return true;
}
case OP_REAL_TO_NAT: {
u32 result = (u32)stack[--sp] >> 16;
stack[sp++] = result;
return true;
}
case OP_BIT_SHIFT_LEFT: {
MATH_OP_NO_CAST(<<);
}
case OP_BIT_SHIFT_RIGHT: {
MATH_OP_NO_CAST(>>);
}
case OP_BIT_SHIFT_R_EXT: {
MATH_OP(i32, >>);
}
case OP_BIT_AND: {
MATH_OP_NO_CAST(&);
}
case OP_BIT_OR: {
MATH_OP_NO_CAST(|);
}
case OP_BIT_XOR: {
MATH_OP_NO_CAST(^);
}
case OP_JMP: {
u32 jmp_dest = stack[--sp];
if (jmp_dest > cp) {
status = 1;
return true;
}
pc = jmp_dest;
return true;
}
case OP_JMP_FLAG: {
u32 mask;
u32 jmp_dest = stack[--sp];
if (jmp_dest > cp) {
status = 1;
return true;
}
mask = -(u32)(status == 0);
pc = (jmp_dest & mask) | (pc & ~mask);
return true;
}
case OP_JEQ_INT: {
COMPARE_AND_JUMP(i32, ==);
}
case OP_JNE_INT: {
COMPARE_AND_JUMP(i32, !=);
}
case OP_JGT_INT: {
COMPARE_AND_JUMP(i32, >);
}
case OP_JLT_INT: {
COMPARE_AND_JUMP(i32, <);
}
case OP_JLE_INT: {
COMPARE_AND_JUMP(i32, <=);
}
case OP_JGE_INT: {
COMPARE_AND_JUMP(i32, >=);
}
case OP_JEQ_NAT: {
COMPARE_AND_JUMP(u32, ==);
}
case OP_JNE_NAT: {
COMPARE_AND_JUMP(u32, !=);
}
case OP_JGT_NAT: {
COMPARE_AND_JUMP(u32, >);
}
case OP_JLT_NAT: {
COMPARE_AND_JUMP(u32, <);
}
case OP_JLE_NAT: {
COMPARE_AND_JUMP(u32, <=);
}
case OP_JGE_NAT: {
COMPARE_AND_JUMP(u32, >=);
}
case OP_JEQ_REAL: {
COMPARE_AND_JUMP(i32, ==);
}
case OP_JNE_REAL: {
COMPARE_AND_JUMP(i32, !=);
}
case OP_JGE_REAL: {
COMPARE_AND_JUMP(i32, >=);
}
case OP_JGT_REAL: {
COMPARE_AND_JUMP(i32, >);
}
case OP_JLT_REAL: {
COMPARE_AND_JUMP(i32, <);
}
case OP_JLE_REAL: {
COMPARE_AND_JUMP(i32, <=);
}
case OP_INT_TO_STR: {
u32 i = MAX_LEN_INT32;
i32 v = (i32)stack[--sp];
char buffer[MAX_LEN_INT32];
i32 n = v;
bool neg = n < 0;
if (neg)
n = -n;
do {
buffer[--i] = radix_set[n % 10];
n /= 10;
} while (n > 0);
if (neg)
buffer[--i] = '-';
/* Ensure at least one digit is written for 0 */
if (v == 0)
buffer[--i] = '0';
/* Copy from buffer[i] to buffer + MAX_LEN_INT32 */
stack[sp++] = str_alloc(buffer + i, MAX_LEN_INT32 - i);
return pc;
}
case OP_NAT_TO_STR: {
u32 v = (i32)stack[--sp];
char buffer[MAX_LEN_INT32];
u32 n = v;
u32 i = MAX_LEN_INT32;
do {
buffer[--i] = radix_set[n % 10];
n /= 10;
} while (n > 0);
/* Ensure at least one digit is written for 0 */
if (v == 0)
buffer[--i] = '0';
/* Copy from buffer[i] to buffer + MAX_LEN_INT32 */
stack[sp++] = str_alloc(buffer + i, MAX_LEN_INT32 - i);
return pc;
}
case OP_REAL_TO_STR: {
u32 i = 0, j = 0;
i32 q = (i32)stack[--sp];
char buffer[MAX_LEN_INT32];
u32 int_part, frac_part;
if (q < 0) {
buffer[i++] = '-';
q = -q;
}
int_part = q >> 16;
frac_part = q & 0xFFFF;
if (int_part == 0) {
buffer[i++] = radix_set[0];
} else {
char tmp[16];
i32 tmp_i = 0;
while (int_part > 0) {
tmp[tmp_i++] = radix_set[int_part % 10];
int_part /= 10;
}
while (tmp_i > 0) {
buffer[i++] = tmp[--tmp_i];
}
}
buffer[i++] = '.';
for (j = 0; j < 6; j++) {
frac_part *= 10;
buffer[i++] = radix_set[frac_part >> 16];
frac_part &= 0xFFFF;
}
stack[sp++] = str_alloc(buffer + i, MAX_LEN_INT32 - i);
return pc;
}
}
/* something went very wrong */
status = 255;
return false;
}