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undar-lang/vm/vm.c

604 lines
12 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 */
u8 sp; /* child local count */
u32 flag; /* flag */
u8 interrupt; /* device interrupt */
u32 *code; /* code */
u8 *mem; /* memory */
bool step_vm() {
u32 instruction = code[pc++];
u8 opcode = DECODE_OP(instruction);
switch (opcode) {
case OP_HALT: {
/* no need to decode, all are zeros */
return false;
}
case OP_CALL: {
DECODE_A(instruction)
u32 fn_ptr;
u32 rd = fp + (dest * 4);
u32 r1 = src1;
u32 r2 = fp + src2;
fn_ptr = READ_U32(rd);
/* push parents frame value to reset the heap to */
WRITE_U32(mp, fp);
mp += 4;
/* push return address to child frame */
WRITE_U32(mp, pc);
mp += 4;
/* push local address to return the value to */
WRITE_U32(mp, r2);
mp += 4;
/* now set the frame pointer, where the locals start */
fp = mp;
/* move mp by count many locals */
mp += (4 * r1);
/* jump to dest_ptr */
pc = fn_ptr;
return true;
}
case OP_RETURN: {
DECODE_B(instruction)
u32 i, size = 0;
u32 return_local = fp + (dest * 4);
u32 return_value = READ_U32(return_local);
bool is_ptr = (((u32)(1)) << 15) & imm;
bool replaces_value = (((u32)(1)) << 14) & imm;
/* reset mp to saved mp, use header size to get "real" start of frame */
u32 frame_start = fp - FRAME_HEADER_SIZE;
u32 parent_fp = READ_U32(frame_start);
u32 return_address = READ_U32(frame_start + 4);
u32 parent_local_return_address = 4 * READ_U32(frame_start + 8);
USED(replaces_value);
/* reset memory to parents end of memory */
mp = fp - FRAME_HEADER_SIZE;
/* reset the frame pointer */
fp = parent_fp;
/* copy value to end of mp if it is a pointer */
if (is_ptr) {
WRITE_U32(parent_local_return_address, mp);
size = READ_U32(return_value);
WRITE_U32(mp, size);
mp += 4;
for (i = 0; i < size; i++) {
u8 value = READ_U8(return_value + i);
WRITE_U8(mp, value);
mp++;
}
} else {
/* otherwise just write the return value to its location */
WRITE_U32(parent_local_return_address, return_value);
}
/* jump to parent frame */
pc = return_address;
return true;
}
case OP_SYSCALL: {
DECODE_A(instruction)
u32 id = dest;
u32 args = src1;
u32 rd = fp + (src2 * 4);
flag = syscall(id, args, rd);
return true;
}
case OP_LOAD_IMM: {
DECODE_B(instruction)
u32 rd = fp + (dest * 4);
WRITE_U32(rd, imm);
return true;
}
case OP_LOAD_UPPER_IMM: {
DECODE_B(instruction)
u32 rd = fp + (dest * 4);
u32 value = READ_U32(rd);
WRITE_U32(rd, (value | (((u32)(imm)) << 16)));
return true;
}
case OP_LOAD_IND_8: {
}
case OP_LOAD_IND_16: {
}
case OP_LOAD_IND_32: {
}
case OP_LOAD_ABS_8: {
}
case OP_LOAD_ABS_16: {
}
case OP_LOAD_ABS_32: {
}
case OP_LOAD_OFF_8: {
}
case OP_LOAD_OFF_16: {
}
case OP_LOAD_OFF_32: {
}
case OP_STORE_ABS_8: {
}
case OP_STORE_ABS_16: {
}
case OP_STORE_ABS_32: {
}
case OP_STORE_IND_8: {
}
case OP_STORE_IND_16: {
}
case OP_STORE_IND_32: {
}
case OP_STORE_OFF_8: {
}
case OP_STORE_OFF_16: {
}
case OP_STORE_OFF_32: {
}
case OP_MEM_ALLOC: {
DECODE_A(instruction)
u32 size, ldest;
u32 rd = fp + (dest * 4);
u32 r1 = fp + (src1 * 4);
USED(src2);
ldest = READ_U32(rd);
WRITE_U32(ldest, mp);
size = READ_U32(r1);
WRITE_U32(mp, size);
mp += (size + 4);
return true;
}
case OP_MEM_CPY_8: {
DECODE_A(instruction)
u32 i, count, mdest, msrc;
u32 rd = fp + (dest * 4);
u32 r1 = fp + (src1 * 4);
u32 r2 = fp + (src2 * 4);
mdest = READ_U32(rd);
msrc = READ_U32(r1);
count = READ_U32(r2);
if (mdest + count >= mp) {
flag = 1;
return true;
}
for (i = 0; i < count; i++) {
u8 value = READ_U8(mdest + i);
WRITE_U8(msrc + i, value);
}
flag = 0;
return true;
}
case OP_MEM_CPY_16: {
DECODE_A(instruction)
u32 i, count, mdest, msrc;
u32 rd = fp + (dest * 4);
u32 r1 = fp + (src1 * 4);
u32 r2 = fp + (src2 * 4);
mdest = READ_U32(rd);
msrc = READ_U32(r1);
count = READ_U32(r2);
if (mdest + count >= mp) {
flag = 1;
return true;
}
for (i = 0; i < count; i++) {
u16 value = READ_U16(mdest + i);
WRITE_U16(msrc + i, value);
}
flag = 0;
return true;
}
case OP_MEM_CPY_32: {
DECODE_A(instruction)
u32 i, count, mdest, msrc;
u32 rd = fp + (dest * 4);
u32 r1 = fp + (src1 * 4);
u32 r2 = fp + (src2 * 4);
mdest = READ_U32(rd);
msrc = READ_U32(r1);
count = READ_U32(r2);
if (mdest + count >= mp) {
flag = 1;
return true;
}
for (i = 0; i < count; i++) {
u32 value = READ_U32(mdest + i);
WRITE_U32(msrc + i, value);
}
flag = 0;
return true;
}
case OP_MEM_SET_8: {
DECODE_A(instruction)
u32 i, start, end;
u32 rd = fp + (dest * 4);
u32 r1 = fp + (src1 * 4);
u32 r2 = fp + (src2 * 4);
u8 value = (u8)READ_U32(r1);
u32 count = READ_U32(r2);
if (r2 == 0) {
flag = 1;
return true;
}
start = READ_U32(rd);
end = start + count;
if (start >= mp || r2 > mp || end > mp) {
flag = 1;
return true;
}
for (i = start; i < end; i++) {
WRITE_U8(i, value);
}
flag = 0;
return true;
}
case OP_MEM_SET_16: {
DECODE_A(instruction)
u32 i, start, end;
u32 rd = fp + (dest * 4);
u32 r1 = fp + (src1 * 4);
u32 r2 = fp + (src2 * 4);
u16 value = (u16)READ_U32(r1);
u32 count = READ_U32(r2);
if (r2 == 0) {
flag = 1;
return true;
}
start = READ_U32(rd);
end = start + count;
if (start >= mp || r2 > mp || end > mp) {
flag = 1;
return true;
}
for (i = start; i < end; i += 2) {
WRITE_U16(i, value);
}
flag = 0;
return true;
}
case OP_MEM_SET_32: {
DECODE_A(instruction)
u32 i, start, end;
u32 rd = fp + (dest * 4);
u32 r1 = fp + (src1 * 4);
u32 r2 = fp + (src2 * 4);
u32 value = READ_U32(r1);
u32 count = READ_U32(r2);
if (r2 == 0) {
flag = 1;
return true;
}
start = READ_U32(rd);
end = start + count;
if (start >= mp || r2 > mp || end > mp) {
flag = 1;
return true;
}
for (i = start; i < end; i += 4) {
WRITE_U32(i, value);
}
flag = 0;
return true;
}
case OP_MOV: {
DECODE_A(instruction)
u32 rd = fp + (dest * 4);
u32 r1 = fp + (src1 * 4);
u32 value = READ_U32(r1);
USED(src2);
WRITE_U32(rd, value);
return true;
}
case OP_PUSH: {
DECODE_B(instruction)
u32 rd = fp + (dest * 4);
u32 val = READ_U32(rd);
USED(imm);
WRITE_U32((mp + (4 * (sp + 3))), val);
sp++;
return true;
}
case OP_POP: {
DECODE_C(instruction)
USED(imm);
mp -= 4;
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: {
DECODE_A(instruction)
u32 rd = fp + (dest * 4);
u32 r1 = fp + (src1 * 4);
u32 r2 = fp + (src2 * 4);
i32 src1_whole = (i32)READ_U32(r1) >> 16;
i32 src2_whole = (i32)READ_U32(r2) >> 16;
i32 src1_decimal = (i32)READ_U32(r1) & 16;
i32 src2_decimal = (i32)READ_U32(r2) & 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;
WRITE_U32(rd, result);
return true;
}
case OP_DIV_REAL: {
DECODE_A(instruction)
i32 result;
u32 rd = fp + (dest * 4);
u32 r1 = fp + (src1 * 4);
u32 r2 = fp + (src2 * 4);
i32 src1_val = (i32)READ_U32(r1);
i32 src2_val = (i32)READ_U32(r2);
u32 src2_reciprocal = 1;
src2_reciprocal <<= 31;
src2_reciprocal = (u32)(src2_reciprocal / src2_val);
result = src1_val * src2_reciprocal;
result <<= 1;
WRITE_U32(rd, result);
return true;
}
case OP_INT_TO_REAL: {
DECODE_A(instruction)
u32 rd = fp + (dest * 4);
u32 r1 = fp + (src1 * 4);
i32 result = (i32)READ_U32(r1) << 16;
USED(src2);
WRITE_U32(rd, result);
return true;
}
case OP_INT_TO_NAT: {
DECODE_A(instruction)
u32 rd = fp + (dest * 4);
u32 r1 = fp + (src1 * 4);
u32 result = (u32)READ_U32(r1);
USED(src2);
WRITE_U32(rd, result);
return true;
}
case OP_NAT_TO_REAL: {
DECODE_A(instruction)
u32 rd = fp + (dest * 4);
u32 r1 = fp + (src1 * 4);
i32 result = ((i32)READ_U32(r1) << 16);
USED(src2);
WRITE_U32(rd, result);
return true;
}
case OP_NAT_TO_INT: {
DECODE_A(instruction)
u32 rd = fp + (dest * 4);
u32 r1 = fp + (src1 * 4);
i32 result = ((i32)READ_U32(r1));
USED(src2);
WRITE_U32(rd, result);
return true;
}
case OP_REAL_TO_INT: {
DECODE_A(instruction)
u32 rd = fp + (dest * 4);
u32 r1 = fp + (src1 * 4);
i32 result = ((i32)READ_U32(r1) >> 16);
USED(src2);
WRITE_U32(rd, result);
return true;
}
case OP_REAL_TO_NAT: {
DECODE_A(instruction)
u32 rd = fp + (dest * 4);
u32 r1 = fp + (src1 * 4);
u32 result = ((u32)READ_U32(r1) >> 16);
USED(src2);
WRITE_U32(rd, 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_IMM: {
DECODE_C(instruction)
pc = imm;
return true;
}
case OP_JMP_ABS: {
DECODE_A(instruction)
u32 rd = fp + (dest * 4);
u32 jmp_dest = READ_U32(rd);
if (jmp_dest > cp) {
flag = 1;
return true;
}
USED(src1);
USED(src2);
pc = jmp_dest;
return true;
}
case OP_JMP_OFF: {
DECODE_A(instruction)
u32 rd = fp + (dest * 4);
u32 r1 = fp + (src1 * 4);
u32 jmp_dest = READ_U32(rd) + READ_U32(r1);
if (jmp_dest > cp) {
flag = 1;
return true;
}
USED(src2);
pc = jmp_dest;
return true;
}
case OP_JMP_FLAG: {
DECODE_A(instruction)
u32 mask;
u32 rd = fp + (dest * 4);
u32 jmp_dest = READ_U32(rd);
if (jmp_dest > cp) {
flag = 1;
return true;
}
USED(src1);
USED(src2);
mask = -(u32)(flag == 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, <=);
}
}
/* something went very wrong */
flag = 255;
return false;
}