X Tutup
Skip to content

OpCode Reference

Jump to bottom
NateIsStalling edited this page Mar 31, 2023 · 1 revision

The following OpCodes are used by Basic4GL's virtual machine and are defined in OpCode.java

General

Mnemonic OpCode Description
NOP 0x00 No operation
END 0x01 End program
LOAD_CONST 0x02 Load constant into reg
LOAD_VAR 0x03 Load address of variable into reg
LOAD_LOCAL_VAR 0x04 Load address of local variable into reg
DEREF 0x05 Dereference reg (load value at [reg] into reg)
ADD_CONST 0x06 Add constant to reg. Used to address into a structure
ARRAY_INDEX 0x07 IN: reg = array index, reg2 = array address. OUT: reg = element address.
PUSH 0x08 Push reg to stack
POP 0x09 Pop stack into reg2
SAVE 0x0A Save int, real or string in reg into [reg2]
COPY 0x0B Copy structure at [reg2] into [reg]. Instruction value points to data type.
DECLARE 0x0C Allocate a variable
DECLARE_LOCAL 0x0D Allocate a local variable
TIMESHARE 0x0E Perform a timesharing break
FREE_TEMP 0x0F Free temporary data
ALLOC 0x10 Allocate variable memory
DATA_READ 0x11 Read program data into data at [reg]. Instruction contains target data type.
DATA_RESET 0x12 Reset program data pointer
SAVE_PARAM 0x13 Save int, real or string in reg into parameter in pending stack frame. Instruction contains data type. Parameter # is however many parameters have been set since CREATE_USER_FRAME was executed.
SAVE_PARAM_PTR 0x14 Save pointer to data in [reg] into parameter pointer.
COPY_USER_STACK 0x15 Copy data at [reg] to top of user stack. reg is then adjusted to point to the data in the user stack.
MOVE_TEMP 0x16 Free temp data and move data at [reg] into temp data. (Also handles if [reg] points to temp data).
CHECK_PTR 0x17 Check pointer scope before saving to variable. (Ptr is in reg, variable is [reg2])
CHECK_PTRS 0x18 Check all pointers in block at [reg] before copying to [reg2]. Instruction contains data type.
REG_DESTRUCTOR 0x19 Register string destruction block at [reg] (will be temp or stack depending on reg)

Flow control

Mnemonic OpCode Description
JUMP 0x40 Unconditional jump
JUMP_TRUE 0x41 Jump if reg <> 0
JUMP_FALSE 0x42 Jump if reg == 0
CALL_FUNC 0x43 Call external function
CALL_OPERATOR_FUNC 0x44 Call external operator function
CALL_DLL 0x45 Call DLL function
CALL 0x46 Call VM function
CREATE_USER_FRAME 0x47 Create user stack frame in preparation for a call
CALL_USER_FUNC 0x48 Call user defined function
RETURN 0x49 Return from VM function
RETURN_USER_FUNC 0x4A Return from user defined function
NO_VALUE_RETURNED 0x4B Generates a runtime error if executed

0x4C - 0x50 added after version 2.5.0

Mnemonic OpCode Description
BINDCODE 0x4C Bind a runtime code block to be executed
EXEC 0x4D Execute runtime code block
CREATE_RUNTIME_FRAME 0x4F Create a stack frame to call a function/sub in runtime code block
END_CALLBACK 0x50 End callback initiated by built-in function or DLL function, and return control to that function.

Operations

Mathematical

Mnemonic OpCode Description
OP_NEG 0x60
OP_PLUS 0x61 Doubles as string concatenation
OP_MINUS 0x62
OP_TIMES 0x63
OP_DIV 0x64
OP_MOD 0x65

Logical

Mnemonic OpCode Description
OP_NOT 0x80
OP_EQUAL 0x81
OP_NOT_EQUAL 0x82
OP_GREATER 0x83
OP_GREATER_EQUAL 0x84
OP_LESS 0x85
OP_LESS_EQUAL 0x86
OP_AND 0x87
OP_OR 0x88
OP_XOR 0x89

Conversion

Mnemonic OpCode Description
CONV_INT_REAL 0xA0 Convert integer in reg to real
CONV_INT_STRING 0xA1 Convert integer in reg to string
CONV_REAL_STRING 0xA2 Convert real in reg to string
CONV_REAL_INT 0xA3
CONV_INT_REAL2 0xA4 Convert integer in reg2 to real
CONV_INT_STRING2 0xA5 Convert integer in reg2 to string
CONV_REAL_STRING2 0xA6 Convert real in reg2 to string
CONV_REAL_INT2 0xA7

Misc Routine

Mnemonic OpCode Description
RUN 0xC0 Restart program. Re-initializes variables, display, state e.t.c

Debugging

Mnemonic OpCode Description
BREAKPT 0xE0 Breakpoint

Clone this wiki locally
X Tutup