implemented flag for comparison result

.vscode/launch.json

@@ -7,7 +7,7 @@
             "request": "launch",
             "program": "${workspaceFolder}/bin/tcpu",
             "windows": { "program": "${workspaceFolder}/bin/tcpu.exe" },
-            "args": [ "-c", "../examples/conditional_jump.tasm", "o.bin", "--debug", "-i", "o.bin" ],
+            "args": [ "-c", "../examples/loop.tasm", "o.bin", "--debug", "-i", "o.bin" ],
             "cwd": "${workspaceFolder}/bin",
             "preLaunchTask": "build_exec_dbg",
             "stopAtEntry": false,

README.md

@@ -43,7 +43,7 @@ Machine code interpreter written in pure C. Can execute programs up to 1 MEGABYT
 | EXIT |           | stop the program with exit code in `eax` |
 | SYS  |           | call system function |
 |                            |
-| MOVC | `dst_register`, `value` | push constant value into `dst_register` | 
+| MOVC | `dst_register`, `const_value` | push constant value into `dst_register` | 
 | MOVR | `dst_register`, `src_register` | copy value from `src_register` to `dst_register` |
 |                            |
 | ADD | `dst_register`, `src_register` | `dst += src` |
@@ -65,9 +65,9 @@ Machine code interpreter written in pure C. Can execute programs up to 1 MEGABYT
 | XOR | `dst_register`, `src_register` | `dst = dst ^ src` |
 | AND | `dst_register`, `src_register` | `dst = dst & src` |
 |                            |
-| JMP | `dst_register` | goto `dst` |
+| JMP | `dst_address_const` | goto `dst` |
-| JNZ | `dst_register` | if (`cmp_flag` != 0) goto `dst` |
+| JNZ | `dst_address_const` | if (`cmp_flag` != 0) goto `dst` |
-| JZ  | `dst_register` | if (`cmp_flag` == 0) goto `dst` |
+| JZ  | `dst_address_const` | if (`cmp_flag` == 0) goto `dst` |
 
 ### System functions
 To call a system function you need to push values to registers and write `SYS` opcode. The return value of a function will will be avaliable in `ax` after call.

examples/conditional_jump.tasm

@@ -5,9 +5,9 @@ Example of behavior change depending on some condition
 .main:
 movc ax 1
 movc bx 2
-gt cx ax bx
+gt ax bx
-jnz @true cx
+jnz @true
-jz @false cx
+jz @false
 
 .true:
 const8 true.msg "true\n"

examples/loop.tasm

@@ -3,6 +3,7 @@ Example of self-repeating code section
 */
 
 .main:
+movc dx 0; // loop counter
 
 .loop
 const8 datum "ITERATION!!! "
@@ -11,4 +12,11 @@ movc ah 1
 movc rbx @datum
 movc ecx #datum
 sys
-jmp @loop
+
+movc cx 1
+add dx cx
+movc cx 8
+lt dx cx
+jnz @loop
+movc rax 0
+exit

src/VM/VM.h

@@ -31,6 +31,10 @@ typedef struct VM {
         Register array[4];
     } registers;
 
+    struct {
+        bool cmp; // result of comparison operation
+    } flags;
+    
     VMState state;
     char* NULLABLE(error_message); // not null on if state == VMState_InternalError
 

src/instructions/impl/JMP.c

@@ -11,40 +11,26 @@ i32 JMP_impl(VM* vm){
 }
 
 
-// JNZ [destination address] [condition register]
+// JNZ [destination address]
 i32 JNZ_impl(VM* vm){
     u64 dst_addr = 0;
     readVar(dst_addr);
     
-    RegisterCode reg_code = 0;
+    if(vm->flags.cmp != 0){
-    readRegisterCode(reg_code);
-    u64 cond_reg_value = 0;
-    VM_registerRead(vm, &cond_reg_value, reg_code);
-    
-    if(cond_reg_value != 0){
         vm->current_pos = dst_addr;
     }
     
-    return sizeof(dst_addr) + sizeof(reg_code);
+    return sizeof(dst_addr);
 }
 
-// JZ [destination address] [condition register]
+// JZ [destination address]
 i32 JZ_impl(VM* vm){
     u64 dst_addr = 0;
-    { 
+    readVar(dst_addr);
-        if(!VM_dataRead(vm, &dst_addr, vm->current_pos, sizeof(dst_addr)))
-     return -1; 
-     vm->current_pos += sizeof(dst_addr);
-    };
 
-    RegisterCode reg_code = 0;
+    if(vm->flags.cmp == 0){
-    readRegisterCode(reg_code);
-    u64 cond_reg_value = 0;
-    VM_registerRead(vm, &cond_reg_value, reg_code);
-
-    if(cond_reg_value == 0){
         vm->current_pos = dst_addr;
     }
     
-    return sizeof(dst_addr) + sizeof(reg_code);
+    return sizeof(dst_addr);
 }

src/instructions/impl/impl_macros.h

@@ -45,18 +45,15 @@ i32 NAME##_impl (VM* vm) {\
     return sizeof(dst_reg_code) + sizeof(src_reg_code);\
 }
 
-#define OPERATOR_IMPL_3(NAME, OPERATOR)\
+#define OPERATOR_IMPL_CMP_FLAG(NAME, OPERATOR)\
 i32 NAME##_impl (VM* vm) {\
-    RegisterCode dst_reg_code = 0, src0_reg_code = 0, src1_reg_code = 0;\
+    RegisterCode src0_reg_code = 0, src1_reg_code = 0;\
-    readRegisterCode(dst_reg_code);\
     readRegisterCode(src0_reg_code);\
     readRegisterCode(src1_reg_code);\
-    u64 dst_reg_value = 0, src0_reg_value = 0, src1_reg_value = 0;\
+    u64 src0_reg_value = 0, src1_reg_value = 0;\
-    VM_registerRead(vm, &dst_reg_value, dst_reg_code);\
     VM_registerRead(vm, &src0_reg_value, src0_reg_code);\
     VM_registerRead(vm, &src1_reg_value, src1_reg_code);\
     \
-    dst_reg_value = src0_reg_value OPERATOR src1_reg_value;\
+    vm->flags.cmp = src0_reg_value OPERATOR src1_reg_value;\
-    VM_registerWrite(vm, &dst_reg_value, dst_reg_code);\
+    return sizeof(src0_reg_code) + sizeof(src1_reg_code);\
-    return sizeof(dst_reg_code) + sizeof(src0_reg_code) + sizeof(src1_reg_code);\
 }

src/instructions/impl/logical_operators.c

@@ -17,20 +17,20 @@ OPERATOR_IMPL_2(XOR, ^)
 OPERATOR_IMPL_2(AND, &)
 
 
-/// EQ [dst_register] [src0_register] [src1_register]
+/// EQ [src0_register] [src1_register]
-OPERATOR_IMPL_3(EQ, ==)
+OPERATOR_IMPL_CMP_FLAG(EQ, ==)
 
-/// NE [dst_register] [src0_register] [src1_register]
+/// NE [src0_register] [src1_register]
-OPERATOR_IMPL_3(NE, !=)
+OPERATOR_IMPL_CMP_FLAG(NE, !=)
 
-/// LT [dst_register] [src0_register] [src1_register]
+/// LT [src0_register] [src1_register]
-OPERATOR_IMPL_3(LT, <)
+OPERATOR_IMPL_CMP_FLAG(LT, <)
 
-/// LE [dst_register] [src0_register] [src1_register]
+/// LE [src0_register] [src1_register]
-OPERATOR_IMPL_3(LE, <=)
+OPERATOR_IMPL_CMP_FLAG(LE, <=)
 
-/// GT [dst_register] [src0_register] [src1_register]
+/// GT [src0_register] [src1_register]
-OPERATOR_IMPL_3(GT, >)
+OPERATOR_IMPL_CMP_FLAG(GT, >)
 
-/// GE [dst_register] [src0_register] [src1_register]
+/// GE [src0_register] [src1_register]
-OPERATOR_IMPL_3(GE, >=)
+OPERATOR_IMPL_CMP_FLAG(GE, >=)