IT SORTA WORKS LESGOOO

2026-03-23 23:37:39 +01:00
parent 40be72a5c3
commit b607bd13f3
3 changed files with 135 additions and 31 deletions
--- a/twasm/README.md
+++ b/twasm/README.md
@@ -210,11 +210,11 @@ type metadata for the different types is as follows:
 entries are as follows:

 ```
-+----------+--------+----------+
-| 31    24 | 23  16 | 15     0 |
-+----------+--------+----------+
-| reserved | opcode | token ID |
-+----------+--------+----------+
+-----------------+-----------------+----------+
+| 31           24 | 23           16 | 15     0 |
+-----------------+-----------------+----------+
+| dest=reg opcode | dest=r/m opcode | token ID |
+-----------------+-----------------+----------+
 ```

 note the lack of support for multiple-byte opcodes or multiple opcodes for one token ID; these features will likely be added at some point after the parser accumulates too much jank.
--- a/twasm/asm/main.asm
+++ b/twasm/asm/main.asm
@@ -124,16 +124,20 @@ assemble:
    pop rsi

    push rdi
-    ; di = tte of operator
+    push rsi
+                ; di = tte of operator
+    mov sil, 0b ; standard opcode
    call get_opcode
    ; al = opcode
    call .output_byte
+    pop rsi
    pop rdi

    pop rax ; rax = number of tokens processed
    pop rdi ; rdi = total number of tokens
    inc rax
    cmp rax, rdi
+    jge .break
    jmp .loop

  ; di = tte of operator
@@ -144,10 +148,13 @@ assemble:
    pop rsi

    push rdi
-    ; di = tte of operator
+    push rsi
+                ; di = tte of operator
+    mov sil, 0b ; dst=r/m
    call get_opcode
    ; al = opcode
    call .output_byte
+    pop rsi
    pop rdi ; di = tte of operator

    pop rax ; rax = number of tokens processed
@@ -214,12 +221,7 @@ assemble:
    call print.debug
    pop rsi

-    push rdi
-    ; di = tte of operator
-    call get_opcode
-    ; al = opcode
-    call .output_byte
-    pop rdi ; di = tte of operator
+    mov cx, di ; cx = tte of operator

    pop rax
    pop rdi
@@ -237,9 +239,11 @@ assemble:
    pop rdi        ; di = next tte
    je .operator_2_memory_access

+    push rcx
    ; di = next tte
    call get_tte_type
    ; al = type of token
+    pop rcx ; cx = tte of operator

    cmp al, 0x02 ; type: register
    je .operator_2_register
@@ -256,7 +260,80 @@ assemble:
    mov rsi, .msg_operator_2_memory_access
    call print.debug
    pop rsi
-    jmp .unsupported_memory_access
+
+    cmp di, 0x1000                 ; check if token is addressing a register
+    jne .unsupported_memory_access ; if not, unsupported :/
+
+
+    push rdi
+    mov di, cx ; di = tte of operator
+    mov sil, 0 ; dst = r/m
+    call get_opcode
+    ; al = opcode
+    call .output_byte
+    pop rdi
+
+    pop rax
+    pop rdi
+    inc rax
+    cmp rax, rdi
+    jge .break
+    push rdi
+    push rax
+    xor edi, edi
+    mov di, [rax * TOKEN_TABLE_ENTRY_SIZE + TOKEN_TABLE_ADDR] ; di = next tte
+
+    mov si, di ; si = dst tte
+
+    pop rax
+    pop rdi
+    inc rax
+    cmp rax, rdi
+    jge .break
+    push rdi
+    push rax
+    xor edi, edi
+    mov di, [rax * TOKEN_TABLE_ENTRY_SIZE + TOKEN_TABLE_ADDR] ; di = next tte
+
+    push rdi
+    and di, 0xFF00
+    cmp di, 0x1000                ; check if token is a memory address
+    pop rdi                       ; di = next tte
+    je .unsupported_memory_access ; no case of *],[* in asm
+
+    ; di = next tte
+    call get_tte_type
+    ; al = type of token
+
+    cmp al, 0x02
+    je .operator_2_memory_access_register
+
+    pop rax ; rax = number of tokens processed
+    pop rdi ; rdi = total number of tokens
+    inc rax
+    cmp rax, rdi
+    jge .break
+    jmp .loop
+
+  .operator_2_memory_access_register:
+    push rsi
+    mov rsi, .msg_operator_2_memory_access_register
+    call print.debug
+    pop rsi
+
+    ; si = r/m; dst tte
+    ; di = reg; src tte
+    mov dl, 00b ; dl = mod bits
+    call get_ModRM
+    ; al = Mod R/M byte
+    call .output_byte
+
+    pop rax ; rax = number of tokens processed
+    pop rdi ; rdi = total number of tokens
+    inc rax
+    cmp rax, rdi
+    jge .break
+    jmp .loop

  .operator_2_register:
    push rsi
@@ -264,7 +341,15 @@ assemble:
    call print.debug
    pop rsi

-    mov si, di     ; si = `R/M` tte
+    push rdi
+    mov di, cx ; di = tte of operator
+    mov sil, 1 ; dst = reg
+    call get_opcode
+    ; al = opcode
+    call .output_byte
+    pop rdi
+
+    mov si, di ; si = dst tte

    pop rax
    pop rdi
@@ -290,7 +375,7 @@ assemble:
    je .operator_2_register_register

    pop rax ; rax = number of tokens processed
-    pop rdi ; rdi = total nnumber of tokens
+    pop rdi ; rdi = total number of tokens
    inc rax
    cmp rax, rdi
    jge .break
@@ -338,11 +423,9 @@ assemble:
    call print.debug
    pop rsi

-    ; si = `R/M` tte
-    ; di = `reg` tte
    push rsi
-    mov si, di
-    pop rdi
+    mov si, di  ; si = reg; src tte
+    pop rdi     ; di = r/m; dst tte
    mov dl, 11b ; dl = mod bits
    call get_ModRM
    ; al = Mod R/M byte
@@ -388,6 +471,7 @@ assemble:
  .msg_operator_1_register db "operator_1_register", 0x0A, 0x00
  .msg_operator_2 db "operator_2", 0x0A, 0x00
  .msg_operator_2_memory_access db "operator_2_memory_access", 0x0A, 0x00
+  .msg_operator_2_memory_access_register db "operator_2_memory_access_register", 0x0A, 0x00
  .msg_operator_2_register db "operator_2_register", 0x0A, 0x00
  .msg_operator_2_register_memory_access db "operator_2_register_memory_access", 0x0A, 0x00
  .msg_operator_2_register_register db "operator_2_register_register", 0x0A, 0x00
@@ -514,10 +598,13 @@ get_ModRM:
 ; get_opcode
 ;
 ; description:
-; given an operator token, returns its opcode
+; given an operator token, returns its opcode. For operators with multiple
+; opcodes, the variant can be specified.
 ;
 ; parameters:
 ; di = token table entry
+; sil = lower bit: 0: dst=r/m or only opcode
+;                  1: dst=reg or 0x00
 ;
 ; returned:
 ; al = opcode; the rest of rax is zeroed
@@ -525,6 +612,7 @@ get_ModRM:

 get_opcode:
  and rdi, 0xFFFF
+  and rsi, 1
  xor eax, eax

  .loop:
@@ -543,7 +631,7 @@ get_opcode:
    mov al, UNRECOGNISED_ID_OPCODE
    ret
  .found:
-    mov al, [2 + opcodes.by_id + rax * 4]
+    mov al, [rsi + 2 + opcodes.by_id + rax * 4]
    and rax, 0xFF ; mask
    ret

@@ -1707,20 +1795,20 @@ tokens:
 opcodes:
  .by_id:
    dw 0x0053 ; xor
-    db 0x31
-    db 0x00   ; reserved
+    db 0x31   ; r/m <- reg
+    db 0x33   ; reg <- r/m

    dw 0x0054 ; inc
-    db 0xFF
-    db 0x00   ; reserved
+    db 0xFF   ; r/m
+    db 0x00   ;

    dw 0x0056 ; mov
-    db 0x8B
-    db 0x00   ; reserved
+    db 0x89   ; r/m <- reg
+    db 0x8B   ; reg <- r/m

    dw 0x004F ; hlt
-    db 0xF4
-    db 0x00   ; reserved
+    db 0xF4   ; .
+    db 0x00   ;
  .by_id_end:

 msg_welcome db "Welcome to Twasm", 0x0A, 0x00
@@ -1735,7 +1823,7 @@ program:
  db "; one line comment", 0x0A
  db "mov rdx, [rax]", 0x0A
  db "mov [rax], rdx", 0x0A
-  db "hlt"
+  db "hlt", 0x0A
  .size dq $ - program

 msg_end db "end of the binary ->|", 0x0A, 0x00
--- a/twasm/asm/tests.asm
+++ b/twasm/asm/tests.asm
@@ -251,6 +251,11 @@ test_get_tte_typed_metadata:
  cmp al, 0x02                ; # operands
  jne .fail

+  mov di, 0x004F              ; hlt
+  call get_tte_typed_metadata
+  cmp al, 0x00                ; # operands
+  jne .fail
+
  mov di, 0x0003              ; rdx
  call get_tte_typed_metadata
  cmp al, 00001011b           ; reg: 010b
@@ -289,21 +294,32 @@ test_get_opcode:
  call print.test

  mov di, 0x0053 ; xor
+  mov sil, 0b
  call get_opcode
  cmp al, 0x31
  jne .fail

+  mov di, 0x0053 ; xor
+  mov sil, 1b
+  call get_opcode
+  cmp al, 0x33
+  jne .fail
+
+
  mov di, 0x0054  ; inc
+  mov sil, 0b
  call get_opcode
  cmp al, 0xFF
  jne .fail

  mov di, 0x004F  ; hlt
+  mov sil, 0b
  call get_opcode
  cmp al, 0xF4
  jne .fail

  mov di, 0x0003  ; rdx (not an operator)
+  mov sil, 0b
  call get_opcode
  cmp al, UNRECOGNISED_ID_OPCODE
  jne .fail