From c05adee382fec7b28a971cc6460d81e486bd3684 Mon Sep 17 00:00:00 2001
From: andromeda <andromeda@lenovo>
Date: Sun, 15 Mar 2026 21:55:16 +0100
Subject: [PATCH] add octal

---
 twasm/asm/main.asm  | 64 ++++++++++++++++++++++++++++++++++-----------
 twasm/asm/tests.asm | 52 ++++++++++++++++++++++--------------
 2 files changed, 81 insertions(+), 35 deletions(-)

diff --git a/twasm/asm/main.asm b/twasm/asm/main.asm
index 5c41239..069e3f3 100644
--- a/twasm/asm/main.asm
+++ b/twasm/asm/main.asm
@@ -626,7 +626,7 @@ tokenise:
 
     jmp .operator_id_loop
 
-  .found_id
+  .found_id:
     push rdx
     mov dx, [rcx + 4] ; dx = token id
 
@@ -730,6 +730,7 @@ tokenise:
 ; | type | p. | description  |
 ; |------|----|--------------|
 ; | 0x00 | 0x | hexidecimal  |
+; | 0x01 | 0b | octal        |
 ; | 0xFF |    | unrecognised |
 ;
 ; where `p.` is the prefix
@@ -744,24 +745,38 @@ tokenise:
 ; ------------------------------------------------------------------------------
 
 evaluate_constant:
+                ; rsi = number of bytes left
+                ; rdi -> current byte of constant
+  xor eax, eax  ; rax = value of constant
+
   ; TODO fix this cheap trick xD
   mov dl, [rdi]
+  dec rsi ; one fewer byte left
+  inc rdi ; point to next byte
   cmp dl, '0'
   jne .unrecognised
-  dec rsi ; one fewer byte left
-  inc rdi ; point to next byte
 
   mov dl, [rdi]
-  cmp dl, 'x'
-  jne .unrecognised
   dec rsi ; one fewer byte left
   inc rdi ; point to next byte
 
-               ; rsi = number of bytes left
-               ; rdi -> current byte of constant
-  xor eax, eax ; rax = value in hex of constant
+  ; hex case
+  mov rcx, 0x00
+  push rcx
+  cmp dl, 'x'
+  je .hex_loop
+  pop rcx
 
-  .loop:
+  ; octal case
+  mov rcx, 0x01
+  push rcx
+  cmp dl, 'q'
+  je .oct_loop
+  pop rcx
+
+  jmp .unrecognised
+
+  .hex_loop:
     cmp rsi, 0 ; make sure we're in range
     je .break  ; if not, break
 
@@ -772,24 +787,43 @@ evaluate_constant:
     sub dl, '0' ; dl = if digit: digit; else :shrug:
 
     cmp dl, 9     ; if !digit:
-    jg .alpha     ;   letter
-    jmp .continue ; else loop
+    jg .hex_alpha     ;   letter
+    jmp .hex_continue ; else loop
 
-  .alpha
+  .hex_alpha:
     sub dl, 7        ; map [('A'-'0')..('F'-'0')] to [0xA..0xF]
     cmp dl, 0xF      ; if not in the range [0xA..0xF]
     jg .unrecognised ; then unrecognised
 
-  .continue
+  .hex_continue:
     and dl, 0x0F ; mask
     or al, dl    ; and add newest nibble
 
     dec rsi   ; one fewer byte left
     inc rdi   ; point to next byte
-    jmp .loop ; and loop
+    jmp .hex_loop ; and loop
+
+  .oct_loop:
+    cmp rsi, 0 ; make sure we're in range
+    je .break  ; if not, break
+
+    shl rax, 3 ; make room for next octal digit
+
+    mov dl, [rdi] ; dl = next byte of constant
+
+    sub dl, '0'
+    cmp dl, 7
+    jg .unrecognised
+
+    and dl, 7 ; mask
+    or al, dl ; and add newest 3-bit group
+
+    dec rsi       ; one fewer byte left
+    inc rdi       ; point to next byte
+    jmp .oct_loop ; and loop
 
   .break:
-    mov rdx, 0x00 ; hex type
+    pop rdx
     ret
 
   .unrecognised:
diff --git a/twasm/asm/tests.asm b/twasm/asm/tests.asm
index 190f4c2..10c80ad 100644
--- a/twasm/asm/tests.asm
+++ b/twasm/asm/tests.asm
@@ -315,41 +315,50 @@ test_evaluate_constant:
   call print.test
 
   ; just numerals
-  mov rdi, .case0 ; addr of constant
-  mov rsi, 8      ; length of constant
+  mov rdi, .case0h ; addr of constant
+  mov rsi, 8       ; length of constant
   call evaluate_constant
-  cmp rax, [.case0_solution]
+  cmp rax, [.case0h_solution]
   jne .fail
   cmp rdx, 0x00
   jne .fail
 
   ; just chars
-  mov rdi, .case1 ; addr of constant
-  mov rsi, 8      ; length of constant
+  mov rdi, .case1h ; addr of constant
+  mov rsi, 8       ; length of constant
   call evaluate_constant
-  cmp rax, [.case1_solution]
+  cmp rax, [.case1h_solution]
   jne .fail
   cmp rdx, 0x00
   jne .fail
 
   ; just chars
-  mov rdi, .case2 ; addr of constant
-  mov rsi, 12     ; length of constant
+  mov rdi, .case2h ; addr of constant
+  mov rsi, 12      ; length of constant
   call evaluate_constant
-  cmp rax, [.case2_solution]
+  cmp rax, [.case2h_solution]
   jne .fail
   cmp rdx, 0x00
   jne .fail
 
   ; PI
-  mov rdi, .case3 ; addr of constant
-  mov rsi, 18     ; length of constant
+  mov rdi, .case3h ; addr of constant
+  mov rsi, 18      ; length of constant
   call evaluate_constant
-  cmp rax, [.case3_solution]
+  cmp rax, [.case3h_solution]
   jne .fail
   cmp rdx, 0x00
   jne .fail
 
+  ; PI
+  mov rdi, .case0q
+  mov rsi, 16
+  call evaluate_constant
+  cmp rax, [.case0q_solution]
+  jne .fail
+  cmp rdx, 0x01
+  jne .fail
+
   .pass:
     mov rsi, msg_pass
     call print
@@ -359,14 +368,17 @@ test_evaluate_constant:
     call print
     ret
   .msg db "test_evaluate_constant...", 0x00
-  .case0 db "0x012390"
-  .case0_solution dq 0x012390
-  .case1 db "0xABCDEF"
-  .case1_solution dq 0xABCDEF
-  .case2 db "0x1234567890"
-  .case2_solution dq 0x1234567890
-  .case3 db "0x243F6A8885A308D3"
-  .case3_solution dq 0x243F6A8885A308D3
+  .case0h db "0x012390"
+  .case0h_solution dq 0x012390
+  .case1h db "0xABCDEF"
+  .case1h_solution dq 0xABCDEF
+  .case2h db "0x1234567890"
+  .case2h_solution dq 0x1234567890
+  .case3h db "0x243F6A8885A308D3"
+  .case3h_solution dq 0x243F6A8885A308D3
+
+  .case0q db "0q31103755242102"
+  .case0q_solution dq 0q31103755242102
 
 msg_pass:
   db 0x0A