From: Jonas Hvid Date: Sat, 23 Nov 2019 17:00:05 +0000 (+0100) Subject: Implement .U X-Git-Url: https://git.rrq.au/?a=commitdiff_plain;h=59d23425b8efe3004f6452e1fa670582b469af2a;p=rrq%2Fjonasforth.git Implement .U --- diff --git a/main.asm b/main.asm index f665f95..6356be8 100644 --- a/main.asm +++ b/main.asm @@ -212,17 +212,74 @@ HELLO: dq NEWLINE dq EXIT +;; .U prints the value on the stack as an unsigned integer in hexadecimal. +DOTU: + dq .start +.start: + mov [.length], 0 + pop rax ; RAX = value to print + push rsi ; Save value of RSI + + ;; We start by constructing the buffer to print in reverse + +.loop: + mov rdx, 0 + mov rbx, $10 + div rbx ; Put remainer in RDX and quotient in RAX + + ;; Place the appropriate character in the buffer + mov rsi, .chars + add rsi, rdx + mov bl, [rsi] + mov rdi, .rbuffer + add rdi, [.length] + mov [rdi], bl + inc [.length] + + ;; .printed_length is the number of characters that we ulitmately want to + ;; print. If we have printed a non-zero character, then we should update + ;; .printed_length. + cmp bl, '0' + je .skip_updating_real_length + mov rbx, [.length] + mov [.printed_length], rbx +.skip_updating_real_length: + + cmp [.length], 16 + jle .loop + + ;; Flip buffer around, since it is currently reversed + mov rcx, [.printed_length] +.flip: + mov rsi, .rbuffer + add rsi, rcx + dec rsi + mov al, [rsi] + + mov rdi, .buffer + add rdi, [.printed_length] + sub rdi, rcx + mov [rdi], al + + loop .flip + + ;; Print the buffer + mov rax, 1 + mov rdi, 1 + mov rsi, .buffer + mov rdx, [.printed_length] + syscall + + ;; Restore RSI and continue execution + pop rsi + next + MAIN: dq docol dq HELLO - dq READ_WORD - dq LIT, you_typed_string - dq LIT, you_typed_string.length - dq TELL - dq TELL - dq NEWLINE - dq BRANCH, -72 - dq HELLO + dq LIT, 1234567890, DOTU, NEWLINE + dq LIT, $ABCD, DOTU, NEWLINE + dq LIT, $1234ABCD5678EFAB, DOTU, NEWLINE dq TERMINATE segment readable writable @@ -237,6 +294,12 @@ READ_WORD.buffer rb READ_WORD.max_size READ_WORD.length db ? READ_WORD.char_buffer db ? +DOTU.chars db '0123456789ABCDEF' +DOTU.buffer rq 16 ; 64-bit number has no more than 16 digits in hex +DOTU.rbuffer rq 16 +DOTU.length dq ? +DOTU.printed_length dq ? + ;; Return stack rq $2000 return_stack_top: