From 02f53b20b4f7244a84a442bbae10eb8401abcfc5 Mon Sep 17 00:00:00 2001
From: Jonas Hvid <mail@johv.dk>
Date: Mon, 9 Dec 2019 18:09:38 +0100
Subject: [PATCH] Implement some arithmetic words

---
 main.asm | 11 +++++++++++
 sys.f    |  4 ++++
 2 files changed, 15 insertions(+)

diff --git a/main.asm b/main.asm
index 67e9a7b..d2cd54d 100644
--- a/main.asm
+++ b/main.asm
@@ -431,6 +431,17 @@ forth_asm MINUS, '-'
   push rbx
   next
 
+;; Given two integers a and b on the stack, pushes the quotient and remainder of
+;; division of a by b.
+forth_asm TIMESMOD, '/MOD'
+  pop rbx                       ; b
+  pop rax                       ; a
+  mov rdx, 0
+  div rbx
+  push rax                      ; a / b
+  push rdx                      ; a % b
+  next
+
 ;; Get the location of the STATE variable. It can be set with '!' and read with
 ;; '@'.
 forth STATE, 'STATE'
diff --git a/sys.f b/sys.f
index bc9dae9..23fed87 100644
--- a/sys.f
+++ b/sys.f
@@ -9,3 +9,7 @@ EXIT [
   [ S" [" FIND >CFA , ]
   EXIT
 [ IMMEDIATE
+
+: / /MOD DROP ;
+: MOD /MOD SWAP DROP ;
+: NEG 0 SWAP - ;
-- 
2.39.2