From 9d1263da3e1499040fe258ea8dea1c60ae7ccf6a Mon Sep 17 00:00:00 2001
From: plugd <plugd@thelambdalab.xyz>
Date: Fri, 15 Oct 2021 17:22:31 +0200
Subject: [PATCH] Added several more instructions.

---
 ez.el | 155 ++++++++++++++++++++++++++++++++++++++++++++++++++++------
 1 file changed, 139 insertions(+), 16 deletions(-)

diff --git a/ez.el b/ez.el
index 22a4c78..e899ab4 100644
--- a/ez.el
+++ b/ez.el
@@ -30,8 +30,25 @@
 
 ;; Utility functions
 
+(defun ez-decode-signed-bits (n nbits)
+  (if (= 0 (lsh n (- 1 nbits)))
+      n
+    (- n (lsh 1 nbits))))
+
 (defun ez-decode-signed-byte (b)
-  (lsh b ))
+  (ez-decode-signed-bits b 8))
+
+(defun ez-decode-signed-word (w)
+  (ez-decode-signed-bits w 16))
+
+(defun binformat (n &optional s)
+  (unless s
+    (setq s ""))
+  (let ((d (/ n 2))
+        (new-s (concat (number-to-string (mod n 2)) s)))
+    (if (= d 0)
+        new-s
+      (binformat d new-s))))
 
 ;; Memory
 
@@ -353,34 +370,132 @@
         (if (= type 1)
             'b
           'w))
-      types)))))
+      types))))
+
+;; Branches
+
+(defun ez-do-branch (branch)
+  (let* ((branch-byte (ez-read-pc-byte-and-inc))
+         (invert (= 0 (logand branch-byte #b10000000)))
+         (single-byte (= 1 (logand branch-byte #b01000000)))
+         (offset
+          (if single-byte
+              (logand branch-byte #b00111111)
+            (let ((pos (= (logand branch-byte #b00100000) 0))
+                  (val (+ (* 256 (logand branch-byte #b00011111))
+                          (ez-read-pc-byte-and-inc))))
+              (if pos
+                  val
+                (- val 8192))))))
+    (cond
+     ((= offset 0)
+      (ez-op-rfalse))
+     ((= offset 1)
+      (ez-op-rtrue))
+     (t
+      (ez-set-pc (+ (ez-get-pc) offset -2))))))
+
+;; Operations
 
 (defvar ez-op-table
-  '(((2op #x14) add ez-op-add)
+  '(((0op #x00) rtrue ez-op-rtrue)
+    ((0op #x01) rfalse ez-op-rfalse)
+    ((1op #x00) jz ez-op-jz)
+    ((1op #x0B) ret ez-op-ret)
+    ((1op #x0C) jump ez-op-jump)
+    ((2op #x0D) store ez-op-store)
+    ((1op #x0E) load ez-op-load)
+    ((var #x01) storew ez-op-storew)
+    ((2op #x01) je ez-op-je)
+    ((2op #x08) or ez-op-or)
+    ((2op #x09) and ez-op-and)
+    ((2op #x14) add ez-op-add)
     ((2op #x15) sub ez-op-sub)
     ((2op #x16) mul ez-op-mul)
     ((2op #x17) div ez-op-div)
     ((2op #x18) mod ez-op-mod)
     ((var #x00) call_fv ez-op-callf)))
 
+(defun ez-op-ret (operands &optional operand-types)
+  (let ((retval (car operands)))
+    (ez-pop-call-stack-frame)
+    (ez-set-var (ez-read-pc-byte-and-inc) retval))
+  t)
+
+(defun ez-op-rtrue (&optional operands operand-types)
+  (ez-op-ret (list 1)))
+
+(defun ez-op-rfalse (&optional operands operand-types)
+  (ez-op-ret (list 0)))
+
+(defun ez-op-jz (operands operand-types)
+  (ez-do-branch (= (car operands) 0))
+  t)
+
+(defun ez-op-je (operands operand-types)
+  (ez-do-branch (memq (car operands) (cdr operands)))
+  t)
+
+(defun ez-op-jump (operands operand-types)
+  (let ((offset (if (eq (car operand-types) 'b)
+                    (ez-decode-signed-byte (car operands))
+                  (ez-decode-signed-word (car operands)))))
+    (ez-set-pc (+ (ez-get-pc) offset -2)))
+  t)
+
+(defun ez-op-store (operands operand-types)
+  (let ((var (car operands))
+        (a (cadr operands)))
+    (ez-set-var var a))
+  t)
+
+(defun ez-op-load (operands operand-types)
+  (let ((var (car operands)))
+    (ez-set-var (ez-read-pc-byte-and-inc) (ez-get-var var)))
+  t)
+
+(defun ez-op-storew (operands operand-types)
+  (let ((baddr (car operands))
+        (n (cadr operands))
+        (a (caddr operands)))
+    (ez-mem-set-word (+ baddr (* 2 n)) a))
+  t)
+
+(defun ez-op-and (operands operand-types)
+  (let ((a (car operands))
+        (b (cadr operands)))
+    (ez-set-var (ez-read-pc-byte-and-inc) (logand a b)))
+  t)
+
+(defun ez-op-or (operands operand-types)
+  (let ((a (car operands))
+        (b (cadr operands)))
+    (ez-set-var (ez-read-pc-byte-and-inc) (logior a b)))
+  t)
+
 (defun ez-op-add (operands operand-types)
   (let ((a (car operands))
         (b (cadr operands)))
-    (ez-set-var (ez-read-pc-byte-and-inc) (mod (+ a b) #x10000))))
+    (ez-set-var (ez-read-pc-byte-and-inc) (mod (+ a b) #x10000)))
+  t)
 
 (defun ez-op-sub (operands operand-types)
   (let ((a (car operands))
         (b (cadr operands)))
-    (ez-set-var (ez-read-pc-byte-and-inc) (mod (+ (- a b) #x10000) #x10000))))
+    (ez-set-var (ez-read-pc-byte-and-inc) (mod (+ (- a b) #x10000) #x10000)))
+  t)
 
 (defun ez-op-mul (a b)
   (let ((a (car operands))
         (b (cadr operands)))
-    (ez-set-var (ez-read-pc-byte-and-inc) (mod (* a b) #x10000))))
+    (ez-set-var (ez-read-pc-byte-and-inc) (mod (* a b) #x10000)))
+  t)
 
-(defun ez-op-div (a b))
+(defun ez-op-div (a b)
+  (error "Not implemented"))
 
-(defun ez-op-mod (a b))
+(defun ez-op-mod (a b)
+  (error "Not implemented"))
 
 (defun ez-op-callf (operands operand-types)
   (let* ((raddr (car operands))
@@ -411,16 +526,24 @@
 (ez-parse-header)
 (setq ez-call-stack (list (ez-make-call-stack-frame ez-start-pc)))
 (ez-execute-instr)
+
+(binformat #x97)
+"10010111"
+
+
 ez-call-stack
+((28281 nil [33807 0 180 47872 0 0 0 0 0 0 0 0 ...] nil) (22022 nil [33807 65535 0 0 0 0 0 0 0 0 0 0 ...] nil) (20715 nil [0 0 0 0 0 0 0 0 0 0 0 0 ...] nil))
+
+((22049 nil [33807 0 180 47872 0 0 0 0 0 0 0 0 ...] nil) (22022 nil [33807 65535 0 0 0 0 0 0 0 0 0 0 ...] nil) (20715 nil [0 0 0 0 0 0 0 0 0 0 0 0 ...] nil))
+
+
+
+
+
+
+
+
 
-(defun binformat (n &optional s)
-  (unless s
-    (setq s ""))
-  (let ((d (/ n 2))
-        (new-s (concat (number-to-string (mod n 2)) s)))
-    (if (= d 0)
-        new-s
-      (binformat d new-s))))
 
 
 
-- 
2.20.1