From efa6ed21c96f47d122b2be271245b58c096f80a2 Mon Sep 17 00:00:00 2001
From: elvis <elvilio98@gmail.com>
Date: Mon, 2 Dec 2024 14:26:05 +0100
Subject: [PATCH] Added While loop to RISC

---
 lib/miniImp/RISC.ml | 35 +++++++++++++++++++++++++++++++----
 1 file changed, 31 insertions(+), 4 deletions(-)

diff --git a/lib/miniImp/RISC.ml b/lib/miniImp/RISC.ml
index cf69c2d..a7c5b96 100644
--- a/lib/miniImp/RISC.ml
+++ b/lib/miniImp/RISC.ml
@@ -192,7 +192,15 @@ let nextCommonSuccessor (prg: CfgRISC.RISCCfg.t) (node1: Cfg.Node.t) (node2: Cfg
   | a::_ -> Some a
 
 
-let rec helper (prg: CfgRISC.RISCCfg.t) (currentnode: Cfg.Node.t) (alreadyVisited: Cfg.Node.t list) : RISCAssembly.t * Cfg.Node.t list  =
+let rec helper
+    (prg: CfgRISC.RISCCfg.t)
+    (currentnode: Cfg.Node.t)
+    (alreadyVisited: Cfg.Node.t list)
+  : RISCAssembly.t * Cfg.Node.t list  =
+  (* takes the program, the current node and a list of already visited nodes to
+     compute the linearized three address instructions and the list of
+     previoulsy visited nodes plus the newly visited nodes. Stops as soon if
+     node has already been visited or if no nodes are next *)
   if List.mem currentnode alreadyVisited then
     ([], alreadyVisited)
   else (
@@ -214,9 +222,28 @@ let rec helper (prg: CfgRISC.RISCCfg.t) (currentnode: Cfg.Node.t) (alreadyVisite
         failwith "Topology got a little mixed up"
       | Some ncs -> (
           if (ncs.id = nextnode2.id)
-          then (* while or for loop *)
-            failwith "Not implemented"
-          else (* if branches *)
+          then (* while or for loop, three labels are necessary *)
+            let label1 = nextLabel () in
+            let label2 = nextLabel () in
+            let label3 = nextLabel () in
+
+            let res1, _ = (helper prg nextnode1 (currentnode :: nextnode2 :: alreadyVisited)) in
+            let res2, vis2 = (helper prg nextnode2 (currentnode :: nextnode1 :: alreadyVisited)) in
+
+            match List.nth currentcode ((List.length currentcode) - 1) with
+            | BRegOp (_, _, _, r)
+            | BImmOp (_, _, _, r)
+            | URegOp (_, _, r)
+            | Load (_, r)
+            | LoadI (r, _) -> (([Label label1] : RISCAssembly.t) @
+                                currentcode @
+                               ([CJump (r, label2, label3); Label label2] : RISCAssembly.t) @
+                               res1 @
+                               ([Jump label1; Label label3] : RISCAssembly.t) @
+                               res2
+                              , vis2)
+            | _ -> failwith "Missing instruction"
+          else (* if branches, three labels are necessary *)
             let label1 = nextLabel () in
             let label2 = nextLabel () in
             let label3 = nextLabel () in