From 81fd5cb76f9e4b7a5db44f8a51a5fb2cc6bfa694 Mon Sep 17 00:00:00 2001
From: Mikael Pettersson <mikpelinux@gmail.com>
Date: Thu, 30 Jul 2020 17:40:35 +0200
Subject: [PATCH] sim: sim_core:skip/2: new, implement skipping the next
 instruction

---
 erlang/apps/sim/src/sim_core.erl | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/erlang/apps/sim/src/sim_core.erl b/erlang/apps/sim/src/sim_core.erl
index c320f47..a795ac7 100644
--- a/erlang/apps/sim/src/sim_core.erl
+++ b/erlang/apps/sim/src/sim_core.erl
@@ -27,6 +27,7 @@
 -export([ run/6
         , run/2
         , next_pc/2
+        , skip/2
         , page_fault/6
         , c/3
         , cset/4
@@ -81,6 +82,13 @@ next_pc(#core{pc_offset = PCOffset} = Core, Mem) ->
   PCOffset1 = (PCOffset + 1) band ((1 bsl 18) - 1),
   insn_fetch(Core#core{pc_offset = PCOffset1}, Mem).
 
+%% Skip next instruction: increment PC by two but stay in current section.
+-spec skip(#core{}, sim_mem:mem())
+      -> {#core{}, sim_mem:mem(), {ok, integer()} | {error, {module(), term()}}}.
+skip(#core{pc_offset = PCOffset} = Core, Mem) ->
+  PCOffset2 = (PCOffset + 2) band ((1 bsl 18) - 1),
+  insn_fetch(Core#core{pc_offset = PCOffset2}, Mem).
+
 %% Instruction Fetch and Effective Address Calculation =========================
 %% c.f. Toad-1 Architecture Manual, page 41, Figure 1.11