From b5d36b7969f2759147d58a80e0e5b62c215d2998 Mon Sep 17 00:00:00 2001
From: taitep <taitep@taitep.se>
Date: Sat, 27 Dec 2025 21:03:24 +0100
Subject: [PATCH] Initial FENCE implementation

---
 src/instructions.rs | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/src/instructions.rs b/src/instructions.rs
index 8e55d37..e7b95f1 100644
--- a/src/instructions.rs
+++ b/src/instructions.rs
@@ -112,6 +112,16 @@ pub(crate) fn find_and_exec(instr: Instruction, core: &mut Core) -> Result<(), E
                 Err(IllegalInstruction)
             }
         }
+        0b00011 => match instr.funct3() {
+            // MISC_MEM
+            0b000 => {
+                // FENCE is just implemented as a SeqCst fence always here
+                // I dont yet care about the potential performance issue this may bring
+                std::sync::atomic::fence(std::sync::atomic::Ordering::SeqCst);
+                Ok(())
+            }
+            _ => Err(IllegalInstruction),
+        },
         _ => Err(IllegalInstruction),
     }
 }