From 5abd6d4e650b9eeb6dbf58baaa4b19a42dbaf348 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Florian=20N=C3=BCcke?= <florian@nuecke.de>
Date: Mon, 14 Sep 2020 17:50:42 +0200
Subject: [PATCH] Ensure to advance cycles when waiting for interrupt to avoid
 stalling when mtimecmp is based on cycles.

---
 src/main/java/li/cil/circuity/vm/riscv/R5CPU.java | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/src/main/java/li/cil/circuity/vm/riscv/R5CPU.java b/src/main/java/li/cil/circuity/vm/riscv/R5CPU.java
index b8469e71..d5694c64 100644
--- a/src/main/java/li/cil/circuity/vm/riscv/R5CPU.java
+++ b/src/main/java/li/cil/circuity/vm/riscv/R5CPU.java
@@ -199,6 +199,11 @@ public class R5CPU implements Steppable, RealTimeCounter, InterruptController {
     }
 
     public void step(final int cycles) {
+        if (waitingForInterrupt) {
+            mcycle += cycles;
+            return;
+        }
+
         final long cycleLimit = mcycle + cycles;
         while (!waitingForInterrupt && mcycle < cycleLimit) {
             final int pending = mip.get() & mie;
@@ -232,6 +237,10 @@ public class R5CPU implements Steppable, RealTimeCounter, InterruptController {
                 raiseException(e.getExceptionCause(), e.getExceptionValue());
             }
         }
+
+        if (waitingForInterrupt && mcycle < cycleLimit) {
+            mcycle = cycleLimit;
+        }
     }
 
     private void interpret() throws R5Exception, MemoryAccessException {