[sim] fix writeback after ipi clearing

diff --git a/riscv/insns/mfpcr.h b/riscv/insns/mfpcr.h
index b151150f421c5ce05109a29f807ae606ff0d9abd..3f47a1078d74024fc40241ff7bd3e5dc6827813d 100644 (file)
--- a/riscv/insns/mfpcr.h
+++ b/riscv/insns/mfpcr.h
@@ -26,6 +26,7 @@ switch(insn.rtype.rs2)
     val = cause;
     break;
   case 7:
+    val = 0;
     cause &= ~(1 << (IPI_IRQ+CAUSE_IP_SHIFT));
     break;