From 36cdc50d45154163e72fca81c0db1a005ad94cf1 Mon Sep 17 00:00:00 2001
From: Luke Kenneth Casson Leighton <lkcl@lkcl.net>
Date: Tue, 13 Nov 2018 15:57:59 +0000
Subject: [PATCH] modify csrrwi and csrrw back to original, change old val
 inside set_csr

---
 riscv/insns/csrrw.h  | 16 +---------------
 riscv/insns/csrrwi.h | 15 ---------------
 riscv/processor.cc   |  6 ++++--
 3 files changed, 5 insertions(+), 32 deletions(-)

diff --git a/riscv/insns/csrrw.h b/riscv/insns/csrrw.h
index f7876bc..b5aac4a 100644
--- a/riscv/insns/csrrw.h
+++ b/riscv/insns/csrrw.h
@@ -1,18 +1,4 @@
 int csr = validate_csr(insn.csr(), true);
-#ifdef SPIKE_SIMPLEV
-reg_t old = 0; // stop compiler bitchin
-if (csr != CSR_USVVL && csr != CSR_USVMVL)
-{
-    old = p->get_csr(csr);
-}
-p->set_csr(csr, RS1);
-if (csr == CSR_USVVL || csr == CSR_USVMVL)
-{
-    old = p->get_csr(csr);
-}
-#else
-reg_t old = p->get_csr(csr);
-p->set_csr(csr, RS1);
-#endif
+reg_t old = p->set_csr(csr, RS1);
 WRITE_RD(sext_xlen(sv_reg_t(old)));
 serialize();
diff --git a/riscv/insns/csrrwi.h b/riscv/insns/csrrwi.h
index 1fe1945..0daf68b 100644
--- a/riscv/insns/csrrwi.h
+++ b/riscv/insns/csrrwi.h
@@ -1,21 +1,6 @@
 fprintf(stderr, "csrrwi %lx\n", insn.csr());
 int csr = validate_csr(insn.csr(), true);
 fprintf(stderr, "validated %x\n", csr);
-#ifdef SPIKE_SIMPLEV
-reg_t old = 0; // stop compiler bitchin
-if (csr != CSR_USVVL && csr != CSR_USVMVL)
-{
-    old = p->get_csr(csr);
-    p->set_csr(csr, insn.insn_t::rs1());
-}
-else
-if (csr == CSR_USVVL || csr == CSR_USVMVL)
-{
-    p->set_csr(csr, insn.insn_t::rs1()+1); // must add one here
-    old = p->get_csr(csr);
-}
-#else
 reg_t old = p->set_csr(csr, insn.insn_t::rs1());
-#endif
 WRITE_RD(sext_xlen(sv_reg_t(old)));
 serialize();
diff --git a/riscv/processor.cc b/riscv/processor.cc
index bfc5259..b3ea542 100644
--- a/riscv/processor.cc
+++ b/riscv/processor.cc
@@ -497,7 +497,8 @@ reg_t processor_t::set_csr(int which, reg_t val, bool csrrwi)
   {
 #ifdef SPIKE_SIMPLEV
     case CSR_USVMVL:
-      state.sv().mvl = std::min(val, (uint64_t)64); // limited to XLEN width
+      state.sv().mvl = std::min(val+1, (uint64_t)64); // limited to XLEN width
+      old_val = state.sv().mvl - 1;
       // TODO XXX throw exception if val == 0
       fprintf(stderr, "set MVL %lx\n", state.sv().mvl);
       break;
@@ -532,7 +533,8 @@ reg_t processor_t::set_csr(int which, reg_t val, bool csrrwi)
       break;
     }
     case CSR_USVVL:
-      state.sv().vl = std::min(state.sv().mvl, val);
+      state.sv().vl = std::min(state.sv().mvl, val + 1);
+      old_val = state.sv().mvl - 1;
       // TODO XXX throw exception if val == 0
       fprintf(stderr, "set VL %lx\n", state.sv().vl);
       break;
-- 
2.30.2