From 01a7f207c3e94f1cb0dfbfd723663c66a622829d Mon Sep 17 00:00:00 2001
From: Ryan Macnak <rmacnak@google.com>
Date: Thu, 16 Jun 2022 17:56:02 +0000
Subject: [PATCH] [vm] Speed up the RISC-V simulator.

TEST=ci
Change-Id: I8ddba01117d21fcf915d77bc06765a0d576f55ca
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/248682
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Commit-Queue: Ryan Macnak <rmacnak@google.com>
---
 runtime/vm/simulator_riscv.cc | 43 +++++++++++++++++++++++++++++++++++
 runtime/vm/simulator_riscv.h  |  2 ++
 2 files changed, 45 insertions(+)

diff --git a/runtime/vm/simulator_riscv.cc b/runtime/vm/simulator_riscv.cc
index 73cdb726d6f..2229c319582 100644
--- a/runtime/vm/simulator_riscv.cc
+++ b/runtime/vm/simulator_riscv.cc
@@ -383,6 +383,28 @@ int64_t Simulator::Call(intx_t entry,
 }
 
 void Simulator::Execute() {
+  if (LIKELY(FLAG_trace_sim_after == ULLONG_MAX)) {
+    ExecuteNoTrace();
+  } else {
+    ExecuteTrace();
+  }
+}
+
+void Simulator::ExecuteNoTrace() {
+  while (pc_ != kEndSimulatingPC) {
+    uint16_t parcel = *reinterpret_cast<uint16_t*>(pc_);
+    if (IsCInstruction(parcel)) {
+      CInstr instr(parcel);
+      Interpret(instr);
+    } else {
+      Instr instr(*reinterpret_cast<uint32_t*>(pc_));
+      Interpret(instr);
+    }
+    instret_++;
+  }
+}
+
+void Simulator::ExecuteTrace() {
   while (pc_ != kEndSimulatingPC) {
     uint16_t parcel = *reinterpret_cast<uint16_t*>(pc_);
     if (IsCInstruction(parcel)) {
@@ -482,6 +504,7 @@ void Simulator::PrintStack() {
   }
 }
 
+DART_FORCE_INLINE
 void Simulator::Interpret(Instr instr) {
   switch (instr.opcode()) {
     case LUI:
@@ -552,6 +575,7 @@ void Simulator::Interpret(Instr instr) {
   }
 }
 
+DART_FORCE_INLINE
 void Simulator::Interpret(CInstr instr) {
   switch (instr.opcode()) {
     case C_LWSP: {
@@ -812,21 +836,25 @@ void Simulator::Interpret(CInstr instr) {
   pc_ += instr.length();
 }
 
+DART_FORCE_INLINE
 void Simulator::InterpretLUI(Instr instr) {
   set_xreg(instr.rd(), sign_extend(instr.utype_imm()));
   pc_ += instr.length();
 }
 
+DART_FORCE_INLINE
 void Simulator::InterpretAUIPC(Instr instr) {
   set_xreg(instr.rd(), pc_ + sign_extend(instr.utype_imm()));
   pc_ += instr.length();
 }
 
+DART_FORCE_INLINE
 void Simulator::InterpretJAL(Instr instr) {
   set_xreg(instr.rd(), pc_ + instr.length());
   pc_ += sign_extend(instr.jtype_imm());
 }
 
+DART_FORCE_INLINE
 void Simulator::InterpretJALR(Instr instr) {
   uintx_t base = get_xreg(instr.rs1());
   uintx_t offset = static_cast<uintx_t>(instr.itype_imm());
@@ -834,6 +862,7 @@ void Simulator::InterpretJALR(Instr instr) {
   pc_ = base + offset;
 }
 
+DART_FORCE_INLINE
 void Simulator::InterpretBRANCH(Instr instr) {
   switch (instr.funct3()) {
     case BEQ:
@@ -887,6 +916,7 @@ void Simulator::InterpretBRANCH(Instr instr) {
   }
 }
 
+DART_FORCE_INLINE
 void Simulator::InterpretLOAD(Instr instr) {
   uintx_t addr = get_xreg(instr.rs1()) + instr.itype_imm();
   switch (instr.funct3()) {
@@ -919,6 +949,7 @@ void Simulator::InterpretLOAD(Instr instr) {
   pc_ += instr.length();
 }
 
+DART_FORCE_INLINE
 void Simulator::InterpretLOADFP(Instr instr) {
   uintx_t addr = get_xreg(instr.rs1()) + instr.itype_imm();
   switch (instr.funct3()) {
@@ -934,6 +965,7 @@ void Simulator::InterpretLOADFP(Instr instr) {
   pc_ += instr.length();
 }
 
+DART_FORCE_INLINE
 void Simulator::InterpretSTORE(Instr instr) {
   uintx_t addr = get_xreg(instr.rs1()) + instr.stype_imm();
   switch (instr.funct3()) {
@@ -957,6 +989,7 @@ void Simulator::InterpretSTORE(Instr instr) {
   pc_ += instr.length();
 }
 
+DART_FORCE_INLINE
 void Simulator::InterpretSTOREFP(Instr instr) {
   uintx_t addr = get_xreg(instr.rs1()) + instr.stype_imm();
   switch (instr.funct3()) {
@@ -972,6 +1005,7 @@ void Simulator::InterpretSTOREFP(Instr instr) {
   pc_ += instr.length();
 }
 
+DART_FORCE_INLINE
 void Simulator::InterpretOPIMM(Instr instr) {
   switch (instr.funct3()) {
     case ADDI:
@@ -1018,6 +1052,7 @@ void Simulator::InterpretOPIMM(Instr instr) {
   pc_ += instr.length();
 }
 
+DART_FORCE_INLINE
 void Simulator::InterpretOPIMM32(Instr instr) {
   switch (instr.funct3()) {
     case ADDI: {
@@ -1049,6 +1084,7 @@ void Simulator::InterpretOPIMM32(Instr instr) {
   pc_ += instr.length();
 }
 
+DART_FORCE_INLINE
 void Simulator::InterpretOP(Instr instr) {
   switch (instr.funct7()) {
     case 0:
@@ -1065,6 +1101,7 @@ void Simulator::InterpretOP(Instr instr) {
   }
 }
 
+DART_FORCE_INLINE
 void Simulator::InterpretOP_0(Instr instr) {
   switch (instr.funct3()) {
     case ADD:
@@ -1247,6 +1284,7 @@ static uint32_t remuw(uint32_t a, uint32_t b) {
 }
 #endif  // XLEN >= 64
 
+DART_FORCE_INLINE
 void Simulator::InterpretOP_MULDIV(Instr instr) {
   switch (instr.funct3()) {
     case MUL:
@@ -1280,6 +1318,7 @@ void Simulator::InterpretOP_MULDIV(Instr instr) {
   pc_ += instr.length();
 }
 
+DART_FORCE_INLINE
 void Simulator::InterpretOP_SUB(Instr instr) {
   switch (instr.funct3()) {
     case ADD:
@@ -1296,6 +1335,7 @@ void Simulator::InterpretOP_SUB(Instr instr) {
   pc_ += instr.length();
 }
 
+DART_FORCE_INLINE
 void Simulator::InterpretOP32(Instr instr) {
   switch (instr.funct7()) {
 #if XLEN >= 64
@@ -1314,6 +1354,7 @@ void Simulator::InterpretOP32(Instr instr) {
   }
 }
 
+DART_FORCE_INLINE
 void Simulator::InterpretOP32_0(Instr instr) {
   switch (instr.funct3()) {
 #if XLEN >= 64
@@ -1342,6 +1383,7 @@ void Simulator::InterpretOP32_0(Instr instr) {
   pc_ += instr.length();
 }
 
+DART_FORCE_INLINE
 void Simulator::InterpretOP32_SUB(Instr instr) {
   switch (instr.funct3()) {
 #if XLEN >= 64
@@ -1364,6 +1406,7 @@ void Simulator::InterpretOP32_SUB(Instr instr) {
   pc_ += instr.length();
 }
 
+DART_FORCE_INLINE
 void Simulator::InterpretOP32_MULDIV(Instr instr) {
   switch (instr.funct3()) {
 #if XLEN >= 64
diff --git a/runtime/vm/simulator_riscv.h b/runtime/vm/simulator_riscv.h
index 9a5ca232078..d49fed968c9 100644
--- a/runtime/vm/simulator_riscv.h
+++ b/runtime/vm/simulator_riscv.h
@@ -325,6 +325,8 @@ class Simulator {
 
   // Executes RISC-V instructions until the PC reaches kEndSimulatingPC.
   void Execute();
+  void ExecuteNoTrace();
+  void ExecuteTrace();
 
   // Returns true if tracing of executed instructions is enabled.
   bool IsTracingExecution() const;