[sparkplug] Preallocate instruction buffer

We have roughly a 7x (5x on ia32) ratio between bytecode and sparkplug
code. Using this number to preallocate the buffer for the emitted code
we can avoid a few copies for larger functions.

Drive-by-fix: Make sure EnsureSpace is marked V8_INLINE

Bug: v8:11420
Change-Id: I6ec48717d2e030c6118c59f5cdc286c952ec2843
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2835732
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#74085}

src/baseline/baseline-compiler.cc

@@ -230,6 +230,21 @@ void MoveArgumentsForBuiltin(BaselineAssembler* masm, Args... args) {
 
 }  // namespace detail
 
+namespace {
+// Rough upper-bound estimate. Copying the data is most likely more expensive
+// than pre-allocating a large enough buffer.
+#ifdef V8_TARGET_ARCH_IA32
+const int kAverageBytecodeToInstructionRatio = 5;
+#else
+const int kAverageBytecodeToInstructionRatio = 7;
+#endif
+std::unique_ptr<AssemblerBuffer> AllocateBuffer(
+    Handle<BytecodeArray> bytecodes) {
+  int estimated_size = bytecodes->length() * kAverageBytecodeToInstructionRatio;
+  return NewAssemblerBuffer(RoundUp(estimated_size, 4 * KB));
+}
+}  // namespace
+
 BaselineCompiler::BaselineCompiler(
     Isolate* isolate, Handle<SharedFunctionInfo> shared_function_info,
     Handle<BytecodeArray> bytecode)
@@ -237,7 +252,7 @@ BaselineCompiler::BaselineCompiler(
       stats_(isolate->counters()->runtime_call_stats()),
       shared_function_info_(shared_function_info),
       bytecode_(bytecode),
-      masm_(isolate, CodeObjectRequired::kNo),
+      masm_(isolate, CodeObjectRequired::kNo, AllocateBuffer(bytecode)),
       basm_(&masm_),
       iterator_(bytecode_),
       zone_(isolate->allocator(), ZONE_NAME),

src/codegen/arm/assembler-arm-inl.h

@@ -206,7 +206,7 @@ Operand::Operand(Smi value) : rmode_(RelocInfo::NONE) {
 Operand::Operand(Register rm) : rm_(rm), shift_op_(LSL), shift_imm_(0) {}
 
 void Assembler::CheckBuffer() {
-  if (buffer_space() <= kGap) {
+  if (V8_UNLIKELY(buffer_space() <= kGap)) {
     GrowBuffer();
   }
   MaybeCheckConstPool();

src/codegen/arm/assembler-arm.h

@@ -1165,8 +1165,8 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
   // Check if is time to emit a constant pool.
   void CheckConstPool(bool force_emit, bool require_jump);
 
-  void MaybeCheckConstPool() {
-    if (pc_offset() >= next_buffer_check_) {
+  V8_INLINE void MaybeCheckConstPool() {
+    if (V8_UNLIKELY(pc_offset() >= next_buffer_check_)) {
       CheckConstPool(false, true);
     }
   }
@@ -1298,7 +1298,7 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
   // The bound position, before this we cannot do instruction elimination.
   int last_bound_pos_;
 
-  inline void CheckBuffer();
+  V8_INLINE void CheckBuffer();
   void GrowBuffer();
 
   // Instruction generation

src/codegen/arm64/assembler-arm64-inl.h

@@ -1072,12 +1072,12 @@ const Register& Assembler::AppropriateZeroRegFor(const CPURegister& reg) const {
 
 inline void Assembler::CheckBufferSpace() {
   DCHECK_LT(pc_, buffer_start_ + buffer_->size());
-  if (buffer_space() < kGap) {
+  if (V8_UNLIKELY(buffer_space() < kGap)) {
     GrowBuffer();
   }
 }
 
-inline void Assembler::CheckBuffer() {
+V8_INLINE void Assembler::CheckBuffer() {
   CheckBufferSpace();
   if (pc_offset() >= next_veneer_pool_check_) {
     CheckVeneerPool(false, true);
@@ -1085,6 +1085,10 @@ inline void Assembler::CheckBuffer() {
   constpool_.MaybeCheck();
 }
 
+EnsureSpace::EnsureSpace(Assembler* assembler) : block_pools_scope_(assembler) {
+  assembler->CheckBufferSpace();
+}
+
 }  // namespace internal
 }  // namespace v8
 

src/codegen/arm64/assembler-arm64.h

@@ -2634,7 +2634,7 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
   }
 
   void GrowBuffer();
-  void CheckBufferSpace();
+  V8_INLINE void CheckBufferSpace();
   void CheckBuffer();
 
   // Emission of the veneer pools may be blocked in some code sequences.
@@ -2786,9 +2786,7 @@ class PatchingAssembler : public Assembler {
 
 class EnsureSpace {
  public:
-  explicit EnsureSpace(Assembler* assembler) : block_pools_scope_(assembler) {
-    assembler->CheckBufferSpace();
-  }
+  explicit V8_INLINE EnsureSpace(Assembler* assembler);
 
  private:
   Assembler::BlockPoolsScope block_pools_scope_;

src/codegen/ia32/assembler-ia32.h

@@ -1936,10 +1936,10 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
 // checks that we did not generate too much.
 class EnsureSpace {
  public:
-  explicit EnsureSpace(Assembler* assembler) : assembler_(assembler) {
-    if (assembler_->buffer_overflow()) assembler_->GrowBuffer();
+  explicit V8_INLINE EnsureSpace(Assembler* assembler) : assembler_(assembler) {
+    if (V8_UNLIKELY(assembler_->buffer_overflow())) assembler_->GrowBuffer();
 #ifdef DEBUG
-    space_before_ = assembler_->available_space();
+    space_before_ = assembler->available_space();
 #endif
   }
 
@@ -1951,7 +1951,7 @@ class EnsureSpace {
 #endif
 
  private:
-  Assembler* assembler_;
+  Assembler* const assembler_;
 #ifdef DEBUG
   int space_before_;
 #endif

src/codegen/mips/assembler-mips.h

@@ -1907,7 +1907,7 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
 
 class EnsureSpace {
  public:
-  explicit inline EnsureSpace(Assembler* assembler);
+  explicit V8_INLINE EnsureSpace(Assembler* assembler);
 };
 
 class V8_EXPORT_PRIVATE V8_NODISCARD UseScratchRegisterScope {

src/codegen/x64/assembler-x64.h

@@ -2376,8 +2376,8 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
 // checks that we did not generate too much.
 class EnsureSpace {
  public:
-  explicit EnsureSpace(Assembler* assembler) : assembler_(assembler) {
-    if (assembler_->buffer_overflow()) assembler_->GrowBuffer();
+  explicit V8_INLINE EnsureSpace(Assembler* assembler) : assembler_(assembler) {
+    if (V8_UNLIKELY(assembler_->buffer_overflow())) assembler_->GrowBuffer();
 #ifdef DEBUG
     space_before_ = assembler_->available_space();
 #endif
@@ -2391,7 +2391,7 @@ class EnsureSpace {
 #endif
 
  private:
-  Assembler* assembler_;
+  Assembler* const assembler_;
 #ifdef DEBUG
   int space_before_;
 #endif