[arm] Decrease the size of the assembler class by allocating buffers of...

[arm] Decrease the size of the assembler class by allocating buffers of pending constants on the heap.

BUG=chromium:521828
LOG=N

Review URL: https://codereview.chromium.org/1310863005

Cr-Commit-Position: refs/heads/master@{#30602}

src/arm/assembler-arm.cc

@@ -450,6 +450,8 @@ const Instr kLdrStrInstrTypeMask = 0xffff0000;
 Assembler::Assembler(Isolate* isolate, void* buffer, int buffer_size)
     : AssemblerBase(isolate, buffer, buffer_size),
       recorded_ast_id_(TypeFeedbackId::None()),
+      pending_32_bit_constants_(&pending_32_bit_constants_buffer_[0]),
+      pending_64_bit_constants_(&pending_64_bit_constants_buffer_[0]),
       constant_pool_builder_(kLdrMaxReachBits, kVldrMaxReachBits),
       positions_recorder_(this) {
   reloc_info_writer.Reposition(buffer_ + buffer_size_, pc_);
@@ -467,6 +469,12 @@ Assembler::Assembler(Isolate* isolate, void* buffer, int buffer_size)
 
 Assembler::~Assembler() {
   DCHECK(const_pool_blocked_nesting_ == 0);
+  if (pending_32_bit_constants_ != &pending_32_bit_constants_buffer_[0]) {
+    delete[] pending_32_bit_constants_;
+  }
+  if (pending_64_bit_constants_ != &pending_64_bit_constants_buffer_[0]) {
+    delete[] pending_64_bit_constants_;
+  }
 }
 
 
@@ -3666,6 +3674,15 @@ ConstantPoolEntry::Access Assembler::ConstantPoolAddEntry(int position,
     DCHECK(num_pending_32_bit_constants_ < kMaxNumPending32Constants);
     if (num_pending_32_bit_constants_ == 0) {
       first_const_pool_32_use_ = position;
+    } else if (num_pending_32_bit_constants_ == kMinNumPendingConstants &&
+               pending_32_bit_constants_ ==
+                   &pending_32_bit_constants_buffer_[0]) {
+      // Inline buffer is full, switch to dynamically allocated buffer.
+      pending_32_bit_constants_ =
+          new ConstantPoolEntry[kMaxNumPending32Constants];
+      std::copy(&pending_32_bit_constants_buffer_[0],
+                &pending_32_bit_constants_buffer_[kMinNumPendingConstants],
+                &pending_32_bit_constants_[0]);
     }
     ConstantPoolEntry entry(position, value, sharing_ok);
     pending_32_bit_constants_[num_pending_32_bit_constants_++] = entry;
@@ -3686,6 +3703,15 @@ ConstantPoolEntry::Access Assembler::ConstantPoolAddEntry(int position,
     DCHECK(num_pending_64_bit_constants_ < kMaxNumPending64Constants);
     if (num_pending_64_bit_constants_ == 0) {
       first_const_pool_64_use_ = position;
+    } else if (num_pending_64_bit_constants_ == kMinNumPendingConstants &&
+               pending_64_bit_constants_ ==
+                   &pending_64_bit_constants_buffer_[0]) {
+      // Inline buffer is full, switch to dynamically allocated buffer.
+      pending_64_bit_constants_ =
+          new ConstantPoolEntry[kMaxNumPending64Constants];
+      std::copy(&pending_64_bit_constants_buffer_[0],
+                &pending_64_bit_constants_buffer_[kMinNumPendingConstants],
+                &pending_64_bit_constants_[0]);
     }
     ConstantPoolEntry entry(position, value);
     pending_64_bit_constants_[num_pending_64_bit_constants_++] = entry;

src/arm/assembler-arm.h

@@ -1465,6 +1465,7 @@ class Assembler : public AssemblerBase {
   static const int kMaxDistToIntPool = 4*KB;
   static const int kMaxDistToFPPool = 1*KB;
   // All relocations could be integer, it therefore acts as the limit.
+  static const int kMinNumPendingConstants = 4;
   static const int kMaxNumPending32Constants = kMaxDistToIntPool / kInstrSize;
   static const int kMaxNumPending64Constants = kMaxDistToFPPool / kInstrSize;
 
@@ -1598,8 +1599,10 @@ class Assembler : public AssemblerBase {
   // pending relocation entry per instruction.
 
   // The buffers of pending constant pool entries.
-  ConstantPoolEntry pending_32_bit_constants_[kMaxNumPending32Constants];
-  ConstantPoolEntry pending_64_bit_constants_[kMaxNumPending64Constants];
+  ConstantPoolEntry pending_32_bit_constants_buffer_[kMinNumPendingConstants];
+  ConstantPoolEntry pending_64_bit_constants_buffer_[kMinNumPendingConstants];
+  ConstantPoolEntry* pending_32_bit_constants_;
+  ConstantPoolEntry* pending_64_bit_constants_;
   // Number of pending constant pool entries in the 32 bits buffer.
   int num_pending_32_bit_constants_;
   // Number of pending constant pool entries in the 64 bits buffer.

src/ic/access-compiler.h

@@ -78,6 +78,8 @@ class PropertyAccessCompiler BASE_EMBEDDED {
 
   Isolate* isolate_;
   MacroAssembler masm_;
+  // Ensure that MacroAssembler has a reasonable size.
+  STATIC_ASSERT(sizeof(MacroAssembler) < 128 * kPointerSize);
 };
 }
 }  // namespace v8::internal