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

Revert of [arm] Decrease the size of the assembler class by allocating buffers of pending constants on the he… (patchset #2 id:20001 of https://codereview.chromium.org/1309903009/ )

Reason for revert:
Static assert failed on ARM64

Original issue's description:
> [arm] Decrease the size of the assembler class by allocating buffers of pending constants on the heap.
>
> BUG=chromium:521828
> LOG=N
>
> Committed: https://crrev.com/033af3fa511c52bc4049cd278d0623a6c6f9f9c3
> Cr-Commit-Position: refs/heads/master@{#30592}

TBR=jkummerow@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=chromium:521828

Review URL: https://codereview.chromium.org/1307863007

Cr-Commit-Position: refs/heads/master@{#30593}

src/arm/assembler-arm.cc

@@ -450,8 +450,6 @@ 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_);
@@ -469,12 +467,6 @@ 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_;
-  }
 }
 
 
@@ -3674,15 +3666,6 @@ 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;
@@ -3703,15 +3686,6 @@ 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

@@ -1465,7 +1465,6 @@ 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;
 
@@ -1599,10 +1598,8 @@ class Assembler : public AssemblerBase {
   // pending relocation entry per instruction.
 
   // The buffers of pending constant pool entries.
-  ConstantPoolEntry pending_32_bit_constants_buffer_[kMinNumPendingConstants];
-  ConstantPoolEntry pending_64_bit_constants_buffer_[kMinNumPendingConstants];
-  ConstantPoolEntry* pending_32_bit_constants_;
-  ConstantPoolEntry* pending_64_bit_constants_;
+  ConstantPoolEntry pending_32_bit_constants_[kMaxNumPending32Constants];
+  ConstantPoolEntry pending_64_bit_constants_[kMaxNumPending64Constants];
   // 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

@@ -78,8 +78,6 @@ class PropertyAccessCompiler BASE_EMBEDDED {
 
   Isolate* isolate_;
   MacroAssembler masm_;
-  // Ensure that MacroAssembler has a reasonable size.
-  STATIC_ASSERT(sizeof(MacroAssembler) < KB / 2);
 };
 }
 }  // namespace v8::internal