We should never allocate a 0-sized buffer, so never grow from 0.

BUG=
R=ishell@chromium.org

Review URL: https://codereview.chromium.org/446933003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22947 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/arm/assembler-arm.cc

@@ -3202,9 +3202,7 @@ void Assembler::GrowBuffer() {
 
   // Compute new buffer size.
   CodeDesc desc;  // the new buffer
-  if (buffer_size_ == 0) {
-    desc.buffer_size = kMinimalBufferSize;
-  } else if (buffer_size_ < 1*MB) {
+  if (buffer_size_ < 1 * MB) {
     desc.buffer_size = 2*buffer_size_;
   } else {
     desc.buffer_size = buffer_size_ + 1*MB;

src/arm64/assembler-arm64.cc

@@ -2771,9 +2771,7 @@ void Assembler::GrowBuffer() {
 
   // Compute new buffer size.
   CodeDesc desc;  // the new buffer
-  if (buffer_size_ == 0) {
-    desc.buffer_size = kMinimalBufferSize;
-  } else if (buffer_size_ < 1 * MB) {
+  if (buffer_size_ < 1 * MB) {
     desc.buffer_size = 2 * buffer_size_;
   } else {
     desc.buffer_size = buffer_size_ + 1 * MB;

src/assembler.cc

@@ -134,15 +134,10 @@ AssemblerBase::AssemblerBase(Isolate* isolate, void* buffer, int buffer_size)
   if (FLAG_mask_constants_with_cookie && isolate != NULL)  {
     jit_cookie_ = isolate->random_number_generator()->NextInt();
   }
-  if (buffer == NULL) {
-    // Do our own buffer management.
-    buffer = NewArray<byte>(buffer_size);
-    own_buffer_ = true;
-  } else {
-    // Use externally provided buffer instead.
+  own_buffer_ = buffer == NULL;
+  if (buffer_size == 0) buffer_size = kMinimalBufferSize;
   DCHECK(buffer_size > 0);
-    own_buffer_ = false;
-  }
+  if (own_buffer_) buffer = NewArray<byte>(buffer_size);
   buffer_ = static_cast<byte*>(buffer);
   buffer_size_ = buffer_size;
 

src/ia32/assembler-ia32.cc

@@ -2497,11 +2497,8 @@ void Assembler::GrowBuffer() {
 
   // Compute new buffer size.
   CodeDesc desc;  // the new buffer
-  if (buffer_size_ == 0) {
-    desc.buffer_size = kMinimalBufferSize;
-  } else {
-    desc.buffer_size = 2*buffer_size_;
-  }
+  desc.buffer_size = 2 * buffer_size_;
+
   // Some internal data structures overflow for very large buffers,
   // they must ensure that kMaximalBufferSize is not too large.
   if ((desc.buffer_size > kMaximalBufferSize) ||

src/lithium.cc

@@ -457,8 +457,7 @@ LChunk* LChunk::NewChunk(HGraph* graph) {
 
 
 Handle<Code> LChunk::Codegen() {
-  MacroAssembler assembler(info()->isolate(), NULL,
-                           Assembler::kMinimalBufferSize);
+  MacroAssembler assembler(info()->isolate(), NULL, 0);
   LOG_CODE_EVENT(info()->isolate(),
                  CodeStartLinePosInfoRecordEvent(
                      assembler.positions_recorder()));

src/x64/assembler-x64.cc

@@ -331,11 +331,8 @@ void Assembler::GrowBuffer() {
 
   // Compute new buffer size.
   CodeDesc desc;  // the new buffer
-  if (buffer_size_ == 0) {
-    desc.buffer_size = kMinimalBufferSize;
-  } else {
-    desc.buffer_size = 2*buffer_size_;
-  }
+  desc.buffer_size = 2 * buffer_size_;
+
   // Some internal data structures overflow for very large buffers,
   // they must ensure that kMaximalBufferSize is not too large.
   if ((desc.buffer_size > kMaximalBufferSize) ||