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

src/ia32/assembler-ia32.cc

 // Copyright (c) 1994-2006 Sun Microsystems Inc.
 // All Rights Reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions
 // are met:
 //
 // - Redistributions of source code must retain the above copyright notice,
 // this list of conditions and the following disclaimer.
 //
@@ skipping 2479 matching lines @@
   }
 }
 
 
 void Assembler::GrowBuffer() {
   DCHECK(buffer_overflow());
   if (!own_buffer_) FATAL("external code buffer is too small");
 
   // 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) ||
       (desc.buffer_size > isolate()->heap()->MaxOldGenerationSize())) {
     V8::FatalProcessOutOfMemory("Assembler::GrowBuffer");
   }
 
   // Set up new buffer.
   desc.buffer = NewArray<byte>(desc.buffer_size);
   desc.instr_size = pc_offset();
@@ skipping 150 matching lines @@
     fprintf(coverage_log, "%s\n", file_line);
     fflush(coverage_log);
   }
 }
 
 #endif
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32