This patch uses single BytesInstruction Courgette ops to point to long...

This patch uses single BytesInstruction Courgette ops to point to long stretches of the binary file, instead of using one ByteInstruction op, which copies one byte at a time.  This reduces memory usages for very large files, since less data is copied, and fewer Instruction classes are constructed.

BUG=266068

Review URL: https://chromiumcodereview.appspot.com/22728002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@217138 0039d316-1c4b-4281-b951-d872f2087c98

courgette/assembly_program.cc

@@ -422,6 +422,7 @@ EncodedProgram* AssemblyProgram::Encode() const {
         const uint8* byte_values =
           static_cast<BytesInstruction*>(instruction)->byte_values();
         uint32 len = static_cast<BytesInstruction*>(instruction)->len();
+
         if (!encoded->AddCopy(len, byte_values))
           return NULL;
         break;

courgette/disassembler_elf_32.cc

@@ -409,13 +409,13 @@ CheckBool DisassemblerElf32::ParseSimpleRegion(
   const uint8* start = OffsetToPointer(start_file_offset);
   const uint8* end = OffsetToPointer(end_file_offset);
 
-  const uint8* p = start;
+  // Callers don't guarantee start < end
+  if (start >= end) return true;
 
-  while (p < end) {
-    if (!program->EmitByteInstruction(*p))
+  const ptrdiff_t len = end - start;  // Works because vars are byte pointers
+
+  if (!program->EmitBytesInstruction(start, len))
     return false;
-    ++p;
-  }
 
   return true;
 }