This patch uses single BytesInstruction Courgette ops to point to lon…

…g 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))
-      return false;
-    ++p;
-  }
+  const ptrdiff_t len = end - start;  // Works because vars are byte pointers
+
+  if (!program->EmitBytesInstruction(start, len))
+    return false;
 
   return true;
 }