Combine smi and overflow checks for count operations.

src/register-allocator-ia32.cc

 // Copyright 2008 the V8 project authors. 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.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 124 matching lines @@
   for (int i = 0; i < num_registers(); i++) {
     if (!is_used(i)) {
       Register free_reg = { i };
       return Result(free_reg, cgen_);
     }
   }
   return Result(cgen_);
 }
 
 
+Result RegisterAllocator::AllocateByteRegisterWithoutSpilling() {
+  Result result = AllocateWithoutSpilling();
+  // Check that the register is a byte register.  If not, unuse the
+  // register if valid and return an invalid result.
+  if (result.is_valid() && !result.reg().is_byte_register()) {
+    result.Unuse();
+    return Result(cgen_);
+  }
+  return result;
+}
+
+
 Result RegisterAllocator::Allocate() {
   Result result = AllocateWithoutSpilling();
   if (!result.is_valid()) {
     // Ask the current frame to spill a register.
     ASSERT(cgen_->has_valid_frame());
     Register free_reg = cgen_->frame()->SpillAnyRegister();
     if (free_reg.is_valid()) {
       ASSERT(!is_used(free_reg));
       return Result(free_reg, cgen_);
     }
@@ skipping 14 matching lines @@
     cgen_->frame()->Spill(target);
     ASSERT(!is_used(target));
     return Result(target, cgen_);
   }
   // Otherwise (if it's referenced outside the frame) we cannot allocate it.
   return Result(cgen_);
 }
 
 
 } }  // namespace v8::internal