provides a mechanism for optimizing compilers to select the different Register configuration.

src/compiler/pipeline.cc

Index: src/compiler/pipeline.cc
diff --git a/src/compiler/pipeline.cc b/src/compiler/pipeline.cc
index 094a8156fcd8a4438077cade64395fcdb9b56a72..14139ddabf0eaa853dcc7421385d9c98ef63a0fa 100644
--- a/src/compiler/pipeline.cc
+++ b/src/compiler/pipeline.cc
@@ -1306,8 +1306,8 @@ Handle<Code> Pipeline::ScheduleAndGenerateCode(
 
   bool run_verifier = FLAG_turbo_verify_allocation;
   // Allocate registers.
-  AllocateRegisters(RegisterConfiguration::ArchDefault(), call_descriptor,
-                    run_verifier);
+  AllocateRegisters(RegisterConfiguration::ArchDefault(TURBOFAN),
+                    call_descriptor, run_verifier);
   if (data->compilation_failed()) {
     info()->AbortOptimization(kNotEnoughVirtualRegistersRegalloc);
     return Handle<Code>();