[turbofan] Add backend support for float32.

src/arm64/assembler-arm64.h

Index: src/arm64/assembler-arm64.h
diff --git a/src/arm64/assembler-arm64.h b/src/arm64/assembler-arm64.h
index 82b4500d5f0a4a2b983ea3ab423ded6e8831acd9..ba18bb820a6b1922a7a3f0514d8296be75ff7012 100644
--- a/src/arm64/assembler-arm64.h
+++ b/src/arm64/assembler-arm64.h
@@ -276,6 +276,11 @@ struct FPRegister : public CPURegister {
       (kAllocatableHighRangeEnd - kAllocatableHighRangeBegin + 1);
   static int NumAllocatableRegisters() { return kMaxNumAllocatableRegisters; }
 
+  // TODO(turbofan): Proper float32 support.
+  static int NumAllocatableRegistersForTurbofan() {

[titzer, 2014/09/24 08:53:14]

Can we name this something more general? Such as
NumAllocatableFloat32Registers() or something?

[Benedikt Meurer, 2014/09/25 06:09:31]

Done.

+    return NumAllocatableRegisters();
+  }
+
   // Return true if the register is one that crankshaft can allocate.
   bool IsAllocatable() const {
     return (Bit() & kAllocatableFPRegisters) != 0;