PPC: Refactor checks for minus zero.

src/ppc/macro-assembler-ppc.h

Index: src/ppc/macro-assembler-ppc.h
diff --git a/src/ppc/macro-assembler-ppc.h b/src/ppc/macro-assembler-ppc.h
index 171fa6b5295d0743a50a427d82490b7cf17fcef0..2ff613db783fd877c78fb42be262eacd0f728611 100644
--- a/src/ppc/macro-assembler-ppc.h
+++ b/src/ppc/macro-assembler-ppc.h
@@ -864,6 +864,18 @@ class MacroAssembler : public Assembler {
   void TestDoubleIsInt32(DoubleRegister double_input, Register scratch1,
                          Register scratch2, DoubleRegister double_scratch);
 
+  // Check if a double is equal to -0.0.
+  // CR_EQ in cr7 holds the result.
+  void TestDoubleIsMinusZero(DoubleRegister input, Register scratch1,
+                             Register scratch2);
+  void TestHeapNumberIsMinusZero(Register input, Register scratch1,
+                                 Register scratch2);
+
+  // Check the sign of a double.
+  // CR_LT in cr7 holds the result.
+  void TestDoubleSign(DoubleRegister input, Register scratch);
+  void TestHeapNumberSign(Register input, Register scratch);
+
   // Try to convert a double to a signed 32-bit integer.
   // CR_EQ in cr7 is set and result assigned if the conversion is exact.
   void TryDoubleToInt32Exact(Register result, DoubleRegister double_input,