A64: Introduce a DeoptimizeIfMinusZero() helper.

src/a64/macro-assembler-a64.h

 // Copyright 2013 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 882 matching lines @@
                          Register heap_number_map,
                          Label* on_heap_number,
                          Label* on_not_heap_number = NULL);
   void JumpIfHeapNumber(Register object,
                         Label* on_heap_number,
                         Register heap_number_map = NoReg);
   void JumpIfNotHeapNumber(Register object,
                            Label* on_not_heap_number,
                            Register heap_number_map = NoReg);
 
+  // Sets the vs flag if the input is -0.0.
+  void TestForMinusZero(DoubleRegister input);
+
   // Jump to label if the input double register contains -0.0.
   void JumpIfMinusZero(DoubleRegister input, Label* on_negative_zero);
 
   // Generate code to do a lookup in the number string cache. If the number in
   // the register object is found in the cache the generated code falls through
   // with the result in the result register. The object and the result register
   // can be the same. If the number is not found in the cache the code jumps to
   // the label not_found with only the content of register object unchanged.
   void LookupNumberStringCache(Register object,
                                Register result,
                                Register scratch1,
                                Register scratch2,
                                Register scratch3,
                                Label* not_found);
 
   // Saturate a signed 32-bit integer in input to an unsigned 8-bit integer in
   // output.
   void ClampInt32ToUint8(Register in_out);
   void ClampInt32ToUint8(Register output, Register input);
 
   // Saturate a double in input to an unsigned 8-bit integer in output.
   void ClampDoubleToUint8(Register output,
                           DoubleRegister input,
                           DoubleRegister dbl_scratch);
 
   // Try to convert a double to a signed 32-bit int.
   // This succeeds if the result compares equal to the input, so inputs of -0.0
   // are converted to 0 and handled as a success.
+  //
+  // On output the Z flag is set if the conversion was successful.
   void TryConvertDoubleToInt32(Register as_int,
                                FPRegister value,
                                FPRegister scratch_d,
-                               Label* on_successful_conversion,
+                               Label* on_successful_conversion = NULL,
                                Label* on_failed_conversion = NULL) {
     ASSERT(as_int.Is32Bits());
     TryConvertDoubleToInt(as_int, value, scratch_d, on_successful_conversion,
                           on_failed_conversion);
   }
 
   // Try to convert a double to a signed 64-bit int.
   // This succeeds if the result compares equal to the input, so inputs of -0.0
   // are converted to 0 and handled as a success.
+  //
+  // On output the Z flag is set if the conversion was successful.
   void TryConvertDoubleToInt64(Register as_int,
                                FPRegister value,
                                FPRegister scratch_d,
-                               Label* on_successful_conversion,
+                               Label* on_successful_conversion = NULL,
                                Label* on_failed_conversion = NULL) {
     ASSERT(as_int.Is64Bits());
     TryConvertDoubleToInt(as_int, value, scratch_d, on_successful_conversion,
                           on_failed_conversion);
   }
 
   // ---- Object Utilities ----
 
   // Copy fields from 'src' to 'dst', where both are tagged objects.
   // The 'temps' list is a list of X registers which can be used for scratch
@@ skipping 1106 matching lines @@
                   Condition cond,  // eq for new space, ne otherwise.
                   Label* branch);
 
   // Try to convert a double to an int so that integer fast-paths may be
   // used. Not every valid integer value is guaranteed to be caught.
   // It supports both 32-bit and 64-bit integers depending whether 'as_int'
   // is a W or X register.
   //
   // This does not distinguish between +0 and -0, so if this distinction is
   // important it must be checked separately.
+  //
+  // On output the Z flag is set if the conversion was successful.
   void TryConvertDoubleToInt(Register as_int,
                              FPRegister value,
                              FPRegister scratch_d,
-                             Label* on_successful_conversion,
+                             Label* on_successful_conversion = NULL,
                              Label* on_failed_conversion = NULL);
 
   bool generating_stub_;
 #if DEBUG
   // Tell whether any of the macro instruction can be used. When false the
   // MacroAssembler will assert if a method which can emit a variable number
   // of instructions is called.
   bool allow_macro_instructions_;
 #endif
   bool has_frame_;
@@ skipping 201 matching lines @@
 #error "Unsupported option"
 #define CODE_COVERAGE_STRINGIFY(x) #x
 #define CODE_COVERAGE_TOSTRING(x) CODE_COVERAGE_STRINGIFY(x)
 #define __FILE_LINE__ __FILE__ ":" CODE_COVERAGE_TOSTRING(__LINE__)
 #define ACCESS_MASM(masm) masm->stop(__FILE_LINE__); masm->
 #else
 #define ACCESS_MASM(masm) masm->
 #endif
 
 #endif  // V8_A64_MACRO_ASSEMBLER_A64_H_