Rollback trunk to bleeding_edge revision 12525

src/x64/code-stubs-x64.cc

 // Copyright 2012 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 2244 matching lines @@
 
   // Calculate power with integer exponent.
   __ bind(&int_exponent);
   const XMMRegister double_scratch2 = double_exponent;
   // Back up exponent as we need to check if exponent is negative later.
   __ movq(scratch, exponent);  // Back up exponent.
   __ movsd(double_scratch, double_base);  // Back up base.
   __ movsd(double_scratch2, double_result);  // Load double_exponent with 1.
 
   // Get absolute value of exponent.
-  Label no_neg, while_true, while_false;
+  Label no_neg, while_true, no_multiply;
   __ testl(scratch, scratch);
   __ j(positive, &no_neg, Label::kNear);
   __ negl(scratch);
   __ bind(&no_neg);
 
-  __ j(zero, &while_false, Label::kNear);
-  __ shrl(scratch, Immediate(1));
-  // Above condition means CF==0 && ZF==0.  This means that the
-  // bit that has been shifted out is 0 and the result is not 0.
-  __ j(above, &while_true, Label::kNear);
-  __ movsd(double_result, double_scratch);
-  __ j(zero, &while_false, Label::kNear);
-
   __ bind(&while_true);
   __ shrl(scratch, Immediate(1));
+  __ j(not_carry, &no_multiply, Label::kNear);
+  __ mulsd(double_result, double_scratch);
+  __ bind(&no_multiply);
+
   __ mulsd(double_scratch, double_scratch);
-  __ j(above, &while_true, Label::kNear);
-  __ mulsd(double_result, double_scratch);
   __ j(not_zero, &while_true);
 
-  __ bind(&while_false);
   // If the exponent is negative, return 1/result.
   __ testl(exponent, exponent);
   __ j(greater, &done);
   __ divsd(double_scratch2, double_result);
   __ movsd(double_result, double_scratch2);
   // Test whether result is zero.  Bail out to check for subnormal result.
   // Due to subnormals, x^-y == (1/x)^y does not hold in all cases.
   __ xorps(double_scratch2, double_scratch2);
   __ ucomisd(double_scratch2, double_result);
   // double_exponent aliased as double_scratch2 has already been overwritten
@@ skipping 3840 matching lines @@
     RecordWriteStub stub(entry->object,
                          entry->value,
                          entry->address,
                          entry->action,
                          kDontSaveFPRegs);
     stub.GetCode()->set_is_pregenerated(true);
   }
 }
 
 
-bool CodeStub::CanUseFPRegisters() {
-  return true;  // Always have SSE2 on x64.
-}
-
-
 // Takes the input in 3 registers: address_ value_ and object_.  A pointer to
 // the value has just been written into the object, now this stub makes sure
 // we keep the GC informed.  The word in the object where the value has been
 // written is in the address register.
 void RecordWriteStub::Generate(MacroAssembler* masm) {
   Label skip_to_incremental_noncompacting;
   Label skip_to_incremental_compacting;
 
   // The first two instructions are generated with labels so as to get the
   // offset fixed up correctly by the bind(Label*) call.  We patch it back and
@@ skipping 112 matching lines @@
 
 
 void RecordWriteStub::CheckNeedsToInformIncrementalMarker(
     MacroAssembler* masm,
     OnNoNeedToInformIncrementalMarker on_no_need,
     Mode mode) {
   Label on_black;
   Label need_incremental;
   Label need_incremental_pop_object;
 
-  __ movq(regs_.scratch0(), Immediate(~Page::kPageAlignmentMask));
-  __ and_(regs_.scratch0(), regs_.object());
-  __ movq(regs_.scratch1(),
-         Operand(regs_.scratch0(),
-                 MemoryChunk::kWriteBarrierCounterOffset));
-  __ subq(regs_.scratch1(), Immediate(1));
-  __ movq(Operand(regs_.scratch0(),
-                 MemoryChunk::kWriteBarrierCounterOffset),
-         regs_.scratch1());
-  __ j(negative, &need_incremental);
-
   // Let's look at the color of the object:  If it is not black we don't have
   // to inform the incremental marker.
   __ JumpIfBlack(regs_.object(),
                  regs_.scratch0(),
                  regs_.scratch1(),
                  &on_black,
                  Label::kNear);
 
   regs_.Restore(masm);
   if (on_no_need == kUpdateRememberedSetOnNoNeedToInformIncrementalMarker) {
@@ skipping 200 matching lines @@
 #endif
 
   __ Ret();
 }
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64