Rollback trunk to bleeding_edge revision 12525

src/x64/code-stubs-x64.cc

Index: src/x64/code-stubs-x64.cc
diff --git a/src/x64/code-stubs-x64.cc b/src/x64/code-stubs-x64.cc
index 0bad96073d0193545692804c5e817eeab4f1a486..62a89b83b294efa1d747fb30a81cacfa51f10fb0 100644
--- a/src/x64/code-stubs-x64.cc
+++ b/src/x64/code-stubs-x64.cc
@@ -2262,28 +2262,21 @@ void MathPowStub::Generate(MacroAssembler* masm) {
   __ 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));
-  __ mulsd(double_scratch, double_scratch);
-  __ j(above, &while_true, Label::kNear);
+  __ j(not_carry, &no_multiply, Label::kNear);
   __ mulsd(double_result, double_scratch);
+  __ bind(&no_multiply);
+
+  __ mulsd(double_scratch, double_scratch);
   __ j(not_zero, &while_true);
 
-  __ bind(&while_false);
   // If the exponent is negative, return 1/result.
   __ testl(exponent, exponent);
   __ j(greater, &done);
@@ -6144,11 +6137,6 @@ void RecordWriteStub::GenerateFixedRegStubsAheadOfTime() {
 }
 
 
-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
@@ -6281,17 +6269,6 @@ void RecordWriteStub::CheckNeedsToInformIncrementalMarker(
   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(),