From: yangguo <yangguo@chromium.org>
Date: Fri, 27 Mar 2015 09:11:51 +0000 (-0700)
Subject: Revert of [turbofan][arm64] Match fneg for -0.0 - x pattern. (patchset #1 id:1 of... 
X-Git-Tag: upstream/4.7.83~3545
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=98580e4b8300abaa3891f8f4d48f94ff053b2924;p=platform%2Fupstream%2Fv8.git

Revert of [turbofan][arm64] Match fneg for -0.0 - x pattern. (patchset #1 id:1 of https://codereview.chromium.org/1013743006/)

Reason for revert:
Revert due to crash.

Original issue's description:
> [turbofan][arm64] Match fneg for -0.0 - x pattern.
>
> Note that this patch add an extra bit to the ArchOpcodeField.
>
> R=bmeurer@chromium.org
>
> Committed: https://crrev.com/fe7441225100660d01e66ce3bcaefe368f62df81
> Cr-Commit-Position: refs/heads/master@{#27494}

TBR=bmeurer@chromium.org,baptiste.afsa@arm.com
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Review URL: https://codereview.chromium.org/1041633002

Cr-Commit-Position: refs/heads/master@{#27495}
---

diff --git a/src/compiler/arm64/code-generator-arm64.cc b/src/compiler/arm64/code-generator-arm64.cc
index 56f1d9e52..34ec3821f 100644
--- a/src/compiler/arm64/code-generator-arm64.cc
+++ b/src/compiler/arm64/code-generator-arm64.cc
@@ -689,9 +689,6 @@ void CodeGenerator::AssembleArchInstruction(Instruction* instr) {
                        0, 2);
       break;
     }
-    case kArm64Float64Neg:
-      __ Fneg(i.OutputDoubleRegister(), i.InputDoubleRegister(0));
-      break;
     case kArm64Float64Sqrt:
       __ Fsqrt(i.OutputDoubleRegister(), i.InputDoubleRegister(0));
       break;
diff --git a/src/compiler/arm64/instruction-codes-arm64.h b/src/compiler/arm64/instruction-codes-arm64.h
index f9a91d768..ab19216e6 100644
--- a/src/compiler/arm64/instruction-codes-arm64.h
+++ b/src/compiler/arm64/instruction-codes-arm64.h
@@ -85,7 +85,6 @@ namespace compiler {
   V(Arm64Float64Mul)               \
   V(Arm64Float64Div)               \
   V(Arm64Float64Mod)               \
-  V(Arm64Float64Neg)               \
   V(Arm64Float64Sqrt)              \
   V(Arm64Float64RoundDown)         \
   V(Arm64Float64RoundTiesAway)     \
diff --git a/src/compiler/arm64/instruction-selector-arm64.cc b/src/compiler/arm64/instruction-selector-arm64.cc
index 87ed89645..e81c5801b 100644
--- a/src/compiler/arm64/instruction-selector-arm64.cc
+++ b/src/compiler/arm64/instruction-selector-arm64.cc
@@ -1069,22 +1069,17 @@ void InstructionSelector::VisitFloat64Add(Node* node) {
 void InstructionSelector::VisitFloat64Sub(Node* node) {
   Arm64OperandGenerator g(this);
   Float64BinopMatcher m(node);
-  if (m.left().IsMinusZero()) {
-    if (m.right().IsFloat64RoundDown() &&
-        CanCover(m.node(), m.right().node())) {
-      if (m.right().InputAt(0)->opcode() == IrOpcode::kFloat64Sub &&
-          CanCover(m.right().node(), m.right().InputAt(0))) {
-        Float64BinopMatcher mright0(m.right().InputAt(0));
-        if (mright0.left().IsMinusZero()) {
-          Emit(kArm64Float64RoundUp, g.DefineAsRegister(node),
-               g.UseRegister(mright0.right().node()));
-          return;
-        }
+  if (m.left().IsMinusZero() && m.right().IsFloat64RoundDown() &&
+      CanCover(m.node(), m.right().node())) {
+    if (m.right().InputAt(0)->opcode() == IrOpcode::kFloat64Sub &&
+        CanCover(m.right().node(), m.right().InputAt(0))) {
+      Float64BinopMatcher mright0(m.right().InputAt(0));
+      if (mright0.left().IsMinusZero()) {
+        Emit(kArm64Float64RoundUp, g.DefineAsRegister(node),
+             g.UseRegister(mright0.right().node()));
+        return;
       }
     }
-    Emit(kArm64Float64Neg, g.DefineAsRegister(node),
-         g.UseRegister(m.right().node()));
-    return;
   }
   VisitRRRFloat64(this, kArm64Float64Sub, node);
 }
diff --git a/src/compiler/instruction-codes.h b/src/compiler/instruction-codes.h
index d5c04ab12..50e04349e 100644
--- a/src/compiler/instruction-codes.h
+++ b/src/compiler/instruction-codes.h
@@ -127,11 +127,11 @@ typedef int32_t InstructionCode;
 // for code generation. We encode the instruction, addressing mode, and flags
 // continuation into a single InstructionCode which is stored as part of
 // the instruction.
-typedef BitField<ArchOpcode, 0, 8> ArchOpcodeField;
-typedef BitField<AddressingMode, 8, 5> AddressingModeField;
-typedef BitField<FlagsMode, 13, 2> FlagsModeField;
-typedef BitField<FlagsCondition, 15, 4> FlagsConditionField;
-typedef BitField<int, 19, 13> MiscField;
+typedef BitField<ArchOpcode, 0, 7> ArchOpcodeField;
+typedef BitField<AddressingMode, 7, 5> AddressingModeField;
+typedef BitField<FlagsMode, 12, 2> FlagsModeField;
+typedef BitField<FlagsCondition, 14, 4> FlagsConditionField;
+typedef BitField<int, 14, 18> MiscField;
 
 }  // namespace compiler
 }  // namespace internal
diff --git a/test/unittests/compiler/arm64/instruction-selector-arm64-unittest.cc b/test/unittests/compiler/arm64/instruction-selector-arm64-unittest.cc
index 09ef9e8ec..02c8d2e06 100644
--- a/test/unittests/compiler/arm64/instruction-selector-arm64-unittest.cc
+++ b/test/unittests/compiler/arm64/instruction-selector-arm64-unittest.cc
@@ -2257,21 +2257,6 @@ TEST_F(InstructionSelectorTest, Word32Clz) {
   EXPECT_EQ(s.ToVreg(n), s.ToVreg(s[0]->Output()));
 }
 
-
-TEST_F(InstructionSelectorTest, Float64SubWithMinusZero) {
-  StreamBuilder m(this, kMachFloat64, kMachFloat64);
-  Node* const p0 = m.Parameter(0);
-  Node* const n = m.Float64Sub(m.Float64Constant(-0.0), p0);
-  m.Return(n);
-  Stream s = m.Build();
-  ASSERT_EQ(1U, s.size());
-  EXPECT_EQ(kArm64Float64Neg, s[0]->arch_opcode());
-  ASSERT_EQ(1U, s[0]->InputCount());
-  EXPECT_EQ(s.ToVreg(p0), s.ToVreg(s[0]->InputAt(0)));
-  ASSERT_EQ(1U, s[0]->OutputCount());
-  EXPECT_EQ(s.ToVreg(n), s.ToVreg(s[0]->Output()));
-}
-
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8