[turbofan] Fix bogus covering of Word64Equal w/ zero.

Review URL: https://codereview.chromium.org/960783002

Cr-Commit-Position: refs/heads/master@{#26870}

src/compiler/arm64/instruction-selector-arm64.cc

@@ -1250,25 +1250,12 @@ void InstructionSelector::VisitBranch(Node* branch, BasicBlock* tbranch,
   FlagsContinuation cont(kNotEqual, tbranch, fbranch);
 
   // Try to combine with comparisons against 0 by simply inverting the branch.
-  while (CanCover(user, value)) {
-    if (value->opcode() == IrOpcode::kWord32Equal) {
-      Int32BinopMatcher m(value);
-      if (m.right().Is(0)) {
-        user = value;
-        value = m.left().node();
-        cont.Negate();
-      } else {
-        break;
-      }
-    } else if (value->opcode() == IrOpcode::kWord64Equal) {
-      Int64BinopMatcher m(value);
-      if (m.right().Is(0)) {
-        user = value;
-        value = m.left().node();
-        cont.Negate();
-      } else {
-        break;
-      }
+  while (CanCover(user, value) && value->opcode() == IrOpcode::kWord32Equal) {
+    Int32BinopMatcher m(value);
+    if (m.right().Is(0)) {
+      user = value;
+      value = m.left().node();
+      cont.Negate();
     } else {
       break;
     }

src/compiler/x64/instruction-selector-x64.cc

@@ -1068,25 +1068,12 @@ void InstructionSelector::VisitBranch(Node* branch, BasicBlock* tbranch,
   FlagsContinuation cont(kNotEqual, tbranch, fbranch);
 
   // Try to combine with comparisons against 0 by simply inverting the branch.
-  while (CanCover(user, value)) {
-    if (value->opcode() == IrOpcode::kWord32Equal) {
-      Int32BinopMatcher m(value);
-      if (m.right().Is(0)) {
-        user = value;
-        value = m.left().node();
-        cont.Negate();
-      } else {
-        break;
-      }
-    } else if (value->opcode() == IrOpcode::kWord64Equal) {
-      Int64BinopMatcher m(value);
-      if (m.right().Is(0)) {
-        user = value;
-        value = m.left().node();
-        cont.Negate();
-      } else {
-        break;
-      }
+  while (CanCover(user, value) && value->opcode() == IrOpcode::kWord32Equal) {
+    Int32BinopMatcher m(value);
+    if (m.right().Is(0)) {
+      user = value;
+      value = m.left().node();
+      cont.Negate();
     } else {
       break;
     }

test/cctest/compiler/test-run-machops.cc

@@ -4436,6 +4436,26 @@ TEST(RunInt32SubWithOverflowInBranchP) {
 }
 
 
+TEST(RunWord64EqualInBranchP) {
+  int64_t input;
+  MLabel blocka, blockb;
+  RawMachineAssemblerTester<int64_t> m;
+  if (!m.machine()->Is64()) return;
+  Node* value = m.LoadFromPointer(&input, kMachInt64);
+  m.Branch(m.Word64Equal(value, m.Int64Constant(0)), &blocka, &blockb);
+  m.Bind(&blocka);
+  m.Return(m.Int32Constant(1));
+  m.Bind(&blockb);
+  m.Return(m.Int32Constant(2));
+  input = V8_INT64_C(0);
+  CHECK_EQ(1, m.Call());
+  input = V8_INT64_C(1);
+  CHECK_EQ(2, m.Call());
+  input = V8_INT64_C(0x100000000);
+  CHECK_EQ(2, m.Call());
+}
+
+
 TEST(RunChangeInt32ToInt64P) {
   if (kPointerSize < 8) return;
   int64_t actual = -1;
@@ -4793,4 +4813,5 @@ TEST(RunFloat64RoundTiesAway) {
     CHECK_EQ(expected, result);
   }
 }
+
 #endif  // V8_TURBOFAN_TARGET

test/unittests/compiler/arm64/instruction-selector-arm64-unittest.cc

@@ -896,26 +896,6 @@ TEST_F(InstructionSelectorTest, Word64AndBranchWithOneBitMaskOnRight) {
     EXPECT_EQ(InstructionOperand::IMMEDIATE, s[0]->InputAt(1)->kind());
     EXPECT_EQ(bit, s.ToInt64(s[0]->InputAt(1)));
   }
-
-  TRACED_FORRANGE(int, bit, 0, 63) {
-    uint64_t mask = 1L << bit;
-    StreamBuilder m(this, kMachInt64, kMachInt64);
-    MLabel a, b;
-    m.Branch(
-        m.Word64BinaryNot(m.Word64And(m.Parameter(0), m.Int64Constant(mask))),
-        &a, &b);
-    m.Bind(&a);
-    m.Return(m.Int32Constant(1));
-    m.Bind(&b);
-    m.Return(m.Int32Constant(0));
-    Stream s = m.Build();
-    ASSERT_EQ(1U, s.size());
-    EXPECT_EQ(kArm64TestAndBranch, s[0]->arch_opcode());
-    EXPECT_EQ(kEqual, s[0]->flags_condition());
-    EXPECT_EQ(4U, s[0]->InputCount());
-    EXPECT_EQ(InstructionOperand::IMMEDIATE, s[0]->InputAt(1)->kind());
-    EXPECT_EQ(bit, s.ToInt64(s[0]->InputAt(1)));
-  }
 }
 
 
@@ -937,26 +917,6 @@ TEST_F(InstructionSelectorTest, Word64AndBranchWithOneBitMaskOnLeft) {
     EXPECT_EQ(InstructionOperand::IMMEDIATE, s[0]->InputAt(1)->kind());
     EXPECT_EQ(bit, s.ToInt64(s[0]->InputAt(1)));
   }
-
-  TRACED_FORRANGE(int, bit, 0, 63) {
-    uint64_t mask = 1L << bit;
-    StreamBuilder m(this, kMachInt64, kMachInt64);
-    MLabel a, b;
-    m.Branch(
-        m.Word64BinaryNot(m.Word64And(m.Int64Constant(mask), m.Parameter(0))),
-        &a, &b);
-    m.Bind(&a);
-    m.Return(m.Int32Constant(1));
-    m.Bind(&b);
-    m.Return(m.Int32Constant(0));
-    Stream s = m.Build();
-    ASSERT_EQ(1U, s.size());
-    EXPECT_EQ(kArm64TestAndBranch, s[0]->arch_opcode());
-    EXPECT_EQ(kEqual, s[0]->flags_condition());
-    EXPECT_EQ(4U, s[0]->InputCount());
-    EXPECT_EQ(InstructionOperand::IMMEDIATE, s[0]->InputAt(1)->kind());
-    EXPECT_EQ(bit, s.ToInt64(s[0]->InputAt(1)));
-  }
 }