[x64] Fix optimization for certain checked load/stores.

BUG=chromium:439743
LOG=y
TEST=mjsunit
R=svenpanne@chromium.org

Review URL: https://codereview.chromium.org/733893008

Cr-Commit-Position: refs/heads/master@{#25731}

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

@@ -230,12 +230,21 @@ void InstructionSelector::VisitCheckedLoad(Node* node) {
       UNREACHABLE();
       return;
   }
-  InstructionOperand* offset_operand = g.UseRegister(offset);
+  if (offset->opcode() == IrOpcode::kInt32Add && CanCover(node, offset)) {
+    Int32Matcher mlength(length);
+    Int32BinopMatcher moffset(offset);
+    if (mlength.HasValue() && moffset.right().HasValue() &&
+        mlength.Value() >= moffset.right().Value()) {
+      Emit(opcode, g.DefineAsRegister(node), g.UseRegister(buffer),
+           g.UseRegister(moffset.left().node()),
+           g.UseImmediate(moffset.right().node()), g.UseImmediate(length));
+      return;
+    }
+  }
   InstructionOperand* length_operand =
       g.CanBeImmediate(length) ? g.UseImmediate(length) : g.UseRegister(length);
-  Emit(opcode | AddressingModeField::encode(kMode_MR1),
-       g.DefineAsRegister(node), offset_operand, length_operand,
-       g.UseRegister(buffer), offset_operand);
+  Emit(opcode, g.DefineAsRegister(node), g.UseRegister(buffer),
+       g.UseRegister(offset), g.TempImmediate(0), length_operand);
 }
 
 
@@ -269,11 +278,22 @@ void InstructionSelector::VisitCheckedStore(Node* node) {
   }
   InstructionOperand* value_operand =
       g.CanBeImmediate(value) ? g.UseImmediate(value) : g.UseRegister(value);
-  InstructionOperand* offset_operand = g.UseRegister(offset);
+  if (offset->opcode() == IrOpcode::kInt32Add && CanCover(node, offset)) {
+    Int32Matcher mlength(length);
+    Int32BinopMatcher moffset(offset);
+    if (mlength.HasValue() && moffset.right().HasValue() &&
+        mlength.Value() >= moffset.right().Value()) {
+      Emit(opcode, nullptr, g.UseRegister(buffer),
+           g.UseRegister(moffset.left().node()),
+           g.UseImmediate(moffset.right().node()), g.UseImmediate(length),
+           value_operand);
+      return;
+    }
+  }
   InstructionOperand* length_operand =
       g.CanBeImmediate(length) ? g.UseImmediate(length) : g.UseRegister(length);
-  Emit(opcode | AddressingModeField::encode(kMode_MR1), nullptr, offset_operand,
-       length_operand, value_operand, g.UseRegister(buffer), offset_operand);
+  Emit(opcode, nullptr, g.UseRegister(buffer), g.UseRegister(offset),
+       g.TempImmediate(0), length_operand, value_operand);
 }
 
 

test/mjsunit/asm/float32array-negative-offset.js

+// Copyright 2014 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+var stdlib = this;
+var buffer = new ArrayBuffer(64 * 1024);
+var foreign = {}
+
+
+var m = (function Module(stdlib, foreign, heap) {
+  "use asm";
+  var MEM32 = new stdlib.Float32Array(heap);
+  function load(i) {
+    i = i|0;
+    i = +MEM32[i >> 2];
+    return i;
+  }
+  function store(i, v) {
+    i = i|0;
+    v = +v;
+    MEM32[i >> 2] = v;
+  }
+  function load8(i) {
+    i = i|0;
+    i = +MEM32[i + 8 >> 2];
+    return i;
+  }
+  function store8(i, v) {
+    i = i|0;
+    v = +v;
+    MEM32[i + 8 >> 2] = v;
+  }
+  return { load: load, store: store, load8: load8, store8: store8 };
+})(stdlib, foreign, buffer);
+
+assertEquals(NaN, m.load(-8));
+assertEquals(NaN, m.load8(-16));
+m.store(0, 42.0);
+assertEquals(42.0, m.load8(-8));
+m.store8(-8, 99.0);
+assertEquals(99.0, m.load(0));
+assertEquals(99.0, m.load8(-8));

test/mjsunit/asm/float64array-negative-offset.js

+// Copyright 2014 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+var stdlib = this;
+var buffer = new ArrayBuffer(64 * 1024);
+var foreign = {}
+
+
+var m = (function Module(stdlib, foreign, heap) {
+  "use asm";
+  var MEM64 = new stdlib.Float64Array(heap);
+  function load(i) {
+    i = i|0;
+    i = +MEM64[i >> 3];
+    return i;
+  }
+  function store(i, v) {
+    i = i|0;
+    v = +v;
+    MEM64[i >> 3] = v;
+  }
+  function load8(i) {
+    i = i|0;
+    i = +MEM64[i + 8 >> 3];
+    return i;
+  }
+  function store8(i, v) {
+    i = i|0;
+    v = +v;
+    MEM64[i + 8 >> 3] = v;
+  }
+  return { load: load, store: store, load8: load8, store8: store8 };
+})(stdlib, foreign, buffer);
+
+assertEquals(NaN, m.load(-8));
+assertEquals(NaN, m.load8(-16));
+m.store(0, 42.0);
+assertEquals(42.0, m.load8(-8));
+m.store8(-8, 99.0);
+assertEquals(99.0, m.load(0));
+assertEquals(99.0, m.load8(-8));

test/mjsunit/asm/int16array-negative-offset.js

+// Copyright 2014 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+var stdlib = this;
+var buffer = new ArrayBuffer(64 * 1024);
+var foreign = {}
+
+
+var m = (function Module(stdlib, foreign, heap) {
+  "use asm";
+  var MEM16 = new stdlib.Int16Array(heap);
+  function load(i) {
+    i = i|0;
+    i = MEM16[i >> 1]|0;
+    return i;
+  }
+  function store(i, v) {
+    i = i|0;
+    v = v|0;
+    MEM16[i >> 1] = v;
+  }
+  function load8(i) {
+    i = i|0;
+    i = MEM16[i + 8 >> 1]|0;
+    return i;
+  }
+  function store8(i, v) {
+    i = i|0;
+    v = v|0;
+    MEM16[i + 8 >> 1] = v;
+  }
+  return { load: load, store: store, load8: load8, store8: store8 };
+})(stdlib, foreign, buffer);
+
+assertEquals(0, m.load(-8));
+assertEquals(0, m.load8(-16));
+m.store(0, 42);
+assertEquals(42, m.load8(-8));
+m.store8(-8, 99);
+assertEquals(99, m.load(0));
+assertEquals(99, m.load8(-8));

test/mjsunit/asm/int32array-negative-offset.js

+// Copyright 2014 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+var stdlib = this;
+var buffer = new ArrayBuffer(64 * 1024);
+var foreign = {}
+
+
+var m = (function Module(stdlib, foreign, heap) {
+  "use asm";
+  var MEM32 = new stdlib.Int32Array(heap);
+  function load(i) {
+    i = i|0;
+    i = MEM32[i >> 2]|0;
+    return i;
+  }
+  function store(i, v) {
+    i = i|0;
+    v = v|0;
+    MEM32[i >> 2] = v;
+  }
+  function load8(i) {
+    i = i|0;
+    i = MEM32[i + 8 >> 2]|0;
+    return i;
+  }
+  function store8(i, v) {
+    i = i|0;
+    v = v|0;
+    MEM32[i + 8 >> 2] = v;
+  }
+  return { load: load, store: store, load8: load8, store8: store8 };
+})(stdlib, foreign, buffer);
+
+assertEquals(0, m.load(-8));
+assertEquals(0, m.load8(-16));
+m.store(0, 42);
+assertEquals(42, m.load8(-8));
+m.store8(-8, 99);
+assertEquals(99, m.load(0));
+assertEquals(99, m.load8(-8));

test/mjsunit/asm/int8array-negative-offset.js

+// Copyright 2014 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+var stdlib = this;
+var buffer = new ArrayBuffer(64 * 1024);
+var foreign = {}
+
+
+var m = (function Module(stdlib, foreign, heap) {
+  "use asm";
+  var MEM8 = new stdlib.Int8Array(heap);
+  function load(i) {
+    i = i|0;
+    i = MEM8[i >> 0]|0;
+    return i;
+  }
+  function store(i, v) {
+    i = i|0;
+    v = v|0;
+    MEM8[i >> 0] = v;
+  }
+  function load8(i) {
+    i = i|0;
+    i = MEM8[i + 8 >> 0]|0;
+    return i;
+  }
+  function store8(i, v) {
+    i = i|0;
+    v = v|0;
+    MEM8[i + 8 >> 0] = v;
+  }
+  return { load: load, store: store, load8: load8, store8: store8 };
+})(stdlib, foreign, buffer);
+
+assertEquals(0, m.load(-8));
+assertEquals(0, m.load8(-16));
+m.store(0, 42);
+assertEquals(42, m.load8(-8));
+m.store8(-8, 99);
+assertEquals(99, m.load(0));
+assertEquals(99, m.load8(-8));