Land the Fan (disabled)

test/cctest/compiler/test-machine-operator-reducer.cc

+// 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.
+
+#include "test/cctest/cctest.h"
+
+#include "src/base/utils/random-number-generator.h"
+#include "src/compiler/graph-inl.h"
+#include "src/compiler/machine-operator-reducer.h"
+#include "test/cctest/compiler/value-helper.h"
+
+using namespace v8::internal;
+using namespace v8::internal::compiler;
+
+template <typename T>
+Operator* NewConstantOperator(CommonOperatorBuilder* common, volatile T value);
+
+template <>
+Operator* NewConstantOperator<int32_t>(CommonOperatorBuilder* common,
+                                       volatile int32_t value) {
+  return common->Int32Constant(value);
+}
+
+template <>
+Operator* NewConstantOperator<double>(CommonOperatorBuilder* common,
+                                      volatile double value) {
+  return common->Float64Constant(value);
+}
+
+
+class ReducerTester : public HandleAndZoneScope {
+ public:
+  ReducerTester()
+    : isolate(main_isolate()),
+      binop(NULL),
+      unop(NULL),
+      machine(main_zone()),
+      common(main_zone()),
+      graph(main_zone()),
+      maxuint32(Constant<int32_t>(kMaxUInt32)) {
+  }
+
+  Isolate* isolate;
+  Operator* binop;
+  Operator* unop;
+  MachineOperatorBuilder machine;
+  CommonOperatorBuilder common;
+  Graph graph;
+  Node* maxuint32;
+
+  template <typename T>
+  Node* Constant(volatile T value) {
+    return graph.NewNode(NewConstantOperator<T>(&common, value));
+  }
+
+  // Check that the reduction of this binop applied to constants {a} and {b}
+  // yields the {expect} value.
+  template <typename T>
+  void CheckFoldBinop(volatile T expect, volatile T a, volatile T b) {
+    CheckFoldBinop<T>(expect, Constant<T>(a), Constant<T>(b));
+  }
+
+  // Check that the reduction of this binop applied to {a} and {b} yields
+  // the {expect} value.
+  template <typename T>
+  void CheckFoldBinop(volatile T expect, Node* a, Node* b) {
+    CHECK_NE(NULL, binop);
+    Node* n = graph.NewNode(binop, a, b);
+    MachineOperatorReducer reducer(&graph);
+    Reduction reduction = reducer.Reduce(n);
+    CHECK(reduction.Changed());
+    CHECK_NE(n, reduction.replacement());
+    CHECK_EQ(expect, ValueOf<T>(reduction.replacement()->op()));
+  }
+
+  // Check that the reduction of this binop applied to {a} and {b} yields
+  // the {expect} node.
+  void CheckBinop(Node* expect, Node* a, Node* b) {
+    CHECK_NE(NULL, binop);
+    Node* n = graph.NewNode(binop, a, b);
+    MachineOperatorReducer reducer(&graph);
+    Reduction reduction = reducer.Reduce(n);
+    CHECK(reduction.Changed());
+    CHECK_EQ(expect, reduction.replacement());
+  }
+
+  // Check that the reduction of this binop applied to {left} and {right} yields
+  // this binop applied to {left_expect} and {right_expect}.
+  void CheckFoldBinop(Node* left_expect,
+                      Node* right_expect,
+                      Node* left,
+                      Node* right) {
+    CHECK_NE(NULL, binop);
+    Node* n = graph.NewNode(binop, left, right);
+    MachineOperatorReducer reducer(&graph);
+    Reduction reduction = reducer.Reduce(n);
+    CHECK(reduction.Changed());
+    CHECK_EQ(binop, reduction.replacement()->op());
+    CHECK_EQ(left_expect, reduction.replacement()->InputAt(0));
+    CHECK_EQ(right_expect, reduction.replacement()->InputAt(1));
+  }
+
+  // Check that the reduction of this binop applied to {left} and {right} yields
+  // the {op_expect} applied to {left_expect} and {right_expect}.
+  template <typename T>
+  void CheckFoldBinop(volatile T left_expect,
+                      Operator* op_expect,
+                      Node* right_expect,
+                      Node* left,
+                      Node* right) {
+    CHECK_NE(NULL, binop);
+    Node* n = graph.NewNode(binop, left, right);
+    MachineOperatorReducer reducer(&graph);
+    Reduction r = reducer.Reduce(n);
+    CHECK(r.Changed());
+    CHECK_EQ(op_expect->opcode(), r.replacement()->op()->opcode());
+    CHECK_EQ(left_expect, ValueOf<T>(r.replacement()->InputAt(0)->op()));
+    CHECK_EQ(right_expect, r.replacement()->InputAt(1));
+  }
+
+  // Check that the reduction of this binop applied to {left} and {right} yields
+  // the {op_expect} applied to {left_expect} and {right_expect}.
+  template <typename T>
+  void CheckFoldBinop(Node* left_expect,
+                      Operator* op_expect,
+                      volatile T right_expect,
+                      Node* left,
+                      Node* right) {
+    CHECK_NE(NULL, binop);
+    Node* n = graph.NewNode(binop, left, right);
+    MachineOperatorReducer reducer(&graph);
+    Reduction r = reducer.Reduce(n);
+    CHECK(r.Changed());
+    CHECK_EQ(op_expect->opcode(), r.replacement()->op()->opcode());
+    CHECK_EQ(left_expect, r.replacement()->InputAt(0));
+    CHECK_EQ(right_expect, ValueOf<T>(r.replacement()->InputAt(1)->op()));
+  }
+
+  // Check that if the given constant appears on the left, the reducer will
+  // swap it to be on the right.
+  template <typename T>
+  void CheckPutConstantOnRight(volatile T constant) {
+    // TODO(titzer): CHECK(binop->HasProperty(Operator::kCommutative));
+    Node* p = Parameter();
+    Node* k = Constant<T>(constant);
+    {
+      Node* n = graph.NewNode(binop, k, p);
+      MachineOperatorReducer reducer(&graph);
+      Reduction reduction = reducer.Reduce(n);
+      CHECK(!reduction.Changed() || reduction.replacement() == n);
+      CHECK_EQ(p, n->InputAt(0));
+      CHECK_EQ(k, n->InputAt(1));
+    }
+    {
+      Node* n = graph.NewNode(binop, p, k);
+      MachineOperatorReducer reducer(&graph);
+      Reduction reduction = reducer.Reduce(n);
+      CHECK(!reduction.Changed());
+      CHECK_EQ(p, n->InputAt(0));
+      CHECK_EQ(k, n->InputAt(1));
+    }
+  }
+
+  // Check that if the given constant appears on the left, the reducer will
+  // *NOT* swap it to be on the right.
+  template <typename T>
+  void CheckDontPutConstantOnRight(volatile T constant) {
+    CHECK(!binop->HasProperty(Operator::kCommutative));
+    Node* p = Parameter();
+    Node* k = Constant<T>(constant);
+    Node* n = graph.NewNode(binop, k, p);
+    MachineOperatorReducer reducer(&graph);
+    Reduction reduction = reducer.Reduce(n);
+    CHECK(!reduction.Changed());
+    CHECK_EQ(k, n->InputAt(0));
+    CHECK_EQ(p, n->InputAt(1));
+  }
+
+  Node* Parameter(int32_t index = 0) {
+    return graph.NewNode(common.Parameter(index));
+  }
+};
+
+
+TEST(ReduceWord32And) {
+  ReducerTester R;
+  R.binop = R.machine.Word32And();
+
+  FOR_INT32_INPUTS(pl) {
+    FOR_INT32_INPUTS(pr) {
+      int32_t x = *pl, y = *pr;
+      R.CheckFoldBinop<int32_t>(x & y, x, y);
+    }
+  }
+
+  R.CheckPutConstantOnRight(33);
+  R.CheckPutConstantOnRight(44000);
+
+  Node* x = R.Parameter();
+  Node* zero = R.Constant<int32_t>(0);
+  Node* minus_1 = R.Constant<int32_t>(-1);
+
+  R.CheckBinop(zero, x, zero);  // x  & 0  => 0
+  R.CheckBinop(zero, zero, x);  // 0  & x  => 0
+  R.CheckBinop(x, x, minus_1);  // x  & -1 => 0
+  R.CheckBinop(x, minus_1, x);  // -1 & x  => 0
+  R.CheckBinop(x, x, x);        // x  & x  => x
+}
+
+
+TEST(ReduceWord32Or) {
+  ReducerTester R;
+  R.binop = R.machine.Word32Or();
+
+  FOR_INT32_INPUTS(pl) {
+    FOR_INT32_INPUTS(pr) {
+      int32_t x = *pl, y = *pr;
+      R.CheckFoldBinop<int32_t>(x | y, x, y);
+    }
+  }
+
+  R.CheckPutConstantOnRight(36);
+  R.CheckPutConstantOnRight(44001);
+
+  Node* x = R.Parameter();
+  Node* zero = R.Constant<int32_t>(0);
+  Node* minus_1 = R.Constant<int32_t>(-1);
+
+  R.CheckBinop(x, x, zero);           // x  & 0  => x
+  R.CheckBinop(x, zero, x);           // 0  & x  => x
+  R.CheckBinop(minus_1, x, minus_1);  // x  & -1 => -1
+  R.CheckBinop(minus_1, minus_1, x);  // -1 & x  => -1
+  R.CheckBinop(x, x, x);              // x  & x  => x
+}
+
+
+TEST(ReduceWord32Xor) {
+  ReducerTester R;
+  R.binop = R.machine.Word32Xor();
+
+  FOR_INT32_INPUTS(pl) {
+    FOR_INT32_INPUTS(pr) {
+      int32_t x = *pl, y = *pr;
+      R.CheckFoldBinop<int32_t>(x ^ y, x, y);
+    }
+  }
+
+  R.CheckPutConstantOnRight(39);
+  R.CheckPutConstantOnRight(4403);
+
+  Node* x = R.Parameter();
+  Node* zero = R.Constant<int32_t>(0);
+
+  R.CheckBinop(x, x, zero);            // x ^ 0  => x
+  R.CheckBinop(x, zero, x);            // 0 ^ x  => x
+  R.CheckFoldBinop<int32_t>(0, x, x);  // x ^ x  => 0
+}
+
+
+TEST(ReduceWord32Shl) {
+  ReducerTester R;
+  R.binop = R.machine.Word32Shl();
+
+  // TODO(titzer): out of range shifts
+  FOR_INT32_INPUTS(i) {
+    for (int y = 0; y < 32; y++) {
+      int32_t x = *i;
+      R.CheckFoldBinop<int32_t>(x << y, x, y);
+    }
+  }
+
+  R.CheckDontPutConstantOnRight(44);
+
+  Node* x = R.Parameter();
+  Node* zero = R.Constant<int32_t>(0);
+
+  R.CheckBinop(x, x, zero);           // x << 0  => x
+}
+
+
+TEST(ReduceWord32Shr) {
+  ReducerTester R;
+  R.binop = R.machine.Word32Shr();
+
+  // TODO(titzer): test out of range shifts
+  FOR_UINT32_INPUTS(i) {
+    for (uint32_t y = 0; y < 32; y++) {
+      uint32_t x = *i;
+      R.CheckFoldBinop<int32_t>(x >> y, x, y);
+    }
+  }
+
+  R.CheckDontPutConstantOnRight(44);
+
+  Node* x = R.Parameter();
+  Node* zero = R.Constant<int32_t>(0);
+
+  R.CheckBinop(x, x, zero);           // x >>> 0  => x
+}
+
+
+TEST(ReduceWord32Sar) {
+  ReducerTester R;
+  R.binop = R.machine.Word32Sar();
+
+  // TODO(titzer): test out of range shifts
+  FOR_INT32_INPUTS(i) {
+    for (int32_t y = 0; y < 32; y++) {
+      int32_t x = *i;
+      R.CheckFoldBinop<int32_t>(x >> y, x, y);
+    }
+  }
+
+  R.CheckDontPutConstantOnRight(44);
+
+  Node* x = R.Parameter();
+  Node* zero = R.Constant<int32_t>(0);
+
+  R.CheckBinop(x, x, zero);           // x >> 0  => x
+}
+
+
+TEST(ReduceWord32Equal) {
+  ReducerTester R;
+  R.binop = R.machine.Word32Equal();
+
+  FOR_INT32_INPUTS(pl) {
+    FOR_INT32_INPUTS(pr) {
+      int32_t x = *pl, y = *pr;
+      R.CheckFoldBinop<int32_t>(x == y ? 1 : 0, x, y);
+    }
+  }
+
+  R.CheckPutConstantOnRight(48);
+  R.CheckPutConstantOnRight(-48);
+
+  Node* x = R.Parameter(0);
+  Node* y = R.Parameter(1);
+  Node* zero = R.Constant<int32_t>(0);
+  Node* sub = R.graph.NewNode(R.machine.Int32Sub(), x, y);
+
+  R.CheckFoldBinop<int32_t>(1, x, x);  // x == x  => 1
+  R.CheckFoldBinop(x, y, sub, zero);   // x - y == 0  => x == y
+  R.CheckFoldBinop(x, y, zero, sub);   // 0 == x - y  => x == y
+}
+
+
+TEST(ReduceInt32Add) {
+  ReducerTester R;
+  R.binop = R.machine.Int32Add();
+
+  FOR_INT32_INPUTS(pl) {
+    FOR_INT32_INPUTS(pr) {
+      int32_t x = *pl, y = *pr;
+      R.CheckFoldBinop<int32_t>(x + y, x, y);  // TODO(titzer): signed overflow
+    }
+  }
+
+  R.CheckPutConstantOnRight(41);
+  R.CheckPutConstantOnRight(4407);
+
+  Node* x = R.Parameter();
+  Node* zero = R.Constant<int32_t>(0);
+
+  R.CheckBinop(x, x, zero);           // x + 0  => x
+  R.CheckBinop(x, zero, x);           // 0 + x  => x
+}
+
+
+TEST(ReduceInt32Sub) {
+  ReducerTester R;
+  R.binop = R.machine.Int32Sub();
+
+  FOR_INT32_INPUTS(pl) {
+    FOR_INT32_INPUTS(pr) {
+      int32_t x = *pl, y = *pr;
+      R.CheckFoldBinop<int32_t>(x - y, x, y);
+    }
+  }
+
+  R.CheckDontPutConstantOnRight(412);
+
+  Node* x = R.Parameter();
+  Node* zero = R.Constant<int32_t>(0);
+
+  R.CheckBinop(x, x, zero);           // x - 0  => x
+}
+
+
+TEST(ReduceInt32Mul) {
+  ReducerTester R;
+  R.binop = R.machine.Int32Mul();
+
+  FOR_INT32_INPUTS(pl) {
+    FOR_INT32_INPUTS(pr) {
+      int32_t x = *pl, y = *pr;
+      R.CheckFoldBinop<int32_t>(x * y, x, y);  // TODO(titzer): signed overflow
+    }
+  }
+
+  R.CheckPutConstantOnRight(4111);
+  R.CheckPutConstantOnRight(-4407);
+
+  Node* x = R.Parameter();
+  Node* zero = R.Constant<int32_t>(0);
+  Node* one = R.Constant<int32_t>(1);
+  Node* minus_one = R.Constant<int32_t>(-1);
+
+  R.CheckBinop(zero, x, zero);                    // x * 0  => 0
+  R.CheckBinop(zero, zero, x);                    // 0 * x  => 0
+  R.CheckBinop(x, x, one);                        // x * 1  => x
+  R.CheckBinop(x, one, x);                        // 1 * x  => x
+  R.CheckFoldBinop<int32_t>(0, R.machine.Int32Sub(), x,
+                            minus_one, x);        // -1 * x  => 0 - x
+  R.CheckFoldBinop<int32_t>(0, R.machine.Int32Sub(), x,
+                            x, minus_one);        // x * -1  => 0 - x
+
+  for (int32_t n = 1; n < 31; ++n) {
+    Node* multiplier = R.Constant<int32_t>(1 << n);
+    R.CheckFoldBinop<int32_t>(x, R.machine.Word32Shl(), n,
+                              x, multiplier);     // x * 2^n => x << n
+    R.CheckFoldBinop<int32_t>(x, R.machine.Word32Shl(), n,
+                              multiplier, x);     // 2^n * x => x << n
+  }
+}
+
+
+TEST(ReduceInt32Div) {
+  ReducerTester R;
+  R.binop = R.machine.Int32Div();
+
+  FOR_INT32_INPUTS(pl) {
+    FOR_INT32_INPUTS(pr) {
+      int32_t x = *pl, y = *pr;
+      if (y == 0) continue;              // TODO(titzer): test / 0
+      int32_t r = y == -1 ? -x : x / y;  // INT_MIN / -1 may explode in C
+      R.CheckFoldBinop<int32_t>(r, x, y);
+    }
+  }
+
+  R.CheckDontPutConstantOnRight(41111);
+  R.CheckDontPutConstantOnRight(-44071);
+
+  Node* x = R.Parameter();
+  Node* one = R.Constant<int32_t>(1);
+  Node* minus_one = R.Constant<int32_t>(-1);
+
+  R.CheckBinop(x, x, one);                  // x / 1  => x
+  // TODO(titzer):                          // 0 / x  => 0 if x != 0
+  // TODO(titzer):                          // x / 2^n => x >> n and round
+  R.CheckFoldBinop<int32_t>(0, R.machine.Int32Sub(), x,
+                            x, minus_one);  // x / -1  => 0 - x
+}
+
+
+TEST(ReduceInt32UDiv) {
+  ReducerTester R;
+  R.binop = R.machine.Int32UDiv();
+
+  FOR_UINT32_INPUTS(pl) {
+    FOR_UINT32_INPUTS(pr) {
+      uint32_t x = *pl, y = *pr;
+      if (y == 0) continue;  // TODO(titzer): test / 0
+      R.CheckFoldBinop<int32_t>(x / y, x, y);
+    }
+  }
+
+  R.CheckDontPutConstantOnRight(41311);
+  R.CheckDontPutConstantOnRight(-44371);
+
+  Node* x = R.Parameter();
+  Node* one = R.Constant<int32_t>(1);
+
+  R.CheckBinop(x, x, one);                    // x / 1  => x
+  // TODO(titzer):                            // 0 / x  => 0 if x != 0
+
+  for (uint32_t n = 1; n < 32; ++n) {
+    Node* divisor = R.Constant<int32_t>(1u << n);
+    R.CheckFoldBinop<int32_t>(x, R.machine.Word32Shr(), n,
+                              x, divisor);    // x / 2^n => x >> n
+  }
+}
+
+
+TEST(ReduceInt32Mod) {
+  ReducerTester R;
+  R.binop = R.machine.Int32Mod();
+
+  FOR_INT32_INPUTS(pl) {
+    FOR_INT32_INPUTS(pr) {
+      int32_t x = *pl, y = *pr;
+      if (y == 0) continue;             // TODO(titzer): test % 0
+      int32_t r = y == -1 ? 0 : x % y;  // INT_MIN % -1 may explode in C
+      R.CheckFoldBinop<int32_t>(r, x, y);
+    }
+  }
+
+  R.CheckDontPutConstantOnRight(413);
+  R.CheckDontPutConstantOnRight(-4401);
+
+  Node* x = R.Parameter();
+  Node* one = R.Constant<int32_t>(1);
+
+  R.CheckFoldBinop<int32_t>(0, x, one);  // x % 1  => 0
+  // TODO(titzer):                       // x % 2^n => x & 2^n-1 and round
+}
+
+
+TEST(ReduceInt32UMod) {
+  ReducerTester R;
+  R.binop = R.machine.Int32UMod();
+
+  FOR_INT32_INPUTS(pl) {
+    FOR_INT32_INPUTS(pr) {
+      uint32_t x = *pl, y = *pr;
+      if (y == 0) continue;  // TODO(titzer): test x % 0
+      R.CheckFoldBinop<int32_t>(x % y, x, y);
+    }
+  }
+
+  R.CheckDontPutConstantOnRight(417);
+  R.CheckDontPutConstantOnRight(-4371);
+
+  Node* x = R.Parameter();
+  Node* one = R.Constant<int32_t>(1);
+
+  R.CheckFoldBinop<int32_t>(0, x, one);           // x % 1  => 0
+
+  for (uint32_t n = 1; n < 32; ++n) {
+    Node* divisor = R.Constant<int32_t>(1u << n);
+    R.CheckFoldBinop<int32_t>(x, R.machine.Word32And(), (1u << n) - 1,
+                              x, divisor);        // x % 2^n => x & 2^n-1
+  }
+}
+
+
+TEST(ReduceInt32LessThan) {
+  ReducerTester R;
+  R.binop = R.machine.Int32LessThan();
+
+  FOR_INT32_INPUTS(pl) {
+    FOR_INT32_INPUTS(pr) {
+      int32_t x = *pl, y = *pr;
+      R.CheckFoldBinop<int32_t>(x < y ? 1 : 0, x, y);
+    }
+  }
+
+  R.CheckDontPutConstantOnRight(41399);
+  R.CheckDontPutConstantOnRight(-440197);
+
+  Node* x = R.Parameter(0);
+  Node* y = R.Parameter(1);
+  Node* zero = R.Constant<int32_t>(0);
+  Node* sub = R.graph.NewNode(R.machine.Int32Sub(), x, y);
+
+  R.CheckFoldBinop<int32_t>(0, x, x);  // x < x  => 0
+  R.CheckFoldBinop(x, y, sub, zero);   // x - y < 0 => x < y
+  R.CheckFoldBinop(y, x, zero, sub);   // 0 < x - y => y < x
+}
+
+
+TEST(ReduceInt32LessThanOrEqual) {
+  ReducerTester R;
+  R.binop = R.machine.Int32LessThanOrEqual();
+
+  FOR_INT32_INPUTS(pl) {
+    FOR_INT32_INPUTS(pr) {
+      int32_t x = *pl, y = *pr;
+      R.CheckFoldBinop<int32_t>(x <= y ? 1 : 0, x, y);
+    }
+  }
+
+  FOR_INT32_INPUTS(i) { R.CheckDontPutConstantOnRight<int32_t>(*i); }
+
+  Node* x = R.Parameter(0);
+  Node* y = R.Parameter(1);
+  Node* zero = R.Constant<int32_t>(0);
+  Node* sub = R.graph.NewNode(R.machine.Int32Sub(), x, y);
+
+  R.CheckFoldBinop<int32_t>(1, x, x);  // x <= x => 1
+  R.CheckFoldBinop(x, y, sub, zero);   // x - y <= 0 => x <= y
+  R.CheckFoldBinop(y, x, zero, sub);   // 0 <= x - y => y <= x
+}
+
+
+TEST(ReduceUint32LessThan) {
+  ReducerTester R;
+  R.binop = R.machine.Uint32LessThan();
+
+  FOR_UINT32_INPUTS(pl) {
+    FOR_UINT32_INPUTS(pr) {
+      uint32_t x = *pl, y = *pr;
+      R.CheckFoldBinop<int32_t>(x < y ? 1 : 0, x, y);
+    }
+  }
+
+  R.CheckDontPutConstantOnRight(41399);
+  R.CheckDontPutConstantOnRight(-440197);
+
+  Node* x = R.Parameter();
+  Node* max = R.maxuint32;
+  Node* zero = R.Constant<int32_t>(0);
+
+  R.CheckFoldBinop<int32_t>(0, max, x);         // M < x  => 0
+  R.CheckFoldBinop<int32_t>(0, x, zero);        // x < 0  => 0
+  R.CheckFoldBinop<int32_t>(0, x, x);           // x < x  => 0
+}
+
+
+TEST(ReduceUint32LessThanOrEqual) {
+  ReducerTester R;
+  R.binop = R.machine.Uint32LessThanOrEqual();
+
+  FOR_UINT32_INPUTS(pl) {
+    FOR_UINT32_INPUTS(pr) {
+      uint32_t x = *pl, y = *pr;
+      R.CheckFoldBinop<int32_t>(x <= y ? 1 : 0, x, y);
+    }
+  }
+
+  R.CheckDontPutConstantOnRight(41399);
+  R.CheckDontPutConstantOnRight(-440197);
+
+  Node* x = R.Parameter();
+  Node* max = R.maxuint32;
+  Node* zero = R.Constant<int32_t>(0);
+
+  R.CheckFoldBinop<int32_t>(1, x, max);         // x <= M  => 1
+  R.CheckFoldBinop<int32_t>(1, zero, x);        // 0 <= x  => 1
+  R.CheckFoldBinop<int32_t>(1, x, x);           // x <= x  => 1
+}
+
+
+TEST(ReduceLoadStore) {
+  ReducerTester R;
+
+  Node* base = R.Constant<int32_t>(11);
+  Node* index = R.Constant<int32_t>(4);
+  Node* load = R.graph.NewNode(R.machine.Load(kMachineWord32), base, index);
+
+  {
+    MachineOperatorReducer reducer(&R.graph);
+    Reduction reduction = reducer.Reduce(load);
+    CHECK(!reduction.Changed());  // loads should not be reduced.
+  }
+
+  {
+    Node* store = R.graph.NewNode(R.machine.Store(kMachineWord32),
+                                  base, index, load);
+    MachineOperatorReducer reducer(&R.graph);
+    Reduction reduction = reducer.Reduce(store);
+    CHECK(!reduction.Changed());  // stores should not be reduced.
+  }
+}
+
+
+static void CheckNans(ReducerTester* R) {
+  Node* x = R->Parameter();
+  std::vector<double> nans = ValueHelper::nan_vector();
+  for (std::vector<double>::const_iterator pl = nans.begin(); pl != nans.end();
+       ++pl) {
+    for (std::vector<double>::const_iterator pr = nans.begin();
+         pr != nans.end(); ++pr) {
+      Node* nan1 = R->Constant<double>(*pl);
+      Node* nan2 = R->Constant<double>(*pr);
+      R->CheckBinop(nan1, x, nan1);     // x % NaN => NaN
+      R->CheckBinop(nan1, nan1, x);     // NaN % x => NaN
+      R->CheckBinop(nan1, nan2, nan1);  // NaN % NaN => NaN
+    }
+  }
+}
+
+
+TEST(ReduceFloat64Add) {
+  ReducerTester R;
+  R.binop = R.machine.Float64Add();
+
+  FOR_FLOAT64_INPUTS(pl) {
+    FOR_FLOAT64_INPUTS(pr) {
+      double x = *pl, y = *pr;
+      R.CheckFoldBinop<double>(x + y, x, y);
+    }
+  }
+
+  FOR_FLOAT64_INPUTS(i) { R.CheckPutConstantOnRight(*i); }
+  // TODO(titzer): CheckNans(&R);
+}
+
+
+TEST(ReduceFloat64Sub) {
+  ReducerTester R;
+  R.binop = R.machine.Float64Sub();
+
+  FOR_FLOAT64_INPUTS(pl) {
+    FOR_FLOAT64_INPUTS(pr) {
+      double x = *pl, y = *pr;
+      R.CheckFoldBinop<double>(x - y, x, y);
+    }
+  }
+  // TODO(titzer): CheckNans(&R);
+}
+
+
+TEST(ReduceFloat64Mul) {
+  ReducerTester R;
+  R.binop = R.machine.Float64Mul();
+
+  FOR_FLOAT64_INPUTS(pl) {
+    FOR_FLOAT64_INPUTS(pr) {
+      double x = *pl, y = *pr;
+      R.CheckFoldBinop<double>(x * y, x, y);
+    }
+  }
+
+  double inf = V8_INFINITY;
+  R.CheckPutConstantOnRight(-inf);
+  R.CheckPutConstantOnRight(-0.1);
+  R.CheckPutConstantOnRight(0.1);
+  R.CheckPutConstantOnRight(inf);
+
+  Node* x = R.Parameter();
+  Node* one = R.Constant<double>(1.0);
+
+  R.CheckBinop(x, x, one);                      // x * 1.0 => x
+  R.CheckBinop(x, one, x);                      // 1.0 * x => x
+
+  CheckNans(&R);
+}
+
+
+TEST(ReduceFloat64Div) {
+  ReducerTester R;
+  R.binop = R.machine.Float64Div();
+
+  FOR_FLOAT64_INPUTS(pl) {
+    FOR_FLOAT64_INPUTS(pr) {
+      double x = *pl, y = *pr;
+      R.CheckFoldBinop<double>(x / y, x, y);
+    }
+  }
+
+  Node* x = R.Parameter();
+  Node* one = R.Constant<double>(1.0);
+
+  R.CheckBinop(x, x, one);                      // x / 1.0 => x
+
+  CheckNans(&R);
+}
+
+
+TEST(ReduceFloat64Mod) {
+  ReducerTester R;
+  R.binop = R.machine.Float64Mod();
+
+  FOR_FLOAT64_INPUTS(pl) {
+    FOR_FLOAT64_INPUTS(pr) {
+      double x = *pl, y = *pr;
+      R.CheckFoldBinop<double>(modulo(x, y), x, y);
+    }
+  }
+
+  CheckNans(&R);
+}
+
+
+// TODO(titzer): test MachineOperatorReducer for Word64And
+// TODO(titzer): test MachineOperatorReducer for Word64Or
+// TODO(titzer): test MachineOperatorReducer for Word64Xor
+// TODO(titzer): test MachineOperatorReducer for Word64Shl
+// TODO(titzer): test MachineOperatorReducer for Word64Shr
+// TODO(titzer): test MachineOperatorReducer for Word64Sar
+// TODO(titzer): test MachineOperatorReducer for Word64Equal
+// TODO(titzer): test MachineOperatorReducer for Word64Not
+// TODO(titzer): test MachineOperatorReducer for Int64Add
+// TODO(titzer): test MachineOperatorReducer for Int64Sub
+// TODO(titzer): test MachineOperatorReducer for Int64Mul
+// TODO(titzer): test MachineOperatorReducer for Int64UMul
+// TODO(titzer): test MachineOperatorReducer for Int64Div
+// TODO(titzer): test MachineOperatorReducer for Int64UDiv
+// TODO(titzer): test MachineOperatorReducer for Int64Mod
+// TODO(titzer): test MachineOperatorReducer for Int64UMod
+// TODO(titzer): test MachineOperatorReducer for Int64Neg
+// TODO(titzer): test MachineOperatorReducer for ConvertInt32ToFloat64
+// TODO(titzer): test MachineOperatorReducer for ConvertFloat64ToInt32
+// TODO(titzer): test MachineOperatorReducer for Float64Compare