[turbofan] Generalize constant propagation.

Also support additional number types (singleton ranges, NaN and minus
zero) for constant propagation in typed lowering.

TEST=unittests

Review URL: https://codereview.chromium.org/829303002

Cr-Commit-Position: refs/heads/master@{#25963}

src/compiler/js-typed-lowering.cc

@@ -837,14 +837,36 @@ Reduction JSTypedLowering::ReduceJSStoreContext(Node* node) {
 
 Reduction JSTypedLowering::Reduce(Node* node) {
   // Check if the output type is a singleton.  In that case we already know the
-  // result value and can simply replace the node unless there are effects.
+  // result value and can simply replace the node if it's eliminable.
   if (NodeProperties::IsTyped(node) &&
-      NodeProperties::GetBounds(node).upper->IsConstant() &&
       !IrOpcode::IsLeafOpcode(node->opcode()) &&
-      node->op()->EffectOutputCount() == 0) {
-    return ReplaceEagerly(node, jsgraph()->Constant(
-        NodeProperties::GetBounds(node).upper->AsConstant()->Value()));
-    // TODO(neis): Extend this to Range(x,x), NaN, MinusZero, ...?
+      node->op()->HasProperty(Operator::kEliminatable)) {
+    Type* upper = NodeProperties::GetBounds(node).upper;
+    if (upper->IsConstant()) {
+      Node* replacement = jsgraph()->Constant(upper->AsConstant()->Value());
+      NodeProperties::ReplaceWithValue(node, replacement);
+      return Changed(replacement);
+    } else if (upper->Is(Type::MinusZero())) {
+      Node* replacement = jsgraph()->Constant(factory()->minus_zero_value());
+      NodeProperties::ReplaceWithValue(node, replacement);
+      return Changed(replacement);
+    } else if (upper->Is(Type::NaN())) {
+      Node* replacement = jsgraph()->NaNConstant();
+      NodeProperties::ReplaceWithValue(node, replacement);
+      return Changed(replacement);
+    } else if (upper->Is(Type::Null())) {
+      Node* replacement = jsgraph()->NullConstant();
+      NodeProperties::ReplaceWithValue(node, replacement);
+      return Changed(replacement);
+    } else if (upper->Is(Type::PlainNumber()) && upper->Min() == upper->Max()) {
+      Node* replacement = jsgraph()->Constant(upper->Min());
+      NodeProperties::ReplaceWithValue(node, replacement);
+      return Changed(replacement);
+    } else if (upper->Is(Type::Undefined())) {
+      Node* replacement = jsgraph()->UndefinedConstant();
+      NodeProperties::ReplaceWithValue(node, replacement);
+      return Changed(replacement);
+    }
   }
   switch (node->opcode()) {
     case IrOpcode::kJSEqual:

test/unittests/compiler/js-typed-lowering-unittest.cc

@@ -14,6 +14,7 @@
 #include "testing/gmock-support.h"
 
 using testing::BitEq;
+using testing::IsNaN;
 
 
 namespace v8 {
@@ -28,9 +29,35 @@ const ExternalArrayType kExternalArrayTypes[] = {
     kExternalFloat32Array, kExternalFloat64Array};
 
 
+const double kFloat64Values[] = {
+    -V8_INFINITY, -4.23878e+275, -5.82632e+265, -6.60355e+220, -6.26172e+212,
+    -2.56222e+211, -4.82408e+201, -1.84106e+157, -1.63662e+127, -1.55772e+100,
+    -1.67813e+72, -2.3382e+55, -3.179e+30, -1.441e+09, -1.0647e+09,
+    -7.99361e+08, -5.77375e+08, -2.20984e+08, -32757, -13171, -9970, -3984,
+    -107, -105, -92, -77, -61, -0.000208163, -1.86685e-06, -1.17296e-10,
+    -9.26358e-11, -5.08004e-60, -1.74753e-65, -1.06561e-71, -5.67879e-79,
+    -5.78459e-130, -2.90989e-171, -7.15489e-243, -3.76242e-252, -1.05639e-263,
+    -4.40497e-267, -2.19666e-273, -4.9998e-276, -5.59821e-278, -2.03855e-282,
+    -5.99335e-283, -7.17554e-284, -3.11744e-309, -0.0, 0.0, 2.22507e-308,
+    1.30127e-270, 7.62898e-260, 4.00313e-249, 3.16829e-233, 1.85244e-228,
+    2.03544e-129, 1.35126e-110, 1.01182e-106, 5.26333e-94, 1.35292e-90,
+    2.85394e-83, 1.78323e-77, 5.4967e-57, 1.03207e-25, 4.57401e-25, 1.58738e-05,
+    2, 125, 2310, 9636, 14802, 17168, 28945, 29305, 4.81336e+07, 1.41207e+08,
+    4.65962e+08, 1.40499e+09, 2.12648e+09, 8.80006e+30, 1.4446e+45, 1.12164e+54,
+    2.48188e+89, 6.71121e+102, 3.074e+112, 4.9699e+152, 5.58383e+166,
+    4.30654e+172, 7.08824e+185, 9.6586e+214, 2.028e+223, 6.63277e+243,
+    1.56192e+261, 1.23202e+269, 5.72883e+289, 8.5798e+290, 1.40256e+294,
+    1.79769e+308, V8_INFINITY};
+
+
 const size_t kIndices[] = {0, 1, 42, 100, 1024};
 
 
+const double kIntegerValues[] = {-V8_INFINITY, INT_MIN, -1000.0,  -42.0,
+                                 -1.0,         0.0,     1.0,      42.0,
+                                 1000.0,       INT_MAX, UINT_MAX, V8_INFINITY};
+
+
 Type* const kJSTypes[] = {Type::Undefined(), Type::Null(),   Type::Boolean(),
                           Type::Number(),    Type::String(), Type::Object()};
 
@@ -152,6 +179,105 @@ TEST_F(JSTypedLoweringTest, JSUnaryNotWithAny) {
 }
 
 
+// -----------------------------------------------------------------------------
+// Constant propagation
+
+
+TEST_F(JSTypedLoweringTest, ParameterWithMinusZero) {
+  {
+    Reduction r = Reduce(
+        Parameter(Type::Constant(factory()->minus_zero_value(), zone())));
+    ASSERT_TRUE(r.Changed());
+    EXPECT_THAT(r.replacement(), IsNumberConstant(-0.0));
+  }
+  {
+    Reduction r = Reduce(Parameter(Type::MinusZero()));
+    ASSERT_TRUE(r.Changed());
+    EXPECT_THAT(r.replacement(), IsNumberConstant(-0.0));
+  }
+  {
+    Reduction r = Reduce(Parameter(
+        Type::Union(Type::MinusZero(),
+                    Type::Constant(factory()->NewNumber(0), zone()), zone())));
+    EXPECT_FALSE(r.Changed());
+  }
+}
+
+
+TEST_F(JSTypedLoweringTest, ParameterWithNull) {
+  Handle<HeapObject> null = factory()->null_value();
+  {
+    Reduction r = Reduce(Parameter(Type::Constant(null, zone())));
+    ASSERT_TRUE(r.Changed());
+    EXPECT_THAT(r.replacement(),
+                IsHeapConstant(Unique<HeapObject>::CreateImmovable(null)));
+  }
+  {
+    Reduction r = Reduce(Parameter(Type::Null()));
+    ASSERT_TRUE(r.Changed());
+    EXPECT_THAT(r.replacement(),
+                IsHeapConstant(Unique<HeapObject>::CreateImmovable(null)));
+  }
+}
+
+
+TEST_F(JSTypedLoweringTest, ParameterWithNaN) {
+  const double kNaNs[] = {base::OS::nan_value(),
+                          std::numeric_limits<double>::quiet_NaN(),
+                          std::numeric_limits<double>::signaling_NaN()};
+  TRACED_FOREACH(double, nan, kNaNs) {
+    Handle<Object> constant = factory()->NewNumber(nan);
+    Reduction r = Reduce(Parameter(Type::Constant(constant, zone())));
+    ASSERT_TRUE(r.Changed());
+    EXPECT_THAT(r.replacement(), IsNumberConstant(IsNaN()));
+  }
+  {
+    Reduction r =
+        Reduce(Parameter(Type::Constant(factory()->nan_value(), zone())));
+    ASSERT_TRUE(r.Changed());
+    EXPECT_THAT(r.replacement(), IsNumberConstant(IsNaN()));
+  }
+  {
+    Reduction r = Reduce(Parameter(Type::NaN()));
+    ASSERT_TRUE(r.Changed());
+    EXPECT_THAT(r.replacement(), IsNumberConstant(IsNaN()));
+  }
+}
+
+
+TEST_F(JSTypedLoweringTest, ParameterWithPlainNumber) {
+  TRACED_FOREACH(double, value, kFloat64Values) {
+    Handle<Object> constant = factory()->NewNumber(value);
+    Reduction r = Reduce(Parameter(Type::Constant(constant, zone())));
+    ASSERT_TRUE(r.Changed());
+    EXPECT_THAT(r.replacement(), IsNumberConstant(value));
+  }
+  TRACED_FOREACH(double, value, kIntegerValues) {
+    Handle<Object> constant = factory()->NewNumber(value);
+    Reduction r = Reduce(Parameter(Type::Range(constant, constant, zone())));
+    ASSERT_TRUE(r.Changed());
+    EXPECT_THAT(r.replacement(), IsNumberConstant(value));
+  }
+}
+
+
+TEST_F(JSTypedLoweringTest, ParameterWithUndefined) {
+  Handle<HeapObject> undefined = factory()->undefined_value();
+  {
+    Reduction r = Reduce(Parameter(Type::Undefined()));
+    ASSERT_TRUE(r.Changed());
+    EXPECT_THAT(r.replacement(),
+                IsHeapConstant(Unique<HeapObject>::CreateImmovable(undefined)));
+  }
+  {
+    Reduction r = Reduce(Parameter(Type::Constant(undefined, zone())));
+    ASSERT_TRUE(r.Changed());
+    EXPECT_THAT(r.replacement(),
+                IsHeapConstant(Unique<HeapObject>::CreateImmovable(undefined)));
+  }
+}
+
+
 // -----------------------------------------------------------------------------
 // JSToBoolean
 

testing/gmock-support.h

@@ -5,6 +5,7 @@
 #ifndef V8_TESTING_GMOCK_SUPPORT_H_
 #define V8_TESTING_GMOCK_SUPPORT_H_
 
+#include <cmath>
 #include <cstring>
 
 #include "testing/gmock/include/gmock/gmock.h"
@@ -96,6 +97,12 @@ inline Matcher<T> CaptureEq(Capture<T>* capture) {
   return MakeMatcher(new internal::CaptureEqMatcher<T>(capture));
 }
 
+
+// Creates a polymorphic matcher that matches any floating point NaN value.
+MATCHER(IsNaN, std::string(negation ? "isn't" : "is") + " not a number") {
+  return std::isnan(arg);
+}
+
 }  // namespace testing
 
 #endif  // V8_TESTING_GMOCK_SUPPORT_H_