Extend JSBuiltinReducer to cover Math.fround as well.

R=bmeurer@chromium.org
TEST=compiler-unittests/JSBuiltinReducerTest.MathFround

Review URL: https://codereview.chromium.org/594183004

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@24187 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/compiler.cc

@@ -323,7 +323,6 @@ class HOptimizedGraphBuilderWithPositions: public HOptimizedGraphBuilder {
 
 
 OptimizedCompileJob::Status OptimizedCompileJob::CreateGraph() {
-  DCHECK(isolate()->use_crankshaft());
   DCHECK(info()->IsOptimizing());
   DCHECK(!info()->IsCompilingForDebugging());
 

src/compiler/graph-unittest.cc

@@ -769,6 +769,7 @@ IS_UNOP_MATCHER(ChangeInt32ToFloat64)
 IS_UNOP_MATCHER(ChangeInt32ToInt64)
 IS_UNOP_MATCHER(ChangeUint32ToFloat64)
 IS_UNOP_MATCHER(ChangeUint32ToUint64)
+IS_UNOP_MATCHER(TruncateFloat64ToFloat32)
 IS_UNOP_MATCHER(TruncateFloat64ToInt32)
 IS_UNOP_MATCHER(TruncateInt64ToInt32)
 IS_UNOP_MATCHER(Float64Sqrt)

src/compiler/graph-unittest.h

@@ -129,6 +129,7 @@ Matcher<Node*> IsChangeInt32ToFloat64(const Matcher<Node*>& input_matcher);
 Matcher<Node*> IsChangeInt32ToInt64(const Matcher<Node*>& input_matcher);
 Matcher<Node*> IsChangeUint32ToFloat64(const Matcher<Node*>& input_matcher);
 Matcher<Node*> IsChangeUint32ToUint64(const Matcher<Node*>& input_matcher);
+Matcher<Node*> IsTruncateFloat64ToFloat32(const Matcher<Node*>& input_matcher);
 Matcher<Node*> IsTruncateFloat64ToInt32(const Matcher<Node*>& input_matcher);
 Matcher<Node*> IsTruncateInt64ToInt32(const Matcher<Node*>& input_matcher);
 Matcher<Node*> IsFloat64Sqrt(const Matcher<Node*>& input_matcher);

src/compiler/js-builtin-reducer-unittest.cc

@@ -172,6 +172,32 @@ TEST_F(JSBuiltinReducerTest, MathImul) {
   }
 }
 
+
+// -----------------------------------------------------------------------------
+// Math.fround
+
+
+TEST_F(JSBuiltinReducerTest, MathFround) {
+  Handle<Object> m =
+      JSObject::GetProperty(isolate()->global_object(),
+                            isolate()->factory()->NewStringFromAsciiChecked(
+                                "Math")).ToHandleChecked();
+  Handle<JSFunction> f = Handle<JSFunction>::cast(
+      JSObject::GetProperty(m, isolate()->factory()->NewStringFromAsciiChecked(
+                                   "fround")).ToHandleChecked());
+
+  TRACED_FOREACH(Type*, t0, kNumberTypes) {
+    Node* p0 = Parameter(t0, 0);
+    Node* fun = HeapConstant(Unique<HeapObject>::CreateUninitialized(f));
+    Node* call = graph()->NewNode(javascript()->Call(3, NO_CALL_FUNCTION_FLAGS),
+                                  fun, UndefinedConstant(), p0);
+    Reduction r = Reduce(call);
+
+    ASSERT_TRUE(r.Changed());
+    EXPECT_THAT(r.replacement(), IsTruncateFloat64ToFloat32(p0));
+  }
+}
+
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8

src/compiler/js-builtin-reducer.cc

@@ -151,6 +151,19 @@ Reduction JSBuiltinReducer::ReduceMathImul(Node* node) {
 }
 
 
+// ES6 draft 08-24-14, section 20.2.2.17.
+Reduction JSBuiltinReducer::ReduceMathFround(Node* node) {
+  JSCallReduction r(node);
+  if (r.InputsMatchOne(Type::Number())) {
+    // Math.fround(a:number) -> TruncateFloat64ToFloat32(a)
+    Node* value =
+        graph()->NewNode(machine()->TruncateFloat64ToFloat32(), r.left());
+    return Replace(value);
+  }
+  return NoChange();
+}
+
+
 Reduction JSBuiltinReducer::Reduce(Node* node) {
   JSCallReduction r(node);
 
@@ -163,6 +176,8 @@ Reduction JSBuiltinReducer::Reduce(Node* node) {
       return ReplaceWithPureReduction(node, ReduceMathMax(node));
     case kMathImul:
       return ReplaceWithPureReduction(node, ReduceMathImul(node));
+    case kMathFround:
+      return ReplaceWithPureReduction(node, ReduceMathFround(node));
     default:
       break;
   }

src/compiler/js-builtin-reducer.h

@@ -33,6 +33,7 @@ class JSBuiltinReducer FINAL : public Reducer {
   Reduction ReduceMathSqrt(Node* node);
   Reduction ReduceMathMax(Node* node);
   Reduction ReduceMathImul(Node* node);
+  Reduction ReduceMathFround(Node* node);
 
   JSGraph* jsgraph_;
   SimplifiedOperatorBuilder simplified_;

test/mjsunit/asm/math-fround.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.
+
+// Flags: --turbo-asm
+
+function Module(stdlib) {
+  "use asm";
+
+  var fround = stdlib.Math.fround;
+
+  // f: double -> float
+  function f(a) {
+    a = +a;
+    return fround(a);
+  }
+
+  return { f: f };
+}
+
+var f = Module({ Math: Math }).f;
+
+assertTrue(isNaN(f(NaN)));
+assertTrue(isNaN(f(undefined)));
+assertTrue(isNaN(f(function() {})));
+
+assertEquals("Infinity", String(1/f(0)));
+assertEquals("-Infinity", String(1/f(-0)));
+assertEquals("Infinity", String(f(Infinity)));
+assertEquals("-Infinity", String(f(-Infinity)));
+assertEquals("Infinity", String(f(1E200)));
+assertEquals("-Infinity", String(f(-1E200)));
+assertEquals("Infinity", String(1/f(1E-300)));
+assertEquals("-Infinity", String(1/f(-1E-300)));
+
+assertEquals(0,                  f(0));
+assertEquals(1,                  f(1));
+assertEquals(1.5,                f(1.5));
+assertEquals(1.3370000123977661, f(1.337));
+assertEquals(-4.300000190734863, f(-4.3));