[builtins] Migrate Math.abs() to TurboFan builtins.

Like the other Math builtins, Math.abs() is now a TurboFan builtin.
It uses RawMachineAssembler::Float64Abs().

R=bmeurer@chromium.org
BUG=v8:5163, v8:5086
LOG=N

Review-Url: https://codereview.chromium.org/2115493002
Cr-Commit-Position: refs/heads/master@{#37433}

src/bootstrapper.cc

@@ -1669,6 +1669,9 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
     Handle<JSObject> math = factory->NewJSObject(cons, TENURED);
     DCHECK(math->IsJSObject());
     JSObject::AddProperty(global, name, math, DONT_ENUM);
+    Handle<JSFunction> math_abs =
+        SimpleInstallFunction(math, "abs", Builtins::kMathAbs, 1, true);
+    native_context()->set_math_abs(*math_abs);
     SimpleInstallFunction(math, "acos", Builtins::kMathAcos, 1, true);
     SimpleInstallFunction(math, "asin", Builtins::kMathAsin, 1, true);
     SimpleInstallFunction(math, "atan", Builtins::kMathAtan, 1, true);

src/builtins.cc

@@ -2240,6 +2240,16 @@ BUILTIN(JsonStringify) {
 // -----------------------------------------------------------------------------
 // ES6 section 20.2.2 Function Properties of the Math Object
 
+// ES6 section - 20.2.2.1 Math.abs ( x )
+void Builtins::Generate_MathAbs(CodeStubAssembler* assembler) {
+  using compiler::Node;
+  Node* x = assembler->Parameter(1);
+  Node* context = assembler->Parameter(4);
+  Node* x_value = assembler->TruncateTaggedToFloat64(context, x);
+  Node* value = assembler->Float64Abs(x_value);
+  Node* result = assembler->ChangeFloat64ToTagged(value);
+  assembler->Return(result);
+}
 
 // ES6 section 20.2.2.2 Math.acos ( x )
 BUILTIN(MathAcos) {
@@ -2250,7 +2260,6 @@ BUILTIN(MathAcos) {
   return *isolate->factory()->NewHeapNumber(std::acos(x->Number()));
 }
 
-
 // ES6 section 20.2.2.4 Math.asin ( x )
 BUILTIN(MathAsin) {
   HandleScope scope(isolate);

src/builtins.h

@@ -311,6 +311,7 @@ class CodeStubAssembler;
   V(MathAtanh, 2)                     \
   V(MathCeil, 2)                      \
   V(MathCbrt, 2)                      \
+  V(MathAbs, 2)                       \
   V(MathExpm1, 2)                     \
   V(MathClz32, 2)                     \
   V(MathCos, 2)                       \
@@ -631,6 +632,8 @@ class Builtins {
   static void Generate_InternalArrayCode(MacroAssembler* masm);
   static void Generate_ArrayCode(MacroAssembler* masm);
 
+  // ES6 section 20.2.2.1 Math.abs ( x )
+  static void Generate_MathAbs(CodeStubAssembler* assembler);
   // ES6 section 20.2.2.6 Math.atan ( x )
   static void Generate_MathAtan(CodeStubAssembler* assembler);
   // ES6 section 20.2.2.8 Math.atan2 ( y, x )

src/compiler/code-assembler.h

@@ -108,6 +108,7 @@ class Schedule;
   V(Word64Ror)
 
 #define CODE_ASSEMBLER_UNARY_OP_LIST(V) \
+  V(Float64Abs)                         \
   V(Float64Atan)                        \
   V(Float64Atanh)                       \
   V(Float64Cos)                         \

src/contexts.h

@@ -89,6 +89,7 @@ enum BindingFlags {
   V(MATH_EXP_INDEX, JSFunction, math_exp)                               \
   V(MATH_FLOOR_INDEX, JSFunction, math_floor)                           \
   V(MATH_LOG_INDEX, JSFunction, math_log)                               \
+  V(MATH_ABS_INDEX, JSFunction, math_abs)                               \
   V(MATH_SQRT_INDEX, JSFunction, math_sqrt)
 
 #define NATIVE_CONTEXT_IMPORTED_FIELDS(V)                                   \

src/js/math.js

@@ -13,22 +13,13 @@
 // The first two slots are reserved to persist PRNG state.
 define kRandomNumberStart = 2;
 
-var GlobalFloat64Array = global.Float64Array;
 var GlobalMath = global.Math;
-var GlobalObject = global.Object;
 var NaN = %GetRootNaN();
 var nextRandomIndex = 0;
 var randomNumbers = UNDEFINED;
 var toStringTagSymbol = utils.ImportNow("to_string_tag_symbol");
 
 //-------------------------------------------------------------------
-
-// ECMA 262 - 15.8.2.1
-function MathAbs(x) {
-  x = +x;
-  return (x > 0) ? x : 0 - x;
-}
-
 // ECMA 262 - 15.8.2.14
 function MathRandom() {
   // While creating a startup snapshot, %GenerateRandomNumbers returns a
@@ -83,7 +74,7 @@ function MathHypot(x, y) {  // Function length is 2.
   var length = arguments.length;
   var max = 0;
   for (var i = 0; i < length; i++) {
-    var n = MathAbs(arguments[i]);
+    var n = %math_abs(arguments[i]);
     if (n > max) max = n;
     arguments[i] = n;
   }
@@ -119,7 +110,6 @@ utils.InstallConstants(GlobalMath, [
 // set their names.
 utils.InstallFunctions(GlobalMath, DONT_ENUM, [
   "random", MathRandom,
-  "abs", MathAbs,
   "sign", MathSign,
   "asinh", MathAsinh,
   "acosh", MathAcosh,
@@ -133,7 +123,6 @@ utils.InstallFunctions(GlobalMath, DONT_ENUM, [
 // Exports
 
 utils.Export(function(to) {
-  to.MathAbs = MathAbs;
   to.MathRandom = MathRandom;
 });
 

src/js/v8natives.js

@@ -9,23 +9,19 @@
 // ----------------------------------------------------------------------------
 // Imports
 
-var GlobalArray = global.Array;
 var GlobalNumber = global.Number;
 var GlobalObject = global.Object;
 var iteratorSymbol = utils.ImportNow("iterator_symbol");
 var MakeRangeError;
 var MakeSyntaxError;
 var MakeTypeError;
-var MathAbs;
 var NaN = %GetRootNaN();
 var ObjectToString = utils.ImportNow("object_to_string");
-var toStringTagSymbol = utils.ImportNow("to_string_tag_symbol");
 
 utils.Import(function(from) {
   MakeRangeError = from.MakeRangeError;
   MakeSyntaxError = from.MakeSyntaxError;
   MakeTypeError = from.MakeTypeError;
-  MathAbs = from.MathAbs;
 });
 
 // ----------------------------------------------------------------------------
@@ -367,7 +363,7 @@ function NumberIsSafeInteger(number) {
   if (NumberIsFinite(number)) {
     var integral = TO_INTEGER(number);
     if (integral == number) {
-      return MathAbs(integral) <= kMaxSafeInteger;
+      return %math_abs(integral) <= kMaxSafeInteger;
     }
   }
   return false;

test/mjsunit/mirror-script.js

@@ -84,6 +84,6 @@ function testScriptMirror(f, file_name, file_lines, type, compilation_type,
 
 // Test the script mirror for different functions.
 testScriptMirror(function(){}, 'mirror-script.js', 90, 2, 0);
-testScriptMirror(Math.abs, 'native math.js', -1, 0, 0);
+testScriptMirror(Math.random, 'native math.js', -1, 0, 0);
 testScriptMirror(eval('(function(){})'), null, 1, 2, 1, '(function(){})', 87);
 testScriptMirror(eval('(function(){\n  })'), null, 2, 2, 1, '(function(){\n  })', 88);