X87: [builtins] Migrate Math.log to TurboFan.

  port f2da19fe (r36703)

  original commit message:
  Introduce a dedicated Float64Log machine operator, that is either
  implemented by a direct C call or by platform specific code, i.e.
  using the FPU on x64 and ia32.

  This operator is used to implement Math.log as a proper TurboFan
  builtin on top of the CodeStubAssembler.

  Also introduce a NumberLog simplified operator on top of Float64Log
  and use that for the fast inline path of Math.log inside TurboFan
  optimized code.

BUG=

Review-Url: https://codereview.chromium.org/2034393002
Cr-Commit-Position: refs/heads/master@{#36727}

src/compiler/x87/code-generator-x87.cc

@@ -898,6 +898,18 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     case kX87Popcnt:
       __ Popcnt(i.OutputRegister(), i.InputOperand(0));
       break;
+    case kX87Float64Log:
+      if (FLAG_debug_code && FLAG_enable_slow_asserts) {
+        __ VerifyX87StackDepth(1);
+      }
+      __ X87SetFPUCW(0x027F);
+      __ fstp(0);
+      __ fldln2();
+      __ fld_d(MemOperand(esp, 0));
+      __ fyl2x();
+      __ lea(esp, Operand(esp, kDoubleSize));
+      __ X87SetFPUCW(0x037F);
+      break;
     case kX87LoadFloat64Constant: {
       InstructionOperand* source = instr->InputAt(0);
       InstructionOperand* destination = instr->Output();

src/compiler/x87/instruction-codes-x87.h

@@ -44,6 +44,7 @@ namespace compiler {
   V(X87Ror)                        \
   V(X87Lzcnt)                      \
   V(X87Popcnt)                     \
+  V(X87Float64Log)                 \
   V(X87Float32Cmp)                 \
   V(X87Float32Add)                 \
   V(X87Float32Sub)                 \

src/compiler/x87/instruction-selector-x87.cc

@@ -1009,6 +1009,11 @@ void InstructionSelector::VisitFloat64Abs(Node* node) {
   Emit(kX87Float64Abs, g.DefineAsFixed(node, stX_0), 0, nullptr);
 }
 
+void InstructionSelector::VisitFloat64Log(Node* node) {
+  X87OperandGenerator g(this);
+  Emit(kX87PushFloat64, g.NoOutput(), g.Use(node->InputAt(0)));
+  Emit(kX87Float64Log, g.DefineAsFixed(node, stX_0), 0, nullptr);
+}
 
 void InstructionSelector::VisitFloat32Sqrt(Node* node) {
   X87OperandGenerator g(this);