Revert of [builtins] Introduce proper Float64Exp operator.

src/ia32/codegen-ia32.cc

Index: src/ia32/codegen-ia32.cc
diff --git a/src/ia32/codegen-ia32.cc b/src/ia32/codegen-ia32.cc
index 18e53641e676d2ba2ea35f2a3ba2af5640ca48cf..267fe5c596d2d14e13d8bfc25f722e26be3353b5 100644
--- a/src/ia32/codegen-ia32.cc
+++ b/src/ia32/codegen-ia32.cc
@@ -32,6 +32,43 @@
 
 
 #define __ masm.
+
+
+UnaryMathFunctionWithIsolate CreateExpFunction(Isolate* isolate) {
+  size_t actual_size;
+  byte* buffer =
+      static_cast<byte*>(base::OS::Allocate(1 * KB, &actual_size, true));
+  if (buffer == nullptr) return nullptr;
+  ExternalReference::InitializeMathExpData();
+
+  MacroAssembler masm(isolate, buffer, static_cast<int>(actual_size),
+                      CodeObjectRequired::kNo);
+  // esp[1 * kPointerSize]: raw double input
+  // esp[0 * kPointerSize]: return address
+  {
+    XMMRegister input = xmm1;
+    XMMRegister result = xmm2;
+    __ movsd(input, Operand(esp, 1 * kPointerSize));
+    __ push(eax);
+    __ push(ebx);
+
+    MathExpGenerator::EmitMathExp(&masm, input, result, xmm0, eax, ebx);
+
+    __ pop(ebx);
+    __ pop(eax);
+    __ movsd(Operand(esp, 1 * kPointerSize), result);
+    __ fld_d(Operand(esp, 1 * kPointerSize));
+    __ Ret();
+  }
+
+  CodeDesc desc;
+  masm.GetCode(&desc);
+  DCHECK(!RelocInfo::RequiresRelocation(desc));
+
+  Assembler::FlushICache(isolate, buffer, actual_size);
+  base::OS::ProtectCode(buffer, actual_size);
+  return FUNCTION_CAST<UnaryMathFunctionWithIsolate>(buffer);
+}
 
 
 UnaryMathFunctionWithIsolate CreateSqrtFunction(Isolate* isolate) {
@@ -891,6 +928,64 @@
   __ bind(&done);
 }
 
+
+static Operand ExpConstant(int index) {
+  return Operand::StaticVariable(ExternalReference::math_exp_constants(index));
+}
+
+
+void MathExpGenerator::EmitMathExp(MacroAssembler* masm,
+                                   XMMRegister input,
+                                   XMMRegister result,
+                                   XMMRegister double_scratch,
+                                   Register temp1,
+                                   Register temp2) {
+  DCHECK(!input.is(double_scratch));
+  DCHECK(!input.is(result));
+  DCHECK(!result.is(double_scratch));
+  DCHECK(!temp1.is(temp2));
+  DCHECK(ExternalReference::math_exp_constants(0).address() != NULL);
+  DCHECK(!masm->serializer_enabled());  // External references not serializable.
+
+  Label done;
+
+  __ movsd(double_scratch, ExpConstant(0));
+  __ xorpd(result, result);
+  __ ucomisd(double_scratch, input);
+  __ j(above_equal, &done);
+  __ ucomisd(input, ExpConstant(1));
+  __ movsd(result, ExpConstant(2));
+  __ j(above_equal, &done);
+  __ movsd(double_scratch, ExpConstant(3));
+  __ movsd(result, ExpConstant(4));
+  __ mulsd(double_scratch, input);
+  __ addsd(double_scratch, result);
+  __ movd(temp2, double_scratch);
+  __ subsd(double_scratch, result);
+  __ movsd(result, ExpConstant(6));
+  __ mulsd(double_scratch, ExpConstant(5));
+  __ subsd(double_scratch, input);
+  __ subsd(result, double_scratch);
+  __ movsd(input, double_scratch);
+  __ mulsd(input, double_scratch);
+  __ mulsd(result, input);
+  __ mov(temp1, temp2);
+  __ mulsd(result, ExpConstant(7));
+  __ subsd(result, double_scratch);
+  __ add(temp1, Immediate(0x1ff800));
+  __ addsd(result, ExpConstant(8));
+  __ and_(temp2, Immediate(0x7ff));
+  __ shr(temp1, 11);
+  __ shl(temp1, 20);
+  __ movd(input, temp1);
+  __ pshufd(input, input, static_cast<uint8_t>(0xe1));  // Order: 11 10 00 01
+  __ movsd(double_scratch, Operand::StaticArray(
+      temp2, times_8, ExternalReference::math_exp_log_table()));
+  __ orps(input, double_scratch);
+  __ mulsd(result, input);
+  __ bind(&done);
+}
+
 #undef __