[builtins] Introduce proper base::ieee754::log.

src/crankshaft/ia32/lithium-codegen-ia32.cc

 // Copyright 2012 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.
 
 #if V8_TARGET_ARCH_IA32
 
 #include "src/crankshaft/ia32/lithium-codegen-ia32.h"
 
 #include "src/base/bits.h"
 #include "src/code-factory.h"
@@ skipping 3382 matching lines @@
     __ CallStub(&stub);
   } else {
     DCHECK(exponent_type.IsDouble());
     MathPowStub stub(isolate(), MathPowStub::DOUBLE);
     __ CallStub(&stub);
   }
 }
 
 
 void LCodeGen::DoMathLog(LMathLog* instr) {
-  DCHECK(instr->value()->Equals(instr->result()));
-  XMMRegister input_reg = ToDoubleRegister(instr->value());
-  XMMRegister xmm_scratch = double_scratch0();
-  Label positive, done, zero;
-  __ xorps(xmm_scratch, xmm_scratch);
-  __ ucomisd(input_reg, xmm_scratch);
-  __ j(above, &positive, Label::kNear);
-  __ j(not_carry, &zero, Label::kNear);
-  __ pcmpeqd(input_reg, input_reg);
-  __ jmp(&done, Label::kNear);
-  __ bind(&zero);
-  ExternalReference ninf =
-      ExternalReference::address_of_negative_infinity();
-  __ movsd(input_reg, Operand::StaticVariable(ninf));
-  __ jmp(&done, Label::kNear);
-  __ bind(&positive);
-  __ fldln2();
-  __ sub(Operand(esp), Immediate(kDoubleSize));
-  __ movsd(Operand(esp, 0), input_reg);
-  __ fld_d(Operand(esp, 0));
-  __ fyl2x();
+  XMMRegister input = ToDoubleRegister(instr->value());
+  XMMRegister result = ToDoubleRegister(instr->result());
+  // Pass one double as argument on the stack.
+  __ PrepareCallCFunction(2, eax);
+  __ movsd(Operand(esp, 0 * kDoubleSize), input);
+  __ CallCFunction(ExternalReference::ieee754_log_function(isolate()), 2);
+  // Return value is in st(0) on ia32.
+  // Store it into the result register.
+  __ sub(esp, Immediate(kDoubleSize));
   __ fstp_d(Operand(esp, 0));
-  __ movsd(input_reg, Operand(esp, 0));
-  __ add(Operand(esp), Immediate(kDoubleSize));
-  __ bind(&done);
+  __ movsd(result, Operand(esp, 0));
+  __ add(esp, Immediate(kDoubleSize));
 }
 
 
 void LCodeGen::DoMathClz32(LMathClz32* instr) {
   Register input = ToRegister(instr->value());
   Register result = ToRegister(instr->result());
 
   __ Lzcnt(result, input);
 }
 
@@ skipping 1881 matching lines @@
   __ bind(deferred->exit());
   __ bind(&done);
 }
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_IA32