X87: [builtins] Introduce proper base::ieee754::log.

src/crankshaft/x87/lithium-codegen-x87.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_X87
 
 #include "src/crankshaft/x87/lithium-codegen-x87.h"
 
 #include "src/base/bits.h"
 #include "src/code-factory.h"
@@ skipping 3661 matching lines @@
     __ CallCFunction(ExternalReference::power_double_double_function(isolate()),
                      4);
     // Return value is in st(0) on ia32.
     X87CommitWrite(result);
   }
 }
 
 
 void LCodeGen::DoMathLog(LMathLog* instr) {
   DCHECK(instr->value()->Equals(instr->result()));
+  X87Register result = ToX87Register(instr->result());
   X87Register input_reg = ToX87Register(instr->value());
   X87Fxch(input_reg);
 
-  Label positive, done, zero, nan_result;
-  __ fldz();
-  __ fld(1);
-  __ FCmp();
-  __ j(below, &nan_result, Label::kNear);
-  __ j(equal, &zero, Label::kNear);
-  // Positive input.
-  // {input, ln2}.
-  __ fldln2();
-  // {ln2, input}.
-  __ fxch();
-  // {result}.
-  __ fyl2x();
-  __ jmp(&done, Label::kNear);
-
-  __ bind(&nan_result);
-  X87PrepareToWrite(input_reg);
-  __ push(Immediate(0xffffffff));
-  __ push(Immediate(0x7fffffff));
-  __ fld_d(MemOperand(esp, 0));
-  __ lea(esp, Operand(esp, kDoubleSize));
-  X87CommitWrite(input_reg);
-  __ jmp(&done, Label::kNear);
-
-  __ bind(&zero);
-  ExternalReference ninf = ExternalReference::address_of_negative_infinity();
-  X87PrepareToWrite(input_reg);
-  __ fld_d(Operand::StaticVariable(ninf));
-  X87CommitWrite(input_reg);
-
-  __ bind(&done);
+  // Pass one double as argument on the stack.
+  __ PrepareCallCFunction(2, eax);
+  __ fstp_d(MemOperand(esp, 0));
+  X87PrepareToWrite(result);
+  __ CallCFunction(ExternalReference::ieee754_log_function(isolate()), 2);
+  // Return value is in st(0) on ia32.
+  X87CommitWrite(result);
 }
 
 
 void LCodeGen::DoMathClz32(LMathClz32* instr) {
   Register input = ToRegister(instr->value());
   Register result = ToRegister(instr->result());
 
   __ Lzcnt(result, input);
 }
 
@@ skipping 2137 matching lines @@
   __ bind(deferred->exit());
   __ bind(&done);
 }
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_X87