ARM: Implement sqrt in inline assembly.

src/arm/codegen-arm.cc

Index: src/arm/codegen-arm.cc
diff --git a/src/arm/codegen-arm.cc b/src/arm/codegen-arm.cc
index b044ca9b30250c03b805d5fde1a3c52f8590c90d..5477b24a7f1e5e0a202bf7317cb8e6205e8a8301 100644
--- a/src/arm/codegen-arm.cc
+++ b/src/arm/codegen-arm.cc
@@ -347,13 +347,33 @@ OS::MemCopyUint16Uint8Function CreateMemCopyUint16Uint8Function(
 }
 #endif
 
-#undef __
+UnaryMathFunction CreateSqrtFunction() {
+#if defined(USE_SIMULATOR)
+  return &std::sqrt;
+#else
+  size_t actual_size;
+  byte* buffer = static_cast<byte*>(OS::Allocate(1 * KB, &actual_size, true));
+  if (buffer == NULL) return &std::sqrt;
 
+  MacroAssembler masm(NULL, buffer, static_cast<int>(actual_size));
 
-UnaryMathFunction CreateSqrtFunction() {
-  return &sqrt;
+  __ GetCFunctionDoubleResult(d0);
+  __ vsqrt(d0, d0);
+  __ SetCallCDoubleArguments(d0);
+  __ Ret();
+
+  CodeDesc desc;
+  masm.GetCode(&desc);
+  ASSERT(!RelocInfo::RequiresRelocation(desc));
+
+  CPU::FlushICache(buffer, actual_size);
+  OS::ProtectCode(buffer, actual_size);
+  return FUNCTION_CAST<UnaryMathFunction>(buffer);
+#endif
 }
 
+#undef __
+
 
 // -------------------------------------------------------------------------
 // Platform-specific RuntimeCallHelper functions.