MIPS/ARM: Fix benchmarks failures on simulator.

src/mips/simulator-mips.cc

Index: src/mips/simulator-mips.cc
diff --git a/src/mips/simulator-mips.cc b/src/mips/simulator-mips.cc
index ea8b65948afe4732a4867024ac93c075d8220cff..1cb330a804115914711e7d88dbcd93f207d2a544 100644
--- a/src/mips/simulator-mips.cc
+++ b/src/mips/simulator-mips.cc
@@ -27,6 +27,7 @@
 
 #include <stdlib.h>
 #include <limits.h>
+#include <fpu_control.h>
 #include <cmath>
 #include <cstdarg>
 #include "v8.h"
@@ -882,6 +883,8 @@ void Simulator::Initialize(Isolate* isolate) {
 
 
 Simulator::Simulator(Isolate* isolate) : isolate_(isolate) {
+  set_host_fp_precision();
+
   i_cache_ = isolate_->simulator_i_cache();
   if (i_cache_ == NULL) {
     i_cache_ = new v8::internal::HashMap(&ICacheMatch);
@@ -2917,6 +2920,20 @@ uintptr_t Simulator::PopAddress() {
 }
 
 
+void Simulator::set_host_fp_precision() {
+#if !V8_HOST_ARCH_MIPS
+  // Set Intel x87 FPU mode to 64-bit double.
+  // The default FPU mode is extended (80-bit),
+  // which can lead to unexpected precision failures.
+  fpu_control_t cw;
+  _FPU_GETCW(cw);
+  cw &= ~_FPU_EXTENDED;
+  cw |= _FPU_DOUBLE;
+  _FPU_SETCW(cw);
+#endif
+}
+
+
 #undef UNSUPPORTED
 
 } }  // namespace v8::internal