Set the FPU precision control to double-precision.

src/x87/macro-assembler-x87.cc

Index: src/x87/macro-assembler-x87.cc
diff --git a/src/x87/macro-assembler-x87.cc b/src/x87/macro-assembler-x87.cc
index ff5db7bdbd0bfd0c208038a0068acc7019b39012..3f522fcb1a15538281c35c0ea6ec2e41e04de381 100644
--- a/src/x87/macro-assembler-x87.cc
+++ b/src/x87/macro-assembler-x87.cc
@@ -767,6 +767,13 @@ void MacroAssembler::X87SetRC(int rc) {
 }
 
 
+void MacroAssembler::X87SetFPUCW(int cw) {
+  push(Immediate(cw));
+  fldcw(MemOperand(esp, 0));
+  add(esp, Immediate(kPointerSize));
+}
+
+
 void MacroAssembler::AssertNumber(Register object) {
   if (emit_debug_code()) {
     Label ok;