Set the FPU precision control to double-precision.

src/x87/lithium-codegen-x87.cc

Index: src/x87/lithium-codegen-x87.cc
diff --git a/src/x87/lithium-codegen-x87.cc b/src/x87/lithium-codegen-x87.cc
index 2766b658fd1a0c28498173e12b527582092ece76..35d95532c1278b8d11771261b32e11906784efa5 100644
--- a/src/x87/lithium-codegen-x87.cc
+++ b/src/x87/lithium-codegen-x87.cc
@@ -2272,6 +2272,8 @@ void LCodeGen::DoArithmeticD(LArithmeticD* instr) {
   if (instr->op() != Token::MOD) {
     X87PrepareBinaryOp(left, right, result);
   }
+  // Set the precision control to double-precision.
+  __ X87SetFPUCW(0x027F);
   switch (instr->op()) {
     case Token::ADD:
       __ fadd_i(1);
@@ -2306,12 +2308,7 @@ void LCodeGen::DoArithmeticD(LArithmeticD* instr) {
       break;
   }
 
-  // Only always explicitly storing to memory to force the round-down for double
-  // arithmetic.
-  __ lea(esp, Operand(esp, -kDoubleSize));
-  __ fstp_d(Operand(esp, 0));
-  __ fld_d(Operand(esp, 0));
-  __ lea(esp, Operand(esp, kDoubleSize));
+  __ X87SetFPUCW(0x037F);
 }