Made the detailed reason for deopts mandatory on ia32. Unified and improved things.

src/ia32/macro-assembler-ia32.cc

Index: src/ia32/macro-assembler-ia32.cc
diff --git a/src/ia32/macro-assembler-ia32.cc b/src/ia32/macro-assembler-ia32.cc
index f938d500182161151c5ebf633dc6f5a8315790aa..fb0acb29ad97ef3190a17e2d07d2a0c311e78b67 100644
--- a/src/ia32/macro-assembler-ia32.cc
+++ b/src/ia32/macro-assembler-ia32.cc
@@ -250,18 +250,17 @@ void MacroAssembler::TruncateDoubleToI(Register result_reg,
 }
 
 
-void MacroAssembler::DoubleToI(Register result_reg,
-                               XMMRegister input_reg,
+void MacroAssembler::DoubleToI(Register result_reg, XMMRegister input_reg,
                                XMMRegister scratch,
                                MinusZeroMode minus_zero_mode,
-                               Label* conversion_failed,
-                               Label::Distance dst) {
+                               Label* lost_precision, Label* is_nan,
+                               Label* minus_zero, Label::Distance dst) {
   DCHECK(!input_reg.is(scratch));
   cvttsd2si(result_reg, Operand(input_reg));
   Cvtsi2sd(scratch, Operand(result_reg));
   ucomisd(scratch, input_reg);
-  j(not_equal, conversion_failed, dst);
-  j(parity_even, conversion_failed, dst);  // NaN.
+  j(not_equal, lost_precision, dst);
+  j(parity_even, is_nan, dst);
   if (minus_zero_mode == FAIL_ON_MINUS_ZERO) {
     Label done;
     // The integer converted back is equal to the original. We
@@ -271,9 +270,9 @@ void MacroAssembler::DoubleToI(Register result_reg,
     movmskpd(result_reg, input_reg);
     // Bit 0 contains the sign of the double in input_reg.
     // If input was positive, we are ok and return 0, otherwise
-    // jump to conversion_failed.
+    // jump to minus_zero.
     and_(result_reg, 1);
-    j(not_zero, conversion_failed, dst);
+    j(not_zero, minus_zero, dst);
     bind(&done);
   }
 }