Subzero: Reduce the amount of #ifdef'd code.

src/IceOperand.cpp

 //===- subzero/src/IceOperand.cpp - High-level operand implementation -----===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file implements the Operand class and its target-independent
@@ skipping 73 matching lines @@
        I != E; ++I) {
     if (OtherBegin < I->first) {
       Result = false;
       break;
     }
     if (OtherBegin < I->second) {
       Result = true;
       break;
     }
   }
-#if 0
-  // An equivalent but less inefficient implementation:
-  LiveRange Temp;
-  Temp.addSegment(OtherBegin, OtherBegin + 1);
-  bool Validation = overlaps(Temp);
-  assert(Result == Validation);
-#endif
+  // This is an equivalent but less inefficient implementation.  It's
+  // expensive enough that we wouldn't want to run it under any build,
+  // but it could be enabled if e.g. the LiveRange implementation
+  // changes and extra testing is needed.
+  if (false) {

[John, 2015/06/22 17:13:46]

Can this be a constexpr bool somewhere, perhaps modified by a compile-time
constant (e.g., -DINEFFICIENT_LIVE_RANGE_CHECK)?

[Jim Stichnoth, 2015/06/23 21:42:07]

Done.

+    LiveRange Temp;
+    Temp.addSegment(OtherBegin, OtherBegin + 1);
+    bool Validation = overlaps(Temp);
+    (void)Validation;
+    assert(Result == Validation);
+  }
   return Result;
 }
 
 // Returns true if the live range contains the given instruction
 // number.  This is only used for validating the live range
 // calculation.  The IsDest argument indicates whether the Variable
 // being tested is used in the Dest position (as opposed to a Src
 // position).
 bool LiveRange::containsValue(InstNumberT Value, bool IsDest) const {
   for (const RangeElementType &I : Range) {
@@ skipping 374 matching lines @@
   if (!ALLOW_DUMP)
     return Str;
   if (W.getWeight() == RegWeight::Inf)
     Str << "Inf";
   else
     Str << W.getWeight();
   return Str;
 }
 
 } // end of namespace Ice