ARM: Add a postRA pass to legalize stack offsets. Greedy approach (reserve IP).

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.
 //
 //===----------------------------------------------------------------------===//
 ///
 /// \file
@@ skipping 397 matching lines @@
   if (Func->isVerbose(IceV_RegOrigins) ||
       (!hasReg() && !Func->getTarget()->hasComputedFrame()))
     Str << "%" << getName(Func);
   if (hasReg()) {
     if (Func->isVerbose(IceV_RegOrigins))
       Str << ":";
     Str << Func->getTarget()->getRegName(RegNum, getType());
   } else if (Func->getTarget()->hasComputedFrame()) {
     if (Func->isVerbose(IceV_RegOrigins))
       Str << ":";
+    int32_t BaseRegisterNumber = getBaseRegNum();
+    if (BaseRegisterNumber == NoRegister)
+      BaseRegisterNumber = Func->getTarget()->getFrameOrStackReg();
     Str << "["
-        << Func->getTarget()->getRegName(
-               Func->getTarget()->getFrameOrStackReg(), IceType_i32);
+        << Func->getTarget()->getRegName(BaseRegisterNumber, IceType_i32);
     int32_t Offset = getStackOffset();
     if (Offset) {
       if (Offset > 0)
         Str << "+";
       Str << Offset;
     }
     Str << "]";
   }
 }
 
@@ skipping 78 matching lines @@
   if (getType() != IceType_i32 && getType() != IceType_i16 &&
       getType() != IceType_i8)
     return false;
   // The Following checks if the signed representation of Value is between
   // -Threshold/2 and +Threshold/2
   bool largerThanThreshold = Threshold / 2 + Value >= Threshold;
   return largerThanThreshold;
 }
 
 } // end of namespace Ice