Subzero: Change -asm-verbose output to print more useful info.

src/IceTargetLoweringX86BaseImpl.h

 //===- subzero/src/IceTargetLoweringX86BaseImpl.h - x86 lowering -*- C++ -*-==//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 ///
 /// \file
@@ skipping 728 matching lines @@
   if (!BuildDefs::dump())
     return;
   Ostream &Str = Ctx->getStrEmit();
   if (Var->hasReg()) {
     Str << "%" << getRegName(Var->getRegNum(), Var->getType());
     return;
   }
   if (Var->mustHaveReg()) {
     llvm_unreachable("Infinite-weight Variable has no register assigned");
   }
-  int32_t Offset = Var->getStackOffset();
+  const int32_t Offset = Var->getStackOffset();
+  int32_t OffsetAdj = 0;
   int32_t BaseRegNum = Var->getBaseRegNum();
   if (BaseRegNum == Variable::NoRegister) {
     BaseRegNum = getFrameOrStackReg();
     if (!hasFramePointer())
-      Offset += getStackAdjustment();
+      OffsetAdj = getStackAdjustment();
   }
-  if (Offset)
-    Str << Offset;
+  // Print in the form "OffsetAdj+Offset(%reg)", taking care that:
+  //   - OffsetAdj may be 0
+  //   - Offset is never printed when it is 0
+  //   - Offset may be positive or symbolic, so a "+" might be needed
+
+  // Only print nonzero OffsetAdj.
+  if (OffsetAdj) {
+    Str << OffsetAdj;
+  }
+  const bool DecorateAsm = Func->getContext()->getFlags().getDecorateAsm();
+  // Only print Offset when it is nonzero, regardless of DecorateAsm.
+  if (Offset) {
+    if (OffsetAdj && (DecorateAsm || Offset > 0)) {
+      Str << "+";
+    }
+    if (DecorateAsm) {
+      Str << Var->getSymbolicStackOffset(Func);
+    } else {
+      Str << Offset;
+    }
+  }
   const Type FrameSPTy = Traits::WordType;
   Str << "(%" << getRegName(BaseRegNum, FrameSPTy) << ")";
 }
 
 template <class Machine>
 typename TargetX86Base<Machine>::Traits::Address
 TargetX86Base<Machine>::stackVarToAsmOperand(const Variable *Var) const {
   if (Var->hasReg())
     llvm_unreachable("Stack Variable has a register assigned");
   if (Var->mustHaveReg()) {
@@ skipping 4688 matching lines @@
   }
   // the offset is not eligible for blinding or pooling, return the original
   // mem operand
   return MemOperand;
 }
 
 } // end of namespace X86Internal
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_ICETARGETLOWERINGX86BASEIMPL_H