Implemented loose checking for potential widened loads

src/IceASanInstrumentation.cpp

 //===- subzero/src/IceASanInstrumentation.cpp - ASan ------------*- C++ -*-===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 ///
 /// \file
@@ skipping 243 matching lines @@
       InstCall::create(Context.getNode()->getCfg(), Instr->getNumArgs(),
                        Instr->getDest(), NewFunc, Instr->isTailcall());
   for (SizeT I = 0, Args = Instr->getNumArgs(); I < Args; ++I)
     NewCall->addArg(Instr->getArg(I));
   Context.insert(NewCall);
   Instr->setDeleted();
 }
 
 void ASanInstrumentation::instrumentLoad(LoweringContext &Context,
                                          InstLoad *Instr) {
+  Constant *Func =
+      Ctx->getConstantExternSym(Ctx->getGlobalString("__asan_check_load"));
   instrumentAccess(Context, Instr->getSourceAddress(),
-                   typeWidthInBytes(Instr->getDest()->getType()));
+                   typeWidthInBytes(Instr->getDest()->getType()), Func);
 }
 
 void ASanInstrumentation::instrumentStore(LoweringContext &Context,
                                           InstStore *Instr) {
+  Constant *Func =
+      Ctx->getConstantExternSym(Ctx->getGlobalString("__asan_check_store"));
   instrumentAccess(Context, Instr->getAddr(),
-                   typeWidthInBytes(Instr->getData()->getType()));
+                   typeWidthInBytes(Instr->getData()->getType()), Func);
 }
 
 // TODO(tlively): Take size of access into account as well
 void ASanInstrumentation::instrumentAccess(LoweringContext &Context,
-                                           Operand *Op, SizeT Size) {
-  Constant *AccessCheck =
-      Ctx->getConstantExternSym(Ctx->getGlobalString("__asan_check"));
+                                           Operand *Op, SizeT Size,
+                                           Constant *CheckFunc) {
   constexpr SizeT NumArgs = 2;
   constexpr Variable *Void = nullptr;
   constexpr bool NoTailCall = false;
   auto *Call = InstCall::create(Context.getNode()->getCfg(), NumArgs, Void,
-                                AccessCheck, NoTailCall);
+                                CheckFunc, NoTailCall);
   Call->addArg(Op);
   Call->addArg(ConstantInteger32::create(Ctx, IceType_i32, Size));
   // play games to insert the call before the access instruction
   InstList::iterator Next = Context.getNext();
   Context.setInsertPoint(Context.getCur());
   Context.insert(Call);
   Context.setNext(Next);
 }
 
 void ASanInstrumentation::instrumentRet(LoweringContext &Context, InstRet *) {
@@ skipping 26 matching lines @@
   Call->addArg(Ctx->getConstantSym(0, Ctx->getGlobalString(RzSizesName)));
 }
 
 // TODO(tlively): make this more efficient with swap idiom
 void ASanInstrumentation::finishFunc(Cfg *Func) {
   (void)Func;
   ICE_TLS_GET_FIELD(LocalDtors)->clear();
 }
 
 } // end of namespace Ice