cl::Hidden,
cl::desc("Convert noalias attributes to metadata during inlining."));
+static cl::opt<bool>
+PreserveAlignmentAssumptions("preserve-alignment-assumptions-during-inlining",
+ cl::init(true), cl::Hidden,
+ cl::desc("Convert align attributes to assumptions during inlining."));
+
bool llvm::InlineFunction(CallInst *CI, InlineFunctionInfo &IFI,
bool InsertLifetime) {
return InlineFunction(CallSite(CI), IFI, InsertLifetime);
}
}
+/// If the inlined function has non-byval align arguments, then
+/// add @llvm.assume-based alignment assumptions to preserve this information.
+static void AddAlignmentAssumptions(CallSite CS, InlineFunctionInfo &IFI) {
+ if (!PreserveAlignmentAssumptions || !IFI.DL)
+ return;
+
+ // To avoid inserting redundant assumptions, we should check for assumptions
+ // already in the caller. To do this, we might need a DT of the caller.
+ DominatorTree DT;
+ bool DTCalculated = false;
+
+ const Function *CalledFunc = CS.getCalledFunction();
+ for (Function::const_arg_iterator I = CalledFunc->arg_begin(),
+ E = CalledFunc->arg_end(); I != E; ++I) {
+ unsigned Align = I->getType()->isPointerTy() ? I->getParamAlignment() : 0;
+ if (Align && !I->hasByValOrInAllocaAttr() && !I->hasNUses(0)) {
+ if (!DTCalculated) {
+ DT.recalculate(const_cast<Function&>(*CS.getInstruction()->getParent()
+ ->getParent()));
+ DTCalculated = true;
+ }
+
+ // If we can already prove the asserted alignment in the context of the
+ // caller, then don't bother inserting the assumption.
+ Value *Arg = CS.getArgument(I->getArgNo());
+ if (getKnownAlignment(Arg, IFI.DL, IFI.AT, CS.getInstruction(),
+ &DT) >= Align)
+ continue;
+
+ IRBuilder<>(CS.getInstruction()).CreateAlignmentAssumption(*IFI.DL, Arg,
+ Align);
+ }
+ }
+}
+
/// UpdateCallGraphAfterInlining - Once we have cloned code over from a callee
/// into the caller, update the specified callgraph to reflect the changes we
/// made. Note that it's possible that not all code was copied over, so only
VMap[I] = ActualArg;
}
+ // Add alignment assumptions if necessary. We do this before the inlined
+ // instructions are actually cloned into the caller so that we can easily
+ // check what will be known at the start of the inlined code.
+ AddAlignmentAssumptions(CS, IFI);
+
// We want the inliner to prune the code as it copies. We would LOVE to
// have no dead or constant instructions leftover after inlining occurs
// (which can happen, e.g., because an argument was constant), but we'll be