TRE: make TRE a bit more aggressive
Make tail recursion elimination a bit more aggressive. This allows us to get
tail recursion on functions that are just branches to a different function. The
fact that the function takes a byval argument does not restrict it from being
optimised into just a tail call.
llvm-svn: 219899
diff --git a/llvm/lib/Transforms/Scalar/TailRecursionElimination.cpp b/llvm/lib/Transforms/Scalar/TailRecursionElimination.cpp
index b758025..f8eafc8 100644
--- a/llvm/lib/Transforms/Scalar/TailRecursionElimination.cpp
+++ b/llvm/lib/Transforms/Scalar/TailRecursionElimination.cpp
@@ -249,12 +249,7 @@
return false;
AllCallsAreTailCalls = true;
- // The local stack holds all alloca instructions and all byval arguments.
AllocaDerivedValueTracker Tracker;
- for (Argument &Arg : F.args()) {
- if (Arg.hasByValAttr())
- Tracker.walk(&Arg);
- }
for (auto &BB : F) {
for (auto &I : BB)
if (AllocaInst *AI = dyn_cast<AllocaInst>(&I))
@@ -310,9 +305,8 @@
for (auto &Arg : CI->arg_operands()) {
if (isa<Constant>(Arg.getUser()))
continue;
- if (Argument *A = dyn_cast<Argument>(Arg.getUser()))
- if (!A->hasByValAttr())
- continue;
+ if (isa<Argument>(Arg.getUser()))
+ continue;
SafeToTail = false;
break;
}