using namespace llvm;
STATISTIC(NumEliminated, "Number of tail calls removed");
+STATISTIC(NumRetDuped, "Number of return duplicated");
STATISTIC(NumAccumAdded, "Number of accumulators introduced");
namespace {
EliminateRecursiveTailCall(CI, FoldReturnIntoUncondBranch(Ret, BB, Pred),
OldEntry, TailCallsAreMarkedTail, ArgumentPHIs,
CannotTailCallElimCallsMarkedTail);
+ ++NumRetDuped;
Change = true;
}
}
--- /dev/null
+; Duplicate the return into if.end to enable TCE.
+; RUN: opt %s -tailcallelim -stats -disable-output |& grep {Number of return duplicated}
+
+define i32 @fib(i32 %n) nounwind ssp {
+entry:
+ %cmp = icmp slt i32 %n, 2
+ br i1 %cmp, label %if.then, label %if.end
+
+if.then: ; preds = %entry
+ br label %return
+
+if.end: ; preds = %entry
+ %sub = add nsw i32 %n, -2
+ %call = call i32 @fib(i32 %sub)
+ %sub3 = add nsw i32 %n, -1
+ %call4 = call i32 @fib(i32 %sub3)
+ %add = add nsw i32 %call, %call4
+ br label %return
+
+return: ; preds = %if.end, %if.then
+ %retval.0 = phi i32 [ 1, %if.then ], [ %add, %if.end ]
+ ret i32 %retval.0
+}