From 774c9320c03dfc17ce588b9b3dc96f91eecc8723 Mon Sep 17 00:00:00 2001 From: Chandler Carruth Date: Fri, 25 Apr 2014 06:38:58 +0000 Subject: [LCG] Now that the loop structure of the core SCC finding routine is factored into a more reasonable form, replace the tail call with a simple outer-loop continuation. It's sad that C++ makes this so awkward to write, but it seems more direct and clear than the tail call at this point. llvm-svn: 207201 --- llvm/lib/Analysis/LazyCallGraph.cpp | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) (limited to 'llvm/lib/Analysis/LazyCallGraph.cpp') diff --git a/llvm/lib/Analysis/LazyCallGraph.cpp b/llvm/lib/Analysis/LazyCallGraph.cpp index 2e4fad3..c9cc0dd 100644 --- a/llvm/lib/Analysis/LazyCallGraph.cpp +++ b/llvm/lib/Analysis/LazyCallGraph.cpp @@ -449,6 +449,7 @@ LazyCallGraph::SCC *LazyCallGraph::getNextSCCInPostOrder() { assert(N->DFSNumber != 0 && "We should always assign a DFS number " "before placing a node onto the stack."); + bool Recurse = false; // Used to simulate recursing onto a child. for (auto I = DFSStack.back().second, E = N->end(); I != E; ++I) { Node &ChildN = *I; if (ChildN.DFSNumber == 0) { @@ -463,7 +464,8 @@ LazyCallGraph::SCC *LazyCallGraph::getNextSCCInPostOrder() { ChildN.LowLink = ChildN.DFSNumber = NextDFSNumber++; SCCEntryNodes.remove(&ChildN.getFunction()); DFSStack.push_back(std::make_pair(&ChildN, ChildN.begin())); - return LazyCallGraph::getNextSCCInPostOrder(); + Recurse = true; + break; } // Track the lowest link of the childen, if any are still in the stack. @@ -472,6 +474,11 @@ LazyCallGraph::SCC *LazyCallGraph::getNextSCCInPostOrder() { if (ChildN.LowLink >= 0 && ChildN.LowLink < N->LowLink) N->LowLink = ChildN.LowLink; } + if (Recurse) + // Continue the outer loop when we exit the inner loop in order to + // recurse onto a child. + continue; + // No more children to process here, pop the node off the stack. DFSStack.pop_back(); -- cgit v1.1