From 62e279bbdb235e247fa43223ba920f97ae27e4ac Mon Sep 17 00:00:00 2001 From: Devang Patel Date: Tue, 24 Jul 2007 01:02:25 +0000 Subject: [PATCH] Unreachable block is not a root node in post dominator tree. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40458 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Analysis/PostDominators.cpp | 8 ++++++-- test/Transforms/ADCE/2007-07-23-InfiniteLoop.ll | 13 +++++++++++++ 2 files changed, 19 insertions(+), 2 deletions(-) create mode 100644 test/Transforms/ADCE/2007-07-23-InfiniteLoop.ll diff --git a/lib/Analysis/PostDominators.cpp b/lib/Analysis/PostDominators.cpp index 48f7b30866f..1188cff0303 100644 --- a/lib/Analysis/PostDominators.cpp +++ b/lib/Analysis/PostDominators.cpp @@ -112,8 +112,12 @@ void PostDominatorTree::calculate(Function &F) { // relationships. These blocks, which have no successors, end with return and // unwind instructions. for (Function::iterator I = F.begin(), E = F.end(); I != E; ++I) - if (succ_begin(I) == succ_end(I)) - Roots.push_back(I); + if (succ_begin(I) == succ_end(I)) { + Instruction *Insn = I->getTerminator(); + // Unreachable block is not a root node. + if (!isa(Insn)) + Roots.push_back(I); + } Vertex.push_back(0); diff --git a/test/Transforms/ADCE/2007-07-23-InfiniteLoop.ll b/test/Transforms/ADCE/2007-07-23-InfiniteLoop.ll new file mode 100644 index 00000000000..f3500ed7e18 --- /dev/null +++ b/test/Transforms/ADCE/2007-07-23-InfiniteLoop.ll @@ -0,0 +1,13 @@ +; RUN: llvm-as < %s | opt -adce | llvm-dis | grep switch +; PR 1564 + +define fastcc void @out() { + start: + br label %loop + unreachable: + unreachable + loop: + switch i32 0, label %unreachable [ + i32 0, label %loop + ] +}