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author | Adam Nemet <anemet@apple.com> | 2014-05-31 16:23:20 +0000 |
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committer | Adam Nemet <anemet@apple.com> | 2014-05-31 16:23:20 +0000 |
commit | 8fb9cfe141ea0ad6e8ec695273b2b8f901ea24c0 (patch) | |
tree | 3d4088eae9ae56896d255f6990aaf3eb169e7f37 /lib/CodeGen/SelectionDAG | |
parent | aa8deedcb2abd03ce312a240d6faa28c2733363d (diff) | |
download | llvm-8fb9cfe141ea0ad6e8ec695273b2b8f901ea24c0.tar.gz llvm-8fb9cfe141ea0ad6e8ec695273b2b8f901ea24c0.tar.bz2 llvm-8fb9cfe141ea0ad6e8ec695273b2b8f901ea24c0.tar.xz |
[SelectionDAG] Force cycle detection in AssignTopologicalOrder before aborting
DAG cycle detection is only enabled with ENABLE_EXPENSIVE_CHECKS. However we
can run it just before we would crash in order to provide more informative
diagnostics.
Now in addition to the "Overran sorted position" message we also get the Node
printed if a cycle was detected.
Tested by building several configs: Debug+Assert, Debug+Assert+Check (this is
ENABLE_EXPENSIVE_CHECKS), Release+Assert and Release. Also tried that the
AssignTopologicalOrder assert produces the expected results.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209977 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/CodeGen/SelectionDAG')
-rw-r--r-- | lib/CodeGen/SelectionDAG/SelectionDAG.cpp | 27 |
1 files changed, 18 insertions, 9 deletions
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp index 0f1d975834..b701add2de 100644 --- a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp +++ b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp @@ -6002,6 +6002,8 @@ unsigned SelectionDAG::AssignTopologicalOrder() { SDNode *S = ++I; dbgs() << "Overran sorted position:\n"; S->dumprFull(this); dbgs() << "\n"; + dbgs() << "Checking if this is due to cycles\n"; + checkForCycles(this, true); #endif llvm_unreachable(nullptr); } @@ -6587,7 +6589,7 @@ bool ShuffleVectorSDNode::isSplatMask(const int *Mask, EVT VT) { return true; } -#ifdef XDEBUG +#ifndef NDEBUG static void checkForCyclesHelper(const SDNode *N, SmallPtrSet<const SDNode*, 32> &Visited, SmallPtrSet<const SDNode*, 32> &Checked, @@ -6614,15 +6616,22 @@ static void checkForCyclesHelper(const SDNode *N, #endif void llvm::checkForCycles(const llvm::SDNode *N, - const llvm::SelectionDAG *DAG) { + const llvm::SelectionDAG *DAG, + bool force) { +#ifndef NDEBUG + bool check = force; #ifdef XDEBUG - assert(N && "Checking nonexistent SDNode"); - SmallPtrSet<const SDNode*, 32> visited; - SmallPtrSet<const SDNode*, 32> checked; - checkForCyclesHelper(N, visited, checked, DAG); -#endif + check = true; +#endif // XDEBUG + if (check) { + assert(N && "Checking nonexistent SDNode"); + SmallPtrSet<const SDNode*, 32> visited; + SmallPtrSet<const SDNode*, 32> checked; + checkForCyclesHelper(N, visited, checked, DAG); + } +#endif // !NDEBUG } -void llvm::checkForCycles(const llvm::SelectionDAG *DAG) { - checkForCycles(DAG->getRoot().getNode(), DAG); +void llvm::checkForCycles(const llvm::SelectionDAG *DAG, bool force) { + checkForCycles(DAG->getRoot().getNode(), DAG, force); } |