6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-02-06 06:33:24 +00:00
Code Issues Projects Releases Wiki Activity

Avoid exponential blow-up when printing DAGs.

Browse Source 
David Greene changed CannotYetSelect() to print the full DAG including multiple
copies of operands reached through different paths in the DAG.  Unfortunately
this blows up exponentially in some cases.  The depth limit of 100 is way too
high to prevent this -- I'm seeing a message string of 150MB with a depth of
only 40 in one particularly bad case, even though the DAG has less than 200
nodes.  Part of the problem is that the printing code is following chain
operands, so if you fail to select an operation with a chain, the printer will
follow all the chained operations back to the entry node.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126899 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Bob Wilson 2011-03-02 23:38:06 +00:00
parent a2cae58411
commit 254c63e336
1 changed files with 5 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
lib/CodeGen/SelectionDAG/SelectionDAG.cpp
View File

@ -6226,6 +6226,9 @@ static void printrWithDepthHelper(raw_ostream &OS, const SDNode *N,
return;
for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
// Don't follow chain operands.
if (N->getOperand(i).getValueType() == MVT::Other)
continue;
OS << '\n';
printrWithDepthHelper(OS, N->getOperand(i).getNode(), G, depth-1, indent+2);
}
@ -6238,7 +6241,7 @@ void SDNode::printrWithDepth(raw_ostream &OS, const SelectionDAG *G,
void SDNode::printrFull(raw_ostream &OS, const SelectionDAG *G) const {
// Don't print impossibly deep things.
printrWithDepth(OS, G, 100);
printrWithDepth(OS, G, 10);
}
void SDNode::dumprWithDepth(const SelectionDAG *G, unsigned depth) const {
@ -6247,7 +6250,7 @@ void SDNode::dumprWithDepth(const SelectionDAG *G, unsigned depth) const {
void SDNode::dumprFull(const SelectionDAG *G) const {
// Don't print impossibly deep things.
dumprWithDepth(G, 100);
dumprWithDepth(G, 10);
}
static void DumpNodes(const SDNode *N, unsigned indent, const SelectionDAG *G) {