Fix non-determinism in DAGISel emitter.
- This manifested as non-determinism in the .inc output in rare cases (when two
distinct patterns ended up being equivalent, which is rather rare). That
meant the pattern matching was non-deterministic, which could eventually mean
the code generator selected different instructions based on the arch.
- It's probably worth making the DAGISel ensure a total ordering (or force the
user to), but the simple fix here is to totally order the Record* maps based
on a unique ID.
- PR4672, PR4711.
Yay:
--
ddunbar@giles:~$ cat ~/llvm.obj.64/lib/Target/*/*.inc | shasum
d1099ff34b21459a5a3e7021c225c080e6017ece -
ddunbar@giles:~$ cat ~/llvm.obj.ppc/lib/Target/*/*.inc | shasum
d1099ff34b21459a5a3e7021c225c080e6017ece -
--
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@79846 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/utils/TableGen/CodeGenDAGPatterns.h b/utils/TableGen/CodeGenDAGPatterns.h
index 56dcfcf..f7198d8 100644
--- a/utils/TableGen/CodeGenDAGPatterns.h
+++ b/utils/TableGen/CodeGenDAGPatterns.h
@@ -462,6 +462,10 @@
std::string getPredicateCheck() const;
};
+// Deterministic comparison of Record*.
+struct RecordPtrCmp {
+ bool operator()(const Record *LHS, const Record *RHS) const;
+};
class CodeGenDAGPatterns {
RecordKeeper &Records;
@@ -469,12 +473,12 @@
std::vector<CodeGenIntrinsic> Intrinsics;
std::vector<CodeGenIntrinsic> TgtIntrinsics;
- std::map<Record*, SDNodeInfo> SDNodes;
- std::map<Record*, std::pair<Record*, std::string> > SDNodeXForms;
- std::map<Record*, ComplexPattern> ComplexPatterns;
- std::map<Record*, TreePattern*> PatternFragments;
- std::map<Record*, DAGDefaultOperand> DefaultOperands;
- std::map<Record*, DAGInstruction> Instructions;
+ std::map<Record*, SDNodeInfo, RecordPtrCmp> SDNodes;
+ std::map<Record*, std::pair<Record*, std::string>, RecordPtrCmp> SDNodeXForms;
+ std::map<Record*, ComplexPattern, RecordPtrCmp> ComplexPatterns;
+ std::map<Record*, TreePattern*, RecordPtrCmp> PatternFragments;
+ std::map<Record*, DAGDefaultOperand, RecordPtrCmp> DefaultOperands;
+ std::map<Record*, DAGInstruction, RecordPtrCmp> Instructions;
// Specific SDNode definitions:
Record *intrinsic_void_sdnode;