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  -
--

llvm-svn: 79846

1 files changed, 10 insertions, 6 deletions

diff --git a/llvm/utils/TableGen/CodeGenDAGPatterns.h b/llvm/utils/TableGen/CodeGenDAGPatterns.h
index 56dcfcff910..f7198d8ae5b 100644
--- a/llvm/utils/TableGen/CodeGenDAGPatterns.h
+++ b/llvm/utils/TableGen/CodeGenDAGPatterns.h
@@ -462,6 +462,10 @@ struct PatternToMatch {
   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 @@ class CodeGenDAGPatterns {
   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;