Fix a tricky issue in the SimplifyDemandedBits code where CombineTo wasn't
exactly the API we wanted to call into. This fixes the crash on crafty last
night.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26269 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index 5fc0967..bb66825 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -21,6 +21,7 @@
#include "llvm/Target/TargetLowering.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/Target/TargetMachine.h"
+#include "llvm/ADT/SetVector.h"
#include "llvm/ADT/StringExtras.h"
#include <iostream>
#include <set>
@@ -2403,6 +2404,66 @@
}
}
+/// ReplaceAllUsesOfValueWith - Replace any uses of From with To, leaving
+/// uses of other values produced by From.Val alone. The Deleted vector is
+/// handled the same was as for ReplaceAllUsesWith.
+void SelectionDAG::ReplaceAllUsesOfValueWith(SDOperand From, SDOperand To,
+ std::vector<SDNode*> &Deleted) {
+ assert(From != To && "Cannot replace a value with itself");
+ // Handle the simple, trivial, case efficiently.
+ if (From.Val->getNumValues() == 1 && To.Val->getNumValues() == 1) {
+ ReplaceAllUsesWith(From, To, &Deleted);
+ return;
+ }
+
+ // Get all of the users in a nice, deterministically ordered, uniqued set.
+ SetVector<SDNode*> Users(From.Val->use_begin(), From.Val->use_end());
+
+ while (!Users.empty()) {
+ // We know that this user uses some value of From. If it is the right
+ // value, update it.
+ SDNode *User = Users.back();
+ Users.pop_back();
+
+ for (SDOperand *Op = User->OperandList,
+ *E = User->OperandList+User->NumOperands; Op != E; ++Op) {
+ if (*Op == From) {
+ // Okay, we know this user needs to be updated. Remove its old self
+ // from the CSE maps.
+ RemoveNodeFromCSEMaps(User);
+
+ // Update all operands that match "From".
+ for (; Op != E; ++Op) {
+ if (*Op == From) {
+ From.Val->removeUser(User);
+ *Op = To;
+ To.Val->addUser(User);
+ }
+ }
+
+ // Now that we have modified User, add it back to the CSE maps. If it
+ // already exists there, recursively merge the results together.
+ if (SDNode *Existing = AddNonLeafNodeToCSEMaps(User)) {
+ unsigned NumDeleted = Deleted.size();
+ ReplaceAllUsesWith(User, Existing, &Deleted);
+
+ // User is now dead.
+ Deleted.push_back(User);
+ DeleteNodeNotInCSEMaps(User);
+
+ // We have to be careful here, because ReplaceAllUsesWith could have
+ // deleted a user of From, which means there may be dangling pointers
+ // in the "Users" setvector. Scan over the deleted node pointers and
+ // remove them from the setvector.
+ for (unsigned i = NumDeleted, e = Deleted.size(); i != e; ++i)
+ Users.remove(Deleted[i]);
+ }
+ break; // Exit the operand scanning loop.
+ }
+ }
+ }
+}
+
//===----------------------------------------------------------------------===//
// SDNode Class