1 files changed, 0 insertions, 49 deletions
diff --git a/utils/TableGen/CodeGenRegisters.cpp b/utils/TableGen/CodeGenRegisters.cpp
index 1fe08b84b8..9d72d0d4bd 100644
--- a/utils/TableGen/CodeGenRegisters.cpp
+++ b/utils/TableGen/CodeGenRegisters.cpp
@@ -526,55 +526,6 @@ CodeGenRegister::addSubRegsPreOrder(SetVector<const CodeGenRegister*> &OSet,
     OSet.insert(I->second);
 }
 
-// Compute overlapping registers.
-//
-// The standard set is all super-registers and all sub-registers, but the
-// target description can add arbitrary overlapping registers via the 'Aliases'
-// field. This complicates things, but we can compute overlapping sets using
-// the following rules:
-//
-// 1. The relation overlap(A, B) is reflexive and symmetric but not transitive.
-//
-// 2. overlap(A, B) implies overlap(A, S) for all S in supers(B).
-//
-// Alternatively:
-//
-//    overlap(A, B) iff there exists:
-//    A' in { A, subregs(A) } and B' in { B, subregs(B) } such that:
-//    A' = B' or A' in aliases(B') or B' in aliases(A').
-//
-// Here subregs(A) is the full flattened sub-register set returned by
-// A.getSubRegs() while aliases(A) is simply the special 'Aliases' field in the
-// description of register A.
-//
-// This also implies that registers with a common sub-register are considered
-// overlapping. This can happen when forming register pairs:
-//
-//    P0 = (R0, R1)
-//    P1 = (R1, R2)
-//    P2 = (R2, R3)
-//
-// In this case, we will infer an overlap between P0 and P1 because of the
-// shared sub-register R1. There is no overlap between P0 and P2.
-//
-void CodeGenRegister::computeOverlaps(CodeGenRegister::Set &Overlaps,
-                                      const CodeGenRegBank &RegBank) const {
-  assert(!RegUnits.empty() && "Compute register units before overlaps.");
-
-  // Register units are assigned such that the overlapping registers are the
-  // super-registers of the root registers of the register units.
-  for (unsigned rui = 0, rue = RegUnits.size(); rui != rue; ++rui) {
-    const RegUnit &RU = RegBank.getRegUnit(RegUnits[rui]);
-    ArrayRef<const CodeGenRegister*> Roots = RU.getRoots();
-    for (unsigned ri = 0, re = Roots.size(); ri != re; ++ri) {
-      const CodeGenRegister *Root = Roots[ri];
-      Overlaps.insert(Root);
-      ArrayRef<const CodeGenRegister*> Supers = Root->getSuperRegs();
-      Overlaps.insert(Supers.begin(), Supers.end());
-    }
-  }
-}
-
 // Get the sum of this register's unit weights.
 unsigned CodeGenRegister::getWeight(const CodeGenRegBank &RegBank) const {
   unsigned Weight = 0;