Revert "Apply rL216114 from upstream LLVM."

This reverts commit 9156e80250ada6f6d39af3b464a918d4855f9a2a.

1 files changed, 2 insertions, 17 deletions

diff --git a/lib/CodeGen/CriticalAntiDepBreaker.cpp b/lib/CodeGen/CriticalAntiDepBreaker.cpp
index d2231ecf68..d3ffcc7847 100644
--- a/lib/CodeGen/CriticalAntiDepBreaker.cpp
+++ b/lib/CodeGen/CriticalAntiDepBreaker.cpp
@@ -94,14 +94,7 @@ void CriticalAntiDepBreaker::FinishBlock() {
 
 void CriticalAntiDepBreaker::Observe(MachineInstr *MI, unsigned Count,
                                      unsigned InsertPosIndex) {
-  // Kill instructions can define registers but are really nops, and there might
-  // be a real definition earlier that needs to be paired with uses dominated by
-  // this kill.
-
-  // FIXME: It may be possible to remove the isKill() restriction once PR18663
-  // has been properly fixed. There can be value in processing kills as seen in
-  // the AggressiveAntiDepBreaker class.
-  if (MI->isDebugValue() || MI->isKill())
+  if (MI->isDebugValue())
     return;
   assert(Count < InsertPosIndex && "Instruction index out of expected range!");
 
@@ -244,7 +237,6 @@ void CriticalAntiDepBreaker::ScanInstruction(MachineInstr *MI,
   // Update liveness.
   // Proceeding upwards, registers that are defed but not used in this
   // instruction are now dead.
-  assert(!MI->isKill() && "Attempting to scan a kill instruction");
 
   if (!TII->isPredicated(MI)) {
     // Predicated defs are modeled as read + write, i.e. similar to two
@@ -535,14 +527,7 @@ BreakAntiDependencies(const std::vector<SUnit>& SUnits,
   unsigned Count = InsertPosIndex - 1;
   for (MachineBasicBlock::iterator I = End, E = Begin; I != E; --Count) {
     MachineInstr *MI = --I;
-    // Kill instructions can define registers but are really nops, and there
-    // might be a real definition earlier that needs to be paired with uses
-    // dominated by this kill.
-    
-    // FIXME: It may be possible to remove the isKill() restriction once PR18663
-    // has been properly fixed. There can be value in processing kills as seen
-    // in the AggressiveAntiDepBreaker class.
-    if (MI->isDebugValue() || MI->isKill())
+    if (MI->isDebugValue())
       continue;
 
     // Check if this instruction has a dependence on the critical path that