Bring in fixes for Cortex-A53 errata + build updates.

Bug: 18034609

Change-Id: I2cf0094eb9df801a84274ff29018431d75da89dd

3 files changed, 18 insertions, 4 deletions

diff --git a/include/llvm/CodeGen/MachineInstr.h b/include/llvm/CodeGen/MachineInstr.h
index 3c82811..1e2db7c 100644
--- a/include/llvm/CodeGen/MachineInstr.h
+++ b/include/llvm/CodeGen/MachineInstr.h
@@ -614,7 +614,6 @@ public:
   /// are not marking copies from and to the same register class with this flag.
   bool isAsCheapAsAMove(QueryType Type = AllInBundle) const {
     // Only returns true for a bundle if all bundled instructions are cheap.
-    // FIXME: This probably requires a target hook.
     return hasProperty(MCID::CheapAsAMove, Type);
   }
 
diff --git a/include/llvm/MC/MCInstrDesc.h b/include/llvm/MC/MCInstrDesc.h
index 5896de7..101778e 100644
--- a/include/llvm/MC/MCInstrDesc.h
+++ b/include/llvm/MC/MCInstrDesc.h
@@ -451,9 +451,12 @@ public:
   }
 
   /// isRematerializable - Returns true if this instruction is a candidate for
-  /// remat.  This flag is deprecated, please don't use it anymore.  If this
-  /// flag is set, the isReallyTriviallyReMaterializable() method is called to
-  /// verify the instruction is really rematable.
+  /// remat. This flag is only used in TargetInstrInfo method
+  /// isTriviallyRematerializable.
+  ///
+  /// If this flag is set, the isReallyTriviallyReMaterializable()
+  /// or isReallyTriviallyReMaterializableGeneric methods are called to verify
+  /// the instruction is really rematable.
   bool isRematerializable() const {
     return Flags & (1 << MCID::Rematerializable);
   }
@@ -464,6 +467,9 @@ public:
   /// where we would like to remat or hoist the instruction, but not if it costs
   /// more than moving the instruction into the appropriate register. Note, we
   /// are not marking copies from and to the same register class with this flag.
+  ///
+  /// This method could be called by interface TargetInstrInfo::isAsCheapAsAMove
+  /// for different subtargets.
   bool isAsCheapAsAMove() const {
     return Flags & (1 << MCID::CheapAsAMove);
   }
diff --git a/include/llvm/Target/TargetInstrInfo.h b/include/llvm/Target/TargetInstrInfo.h
index 87e7c14..a589d0e 100644
--- a/include/llvm/Target/TargetInstrInfo.h
+++ b/include/llvm/Target/TargetInstrInfo.h
@@ -200,6 +200,15 @@ public:
                                  unsigned &Size, unsigned &Offset,
                                  const TargetMachine *TM) const;
 
+  /// isAsCheapAsAMove - Return true if the instruction is as cheap as a move
+  /// instruction.
+  ///
+  /// Targets for different archs need to override this, and different
+  /// micro-architectures can also be finely tuned inside.
+  virtual bool isAsCheapAsAMove(const MachineInstr *MI) const {
+    return MI->isAsCheapAsAMove();
+  }
+
   /// reMaterialize - Re-issue the specified 'original' instruction at the
   /// specific location targeting a new destination register.
   /// The register in Orig->getOperand(0).getReg() will be substituted by