[PATCH] D84862: Make ENDBR instruction a scheduling boundary

[Joao Moreira via Phabricator via llvm-commits]

joaomoreira updated this revision to Diff 282067.
joaomoreira added a comment.

Fixes:

- Applied suggestions made by @RKSimon,
- Fixed "opcode" variable name capitalization.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D84862/new/

https://reviews.llvm.org/D84862

Files:
  llvm/lib/Target/X86/X86InstrInfo.cpp
  llvm/lib/Target/X86/X86InstrInfo.h


Index: llvm/lib/Target/X86/X86InstrInfo.h
===================================================================
--- llvm/lib/Target/X86/X86InstrInfo.h
+++ llvm/lib/Target/X86/X86InstrInfo.h
@@ -409,6 +409,13 @@
   bool areLoadsFromSameBasePtr(SDNode *Load1, SDNode *Load2, int64_t &Offset1,
                                int64_t &Offset2) const override;
 
+  /// isSchedulingBoundary - Overrides the isSchedulingBoundary from
+  ///	Codegen/TargetInstrInfo.cpp to make it capable of identifying ENDBR
+  /// intructions and prevent it from being re-scheduled.
+  bool isSchedulingBoundary(const MachineInstr &MI,
+                            const MachineBasicBlock *MBB,
+                            const MachineFunction &MF) const override;
+
   /// shouldScheduleLoadsNear - This is a used by the pre-regalloc scheduler to
   /// determine (in conjunction with areLoadsFromSameBasePtr) if two loads
   /// should be scheduled togther. On some targets if two loads are loading from
Index: llvm/lib/Target/X86/X86InstrInfo.cpp
===================================================================
--- llvm/lib/Target/X86/X86InstrInfo.cpp
+++ llvm/lib/Target/X86/X86InstrInfo.cpp
@@ -6675,6 +6675,18 @@
   return true;
 }
 
+bool X86InstrInfo::isSchedulingBoundary(const MachineInstr &MI,
+                                        const MachineBasicBlock *MBB,
+                                        const MachineFunction &MF) const {
+
+  // ENDBR instructions should not be scheduled around.
+  unsigned Opcode = MI.getOpcode();
+  if (Opcode == X86::ENDBR64 || Opcode == X86::ENDBR32)
+    return true;
+
+  return TargetInstrInfo::isSchedulingBoundary(MI, MBB, MF);
+}
+
 bool X86InstrInfo::
 reverseBranchCondition(SmallVectorImpl<MachineOperand> &Cond) const {
   assert(Cond.size() == 1 && "Invalid X86 branch condition!");


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