[RISCV] Implement branch analysis

This is a prerequisite for the branch relaxation pass, and allows a number of
optimisation passes (e.g. BranchFolding and MachineBlockPlacement) to work.

Differential Revision: https://reviews.llvm.org/D40808

llvm-svn: 322222

1 files changed, 16 insertions, 0 deletions

diff --git a/llvm/lib/Target/RISCV/RISCVInstrInfo.h b/llvm/lib/Target/RISCV/RISCVInstrInfo.h
index cb2ed0beef1..772bc2cae80 100644
--- a/llvm/lib/Target/RISCV/RISCVInstrInfo.h
+++ b/llvm/lib/Target/RISCV/RISCVInstrInfo.h
@@ -46,6 +46,22 @@ public:
   void movImm32(MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
                 const DebugLoc &DL, unsigned DstReg, uint64_t Val,
                 MachineInstr::MIFlag Flag = MachineInstr::NoFlags) const;
+
+  bool analyzeBranch(MachineBasicBlock &MBB, MachineBasicBlock *&TBB,
+                     MachineBasicBlock *&FBB,
+                     SmallVectorImpl<MachineOperand> &Cond,
+                     bool AllowModify) const override;
+
+  unsigned insertBranch(MachineBasicBlock &MBB, MachineBasicBlock *TBB,
+                        MachineBasicBlock *FBB, ArrayRef<MachineOperand> Cond,
+                        const DebugLoc &dl,
+                        int *BytesAdded = nullptr) const override;
+
+  unsigned removeBranch(MachineBasicBlock &MBB,
+                        int *BytesRemoved = nullptr) const override;
+
+  bool
+  reverseBranchCondition(SmallVectorImpl<MachineOperand> &Cond) const override;
 };
 }
 #endif