Slightly change the meaning of the reMaterialize target hook when the original

instruction defines subregisters.

Any existing subreg indices on the original instruction are preserved or
composed with the new subreg index.

Also substitute multiple operands mentioning the original register by using the
new MachineInstr::substituteRegister() function. This is necessary because there
will soon be <imp-def> operands added to non read-modify-write partial
definitions. This instruction:

  %reg1234:foo = FLAP %reg1234<imp-def>

will reMaterialize(%reg3333, bar) like this:

  %reg3333:bar-foo = FLAP %reg333:bar<imp-def>

Finally, replace the TargetRegisterInfo pointer argument with a reference to
indicate that it cannot be NULL.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@105358 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 10 insertions, 2 deletions

diff --git a/include/llvm/CodeGen/MachineInstr.h b/include/llvm/CodeGen/MachineInstr.h
index cf691bb..1171c3a 100644
--- a/include/llvm/CodeGen/MachineInstr.h
+++ b/include/llvm/CodeGen/MachineInstr.h
@@ -339,6 +339,11 @@ public:
   /// copyPredicates - Copies predicate operand(s) from MI.
   void copyPredicates(const MachineInstr *MI);
 
+  /// substituteRegister - Replace all occurrences of FromReg with ToReg:SubIdx,
+  /// properly composing subreg indices where necessary.
+  void substituteRegister(unsigned FromReg, unsigned ToReg, unsigned SubIdx,
+                          const TargetRegisterInfo &RegInfo);
+
   /// addRegisterKilled - We have determined MI kills a register. Look for the
   /// operand that uses it and mark it as IsKill. If AddIfNotFound is true,
   /// add a implicit operand if it's not found. Returns true if the operand
diff --git a/include/llvm/Target/TargetInstrInfo.h b/include/llvm/Target/TargetInstrInfo.h
index 2e5697e..98a5f57 100644
--- a/include/llvm/Target/TargetInstrInfo.h
+++ b/include/llvm/Target/TargetInstrInfo.h
@@ -194,11 +194,14 @@ public:
 
   /// 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
+  /// DestReg:SubIdx. Any existing subreg index is preserved or composed with
+  /// SubIdx.
   virtual void reMaterialize(MachineBasicBlock &MBB,
                              MachineBasicBlock::iterator MI,
                              unsigned DestReg, unsigned SubIdx,
                              const MachineInstr *Orig,
-                             const TargetRegisterInfo *TRI) const = 0;
+                             const TargetRegisterInfo &TRI) const = 0;
 
   /// duplicate - Create a duplicate of the Orig instruction in MF. This is like
   /// MachineFunction::CloneMachineInstr(), but the target may update operands
@@ -585,7 +588,7 @@ public:
                              MachineBasicBlock::iterator MI,
                              unsigned DestReg, unsigned SubReg,
                              const MachineInstr *Orig,
-                             const TargetRegisterInfo *TRI) const;
+                             const TargetRegisterInfo &TRI) const;
   virtual MachineInstr *duplicate(MachineInstr *Orig,
                                   MachineFunction &MF) const;
   virtual bool produceSameValue(const MachineInstr *MI0,