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

6 files changed, 29 insertions, 15 deletions

diff --git a/lib/CodeGen/MachineInstr.cpp b/lib/CodeGen/MachineInstr.cpp
index 402178dc6d..7e60c3215d 100644
--- a/lib/CodeGen/MachineInstr.cpp
+++ b/lib/CodeGen/MachineInstr.cpp
@@ -1037,6 +1037,29 @@ void MachineInstr::copyPredicates(const MachineInstr *MI) {
   }
 }
 
+void MachineInstr::substituteRegister(unsigned FromReg,
+                                      unsigned ToReg,
+                                      unsigned SubIdx,
+                                      const TargetRegisterInfo &RegInfo) {
+  if (TargetRegisterInfo::isPhysicalRegister(ToReg)) {
+    if (SubIdx)
+      ToReg = RegInfo.getSubReg(ToReg, SubIdx);
+    for (unsigned i = 0, e = getNumOperands(); i != e; ++i) {
+      MachineOperand &MO = getOperand(i);
+      if (!MO.isReg() || MO.getReg() != FromReg)
+        continue;
+      MO.substPhysReg(ToReg, RegInfo);
+    }
+  } else {
+    for (unsigned i = 0, e = getNumOperands(); i != e; ++i) {
+      MachineOperand &MO = getOperand(i);
+      if (!MO.isReg() || MO.getReg() != FromReg)
+        continue;
+      MO.substVirtReg(ToReg, SubIdx, RegInfo);
+    }
+  }
+}
+
 /// isSafeToMove - Return true if it is safe to move this instruction. If
 /// SawStore is set to true, it means that there is a store (or call) between
 /// the instruction's location and its intended destination.
diff --git a/lib/CodeGen/PreAllocSplitting.cpp b/lib/CodeGen/PreAllocSplitting.cpp
index 96e7327a7e..42d404de10 100644
--- a/lib/CodeGen/PreAllocSplitting.cpp
+++ b/lib/CodeGen/PreAllocSplitting.cpp
@@ -854,7 +854,7 @@ bool PreAllocSplitting::Rematerialize(unsigned VReg, VNInfo* ValNo,
   if (KillPt == DefMI->getParent()->end())
     return false;
   
-  TII->reMaterialize(MBB, RestorePt, VReg, 0, DefMI, TRI);
+  TII->reMaterialize(MBB, RestorePt, VReg, 0, DefMI, *TRI);
   SlotIndex RematIdx = LIs->InsertMachineInstrInMaps(prior(RestorePt));
   
   ReconstructLiveInterval(CurrLI);
diff --git a/lib/CodeGen/SimpleRegisterCoalescing.cpp b/lib/CodeGen/SimpleRegisterCoalescing.cpp
index 7c1bc47fa9..ed217141ad 100644
--- a/lib/CodeGen/SimpleRegisterCoalescing.cpp
+++ b/lib/CodeGen/SimpleRegisterCoalescing.cpp
@@ -727,7 +727,7 @@ bool SimpleRegisterCoalescing::ReMaterializeTrivialDef(LiveInterval &SrcInt,
 
   MachineBasicBlock::iterator MII =
     llvm::next(MachineBasicBlock::iterator(CopyMI));
-  tii_->reMaterialize(*MBB, MII, DstReg, DstSubIdx, DefMI, tri_);
+  tii_->reMaterialize(*MBB, MII, DstReg, DstSubIdx, DefMI, *tri_);
   MachineInstr *NewMI = prior(MII);
 
   if (checkForDeadDef) {
diff --git a/lib/CodeGen/TargetInstrInfoImpl.cpp b/lib/CodeGen/TargetInstrInfoImpl.cpp
index 0ad6619ac4..46178aaca0 100644
--- a/lib/CodeGen/TargetInstrInfoImpl.cpp
+++ b/lib/CodeGen/TargetInstrInfoImpl.cpp
@@ -136,17 +136,9 @@ void TargetInstrInfoImpl::reMaterialize(MachineBasicBlock &MBB,
                                         unsigned DestReg,
                                         unsigned SubIdx,
                                         const MachineInstr *Orig,
-                                        const TargetRegisterInfo *TRI) const {
+                                        const TargetRegisterInfo &TRI) const {
   MachineInstr *MI = MBB.getParent()->CloneMachineInstr(Orig);
-  MachineOperand &MO = MI->getOperand(0);
-  if (TargetRegisterInfo::isVirtualRegister(DestReg)) {
-    MO.setReg(DestReg);
-    MO.setSubReg(SubIdx);
-  } else if (SubIdx) {
-    MO.setReg(TRI->getSubReg(DestReg, SubIdx));
-  } else {
-    MO.setReg(DestReg);
-  }
+  MI->substituteRegister(MI->getOperand(0).getReg(), DestReg, SubIdx, TRI);
   MBB.insert(I, MI);
 }
 
diff --git a/lib/CodeGen/TwoAddressInstructionPass.cpp b/lib/CodeGen/TwoAddressInstructionPass.cpp
index cd475cc0a9..892ec623cc 100644
--- a/lib/CodeGen/TwoAddressInstructionPass.cpp
+++ b/lib/CodeGen/TwoAddressInstructionPass.cpp
@@ -1047,7 +1047,7 @@ bool TwoAddressInstructionPass::runOnMachineFunction(MachineFunction &MF) {
               isProfitableToReMat(regB, rc, mi, DefMI, mbbi, Dist)){
             DEBUG(dbgs() << "2addr: REMATTING : " << *DefMI << "\n");
             unsigned regASubIdx = mi->getOperand(DstIdx).getSubReg();
-            TII->reMaterialize(*mbbi, mi, regA, regASubIdx, DefMI, TRI);
+            TII->reMaterialize(*mbbi, mi, regA, regASubIdx, DefMI, *TRI);
             ReMatRegs.set(regB);
             ++NumReMats;
           } else {
diff --git a/lib/CodeGen/VirtRegRewriter.cpp b/lib/CodeGen/VirtRegRewriter.cpp
index 871d83628a..361d35e8a8 100644
--- a/lib/CodeGen/VirtRegRewriter.cpp
+++ b/lib/CodeGen/VirtRegRewriter.cpp
@@ -667,8 +667,7 @@ static void ReMaterialize(MachineBasicBlock &MBB,
   assert(TID.getNumDefs() == 1 &&
          "Don't know how to remat instructions that define > 1 values!");
 #endif
-  TII->reMaterialize(MBB, MII, DestReg,
-                     ReMatDefMI->getOperand(0).getSubReg(), ReMatDefMI, TRI);
+  TII->reMaterialize(MBB, MII, DestReg, 0, ReMatDefMI, *TRI);
   MachineInstr *NewMI = prior(MII);
   for (unsigned i = 0, e = NewMI->getNumOperands(); i != e; ++i) {
     MachineOperand &MO = NewMI->getOperand(i);