[llvm-branch-commits] [llvm-branch] r106519 - in /llvm/branches/Apple/Troughton: include/llvm/Target/TargetInstrInfo.h lib/CodeGen/BranchFolding.cpp lib/CodeGen/BranchFolding.h lib/CodeGen/TargetInstrInfoImpl.cpp lib/Target/ARM/Thumb2ITBlockPass.cpp lib/Target/ARM/Thumb2InstrInfo.cpp lib/Target/ARM/Thumb2InstrInfo.h test/CodeGen/Thumb2/2010-06-21-TailMergeBug.ll

Evan Cheng evan.cheng at apple.com
Mon Jun 21 18:22:43 PDT 2010


Author: evancheng
Date: Mon Jun 21 20:22:43 2010
New Revision: 106519

URL: http://llvm.org/viewvc/llvm-project?rev=106519&view=rev
Log:
Merge 106517.

Added:
    llvm/branches/Apple/Troughton/test/CodeGen/Thumb2/2010-06-21-TailMergeBug.ll
      - copied unchanged from r106517, llvm/trunk/test/CodeGen/Thumb2/2010-06-21-TailMergeBug.ll
Modified:
    llvm/branches/Apple/Troughton/include/llvm/Target/TargetInstrInfo.h
    llvm/branches/Apple/Troughton/lib/CodeGen/BranchFolding.cpp
    llvm/branches/Apple/Troughton/lib/CodeGen/BranchFolding.h
    llvm/branches/Apple/Troughton/lib/CodeGen/TargetInstrInfoImpl.cpp
    llvm/branches/Apple/Troughton/lib/Target/ARM/Thumb2ITBlockPass.cpp
    llvm/branches/Apple/Troughton/lib/Target/ARM/Thumb2InstrInfo.cpp
    llvm/branches/Apple/Troughton/lib/Target/ARM/Thumb2InstrInfo.h

Modified: llvm/branches/Apple/Troughton/include/llvm/Target/TargetInstrInfo.h
URL: http://llvm.org/viewvc/llvm-project/llvm/branches/Apple/Troughton/include/llvm/Target/TargetInstrInfo.h?rev=106519&r1=106518&r2=106519&view=diff
==============================================================================
--- llvm/branches/Apple/Troughton/include/llvm/Target/TargetInstrInfo.h (original)
+++ llvm/branches/Apple/Troughton/include/llvm/Target/TargetInstrInfo.h Mon Jun 21 20:22:43 2010
@@ -326,6 +326,14 @@
   /// used by the tail merging pass.
   virtual void ReplaceTailWithBranchTo(MachineBasicBlock::iterator Tail,
                                        MachineBasicBlock *NewDest) const = 0;
+
+  /// isLegalToSplitMBBAt - Return true if it's legal to split the given basic
+  /// block at the specified instruction (i.e. instruction would be the start
+  /// of a new basic block).
+  virtual bool isLegalToSplitMBBAt(MachineBasicBlock &MBB,
+                                   MachineBasicBlock::iterator MBBI) const {
+    return true;
+  }
   
   /// copyRegToReg - Emit instructions to copy between a pair of registers. It
   /// returns false if the target does not how to copy between the specified

Modified: llvm/branches/Apple/Troughton/lib/CodeGen/BranchFolding.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/branches/Apple/Troughton/lib/CodeGen/BranchFolding.cpp?rev=106519&r1=106518&r2=106519&view=diff
==============================================================================
--- llvm/branches/Apple/Troughton/lib/CodeGen/BranchFolding.cpp (original)
+++ llvm/branches/Apple/Troughton/lib/CodeGen/BranchFolding.cpp Mon Jun 21 20:22:43 2010
@@ -370,6 +370,9 @@
 /// iterator.  This returns the new MBB.
 MachineBasicBlock *BranchFolder::SplitMBBAt(MachineBasicBlock &CurMBB,
                                             MachineBasicBlock::iterator BBI1) {
+  if (!TII->isLegalToSplitMBBAt(CurMBB, BBI1))
+    return 0;
+
   MachineFunction &MF = *CurMBB.getParent();
 
   // Create the fall-through block.
@@ -612,9 +615,10 @@
 
 /// CreateCommonTailOnlyBlock - None of the blocks to be tail-merged consist
 /// only of the common tail.  Create a block that does by splitting one.
-unsigned BranchFolder::CreateCommonTailOnlyBlock(MachineBasicBlock *&PredBB,
-                                             unsigned maxCommonTailLength) {
-  unsigned commonTailIndex = 0;
+bool BranchFolder::CreateCommonTailOnlyBlock(MachineBasicBlock *&PredBB,
+                                             unsigned maxCommonTailLength,
+                                             unsigned &commonTailIndex) {
+  commonTailIndex = 0;
   unsigned TimeEstimate = ~0U;
   for (unsigned i = 0, e = SameTails.size(); i != e; ++i) {
     // Use PredBB if possible; that doesn't require a new branch.
@@ -642,6 +646,11 @@
                << maxCommonTailLength);
 
   MachineBasicBlock *newMBB = SplitMBBAt(*MBB, BBI);
+  if (!newMBB) {
+    DEBUG(dbgs() << "... failed!");
+    return false;
+  }
+
   SameTails[commonTailIndex].setBlock(newMBB);
   SameTails[commonTailIndex].setTailStartPos(newMBB->begin());
 
@@ -649,7 +658,7 @@
   if (PredBB == MBB)
     PredBB = newMBB;
 
-  return commonTailIndex;
+  return true;
 }
 
 // See if any of the blocks in MergePotentials (which all have a common single
@@ -744,7 +753,11 @@
          !SameTails[commonTailIndex].tailIsWholeBlock())) {
       // None of the blocks consist entirely of the common tail.
       // Split a block so that one does.
-      commonTailIndex = CreateCommonTailOnlyBlock(PredBB, maxCommonTailLength);
+      if (!CreateCommonTailOnlyBlock(PredBB,
+                                     maxCommonTailLength, commonTailIndex)) {
+        RemoveBlocksWithHash(CurHash, SuccBB, PredBB);
+        continue;
+      }
     }
 
     MachineBasicBlock *MBB = SameTails[commonTailIndex].getBlock();

Modified: llvm/branches/Apple/Troughton/lib/CodeGen/BranchFolding.h
URL: http://llvm.org/viewvc/llvm-project/llvm/branches/Apple/Troughton/lib/CodeGen/BranchFolding.h?rev=106519&r1=106518&r2=106519&view=diff
==============================================================================
--- llvm/branches/Apple/Troughton/lib/CodeGen/BranchFolding.h (original)
+++ llvm/branches/Apple/Troughton/lib/CodeGen/BranchFolding.h Mon Jun 21 20:22:43 2010
@@ -102,8 +102,9 @@
                               MachineBasicBlock *PredBB);
     void RemoveBlocksWithHash(unsigned CurHash, MachineBasicBlock* SuccBB,
                                                 MachineBasicBlock* PredBB);
-    unsigned CreateCommonTailOnlyBlock(MachineBasicBlock *&PredBB,
-                                       unsigned maxCommonTailLength);
+    bool CreateCommonTailOnlyBlock(MachineBasicBlock *&PredBB,
+                                   unsigned maxCommonTailLength,
+                                   unsigned &commonTailIndex);
 
     bool OptimizeBranches(MachineFunction &MF);
     bool OptimizeBlock(MachineBasicBlock *MBB);

Modified: llvm/branches/Apple/Troughton/lib/CodeGen/TargetInstrInfoImpl.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/branches/Apple/Troughton/lib/CodeGen/TargetInstrInfoImpl.cpp?rev=106519&r1=106518&r2=106519&view=diff
==============================================================================
--- llvm/branches/Apple/Troughton/lib/CodeGen/TargetInstrInfoImpl.cpp (original)
+++ llvm/branches/Apple/Troughton/lib/CodeGen/TargetInstrInfoImpl.cpp Mon Jun 21 20:22:43 2010
@@ -28,6 +28,8 @@
 #include "llvm/Support/raw_ostream.h"
 using namespace llvm;
 
+/// ReplaceTailWithBranchTo - Delete the instruction OldInst and everything
+/// after it, replacing it with an unconditional branch to NewDest.
 void
 TargetInstrInfoImpl::ReplaceTailWithBranchTo(MachineBasicBlock::iterator Tail,
                                              MachineBasicBlock *NewDest) const {

Modified: llvm/branches/Apple/Troughton/lib/Target/ARM/Thumb2ITBlockPass.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/branches/Apple/Troughton/lib/Target/ARM/Thumb2ITBlockPass.cpp?rev=106519&r1=106518&r2=106519&view=diff
==============================================================================
--- llvm/branches/Apple/Troughton/lib/Target/ARM/Thumb2ITBlockPass.cpp (original)
+++ llvm/branches/Apple/Troughton/lib/Target/ARM/Thumb2ITBlockPass.cpp Mon Jun 21 20:22:43 2010
@@ -62,13 +62,6 @@
   char Thumb2ITBlockPass::ID = 0;
 }
 
-static ARMCC::CondCodes getPredicate(const MachineInstr *MI, unsigned &PredReg){
-  unsigned Opc = MI->getOpcode();
-  if (Opc == ARM::tBcc || Opc == ARM::t2Bcc)
-    return ARMCC::AL;
-  return llvm::getInstrPredicate(MI, PredReg);
-}
-
 bool
 Thumb2ITBlockPass::MoveCPSRUseUp(MachineBasicBlock &MBB,
                                  MachineBasicBlock::iterator MBBI,
@@ -82,7 +75,7 @@
   for (unsigned i = 0; i < 4; ++i) {
     MachineInstr *MI = &*I;
     unsigned MPredReg = 0;
-    ARMCC::CondCodes MCC = getPredicate(MI, MPredReg);
+    ARMCC::CondCodes MCC = llvm::getITInstrPredicate(MI, MPredReg);
     if (MCC != ARMCC::AL) {
       if (MPredReg != PredReg || (MCC != CC && MCC != OCC))
         return false;
@@ -209,7 +202,7 @@
     return false;
 
   unsigned PredReg = 0;
-  ARMCC::CondCodes CC = getPredicate(First, PredReg);
+  ARMCC::CondCodes CC = llvm::getITInstrPredicate(First, PredReg);
   if (CC == ARMCC::AL)
     return Modified;
 
@@ -222,7 +215,7 @@
       return Modified;
     MachineInstr *NMI = &*MBBI;
     unsigned NPredReg = 0;
-    ARMCC::CondCodes NCC = getPredicate(NMI, NPredReg);
+    ARMCC::CondCodes NCC = llvm::getITInstrPredicate(NMI, NPredReg);
     if (NCC != CC && NCC != OCC) {
       if (NCC != ARMCC::AL)
         return Modified;
@@ -321,7 +314,7 @@
       while (I != E && I->isDebugValue())
         ++I;
       unsigned NPredReg = 0;
-      ARMCC::CondCodes NCC = getPredicate(I, NPredReg);
+      ARMCC::CondCodes NCC = llvm::getITInstrPredicate(I, NPredReg);
       if (NCC == CC || NCC == OCC)
         return true;
     }
@@ -339,7 +332,7 @@
     MachineInstr *MI = &*MBBI;
     DebugLoc dl = MI->getDebugLoc();
     unsigned PredReg = 0;
-    ARMCC::CondCodes CC = getPredicate(MI, PredReg);
+    ARMCC::CondCodes CC = llvm::getITInstrPredicate(MI, PredReg);
     if (CC == ARMCC::AL) {
       ++MBBI;
       continue;
@@ -375,7 +368,7 @@
       MI = NMI;
 
       unsigned NPredReg = 0;
-      ARMCC::CondCodes NCC = getPredicate(NMI, NPredReg);
+      ARMCC::CondCodes NCC = llvm::getITInstrPredicate(NMI, NPredReg);
       if (NCC == CC || NCC == OCC) {
         Mask |= (NCC & 1) << Pos;
         // Add implicit use of ITSTATE.

Modified: llvm/branches/Apple/Troughton/lib/Target/ARM/Thumb2InstrInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/branches/Apple/Troughton/lib/Target/ARM/Thumb2InstrInfo.cpp?rev=106519&r1=106518&r2=106519&view=diff
==============================================================================
--- llvm/branches/Apple/Troughton/lib/Target/ARM/Thumb2InstrInfo.cpp (original)
+++ llvm/branches/Apple/Troughton/lib/Target/ARM/Thumb2InstrInfo.cpp Mon Jun 21 20:22:43 2010
@@ -88,6 +88,14 @@
 }
 
 bool
+Thumb2InstrInfo::isLegalToSplitMBBAt(MachineBasicBlock &MBB,
+                                     MachineBasicBlock::iterator MBBI) const {
+  unsigned PredReg = 0;
+  return llvm::getITInstrPredicate(MBBI, PredReg) == ARMCC::AL;
+}
+
+
+bool
 Thumb2InstrInfo::copyRegToReg(MachineBasicBlock &MBB,
                               MachineBasicBlock::iterator I,
                               unsigned DestReg, unsigned SrcReg,
@@ -605,3 +613,11 @@
     MBB->insert(++MBBI, SrcMI);
   }
 }
+
+ARMCC::CondCodes
+llvm::getITInstrPredicate(const MachineInstr *MI, unsigned &PredReg) {
+  unsigned Opc = MI->getOpcode();
+  if (Opc == ARM::tBcc || Opc == ARM::t2Bcc)
+    return ARMCC::AL;
+  return llvm::getInstrPredicate(MI, PredReg);
+}

Modified: llvm/branches/Apple/Troughton/lib/Target/ARM/Thumb2InstrInfo.h
URL: http://llvm.org/viewvc/llvm-project/llvm/branches/Apple/Troughton/lib/Target/ARM/Thumb2InstrInfo.h?rev=106519&r1=106518&r2=106519&view=diff
==============================================================================
--- llvm/branches/Apple/Troughton/lib/Target/ARM/Thumb2InstrInfo.h (original)
+++ llvm/branches/Apple/Troughton/lib/Target/ARM/Thumb2InstrInfo.h Mon Jun 21 20:22:43 2010
@@ -35,6 +35,9 @@
   void ReplaceTailWithBranchTo(MachineBasicBlock::iterator Tail,
                                MachineBasicBlock *NewDest) const;
 
+  bool isLegalToSplitMBBAt(MachineBasicBlock &MBB,
+                           MachineBasicBlock::iterator MBBI) const;
+
   bool copyRegToReg(MachineBasicBlock &MBB,
                     MachineBasicBlock::iterator I,
                     unsigned DestReg, unsigned SrcReg,
@@ -68,6 +71,13 @@
   ScheduleHazardRecognizer *
   CreateTargetPostRAHazardRecognizer(const InstrItineraryData &II) const;
 };
+
+/// getITInstrPredicate - Valid only in Thumb2 mode. This function is identical
+/// to llvm::getInstrPredicate except it returns AL for conditional branch
+/// instructions which are "predicated", but are not in IT blocks.
+ARMCC::CondCodes getITInstrPredicate(const MachineInstr *MI, unsigned &PredReg);
+
+
 }
 
 #endif // THUMB2INSTRUCTIONINFO_H





More information about the llvm-branch-commits mailing list