[llvm-commits] CVS: llvm/lib/Target/Alpha/AlphaLLRP.cpp Alpha.h AlphaTargetMachine.cpp

Andrew Lenharth alenhar2 at cs.uiuc.edu
Mon Sep 18 12:44:44 PDT 2006



Changes in directory llvm/lib/Target/Alpha:

AlphaLLRP.cpp added (r1.1)
Alpha.h updated: 1.6 -> 1.7
AlphaTargetMachine.cpp updated: 1.31 -> 1.32
---
Log message:

A pass to remove the worst of the replay trap offenders, and as a bonus, align basic blocks when it is free to do so

---
Diffs of the changes:  (+146 -0)

 Alpha.h                |    2 
 AlphaLLRP.cpp          |  143 +++++++++++++++++++++++++++++++++++++++++++++++++
 AlphaTargetMachine.cpp |    1 
 3 files changed, 146 insertions(+)


Index: llvm/lib/Target/Alpha/AlphaLLRP.cpp
diff -c /dev/null llvm/lib/Target/Alpha/AlphaLLRP.cpp:1.1
*** /dev/null	Mon Sep 18 14:44:39 2006
--- llvm/lib/Target/Alpha/AlphaLLRP.cpp	Mon Sep 18 14:44:29 2006
***************
*** 0 ****
--- 1,143 ----
+ //===-- AlphaLLRP.cpp - Alpha Load Load Replay Trap elimination pass. -- --===//
+ //
+ //                     The LLVM Compiler Infrastructure
+ //
+ // This file was developed by Andrew Lenharth and is distributed under the
+ // University of Illinois Open Source License. See LICENSE.TXT for details.
+ //
+ //===----------------------------------------------------------------------===//
+ //
+ // Here we check for potential replay traps introduced by the spiller
+ // We also align some branch targets if we can do so for free
+ //===----------------------------------------------------------------------===//
+ 
+ 
+ #include "Alpha.h"
+ #include "llvm/CodeGen/MachineFunctionPass.h"
+ #include "llvm/CodeGen/MachineInstrBuilder.h"
+ #include "llvm/ADT/SetOperations.h"
+ #include "llvm/ADT/Statistic.h"
+ #include "llvm/Support/CommandLine.h"
+ using namespace llvm;
+ 
+ namespace {
+   Statistic<> nopintro("alpha-nops", "Number of nops inserted");
+   Statistic<> nopalign("alpha-nops-align", 
+ 		       "Number of nops inserted for alignment");
+ 
+   cl::opt<bool>
+   AlignAll("alpha-align-all", cl::Hidden,
+                    cl::desc("Align all blocks"));
+ 
+   struct AlphaLLRPPass : public MachineFunctionPass {
+     /// Target machine description which we query for reg. names, data
+     /// layout, etc.
+     ///
+     AlphaTargetMachine &TM;
+ 
+     AlphaLLRPPass(AlphaTargetMachine &tm) : TM(tm) { }
+ 
+     virtual const char *getPassName() const {
+       return "Alpha NOP inserter";
+     }
+ 
+     bool runOnMachineFunction(MachineFunction &F) {
+       bool Changed = false;
+       MachineInstr* prev[3] = {0,0,0};
+       unsigned count = 0;
+       for (MachineFunction::iterator FI = F.begin(), FE = F.end();
+            FI != FE; ++FI) {
+ 	MachineBasicBlock& MBB = *FI;
+ 	bool ub = false;
+ 	  for (MachineBasicBlock::iterator I = MBB.begin(); I != MBB.end(); ) {
+ 	    if (count%4 == 0)
+ 	      prev[0] = prev[1] = prev[2] = 0; //Slots cleared at fetch boundary
+ 	    ++count;
+ 	    MachineInstr *MI = I++;
+ 	    switch (MI->getOpcode()) {
+ 	    case Alpha::LDQ:  case Alpha::LDL:
+ 	    case Alpha::LDWU: case Alpha::LDBU:
+ 	    case Alpha::LDT: case Alpha::LDS:
+ 	      
+ 	    case Alpha::STQ:  case Alpha::STL:
+ 	    case Alpha::STW:  case Alpha::STB:
+ 	    case Alpha::STT: case Alpha::STS:
+ 	      if (MI->getOperand(2).getReg() == Alpha::R30) {
+ 		if (prev[0] 
+ 		    && prev[0]->getOperand(2).getReg() == 
+ 		    MI->getOperand(2).getReg()
+ 		    && prev[0]->getOperand(1).getImmedValue() == 
+ 		    MI->getOperand(1).getImmedValue()) {
+ 		  prev[0] = prev[1];
+ 		  prev[1] = prev[2];
+ 		  prev[2] = 0;
+ 		  BuildMI(MBB, MI, Alpha::BIS, 2, Alpha::R31).addReg(Alpha::R31)
+ 		    .addReg(Alpha::R31); 
+ 		  Changed = true; nopintro += 1;
+ 		  count += 1;
+ 		} else if (prev[1] 
+ 			   && prev[1]->getOperand(2).getReg() == 
+ 			   MI->getOperand(2).getReg()
+ 			   && prev[1]->getOperand(1).getImmedValue() == 
+ 			   MI->getOperand(1).getImmedValue()) {
+ 		  prev[0] = prev[2];
+ 		  prev[1] = prev[2] = 0;
+ 		  BuildMI(MBB, MI, Alpha::BIS, 2, Alpha::R31).addReg(Alpha::R31)
+ 		    .addReg(Alpha::R31); 
+ 		  BuildMI(MBB, MI, Alpha::BIS, 2, Alpha::R31).addReg(Alpha::R31)
+ 		    .addReg(Alpha::R31);
+ 		  Changed = true; nopintro += 2;
+ 		  count += 2;
+ 		} else if (prev[2] 
+ 			   && prev[2]->getOperand(2).getReg() == 
+ 			   MI->getOperand(2).getReg()
+ 			   && prev[2]->getOperand(1).getImmedValue() == 
+ 			   MI->getOperand(1).getImmedValue()) {
+ 		  prev[0] = prev[1] = prev[2] = 0;
+ 		  BuildMI(MBB, MI, Alpha::BIS, 2, Alpha::R31).addReg(Alpha::R31)
+ 		    .addReg(Alpha::R31);
+ 		  BuildMI(MBB, MI, Alpha::BIS, 2, Alpha::R31).addReg(Alpha::R31)
+ 		    .addReg(Alpha::R31);
+ 		  BuildMI(MBB, MI, Alpha::BIS, 2, Alpha::R31).addReg(Alpha::R31)
+ 		    .addReg(Alpha::R31);
+ 		  Changed = true; nopintro += 3;
+ 		  count += 3;
+ 		}
+ 		prev[0] = prev[1];
+ 		prev[1] = prev[2];
+ 		prev[2] = MI;
+ 		break;
+ 	      }
+ 	      //fall through
+ 	    case Alpha::BR:
+ 	    case Alpha::JMP:
+ 	      ub = true;
+ 	      //fall through
+ 	    default:
+ 	      prev[0] = prev[1];
+ 	      prev[1] = prev[2];
+ 	      prev[2] = 0;
+ 	      break;
+ 	    }
+ 	  }
+ 	  if (ub || AlignAll) {
+ 	    //we can align stuff for free at this point
+ 	    while (count % 4) {
+ 	      BuildMI(MBB, MBB.end(), Alpha::BIS, 2, Alpha::R31)
+ 		.addReg(Alpha::R31).addReg(Alpha::R31);
+ 	      ++count;
+ 	      ++nopalign;
+ 	      prev[0] = prev[1];
+ 	      prev[1] = prev[2];
+ 	      prev[2] = 0;
+ 	    }
+ 	  }
+       }
+       return Changed;
+     }
+   };
+ } // end of anonymous namespace
+ 
+ FunctionPass *llvm::createAlphaLLRPPass(AlphaTargetMachine &tm) {
+   return new AlphaLLRPPass(tm);
+ }


Index: llvm/lib/Target/Alpha/Alpha.h
diff -u llvm/lib/Target/Alpha/Alpha.h:1.6 llvm/lib/Target/Alpha/Alpha.h:1.7
--- llvm/lib/Target/Alpha/Alpha.h:1.6	Tue Jul 25 15:40:54 2006
+++ llvm/lib/Target/Alpha/Alpha.h	Mon Sep 18 14:44:29 2006
@@ -31,6 +31,8 @@
   FunctionPass *createAlphaPatternInstructionSelector(TargetMachine &TM);
   FunctionPass *createAlphaCodeEmitterPass(AlphaTargetMachine &TM,
                                            MachineCodeEmitter &MCE);
+  FunctionPass *createAlphaLLRPPass(AlphaTargetMachine &tm);
+
 } // end namespace llvm;
 
 // Defines symbolic names for Alpha registers.  This defines a mapping from


Index: llvm/lib/Target/Alpha/AlphaTargetMachine.cpp
diff -u llvm/lib/Target/Alpha/AlphaTargetMachine.cpp:1.31 llvm/lib/Target/Alpha/AlphaTargetMachine.cpp:1.32
--- llvm/lib/Target/Alpha/AlphaTargetMachine.cpp:1.31	Thu Sep  7 18:39:26 2006
+++ llvm/lib/Target/Alpha/AlphaTargetMachine.cpp	Mon Sep 18 14:44:29 2006
@@ -77,6 +77,7 @@
 }
 bool AlphaTargetMachine::addAssemblyEmitter(FunctionPassManager &PM, bool Fast, 
                                             std::ostream &Out) {
+  PM.add(createAlphaLLRPPass(*this));
   PM.add(createAlphaCodePrinterPass(Out, *this));
   return false;
 }






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