SystemZElimCompare.cpp File Reference

#include "SystemZ.h"
#include "SystemZInstrInfo.h"
#include "SystemZTargetMachine.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/CodeGen/LiveRegUnits.h"
#include "llvm/CodeGen/MachineBasicBlock.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineFunctionAnalysisManager.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineOperand.h"
#include "llvm/CodeGen/MachinePassManager.h"
#include "llvm/CodeGen/TargetRegisterInfo.h"
#include "llvm/CodeGen/TargetSubtargetInfo.h"
#include "llvm/IR/Analysis.h"
#include "llvm/MC/MCInstrDesc.h"
#include "llvm/Pass.h"
#include <cassert>
#include <cstdint>

Go to the source code of this file.

Macros
#define	DEBUG_TYPE   "systemz-elim-compare"

Functions
	STATISTIC (BranchOnCounts, "Number of branch-on-count instructions")
	STATISTIC (LoadAndTraps, "Number of load-and-trap instructions")
	STATISTIC (EliminatedComparisons, "Number of eliminated comparisons")
	STATISTIC (FusedComparisons, "Number of fused compare-and-branch instructions")
	INITIALIZE_PASS (SystemZElimCompareLegacy, DEBUG_TYPE, "SystemZ Comparison Elimination", false, false) static bool preservesValueOf(MachineInstr &MI
static bool	resultTests (MachineInstr &MI, unsigned Reg)
static Reference	getRegReferences (MachineInstr &MI, unsigned Reg, const TargetRegisterInfo *TRI)
static bool	convertToBRCT (MachineInstr &MI, MachineInstr &Compare, SmallVectorImpl< MachineInstr * > &CCUsers, const SystemZInstrInfo *TII, const TargetRegisterInfo *TRI)
static bool	convertToLoadAndTrap (MachineInstr &MI, MachineInstr &Compare, SmallVectorImpl< MachineInstr * > &CCUsers, const SystemZInstrInfo *TII, const TargetRegisterInfo *TRI)
static bool	isAddWithImmediate (unsigned Opcode)
static bool	adjustCCMasksForInstr (MachineInstr &MI, MachineInstr &Compare, SmallVectorImpl< MachineInstr * > &CCUsers, unsigned ConvOpc, const SystemZInstrInfo *TII, const TargetRegisterInfo *TRI)
static bool	convertToLoadAndTest (MachineInstr &MI, MachineInstr &Compare, SmallVectorImpl< MachineInstr * > &CCUsers, const SystemZInstrInfo *TII, const TargetRegisterInfo *TRI)
static bool	convertToLogical (MachineInstr &MI, MachineInstr &Compare, SmallVectorImpl< MachineInstr * > &CCUsers, const SystemZInstrInfo *TII, const TargetRegisterInfo *TRI)
static bool	optimizeCompareZero (MachineInstr &Compare, SmallVectorImpl< MachineInstr * > &CCUsers, const SystemZInstrInfo *TII, const TargetRegisterInfo *TRI)
static bool	fuseCompareOperations (MachineInstr &Compare, SmallVectorImpl< MachineInstr * > &CCUsers, const SystemZInstrInfo *TII, const TargetRegisterInfo *TRI)
static bool	processBlock (MachineBasicBlock &MBB, const SystemZInstrInfo *TII, const TargetRegisterInfo *TRI)
static bool	runElimCompareOnMF (MachineFunction &F)

Variables
unsigned	Reg

Macro Definition Documentation

DEBUG_TYPE

#define DEBUG_TYPE   "systemz-elim-compare"

Definition at line 40 of file SystemZElimCompare.cpp.

Function Documentation

adjustCCMasksForInstr()

bool adjustCCMasksForInstr ( MachineInstr & MI, MachineInstr & Compare, SmallVectorImpl< MachineInstr * > & CCUsers, unsigned ConvOpc, const SystemZInstrInfo * TII, const TargetRegisterInfo * TRI )

static

Definition at line 267 of file SystemZElimCompare.cpp.

References assert(), llvm::SystemZII::CCIfNoSignedWrap, llvm::SystemZ::CCMASK_ARITH_OVERFLOW, llvm::SystemZ::CCMASK_CMP_EQ, llvm::SystemZ::CCMASK_CMP_GT, llvm::SystemZ::CCMASK_CMP_LT, llvm::SystemZ::CCMASK_LOGICAL_NONZERO, llvm::SystemZ::CCMASK_LOGICAL_ZERO, llvm::SystemZII::CCMaskFirst, llvm::SystemZII::CCMaskLast, contains(), E(), llvm::SystemZII::getCCValues(), llvm::SystemZII::getCompareZeroCCMask(), I, isAddWithImmediate(), llvm::SystemZII::IsLogical, MBBI, MI, llvm::MachineInstr::NoSWrap, llvm::SmallVectorTemplateBase< T, bool >::push_back(), RHS, llvm::SmallVectorTemplateCommon< T, typename >::size(), TII, and TRI.

Referenced by convertToLoadAndTest(), convertToLogical(), and optimizeCompareZero().

convertToBRCT()

bool convertToBRCT ( MachineInstr & MI, MachineInstr & Compare, SmallVectorImpl< MachineInstr * > & CCUsers, const SystemZInstrInfo * TII, const TargetRegisterInfo * TRI )

static

Definition at line 144 of file SystemZElimCompare.cpp.

References llvm::MachineInstrBuilder::add(), llvm::MachineInstrBuilder::addReg(), llvm::SystemZ::CCMASK_CMP_NE, llvm::SystemZ::CCMASK_ICMP, llvm::Dead, getRegReferences(), llvm::ImplicitDefine, MBBI, MI, llvm::SmallVectorTemplateCommon< T, typename >::size(), TII, and TRI.

Referenced by optimizeCompareZero().

convertToLoadAndTest()

bool convertToLoadAndTest ( MachineInstr & MI, MachineInstr & Compare, SmallVectorImpl< MachineInstr * > & CCUsers, const SystemZInstrInfo * TII, const TargetRegisterInfo * TRI )

static

Definition at line 407 of file SystemZElimCompare.cpp.

References adjustCCMasksForInstr(), llvm::BuildMI(), MI, llvm::MachineInstr::NoFPExcept, TII, and TRI.

Referenced by optimizeCompareZero().

convertToLoadAndTrap()

bool convertToLoadAndTrap ( MachineInstr & MI, MachineInstr & Compare, SmallVectorImpl< MachineInstr * > & CCUsers, const SystemZInstrInfo * TII, const TargetRegisterInfo * TRI )

static

Definition at line 202 of file SystemZElimCompare.cpp.

References llvm::MachineInstrBuilder::add(), llvm::SystemZ::CCMASK_CMP_EQ, llvm::SystemZ::CCMASK_ICMP, getRegReferences(), MBBI, MI, llvm::SmallVectorTemplateCommon< T, typename >::size(), TII, and TRI.

Referenced by optimizeCompareZero().

convertToLogical()

bool convertToLogical ( MachineInstr & MI, MachineInstr & Compare, SmallVectorImpl< MachineInstr * > & CCUsers, const SystemZInstrInfo * TII, const TargetRegisterInfo * TRI )

static

Definition at line 439 of file SystemZElimCompare.cpp.

References adjustCCMasksForInstr(), MI, TII, and TRI.

Referenced by optimizeCompareZero().

fuseCompareOperations()

bool fuseCompareOperations ( MachineInstr & Compare, SmallVectorImpl< MachineInstr * > & CCUsers, const SystemZInstrInfo * TII, const TargetRegisterInfo * TRI )

static

Definition at line 562 of file SystemZElimCompare.cpp.

References llvm::MachineInstrBuilder::add(), llvm::MachineInstrBuilder::addReg(), llvm::MachineInstrBuilder::addRegMask(), assert(), llvm::SystemZ::CCMASK_ICMP, llvm::SystemZII::CompareAndBranch, llvm::SystemZII::CompareAndReturn, llvm::SystemZII::CompareAndSibcall, llvm::SystemZII::CompareAndTrap, llvm::Dead, llvm::MachineOperand::getImm(), I, llvm::ImplicitDefine, MBBI, Register, llvm::SmallVectorTemplateCommon< T, typename >::size(), TII, and TRI.

Referenced by processBlock().

getRegReferences()

Reference getRegReferences ( MachineInstr & MI, unsigned Reg, const TargetRegisterInfo * TRI )

static

Definition at line 120 of file SystemZElimCompare.cpp.

References MI, llvm::Ref, Reg, and TRI.

Referenced by convertToBRCT(), convertToLoadAndTrap(), and optimizeCompareZero().

INITIALIZE_PASS()

INITIALIZE_PASS	(	SystemZElimCompareLegacy	,
		DEBUG_TYPE	,
		"SystemZ Comparison Elimination"	,
		false	,
		false	) &

References DEBUG_TYPE.

isAddWithImmediate()

bool isAddWithImmediate ( unsigned Opcode )

static

Definition at line 245 of file SystemZElimCompare.cpp.

Referenced by adjustCCMasksForInstr().

optimizeCompareZero()

bool optimizeCompareZero ( MachineInstr & Compare, SmallVectorImpl< MachineInstr * > & CCUsers, const SystemZInstrInfo * TII, const TargetRegisterInfo * TRI )

static

Definition at line 485 of file SystemZElimCompare.cpp.

References adjustCCMasksForInstr(), convertToBRCT(), convertToLoadAndTest(), convertToLoadAndTrap(), convertToLogical(), getRegReferences(), llvm::make_early_inc_range(), llvm::make_range(), MBB, MBBI, MI, resultTests(), TII, and TRI.

Referenced by processBlock().

processBlock()

bool processBlock ( MachineBasicBlock & MBB, const SystemZInstrInfo * TII, const TargetRegisterInfo * TRI )

static

Definition at line 671 of file SystemZElimCompare.cpp.

References Changed, llvm::SmallVectorImpl< T >::clear(), fuseCompareOperations(), MBB, MBBI, MI, optimizeCompareZero(), llvm::SmallVectorTemplateBase< T, bool >::push_back(), TII, and TRI.

Referenced by runElimCompareOnMF().

resultTests()

bool resultTests ( MachineInstr & MI, unsigned Reg )

static

Definition at line 111 of file SystemZElimCompare.cpp.

References MI, and Reg.

Referenced by optimizeCompareZero().

runElimCompareOnMF()

bool runElimCompareOnMF ( MachineFunction & F )

static

Definition at line 705 of file SystemZElimCompare.cpp.

References Changed, F, MBB, processBlock(), TII, and TRI.

Referenced by llvm::SystemZElimComparePass::run().

STATISTIC() [1/4]

STATISTIC	(	BranchOnCounts	,
		"Number of branch-on-count instructions"	)

STATISTIC() [2/4]

STATISTIC	(	EliminatedComparisons	,
		"Number of eliminated comparisons"	)

STATISTIC() [3/4]

STATISTIC	(	FusedComparisons	,
		"Number of fused compare-and-branch instructions"	)

References llvm::Other.

STATISTIC() [4/4]

STATISTIC	(	LoadAndTraps	,
		"Number of load-and-trap instructions"	)

Variable Documentation

Reg

unsigned Reg

Initial value:

{
  switch (MI.getOpcode()) {
  case SystemZ::LR:
  case SystemZ::LGR:
  case SystemZ::LGFR:
  case SystemZ::LTR:
  case SystemZ::LTGR:
  case SystemZ::LTGFR:
    if (MI.getOperand(1).getReg() == Reg)
      return true;
  }
 
  return false

Definition at line 94 of file SystemZElimCompare.cpp.