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authorChandler Carruth <chandlerc@gmail.com>2012-04-18 21:31:19 +0000
committerChandler Carruth <chandlerc@gmail.com>2012-04-18 21:31:19 +0000
commit37097623bbde5420f81ab8d1d056700f8f258025 (patch)
treeb28d967c37df1d3285d5ea35ea098a70e3a2e03b /lib/Target/Hexagon/HexagonCopyToCombine.cpp
parent722b6f18536a1b23a03bfb55440f098da0a7762d (diff)
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This reverts a long string of commits to the Hexagon backend. These
commits have had several major issues pointed out in review, and those issues are not being addressed in a timely fashion. Furthermore, this was all committed leading up to the v3.1 branch, and we don't need piles of code with outstanding issues in the branch. It is possible that not all of these commits were necessary to revert to get us back to a green state, but I'm going to let the Hexagon maintainer sort that out. They can recommit, in order, after addressing the feedback. Reverted commits, with some notes: Primary commit r154616: HexagonPacketizer - There are lots of review comments here. This is the primary reason for reverting. In particular, it introduced large amount of warnings due to a bad construct in tablegen. - Follow-up commits that should be folded back into this when reposting: - r154622: CMake fixes - r154660: Fix numerous build warnings in release builds. - Please don't resubmit this until the three commits above are included, and the issues in review addressed. Primary commit r154695: Pass to replace transfer/copy ... - Reverted to minimize merge conflicts. I'm not aware of specific issues with this patch. Primary commit r154703: New Value Jump. - Primarily reverted due to merge conflicts. - Follow-up commits that should be folded back into this when reposting: - r154703: Remove iostream usage - r154758: Fix CMake builds - r154759: Fix build warnings in release builds - Please incorporate these fixes and and review feedback before resubmitting. Primary commit r154829: Hexagon V5 (floating point) support. - Primarily reverted due to merge conflicts. - Follow-up commits that should be folded back into this when reposting: - r154841: Remove unused variable (fixing build warnings) There are also accompanying Clang commits that will be reverted for consistency. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@155047 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Target/Hexagon/HexagonCopyToCombine.cpp')
-rw-r--r--lib/Target/Hexagon/HexagonCopyToCombine.cpp475
1 files changed, 0 insertions, 475 deletions
diff --git a/lib/Target/Hexagon/HexagonCopyToCombine.cpp b/lib/Target/Hexagon/HexagonCopyToCombine.cpp
deleted file mode 100644
index e93d278c82..0000000000
--- a/lib/Target/Hexagon/HexagonCopyToCombine.cpp
+++ /dev/null
@@ -1,475 +0,0 @@
-//===------- HexagonCopyToCombine.cpp - Hexagon Copy-To-Combine Pass ------===//
-//
-// The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-// This pass replaces transfer instructions by combine instructions.
-// We walk along a basic block and look for two combinable instructions and try
-// to move them together. If we can move them next to each other we do so and
-// replace them with a combine instruction.
-//===----------------------------------------------------------------------===//
-#define DEBUG_TYPE "hexagon-copy-combine"
-
-#include "llvm/PassSupport.h"
-#include "llvm/CodeGen/Passes.h"
-#include "llvm/CodeGen/MachineBasicBlock.h"
-#include "llvm/CodeGen/MachineFunction.h"
-#include "llvm/CodeGen/MachineFunctionPass.h"
-#include "llvm/CodeGen/MachineInstr.h"
-#include "llvm/CodeGen/MachineInstrBuilder.h"
-#include "llvm/Target/TargetRegisterInfo.h"
-#include "llvm/Support/CommandLine.h"
-#include "llvm/Support/Debug.h"
-#include "llvm/Support/raw_ostream.h"
-
-#include "Hexagon.h"
-#include "HexagonInstrInfo.h"
-#include "HexagonRegisterInfo.h"
-#include "HexagonSubtarget.h"
-#include "HexagonTargetMachine.h"
-#include "HexagonMachineFunctionInfo.h"
-
-using namespace llvm;
-
-static
-cl::opt<bool> IsCombinesDisabled("disable-merge-into-combines",
- cl::Hidden, cl::ZeroOrMore,
- cl::init(false),
- cl::desc("Disable merging into combines"));
-
-namespace {
-
-class HexagonCopyToCombine : public MachineFunctionPass {
- const HexagonInstrInfo *TII;
- const TargetRegisterInfo *TRI;
-public:
- static char ID;
-
- HexagonCopyToCombine() : MachineFunctionPass(ID) { }
-
- virtual void getAnalysisUsage(AnalysisUsage &AU) const {
- MachineFunctionPass::getAnalysisUsage(AU);
- }
-
- const char *getPassName() const {
- return "Hexagon Copy-To-Combine Pass";
- }
-
- virtual bool runOnMachineFunction(MachineFunction &Fn);
-
-private:
- MachineInstr *findPairable(MachineInstr *I1, bool &DoInsertAtI1);
-
- void combine(MachineInstr *I1, MachineInstr *I2,
- MachineBasicBlock::iterator &MI, bool DoInsertAtI1);
-
- bool isSafeToMoveTogether(MachineInstr *I1, MachineInstr *I2,
- unsigned I1DestReg, unsigned I2DestReg,
- bool &DoInsertAtI1);
-
- void emitCombineRR(MachineBasicBlock::iterator &Before, unsigned DestReg,
- MachineOperand &HiOperand, MachineOperand &LoOperand);
-
- void emitCombineRI(MachineBasicBlock::iterator &Before, unsigned DestReg,
- MachineOperand &HiOperand, MachineOperand &LoOperand);
-
- void emitCombineIR(MachineBasicBlock::iterator &Before, unsigned DestReg,
- MachineOperand &HiOperand, MachineOperand &LoOperand);
-
- void emitCombineII(MachineBasicBlock::iterator &Before, unsigned DestReg,
- MachineOperand &HiOperand, MachineOperand &LoOperand);
-};
-
-} // End anonymous namespace.
-
-char HexagonCopyToCombine::ID = 0;
-
-static bool isCombinableInstType(MachineInstr *MI,
- const HexagonInstrInfo *TII) {
- switch(MI->getOpcode()) {
- case Hexagon::TFR: {
- // A COPY instruction can be combined if its arguments are IntRegs (32bit).
- assert(MI->getOperand(0).isReg() && MI->getOperand(1).isReg());
-
- unsigned DestReg = MI->getOperand(0).getReg();
- unsigned SrcReg = MI->getOperand(1).getReg();
- return Hexagon::IntRegsRegClass.contains(DestReg) &&
- Hexagon::IntRegsRegClass.contains(SrcReg);
- }
-
- case Hexagon::TFRI: {
- // A transfer-immediate can be combined if its argument is a signed 8bit
- // value.
- assert(MI->getOperand(0).isReg() && MI->getOperand(1).isImm());
- unsigned DestReg = MI->getOperand(0).getReg();
- return Hexagon::IntRegsRegClass.contains(DestReg) &&
- isInt<8>(MI->getOperand(1).getImm());
- }
- default:
- break;
- }
-
- return false;
-}
-
-
-/// areCombinableOperations - Returns true if the two instruction can be merge
-/// into a combine (ignoring register constraints).
-static bool areCombinableOperations(const TargetRegisterInfo *TRI,
- MachineInstr *I1, MachineInstr *I2) {
- assert((I1->getOpcode() == Hexagon::TFR ||
- I1->getOpcode() == Hexagon::TFRI) &&
- (I2->getOpcode() == Hexagon::TFR ||
- I2->getOpcode() == Hexagon::TFRI) &&
- "Assume individual instructions are of a combinable type");
-
- const HexagonRegisterInfo *QRI =
- static_cast<const HexagonRegisterInfo *>(TRI);
-
- // V4 added some combine variations (mixed immediate and register source
- // operands), if we are on < V4 we can only combine 2 register-to-register
- // moves and 2 immediate-to-register moves.
- if (QRI->Subtarget.getHexagonArchVersion() < HexagonSubtarget::V4)
- return I1->getOpcode() == I2->getOpcode();
-
- return true;
-}
-
-static bool isEvenReg(unsigned Reg) {
- assert(TargetRegisterInfo::isPhysicalRegister(Reg) &&
- Hexagon::IntRegsRegClass.contains(Reg));
- return (Reg - Hexagon::R0) % 2 == 0;
-}
-
-static void removeKillInfo(MachineInstr *MI, unsigned RegNotKilled) {
- for (unsigned I = 0, E = MI->getNumOperands(); I != E; ++I) {
- MachineOperand &Op = MI->getOperand(I);
- if (!Op.isReg() || Op.getReg() != RegNotKilled || !Op.isKill())
- continue;
- Op.setIsKill(false);
- }
-}
-
-/// isUnsafeToMoveAccross - Returns true if it is unsafe to move a copy
-/// instruction from \p UseReg to \p DestReg over the instruction \p I.
-bool isUnsafeToMoveAccross(MachineInstr *I, unsigned UseReg, unsigned DestReg,
- const TargetRegisterInfo *TRI) {
- return (UseReg && (I->modifiesRegister(UseReg, TRI))) ||
- I->modifiesRegister(DestReg, TRI) ||
- I->readsRegister(DestReg, TRI) ||
- I->hasUnmodeledSideEffects() ||
- I->isInlineAsm() || I->isDebugValue();
-}
-
-/// isSafeToMoveTogether - Returns true if it is safe to move I1 next to I2 such
-/// that the two instructions can be paired in a combine.
-bool HexagonCopyToCombine::isSafeToMoveTogether(MachineInstr *I1,
- MachineInstr *I2,
- unsigned I1DestReg,
- unsigned I2DestReg,
- bool &DoInsertAtI1) {
- bool isSafe = true;
-
- // First try to move I2 towards I1.
- {
- // A reverse_iterator instantiated like below starts before I2, and I1
- // respectively.
- // Look at instructions I in between I2 and (including) I1.
- MachineBasicBlock::reverse_iterator I(I2),
- End = MachineBasicBlock::reverse_iterator(I1);
- bool IsImmUseReg = I2->getOperand(1).isImm();
- unsigned I2UseReg = IsImmUseReg ? 0 : I2->getOperand(1).getReg();
-
- // If I2 kills its operand and we move I2 over an instruction that also
- // uses I2's use reg we need to modify that (first) instruction to now kill
- // this reg.
- unsigned KilledOperand = 0;
- if (I2->killsRegister(I2UseReg))
- KilledOperand = I2UseReg;
- MachineInstr *KillingInstr = 0;
-
- for (; I != End; ++I) {
- // If the intervening instruction I:
- // * modifies I2's use reg
- // * modifies I2's def reg
- // * reads I2's def reg
- // * or has unmodelled side effects
- // we can't move I2 across it.
- if (isUnsafeToMoveAccross(&*I, I2UseReg, I2DestReg, TRI)) {
- isSafe = false;
- break;
- }
-
- // Update first use of the killed operand.
- if (!KillingInstr && KilledOperand &&
- I->readsRegister(KilledOperand, TRI))
- KillingInstr = &*I;
- }
- if (isSafe) {
- // Update the intermediate instruction to with the kill flag.
- if (KillingInstr) {
- bool Added = KillingInstr->addRegisterKilled(KilledOperand, TRI, true);
- assert(Added && "Must successfully update kill flag");
- (void)Added;
- removeKillInfo(I2, KilledOperand);
- }
- DoInsertAtI1 = true;
- return true;
- }
- }
-
- // Try to move I1 towards I2.
- {
- // Look at instructions I in between I1 and (including) I2.
- MachineBasicBlock::iterator I(I1),
- End(llvm::next(MachineBasicBlock::iterator(I2)));
- bool IsImmUseReg = I1->getOperand(1).isImm();
- unsigned I1UseReg = IsImmUseReg ? 0 : I1->getOperand(1).getReg();
- // Track killed operands. If we move accross an instruction that kills our
- // operand, we need to update the kill information on the moved I1. It kills
- // the operand now.
- MachineInstr *KillingInstr = 0;
- unsigned KilledOperand = 0;
-
- while(++I != End) {
- // If the intervening instruction I:
- // * modifies I1's use reg
- // * modifies I1's def reg
- // * reads I1's def reg
- // * or has unmodelled side effects
- // We introduce this special case because llvm has no api to remove a
- // kill flag for a register (a removeRegisterKilled() analogous to
- // addRegisterKilled) that handles aliased register correctly.
- // * or has a killed aliased register use of I1's use reg
- // %D4<def> = TFRI64 16
- // %R6<def> = TFR %R9
- // %R8<def> = KILL %R8, %D4<imp-use,kill>
- // If we want to move R6 = across the KILL instruction we would have
- // to remove the %D4<imp-use,kill> operand. For now, we are
- // conservative and disallow the move.
- // we can't move I1 across it.
- if (isUnsafeToMoveAccross(I, I1UseReg, I1DestReg, TRI) ||
- // Check for an aliased register kill. Bail out if we see one.
- (!I->killsRegister(I1UseReg) && I->killsRegister(I1UseReg, TRI)))
- return false;
-
- // Check for an exact kill (registers match).
- if (I1UseReg && I->killsRegister(I1UseReg)) {
- assert(KillingInstr == 0 && "Should only see one killing instruction");
- KilledOperand = I1UseReg;
- KillingInstr = &*I;
- }
- }
- if (KillingInstr) {
- removeKillInfo(KillingInstr, KilledOperand);
- // Update I1 to set the kill flag. This flag will later be picked up by
- // the new COMBINE instruction.
- bool Added = I1->addRegisterKilled(KilledOperand, TRI);
- assert(Added && "Must successfully update kill flag");
- (void)Added;
- }
- DoInsertAtI1 = false;
- }
-
- return true;
-}
-
-bool HexagonCopyToCombine::runOnMachineFunction(MachineFunction &MF) {
-
- if (IsCombinesDisabled) return false;
-
- bool HasChanged = false;
-
- // Get target info.
- TRI = MF.getTarget().getRegisterInfo();
- TII = static_cast<const HexagonInstrInfo *>(MF.getTarget().getInstrInfo());
-
- // Traverse basic blocks.
- for (MachineFunction::iterator BI = MF.begin(), BE = MF.end(); BI != BE;
- ++BI) {
- // Traverse instructions in basic block.
- for(MachineBasicBlock::iterator MI = BI->begin(), End = BI->end();
- MI != End;) {
- MachineInstr *I1 = MI++;
-
- // Ignore instructions that are not combinable.
- if (!isCombinableInstType(I1, TII))
- continue;
-
- // Find a second instruction that can be merged into a combine
- // instruction.
- bool DoInsertAtI1 = false;
- MachineInstr *I2 = findPairable(I1, DoInsertAtI1);
- if (I2) {
- HasChanged = true;
- combine(I1, I2, MI, DoInsertAtI1);
- }
- }
- }
-
- return HasChanged;
-}
-
-/// findPairable - Returns an instruction that can be merged with \p I1 into a
-/// COMBINE instruction or 0 if no such instruction can be found. Returns true
-/// in \p DoInsertAtI1 if the combine must be inserted at instruction \p I1
-/// false if the combine must be inserted at the returned instruction.
-MachineInstr *HexagonCopyToCombine::findPairable(MachineInstr *I1,
- bool &DoInsertAtI1) {
- MachineBasicBlock::iterator I2 = llvm::next(MachineBasicBlock::iterator(I1));
- unsigned I1DestReg = I1->getOperand(0).getReg();
-
- for (MachineBasicBlock::iterator End = I1->getParent()->end(); I2 != End;
- ++I2) {
- // Bail out early if we see a second definition of I1DestReg.
- if (I2->modifiesRegister(I1DestReg, TRI))
- break;
-
- // Ignore non-combinable instructions.
- if (!isCombinableInstType(I2, TII))
- continue;
-
- unsigned I2DestReg = I2->getOperand(0).getReg();
-
- // Check that registers are adjacent and that the first destination register
- // is even.
- bool IsI1BeforeI2 = (I2DestReg - I1DestReg) == 1;
- bool IsI2BeforeI1 = (I1DestReg - I2DestReg) == 1;
- unsigned FirstRegIndex = IsI1BeforeI2 ? I1DestReg : I2DestReg;
- if ((!IsI1BeforeI2 && !IsI2BeforeI1) || !isEvenReg(FirstRegIndex))
- continue;
-
- // Check that the two instructions are combinable. V4 allows more
- // instructions to be merged into a combine.
- if (!areCombinableOperations(TRI, I1, I2))
- break;
-
- if (isSafeToMoveTogether(I1, I2, I1DestReg, I2DestReg,
- DoInsertAtI1))
- return I2;
-
- // Not safe. Stop searching.
- break;
- }
- return 0;
-}
-
-void HexagonCopyToCombine::combine(MachineInstr *I1, MachineInstr *I2,
- MachineBasicBlock::iterator &MI,
- bool DoInsertAtI1) {
- // We are going to delete I2. If MI points to I2 advance it to the next
- // instruction.
- if ((MachineInstr *)MI == I2) ++MI;
-
- // Figure out whether I1 or I2 goes into the lowreg part.
- unsigned I1DestReg = I1->getOperand(0).getReg();
- unsigned I2DestReg = I2->getOperand(0).getReg();
- bool IsI1Loreg = (I2DestReg - I1DestReg) == 1;
- unsigned LoRegDef = IsI1Loreg ? I1DestReg : I2DestReg;
-
- // Get the double word register.
- unsigned DoubleRegDest =
- TRI->getMatchingSuperReg(LoRegDef, Hexagon::subreg_loreg,
- Hexagon::DoubleRegsRegisterClass);
- assert(DoubleRegDest != 0 && "Expect a valid register");
-
-
- // Setup source operands.
- MachineOperand &LoOperand = IsI1Loreg ? I1->getOperand(1) :
- I2->getOperand(1);
- MachineOperand &HiOperand = IsI1Loreg ? I2->getOperand(1) :
- I1->getOperand(1);
-
- // Figure out which source is a register and which a constant.
- bool IsHiReg = HiOperand.isReg();
- bool IsLoReg = LoOperand.isReg();
-
- MachineBasicBlock::iterator InsertPt(DoInsertAtI1 ? I1 : I2);
- // Emit combine.
- if (IsHiReg && IsLoReg)
- emitCombineRR(InsertPt, DoubleRegDest, HiOperand, LoOperand);
- else if (IsHiReg)
- emitCombineRI(InsertPt, DoubleRegDest, HiOperand, LoOperand);
- else if (IsLoReg)
- emitCombineIR(InsertPt, DoubleRegDest, HiOperand, LoOperand);
- else
- emitCombineII(InsertPt, DoubleRegDest, HiOperand, LoOperand);
-
- I1->eraseFromParent();
- I2->eraseFromParent();
-}
-
-void HexagonCopyToCombine::emitCombineII(MachineBasicBlock::iterator &InsertPt,
- unsigned DoubleDestReg,
- MachineOperand &HiOperand,
- MachineOperand &LoOperand) {
- DebugLoc DL = InsertPt->getDebugLoc();
- MachineBasicBlock *BB = InsertPt->getParent();
-
- // Insert new combine instruction.
- // DoubleRegDest = combine #HiImm, #LoImm
- BuildMI(*BB, InsertPt, DL, TII->get(Hexagon::COMBINE_ii), DoubleDestReg)
- .addImm(HiOperand.getImm())
- .addImm(LoOperand.getImm());
-}
-
-void HexagonCopyToCombine::emitCombineIR(MachineBasicBlock::iterator &InsertPt,
- unsigned DoubleDestReg,
- MachineOperand &HiOperand,
- MachineOperand &LoOperand) {
- unsigned LoReg = LoOperand.getReg();
- unsigned LoRegKillFlag = getKillRegState(LoOperand.isKill());
-
- DebugLoc DL = InsertPt->getDebugLoc();
- MachineBasicBlock *BB = InsertPt->getParent();
-
- // Insert new combine instruction.
- // DoubleRegDest = combine #HiImm, LoReg
- BuildMI(*BB, InsertPt, DL, TII->get(Hexagon::COMBINE_ir_V4), DoubleDestReg)
- .addImm(HiOperand.getImm())
- .addReg(LoReg, LoRegKillFlag);
-}
-
-void HexagonCopyToCombine::emitCombineRI(MachineBasicBlock::iterator &InsertPt,
- unsigned DoubleDestReg,
- MachineOperand &HiOperand,
- MachineOperand &LoOperand) {
- unsigned HiRegKillFlag = getKillRegState(HiOperand.isKill());
- unsigned HiReg = HiOperand.getReg();
-
- DebugLoc DL = InsertPt->getDebugLoc();
- MachineBasicBlock *BB = InsertPt->getParent();
-
- // Insert new combine instruction.
- // DoubleRegDest = combine HiReg, #LoImm
- BuildMI(*BB, InsertPt, DL, TII->get(Hexagon::COMBINE_ri_V4), DoubleDestReg)
- .addReg(HiReg, HiRegKillFlag)
- .addImm(LoOperand.getImm());
-}
-
-void HexagonCopyToCombine::emitCombineRR(MachineBasicBlock::iterator &InsertPt,
- unsigned DoubleDestReg,
- MachineOperand &HiOperand,
- MachineOperand &LoOperand) {
- unsigned LoRegKillFlag = getKillRegState(LoOperand.isKill());
- unsigned HiRegKillFlag = getKillRegState(HiOperand.isKill());
- unsigned LoReg = LoOperand.getReg();
- unsigned HiReg = HiOperand.getReg();
-
- DebugLoc DL = InsertPt->getDebugLoc();
- MachineBasicBlock *BB = InsertPt->getParent();
-
- // Insert new combine instruction.
- // DoubleRegDest = combine HiReg, LoReg
- BuildMI(*BB, InsertPt, DL, TII->get(Hexagon::COMBINE_rr), DoubleDestReg)
- .addReg(HiReg, HiRegKillFlag)
- .addReg(LoReg, LoRegKillFlag);
-}
-
-FunctionPass *llvm::createHexagonCopyToCombine() {
- return new HexagonCopyToCombine();
-}
-