ARMConstantIslandPass.cpp revision de17fb6e4dd8f169f707d58d4e124c8d4d2c7dba
1a8e2989ece6dc46df59b0768184028257f913843Evan Cheng//===-- ARMConstantIslandPass.cpp - ARM constant islands --------*- C++ -*-===// 2a8e2989ece6dc46df59b0768184028257f913843Evan Cheng// 3a8e2989ece6dc46df59b0768184028257f913843Evan Cheng// The LLVM Compiler Infrastructure 4a8e2989ece6dc46df59b0768184028257f913843Evan Cheng// 54ee451de366474b9c228b4e5fa573795a715216dChris Lattner// This file is distributed under the University of Illinois Open Source 64ee451de366474b9c228b4e5fa573795a715216dChris Lattner// License. See LICENSE.TXT for details. 7a8e2989ece6dc46df59b0768184028257f913843Evan Cheng// 8a8e2989ece6dc46df59b0768184028257f913843Evan Cheng//===----------------------------------------------------------------------===// 9a8e2989ece6dc46df59b0768184028257f913843Evan Cheng// 10a8e2989ece6dc46df59b0768184028257f913843Evan Cheng// This file contains a pass that splits the constant pool up into 'islands' 11a8e2989ece6dc46df59b0768184028257f913843Evan Cheng// which are scattered through-out the function. This is required due to the 12a8e2989ece6dc46df59b0768184028257f913843Evan Cheng// limited pc-relative displacements that ARM has. 13a8e2989ece6dc46df59b0768184028257f913843Evan Cheng// 14a8e2989ece6dc46df59b0768184028257f913843Evan Cheng//===----------------------------------------------------------------------===// 15a8e2989ece6dc46df59b0768184028257f913843Evan Cheng 16a8e2989ece6dc46df59b0768184028257f913843Evan Cheng#define DEBUG_TYPE "arm-cp-islands" 17a8e2989ece6dc46df59b0768184028257f913843Evan Cheng#include "ARM.h" 18d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng#include "ARMAddressingModes.h" 19af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng#include "ARMMachineFunctionInfo.h" 20a8e2989ece6dc46df59b0768184028257f913843Evan Cheng#include "ARMInstrInfo.h" 21a8e2989ece6dc46df59b0768184028257f913843Evan Cheng#include "llvm/CodeGen/MachineConstantPool.h" 22a8e2989ece6dc46df59b0768184028257f913843Evan Cheng#include "llvm/CodeGen/MachineFunctionPass.h" 23a8e2989ece6dc46df59b0768184028257f913843Evan Cheng#include "llvm/CodeGen/MachineInstrBuilder.h" 245657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng#include "llvm/CodeGen/MachineJumpTableInfo.h" 25a8e2989ece6dc46df59b0768184028257f913843Evan Cheng#include "llvm/Target/TargetData.h" 26a8e2989ece6dc46df59b0768184028257f913843Evan Cheng#include "llvm/Target/TargetMachine.h" 27a8e2989ece6dc46df59b0768184028257f913843Evan Cheng#include "llvm/Support/Debug.h" 28c25e7581b9b8088910da31702d4ca21c4734c6d7Torok Edwin#include "llvm/Support/ErrorHandling.h" 29705e07f578e2b3af47ddab610feb4e7f2d3063a5Chris Lattner#include "llvm/Support/raw_ostream.h" 30b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson#include "llvm/ADT/SmallSet.h" 31c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng#include "llvm/ADT/SmallVector.h" 32a8e2989ece6dc46df59b0768184028257f913843Evan Cheng#include "llvm/ADT/STLExtras.h" 33a8e2989ece6dc46df59b0768184028257f913843Evan Cheng#include "llvm/ADT/Statistic.h" 34b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson#include <algorithm> 35a8e2989ece6dc46df59b0768184028257f913843Evan Chengusing namespace llvm; 36a8e2989ece6dc46df59b0768184028257f913843Evan Cheng 37a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan ChengSTATISTIC(NumCPEs, "Number of constpool entries"); 38a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan ChengSTATISTIC(NumSplit, "Number of uncond branches inserted"); 39a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan ChengSTATISTIC(NumCBrFixed, "Number of cond branches fixed"); 40a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan ChengSTATISTIC(NumUBrFixed, "Number of uncond branches fixed"); 41a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan ChengSTATISTIC(NumTBs, "Number of table branches generated"); 42a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan ChengSTATISTIC(NumT2CPShrunk, "Number of Thumb2 constantpool instructions shrunk"); 4331b99dd76035067b1c3cc6c7e9d663b7b0210938Evan ChengSTATISTIC(NumT2BrShrunk, "Number of Thumb2 immediate branches shrunk"); 44de17fb6e4dd8f169f707d58d4e124c8d4d2c7dbaEvan ChengSTATISTIC(NumCBZ, "Number of CBZ / CBNZ formed"); 45a8e2989ece6dc46df59b0768184028257f913843Evan Cheng 46a8e2989ece6dc46df59b0768184028257f913843Evan Chengnamespace { 4788e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen /// ARMConstantIslands - Due to limited PC-relative displacements, ARM 48a8e2989ece6dc46df59b0768184028257f913843Evan Cheng /// requires constant pool entries to be scattered among the instructions 49a8e2989ece6dc46df59b0768184028257f913843Evan Cheng /// inside a function. To do this, it completely ignores the normal LLVM 5088e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen /// constant pool; instead, it places constants wherever it feels like with 51a8e2989ece6dc46df59b0768184028257f913843Evan Cheng /// special instructions. 52a8e2989ece6dc46df59b0768184028257f913843Evan Cheng /// 53a8e2989ece6dc46df59b0768184028257f913843Evan Cheng /// The terminology used in this pass includes: 54a8e2989ece6dc46df59b0768184028257f913843Evan Cheng /// Islands - Clumps of constants placed in the function. 55a8e2989ece6dc46df59b0768184028257f913843Evan Cheng /// Water - Potential places where an island could be formed. 56a8e2989ece6dc46df59b0768184028257f913843Evan Cheng /// CPE - A constant pool entry that has been placed somewhere, which 57a8e2989ece6dc46df59b0768184028257f913843Evan Cheng /// tracks a list of users. 586726b6d75a8b679068a58cb954ba97cf9d1690baNick Lewycky class ARMConstantIslands : public MachineFunctionPass { 59a8e2989ece6dc46df59b0768184028257f913843Evan Cheng /// BBSizes - The size of each MachineBasicBlock in bytes of code, indexed 608593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen /// by MBB Number. The two-byte pads required for Thumb alignment are 618593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen /// counted as part of the following block (i.e., the offset and size for 628593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen /// a padded block will both be ==2 mod 4). 63e03cff6812ac41598e2bca7854985dc821a07f44Evan Cheng std::vector<unsigned> BBSizes; 648494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 6599c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen /// BBOffsets - the offset of each MBB in bytes, starting from 0. 668593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen /// The two-byte pads required for Thumb alignment are counted as part of 678593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen /// the following block. 6899c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen std::vector<unsigned> BBOffsets; 6999c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen 70a8e2989ece6dc46df59b0768184028257f913843Evan Cheng /// WaterList - A sorted list of basic blocks where islands could be placed 71a8e2989ece6dc46df59b0768184028257f913843Evan Cheng /// (i.e. blocks that don't fall through to the following block, due 72a8e2989ece6dc46df59b0768184028257f913843Evan Cheng /// to a return, unreachable, or unconditional branch). 73e03cff6812ac41598e2bca7854985dc821a07f44Evan Cheng std::vector<MachineBasicBlock*> WaterList; 74c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng 75b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson /// NewWaterList - The subset of WaterList that was created since the 76b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson /// previous iteration by inserting unconditional branches. 77b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson SmallSet<MachineBasicBlock*, 4> NewWaterList; 78b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson 79034de5f65f9139954cb01d94eaebbaefd294946eBob Wilson typedef std::vector<MachineBasicBlock*>::iterator water_iterator; 80034de5f65f9139954cb01d94eaebbaefd294946eBob Wilson 81a8e2989ece6dc46df59b0768184028257f913843Evan Cheng /// CPUser - One user of a constant pool, keeping the machine instruction 82a8e2989ece6dc46df59b0768184028257f913843Evan Cheng /// pointer, the constant pool being referenced, and the max displacement 83549dda9d82a5ec0a0cbf429a18d33a8e66062424Bob Wilson /// allowed from the instruction to the CP. The HighWaterMark records the 84549dda9d82a5ec0a0cbf429a18d33a8e66062424Bob Wilson /// highest basic block where a new CPEntry can be placed. To ensure this 85549dda9d82a5ec0a0cbf429a18d33a8e66062424Bob Wilson /// pass terminates, the CP entries are initially placed at the end of the 86549dda9d82a5ec0a0cbf429a18d33a8e66062424Bob Wilson /// function and then move monotonically to lower addresses. The 87549dda9d82a5ec0a0cbf429a18d33a8e66062424Bob Wilson /// exception to this rule is when the current CP entry for a particular 88549dda9d82a5ec0a0cbf429a18d33a8e66062424Bob Wilson /// CPUser is out of range, but there is another CP entry for the same 89549dda9d82a5ec0a0cbf429a18d33a8e66062424Bob Wilson /// constant value in range. We want to use the existing in-range CP 90549dda9d82a5ec0a0cbf429a18d33a8e66062424Bob Wilson /// entry, but if it later moves out of range, the search for new water 91549dda9d82a5ec0a0cbf429a18d33a8e66062424Bob Wilson /// should resume where it left off. The HighWaterMark is used to record 92549dda9d82a5ec0a0cbf429a18d33a8e66062424Bob Wilson /// that point. 93a8e2989ece6dc46df59b0768184028257f913843Evan Cheng struct CPUser { 94a8e2989ece6dc46df59b0768184028257f913843Evan Cheng MachineInstr *MI; 95a8e2989ece6dc46df59b0768184028257f913843Evan Cheng MachineInstr *CPEMI; 96549dda9d82a5ec0a0cbf429a18d33a8e66062424Bob Wilson MachineBasicBlock *HighWaterMark; 97a8e2989ece6dc46df59b0768184028257f913843Evan Cheng unsigned MaxDisp; 985d8f1cae76e4e424bf3b4392eddb3f4dbf38662aEvan Cheng bool NegOk; 99d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng bool IsSoImm; 100d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng CPUser(MachineInstr *mi, MachineInstr *cpemi, unsigned maxdisp, 101d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng bool neg, bool soimm) 102549dda9d82a5ec0a0cbf429a18d33a8e66062424Bob Wilson : MI(mi), CPEMI(cpemi), MaxDisp(maxdisp), NegOk(neg), IsSoImm(soimm) { 103549dda9d82a5ec0a0cbf429a18d33a8e66062424Bob Wilson HighWaterMark = CPEMI->getParent(); 104549dda9d82a5ec0a0cbf429a18d33a8e66062424Bob Wilson } 105a8e2989ece6dc46df59b0768184028257f913843Evan Cheng }; 1068494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 107a8e2989ece6dc46df59b0768184028257f913843Evan Cheng /// CPUsers - Keep track of all of the machine instructions that use various 108a8e2989ece6dc46df59b0768184028257f913843Evan Cheng /// constant pools and their max displacement. 109e03cff6812ac41598e2bca7854985dc821a07f44Evan Cheng std::vector<CPUser> CPUsers; 1108494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 111c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng /// CPEntry - One per constant pool entry, keeping the machine instruction 112c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng /// pointer, the constpool index, and the number of CPUser's which 113c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng /// reference this entry. 114c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng struct CPEntry { 115c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng MachineInstr *CPEMI; 116c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng unsigned CPI; 117c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng unsigned RefCount; 118c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng CPEntry(MachineInstr *cpemi, unsigned cpi, unsigned rc = 0) 119c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng : CPEMI(cpemi), CPI(cpi), RefCount(rc) {} 120c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng }; 121c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng 122c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng /// CPEntries - Keep track of all of the constant pool entry machine 12388e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen /// instructions. For each original constpool index (i.e. those that 12488e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen /// existed upon entry to this pass), it keeps a vector of entries. 12588e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen /// Original elements are cloned as we go along; the clones are 12688e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen /// put in the vector of the original element, but have distinct CPIs. 127c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng std::vector<std::vector<CPEntry> > CPEntries; 1288494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 129af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng /// ImmBranch - One per immediate branch, keeping the machine instruction 130af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng /// pointer, conditional or unconditional, the max displacement, 131af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng /// and (if isCond is true) the corresponding unconditional branch 132af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng /// opcode. 133af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng struct ImmBranch { 134af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng MachineInstr *MI; 135c285414988ba026d01e5d8acc07a21cd06fd5732Evan Cheng unsigned MaxDisp : 31; 136c285414988ba026d01e5d8acc07a21cd06fd5732Evan Cheng bool isCond : 1; 137af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng int UncondBr; 138c285414988ba026d01e5d8acc07a21cd06fd5732Evan Cheng ImmBranch(MachineInstr *mi, unsigned maxdisp, bool cond, int ubr) 139c285414988ba026d01e5d8acc07a21cd06fd5732Evan Cheng : MI(mi), MaxDisp(maxdisp), isCond(cond), UncondBr(ubr) {} 140af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng }; 141af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng 1422706f9771de8e90ee6379e70afedd91892bb9c8cEvan Cheng /// ImmBranches - Keep track of all the immediate branch instructions. 143af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng /// 144e03cff6812ac41598e2bca7854985dc821a07f44Evan Cheng std::vector<ImmBranch> ImmBranches; 145af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng 146d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng /// PushPopMIs - Keep track of all the Thumb push / pop instructions. 147d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng /// 148c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng SmallVector<MachineInstr*, 4> PushPopMIs; 149d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng 1505657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng /// T2JumpTables - Keep track of all the Thumb2 jumptable instructions. 1515657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng SmallVector<MachineInstr*, 4> T2JumpTables; 1525657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng 153d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng /// HasFarJump - True if any far jump instruction has been emitted during 154d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng /// the branch fix up pass. 155d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng bool HasFarJump; 156d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng 157a8e2989ece6dc46df59b0768184028257f913843Evan Cheng const TargetInstrInfo *TII; 15825f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng const ARMSubtarget *STI; 1598593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen ARMFunctionInfo *AFI; 160b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen bool isThumb; 161d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng bool isThumb1; 1625e47a9a6e46bd271eba058fb831da1a1edf8707cDavid Goodwin bool isThumb2; 163a8e2989ece6dc46df59b0768184028257f913843Evan Cheng public: 1641997473cf72957d0e70322e2fe6fe2ab141c58a6Devang Patel static char ID; 165ae73dc1448d25b02cabc7c64c86c64371453dda8Dan Gohman ARMConstantIslands() : MachineFunctionPass(&ID) {} 166794fd75c67a2cdc128d67342c6d88a504d186896Devang Patel 1675657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng virtual bool runOnMachineFunction(MachineFunction &MF); 168a8e2989ece6dc46df59b0768184028257f913843Evan Cheng 169a8e2989ece6dc46df59b0768184028257f913843Evan Cheng virtual const char *getPassName() const { 170af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng return "ARM constant island placement and branch shortening pass"; 171a8e2989ece6dc46df59b0768184028257f913843Evan Cheng } 1728494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 173a8e2989ece6dc46df59b0768184028257f913843Evan Cheng private: 1745657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng void DoInitialPlacement(MachineFunction &MF, 175e03cff6812ac41598e2bca7854985dc821a07f44Evan Cheng std::vector<MachineInstr*> &CPEMIs); 176c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng CPEntry *findConstPoolEntry(unsigned CPI, const MachineInstr *CPEMI); 1775657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng void InitialFunctionScan(MachineFunction &MF, 178e03cff6812ac41598e2bca7854985dc821a07f44Evan Cheng const std::vector<MachineInstr*> &CPEMIs); 1790c61584d05894a5543f690803191a8b0da05b8fcEvan Cheng MachineBasicBlock *SplitBlockBeforeInstr(MachineInstr *MI); 180a8e2989ece6dc46df59b0768184028257f913843Evan Cheng void UpdateForInsertedWaterBlock(MachineBasicBlock *NewBB); 18199c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen void AdjustBBOffsetsAfter(MachineBasicBlock *BB, int delta); 182ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng bool DecrementOldEntry(unsigned CPI, MachineInstr* CPEMI); 18388e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen int LookForExistingCPEntry(CPUser& U, unsigned UserOffset); 184b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson bool LookForWater(CPUser&U, unsigned UserOffset, water_iterator &WaterIter); 185b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen void CreateNewWater(unsigned CPUserIndex, unsigned UserOffset, 186757652c5ba820bbea75d8713d7bf3749e4113778Bob Wilson MachineBasicBlock *&NewMBB); 1875657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng bool HandleConstantPoolUser(MachineFunction &MF, unsigned CPUserIndex); 188ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng void RemoveDeadCPEMI(MachineInstr *CPEMI); 189ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng bool RemoveUnusedCPEntries(); 1908494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson bool CPEIsInRange(MachineInstr *MI, unsigned UserOffset, 1915d8f1cae76e4e424bf3b4392eddb3f4dbf38662aEvan Cheng MachineInstr *CPEMI, unsigned Disp, bool NegOk, 1925d8f1cae76e4e424bf3b4392eddb3f4dbf38662aEvan Cheng bool DoDump = false); 19399c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen bool WaterIsInRange(unsigned UserOffset, MachineBasicBlock *Water, 1945d9c4b60204d741c213456e21b87e9af6a3dc627Dale Johannesen CPUser &U); 19599c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen bool OffsetIsInRange(unsigned UserOffset, unsigned TrialOffset, 196d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng unsigned Disp, bool NegativeOK, bool IsSoImm = false); 197c0dbec7e1038ee60b8525eb1e8e3eaa6a839bd5bEvan Cheng bool BBIsInRange(MachineInstr *MI, MachineBasicBlock *BB, unsigned Disp); 1985657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng bool FixUpImmediateBr(MachineFunction &MF, ImmBranch &Br); 1995657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng bool FixUpConditionalBr(MachineFunction &MF, ImmBranch &Br); 2005657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng bool FixUpUnconditionalBr(MachineFunction &MF, ImmBranch &Br); 201d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng bool UndoLRSpillRestore(); 202a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng bool OptimizeThumb2Instructions(MachineFunction &MF); 203a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng bool OptimizeThumb2Branches(MachineFunction &MF); 2045657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng bool OptimizeThumb2JumpTables(MachineFunction &MF); 205a8e2989ece6dc46df59b0768184028257f913843Evan Cheng 206a8e2989ece6dc46df59b0768184028257f913843Evan Cheng unsigned GetOffsetOf(MachineInstr *MI) const; 2078593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen void dumpBBs(); 2085657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng void verify(MachineFunction &MF); 209a8e2989ece6dc46df59b0768184028257f913843Evan Cheng }; 2101997473cf72957d0e70322e2fe6fe2ab141c58a6Devang Patel char ARMConstantIslands::ID = 0; 211a8e2989ece6dc46df59b0768184028257f913843Evan Cheng} 212a8e2989ece6dc46df59b0768184028257f913843Evan Cheng 2138593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen/// verify - check BBOffsets, BBSizes, alignment of islands 2145657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Chengvoid ARMConstantIslands::verify(MachineFunction &MF) { 2158593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen assert(BBOffsets.size() == BBSizes.size()); 2168593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen for (unsigned i = 1, e = BBOffsets.size(); i != e; ++i) 2178593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen assert(BBOffsets[i-1]+BBSizes[i-1] == BBOffsets[i]); 218d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng if (!isThumb) 219d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng return; 220d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng#ifndef NDEBUG 2215657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng for (MachineFunction::iterator MBBI = MF.begin(), E = MF.end(); 222d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng MBBI != E; ++MBBI) { 223d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng MachineBasicBlock *MBB = MBBI; 224d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng if (!MBB->empty() && 225d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng MBB->begin()->getOpcode() == ARM::CONSTPOOL_ENTRY) { 226d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng unsigned MBBId = MBB->getNumber(); 227d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng assert((BBOffsets[MBBId]%4 == 0 && BBSizes[MBBId]%4 == 0) || 228d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng (BBOffsets[MBBId]%4 != 0 && BBSizes[MBBId]%4 != 0)); 2298593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen } 2308593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen } 231d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng#endif 2328593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen} 2338593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen 2348593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen/// print block size and offset information - debugging 2358593e418555fdae21a070357fd8734b4069c17d0Dale Johannesenvoid ARMConstantIslands::dumpBBs() { 2368593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen for (unsigned J = 0, E = BBOffsets.size(); J !=E; ++J) { 237893e1c90a03a53cf13f73849324e83612688428aChris Lattner DEBUG(errs() << "block " << J << " offset " << BBOffsets[J] 238893e1c90a03a53cf13f73849324e83612688428aChris Lattner << " size " << BBSizes[J] << "\n"); 2398593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen } 2408593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen} 2418593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen 242af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng/// createARMConstantIslandPass - returns an instance of the constpool 243af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng/// island pass. 244a8e2989ece6dc46df59b0768184028257f913843Evan ChengFunctionPass *llvm::createARMConstantIslandPass() { 245a8e2989ece6dc46df59b0768184028257f913843Evan Cheng return new ARMConstantIslands(); 246a8e2989ece6dc46df59b0768184028257f913843Evan Cheng} 247a8e2989ece6dc46df59b0768184028257f913843Evan Cheng 2485657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Chengbool ARMConstantIslands::runOnMachineFunction(MachineFunction &MF) { 2495657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng MachineConstantPool &MCP = *MF.getConstantPool(); 2508494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 2515657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng TII = MF.getTarget().getInstrInfo(); 2525657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng AFI = MF.getInfo<ARMFunctionInfo>(); 25325f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng STI = &MF.getTarget().getSubtarget<ARMSubtarget>(); 25425f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng 255b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen isThumb = AFI->isThumbFunction(); 256d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng isThumb1 = AFI->isThumb1OnlyFunction(); 2575e47a9a6e46bd271eba058fb831da1a1edf8707cDavid Goodwin isThumb2 = AFI->isThumb2Function(); 258d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng 259d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng HasFarJump = false; 260d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng 261a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // Renumber all of the machine basic blocks in the function, guaranteeing that 262a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // the numbers agree with the position of the block in the function. 2635657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng MF.RenumberBlocks(); 264a8e2989ece6dc46df59b0768184028257f913843Evan Cheng 265d26b14c34cbcee1448b86b524578fc51cc979023Evan Cheng // Thumb1 functions containing constant pools get 4-byte alignment. 266d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng // This is so we can keep exact track of where the alignment padding goes. 267d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng 268d26b14c34cbcee1448b86b524578fc51cc979023Evan Cheng // Set default. Thumb1 function is 2-byte aligned, ARM and Thumb2 are 4-byte 269d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng // aligned. 270d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng AFI->setAlign(isThumb1 ? 1U : 2U); 27156c42ef3e43f8eb75c435e781d0ac8251c7588a1Dale Johannesen 272a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // Perform the initial placement of the constant pool entries. To start with, 273a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // we put them all at the end of the function. 274e03cff6812ac41598e2bca7854985dc821a07f44Evan Cheng std::vector<MachineInstr*> CPEMIs; 27556c42ef3e43f8eb75c435e781d0ac8251c7588a1Dale Johannesen if (!MCP.isEmpty()) { 2765657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng DoInitialPlacement(MF, CPEMIs); 277d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng if (isThumb1) 27856c42ef3e43f8eb75c435e781d0ac8251c7588a1Dale Johannesen AFI->setAlign(2U); 27956c42ef3e43f8eb75c435e781d0ac8251c7588a1Dale Johannesen } 2808494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 281a8e2989ece6dc46df59b0768184028257f913843Evan Cheng /// The next UID to take is the first unused one. 282f1bbb9577a42cf7dc3079412f1dd7683e3a03665Evan Cheng AFI->initConstPoolEntryUId(CPEMIs.size()); 2838494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 284a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // Do the initial scan of the function, building up information about the 285a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // sizes of each block, the location of all the water, and finding all of the 286a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // constant pool users. 2875657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng InitialFunctionScan(MF, CPEMIs); 288a8e2989ece6dc46df59b0768184028257f913843Evan Cheng CPEMIs.clear(); 2898494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 290ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng /// Remove dead constant pool entries. 291ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng RemoveUnusedCPEntries(); 292ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng 293d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng // Iteratively place constant pool entries and fix up branches until there 294d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng // is no change. 295d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng bool MadeChange = false; 296b6879b2b84df2f642cd39f5bf58584c4a39f8080Evan Cheng unsigned NoCPIters = 0, NoBRIters = 0; 297d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng while (true) { 298b6879b2b84df2f642cd39f5bf58584c4a39f8080Evan Cheng bool CPChange = false; 299a8e2989ece6dc46df59b0768184028257f913843Evan Cheng for (unsigned i = 0, e = CPUsers.size(); i != e; ++i) 300b6879b2b84df2f642cd39f5bf58584c4a39f8080Evan Cheng CPChange |= HandleConstantPoolUser(MF, i); 301b6879b2b84df2f642cd39f5bf58584c4a39f8080Evan Cheng if (CPChange && ++NoCPIters > 30) 302b6879b2b84df2f642cd39f5bf58584c4a39f8080Evan Cheng llvm_unreachable("Constant Island pass failed to converge!"); 3038202010364e1bfe6111f1ce62f154499b80877fbEvan Cheng DEBUG(dumpBBs()); 304b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson 305b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson // Clear NewWaterList now. If we split a block for branches, it should 306b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson // appear as "new water" for the next iteration of constant pool placement. 307b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson NewWaterList.clear(); 308b6879b2b84df2f642cd39f5bf58584c4a39f8080Evan Cheng 309b6879b2b84df2f642cd39f5bf58584c4a39f8080Evan Cheng bool BRChange = false; 310af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng for (unsigned i = 0, e = ImmBranches.size(); i != e; ++i) 311b6879b2b84df2f642cd39f5bf58584c4a39f8080Evan Cheng BRChange |= FixUpImmediateBr(MF, ImmBranches[i]); 312b6879b2b84df2f642cd39f5bf58584c4a39f8080Evan Cheng if (BRChange && ++NoBRIters > 30) 313b6879b2b84df2f642cd39f5bf58584c4a39f8080Evan Cheng llvm_unreachable("Branch Fix Up pass failed to converge!"); 3148202010364e1bfe6111f1ce62f154499b80877fbEvan Cheng DEBUG(dumpBBs()); 315b6879b2b84df2f642cd39f5bf58584c4a39f8080Evan Cheng 316b6879b2b84df2f642cd39f5bf58584c4a39f8080Evan Cheng if (!CPChange && !BRChange) 317d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng break; 318d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng MadeChange = true; 319d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng } 320ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng 321a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng // Shrink 32-bit Thumb2 branch, load, and store instructions. 322a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng if (isThumb2) 323a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng MadeChange |= OptimizeThumb2Instructions(MF); 32425f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng 3258593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // After a while, this might be made debug-only, but it is not expensive. 3265657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng verify(MF); 3278593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen 328d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng // If LR has been forced spilled and no far jumps (i.e. BL) has been issued. 329d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng // Undo the spill / restore of LR if possible. 3305657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng if (isThumb && !HasFarJump && AFI->isLRSpilledForFarJump()) 331d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng MadeChange |= UndoLRSpillRestore(); 332d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng 333a8e2989ece6dc46df59b0768184028257f913843Evan Cheng BBSizes.clear(); 33499c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen BBOffsets.clear(); 335a8e2989ece6dc46df59b0768184028257f913843Evan Cheng WaterList.clear(); 336a8e2989ece6dc46df59b0768184028257f913843Evan Cheng CPUsers.clear(); 337c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng CPEntries.clear(); 338af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng ImmBranches.clear(); 339c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng PushPopMIs.clear(); 3405657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng T2JumpTables.clear(); 341d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng 342d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng return MadeChange; 343a8e2989ece6dc46df59b0768184028257f913843Evan Cheng} 344a8e2989ece6dc46df59b0768184028257f913843Evan Cheng 345a8e2989ece6dc46df59b0768184028257f913843Evan Cheng/// DoInitialPlacement - Perform the initial placement of the constant pool 346a8e2989ece6dc46df59b0768184028257f913843Evan Cheng/// entries. To start with, we put them all at the end of the function. 3475657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Chengvoid ARMConstantIslands::DoInitialPlacement(MachineFunction &MF, 3488494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson std::vector<MachineInstr*> &CPEMIs) { 349a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // Create the basic block to hold the CPE's. 3505657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng MachineBasicBlock *BB = MF.CreateMachineBasicBlock(); 3515657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng MF.push_back(BB); 3528494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 353a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // Add all of the constants from the constant pool to the end block, use an 354a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // identity mapping of CPI's to CPE's. 355a8e2989ece6dc46df59b0768184028257f913843Evan Cheng const std::vector<MachineConstantPoolEntry> &CPs = 3565657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng MF.getConstantPool()->getConstants(); 3578494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 3585657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng const TargetData &TD = *MF.getTarget().getTargetData(); 359a8e2989ece6dc46df59b0768184028257f913843Evan Cheng for (unsigned i = 0, e = CPs.size(); i != e; ++i) { 360777d2306b36816a53bc1ae1244c0dc7d998ae691Duncan Sands unsigned Size = TD.getTypeAllocSize(CPs[i].getType()); 361a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // Verify that all constant pool entries are a multiple of 4 bytes. If not, 362a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // we would have to pad them out or something so that instructions stay 363a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // aligned. 364a8e2989ece6dc46df59b0768184028257f913843Evan Cheng assert((Size & 3) == 0 && "CP Entry not multiple of 4 bytes!"); 365a8e2989ece6dc46df59b0768184028257f913843Evan Cheng MachineInstr *CPEMI = 366b67284057ee130114055309eabe0bcd1af13777dDale Johannesen BuildMI(BB, DebugLoc::getUnknownLoc(), TII->get(ARM::CONSTPOOL_ENTRY)) 367a8e2989ece6dc46df59b0768184028257f913843Evan Cheng .addImm(i).addConstantPoolIndex(i).addImm(Size); 368a8e2989ece6dc46df59b0768184028257f913843Evan Cheng CPEMIs.push_back(CPEMI); 369c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng 370c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng // Add a new CPEntry, but no corresponding CPUser yet. 371c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng std::vector<CPEntry> CPEs; 372c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng CPEs.push_back(CPEntry(CPEMI, i)); 373c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng CPEntries.push_back(CPEs); 374c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng NumCPEs++; 375893e1c90a03a53cf13f73849324e83612688428aChris Lattner DEBUG(errs() << "Moved CPI#" << i << " to end of function as #" << i 376893e1c90a03a53cf13f73849324e83612688428aChris Lattner << "\n"); 377a8e2989ece6dc46df59b0768184028257f913843Evan Cheng } 378a8e2989ece6dc46df59b0768184028257f913843Evan Cheng} 379a8e2989ece6dc46df59b0768184028257f913843Evan Cheng 38088e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen/// BBHasFallthrough - Return true if the specified basic block can fallthrough 381a8e2989ece6dc46df59b0768184028257f913843Evan Cheng/// into the block immediately after it. 382a8e2989ece6dc46df59b0768184028257f913843Evan Chengstatic bool BBHasFallthrough(MachineBasicBlock *MBB) { 383a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // Get the next machine basic block in the function. 384a8e2989ece6dc46df59b0768184028257f913843Evan Cheng MachineFunction::iterator MBBI = MBB; 385a8e2989ece6dc46df59b0768184028257f913843Evan Cheng if (next(MBBI) == MBB->getParent()->end()) // Can't fall off end of function. 386a8e2989ece6dc46df59b0768184028257f913843Evan Cheng return false; 3878494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 388a8e2989ece6dc46df59b0768184028257f913843Evan Cheng MachineBasicBlock *NextBB = next(MBBI); 389a8e2989ece6dc46df59b0768184028257f913843Evan Cheng for (MachineBasicBlock::succ_iterator I = MBB->succ_begin(), 390a8e2989ece6dc46df59b0768184028257f913843Evan Cheng E = MBB->succ_end(); I != E; ++I) 391a8e2989ece6dc46df59b0768184028257f913843Evan Cheng if (*I == NextBB) 392a8e2989ece6dc46df59b0768184028257f913843Evan Cheng return true; 3938494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 394a8e2989ece6dc46df59b0768184028257f913843Evan Cheng return false; 395a8e2989ece6dc46df59b0768184028257f913843Evan Cheng} 396a8e2989ece6dc46df59b0768184028257f913843Evan Cheng 397c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng/// findConstPoolEntry - Given the constpool index and CONSTPOOL_ENTRY MI, 398c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng/// look up the corresponding CPEntry. 399c99ef085b90b32952b484e8843fb66ad65215b61Evan ChengARMConstantIslands::CPEntry 400c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng*ARMConstantIslands::findConstPoolEntry(unsigned CPI, 401c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng const MachineInstr *CPEMI) { 402c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng std::vector<CPEntry> &CPEs = CPEntries[CPI]; 403c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng // Number of entries per constpool index should be small, just do a 404c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng // linear search. 405c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng for (unsigned i = 0, e = CPEs.size(); i != e; ++i) { 406c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng if (CPEs[i].CPEMI == CPEMI) 407c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng return &CPEs[i]; 408c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng } 409c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng return NULL; 410c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng} 411c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng 412a8e2989ece6dc46df59b0768184028257f913843Evan Cheng/// InitialFunctionScan - Do the initial scan of the function, building up 413a8e2989ece6dc46df59b0768184028257f913843Evan Cheng/// information about the sizes of each block, the location of all the water, 414a8e2989ece6dc46df59b0768184028257f913843Evan Cheng/// and finding all of the constant pool users. 4155657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Chengvoid ARMConstantIslands::InitialFunctionScan(MachineFunction &MF, 416e03cff6812ac41598e2bca7854985dc821a07f44Evan Cheng const std::vector<MachineInstr*> &CPEMIs) { 41799c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen unsigned Offset = 0; 4185657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng for (MachineFunction::iterator MBBI = MF.begin(), E = MF.end(); 419a8e2989ece6dc46df59b0768184028257f913843Evan Cheng MBBI != E; ++MBBI) { 420a8e2989ece6dc46df59b0768184028257f913843Evan Cheng MachineBasicBlock &MBB = *MBBI; 4218494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 422a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // If this block doesn't fall through into the next MBB, then this is 423a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // 'water' that a constant pool island could be placed. 424a8e2989ece6dc46df59b0768184028257f913843Evan Cheng if (!BBHasFallthrough(&MBB)) 425a8e2989ece6dc46df59b0768184028257f913843Evan Cheng WaterList.push_back(&MBB); 4268494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 427a8e2989ece6dc46df59b0768184028257f913843Evan Cheng unsigned MBBSize = 0; 428a8e2989ece6dc46df59b0768184028257f913843Evan Cheng for (MachineBasicBlock::iterator I = MBB.begin(), E = MBB.end(); 429a8e2989ece6dc46df59b0768184028257f913843Evan Cheng I != E; ++I) { 430a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // Add instruction size to MBBSize. 43152e724ad7e679ee590f4bd763d55280586a8f1bcNicolas Geoffray MBBSize += TII->GetInstSizeInBytes(I); 432a8e2989ece6dc46df59b0768184028257f913843Evan Cheng 433af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng int Opc = I->getOpcode(); 434749c6f6b5ed301c84aac562e414486549d7b98ebChris Lattner if (I->getDesc().isBranch()) { 435af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng bool isCond = false; 436af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng unsigned Bits = 0; 437af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng unsigned Scale = 1; 438af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng int UOpc = Opc; 439af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng switch (Opc) { 4405657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng default: 4415657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng continue; // Ignore other JT branches 4428593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen case ARM::tBR_JTr: 44366ac53165e17b7c76b8c69e57bde623d44ec492eEvan Cheng // A Thumb1 table jump may involve padding; for the offsets to 4448593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // be right, functions containing these must be 4-byte aligned. 4458593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen AFI->setAlign(2U); 4468593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen if ((Offset+MBBSize)%4 != 0) 4475657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng // FIXME: Add a pseudo ALIGN instruction instead. 4488593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen MBBSize += 2; // padding 4498593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen continue; // Does not get an entry in ImmBranches 4505657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng case ARM::t2BR_JT: 4515657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng T2JumpTables.push_back(I); 4525657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng continue; // Does not get an entry in ImmBranches 453af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng case ARM::Bcc: 454af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng isCond = true; 455af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng UOpc = ARM::B; 456af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng // Fallthrough 457af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng case ARM::B: 458af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng Bits = 24; 459af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng Scale = 4; 460af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng break; 461af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng case ARM::tBcc: 462af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng isCond = true; 463af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng UOpc = ARM::tB; 464af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng Bits = 8; 465af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng Scale = 2; 466af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng break; 467af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng case ARM::tB: 468af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng Bits = 11; 469af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng Scale = 2; 470af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng break; 4715e47a9a6e46bd271eba058fb831da1a1edf8707cDavid Goodwin case ARM::t2Bcc: 4725e47a9a6e46bd271eba058fb831da1a1edf8707cDavid Goodwin isCond = true; 4735e47a9a6e46bd271eba058fb831da1a1edf8707cDavid Goodwin UOpc = ARM::t2B; 4745e47a9a6e46bd271eba058fb831da1a1edf8707cDavid Goodwin Bits = 20; 4755e47a9a6e46bd271eba058fb831da1a1edf8707cDavid Goodwin Scale = 2; 4765e47a9a6e46bd271eba058fb831da1a1edf8707cDavid Goodwin break; 4775e47a9a6e46bd271eba058fb831da1a1edf8707cDavid Goodwin case ARM::t2B: 4785e47a9a6e46bd271eba058fb831da1a1edf8707cDavid Goodwin Bits = 24; 4795e47a9a6e46bd271eba058fb831da1a1edf8707cDavid Goodwin Scale = 2; 4805e47a9a6e46bd271eba058fb831da1a1edf8707cDavid Goodwin break; 481af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng } 482b43216ee4a418257ce5530c02601b77efe86c354Evan Cheng 483b43216ee4a418257ce5530c02601b77efe86c354Evan Cheng // Record this immediate branch. 484bd5d3dbdbe46c7325545a7cb8c891c0347375451Evan Cheng unsigned MaxOffs = ((1 << (Bits-1))-1) * Scale; 485b43216ee4a418257ce5530c02601b77efe86c354Evan Cheng ImmBranches.push_back(ImmBranch(I, MaxOffs, isCond, UOpc)); 486af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng } 487af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng 488d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng if (Opc == ARM::tPUSH || Opc == ARM::tPOP_RET) 489d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng PushPopMIs.push_back(I); 490d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng 491d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng if (Opc == ARM::CONSTPOOL_ENTRY) 492d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng continue; 493d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng 494a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // Scan the instructions for constant pool operands. 495a8e2989ece6dc46df59b0768184028257f913843Evan Cheng for (unsigned op = 0, e = I->getNumOperands(); op != e; ++op) 496d735b8019b0f297d7c14b55adcd887af24d8e602Dan Gohman if (I->getOperand(op).isCPI()) { 497a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // We found one. The addressing mode tells us the max displacement 498a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // from the PC that this instruction permits. 4998494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 500a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // Basic size info comes from the TSFlags field. 501b43216ee4a418257ce5530c02601b77efe86c354Evan Cheng unsigned Bits = 0; 502b43216ee4a418257ce5530c02601b77efe86c354Evan Cheng unsigned Scale = 1; 5035d8f1cae76e4e424bf3b4392eddb3f4dbf38662aEvan Cheng bool NegOk = false; 504d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng bool IsSoImm = false; 505d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng 506d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng switch (Opc) { 5078494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson default: 508c23197a26f34f559ea9797de51e187087c039c42Torok Edwin llvm_unreachable("Unknown addressing mode for CP reference!"); 509a8e2989ece6dc46df59b0768184028257f913843Evan Cheng break; 510d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng 511d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng // Taking the address of a CP entry. 512d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng case ARM::LEApcrel: 513d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng // This takes a SoImm, which is 8 bit immediate rotated. We'll 514d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng // pretend the maximum offset is 255 * 4. Since each instruction 515d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng // 4 byte wide, this is always correct. We'llc heck for other 516d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng // displacements that fits in a SoImm as well. 517d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng Bits = 8; 518d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng Scale = 4; 5195d8f1cae76e4e424bf3b4392eddb3f4dbf38662aEvan Cheng NegOk = true; 520d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng IsSoImm = true; 521a8e2989ece6dc46df59b0768184028257f913843Evan Cheng break; 522d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng case ARM::t2LEApcrel: 523d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng Bits = 12; 5245d8f1cae76e4e424bf3b4392eddb3f4dbf38662aEvan Cheng NegOk = true; 525a8e2989ece6dc46df59b0768184028257f913843Evan Cheng break; 526d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng case ARM::tLEApcrel: 527b43216ee4a418257ce5530c02601b77efe86c354Evan Cheng Bits = 8; 528d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng Scale = 4; 529a8e2989ece6dc46df59b0768184028257f913843Evan Cheng break; 530d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng 531d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng case ARM::LDR: 532d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng case ARM::LDRcp: 533d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng case ARM::t2LDRpci: 534d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng Bits = 12; // +-offset_12 535d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng NegOk = true; 536a8e2989ece6dc46df59b0768184028257f913843Evan Cheng break; 537d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng 538d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng case ARM::tLDRpci: 539d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng case ARM::tLDRcp: 540b43216ee4a418257ce5530c02601b77efe86c354Evan Cheng Bits = 8; 541b43216ee4a418257ce5530c02601b77efe86c354Evan Cheng Scale = 4; // +(offset_8*4) 542012f2d97b78e4eb9128f1d491f2c177768dbe527Evan Cheng break; 543d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng 544d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng case ARM::FLDD: 545d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng case ARM::FLDS: 546d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng Bits = 8; 547d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng Scale = 4; // +-(offset_8*4) 548d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng NegOk = true; 549055b0310f862b91f33699037ce67d3ab8137c20cEvan Cheng break; 550a8e2989ece6dc46df59b0768184028257f913843Evan Cheng } 551b43216ee4a418257ce5530c02601b77efe86c354Evan Cheng 552a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // Remember that this is a user of a CP entry. 5538aa797aa51cd4ea1ec6f46f4891a6897944b75b2Chris Lattner unsigned CPI = I->getOperand(op).getIndex(); 554c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng MachineInstr *CPEMI = CPEMIs[CPI]; 55531b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng unsigned MaxOffs = ((1 << Bits)-1) * Scale; 556d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng CPUsers.push_back(CPUser(I, CPEMI, MaxOffs, NegOk, IsSoImm)); 557c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng 558c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng // Increment corresponding CPEntry reference count. 559c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng CPEntry *CPE = findConstPoolEntry(CPI, CPEMI); 560c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng assert(CPE && "Cannot find a corresponding CPEntry!"); 561c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng CPE->RefCount++; 5628494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 563a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // Instructions can only use one CP entry, don't bother scanning the 564a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // rest of the operands. 565a8e2989ece6dc46df59b0768184028257f913843Evan Cheng break; 566a8e2989ece6dc46df59b0768184028257f913843Evan Cheng } 567a8e2989ece6dc46df59b0768184028257f913843Evan Cheng } 5682021abe154e3cac523755b74fc5e62a2c9dad1fcEvan Cheng 5698593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // In thumb mode, if this block is a constpool island, we may need padding 5708593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // so it's aligned on 4 byte boundary. 571b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen if (isThumb && 57205cc424082f797c5820b19f29f398c9cce9b9928Evan Cheng !MBB.empty() && 5738593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen MBB.begin()->getOpcode() == ARM::CONSTPOOL_ENTRY && 5748593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen (Offset%4) != 0) 5752021abe154e3cac523755b74fc5e62a2c9dad1fcEvan Cheng MBBSize += 2; 5762021abe154e3cac523755b74fc5e62a2c9dad1fcEvan Cheng 577a8e2989ece6dc46df59b0768184028257f913843Evan Cheng BBSizes.push_back(MBBSize); 57899c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen BBOffsets.push_back(Offset); 57999c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen Offset += MBBSize; 580a8e2989ece6dc46df59b0768184028257f913843Evan Cheng } 581a8e2989ece6dc46df59b0768184028257f913843Evan Cheng} 582a8e2989ece6dc46df59b0768184028257f913843Evan Cheng 583a8e2989ece6dc46df59b0768184028257f913843Evan Cheng/// GetOffsetOf - Return the current offset of the specified machine instruction 584a8e2989ece6dc46df59b0768184028257f913843Evan Cheng/// from the start of the function. This offset changes as stuff is moved 585a8e2989ece6dc46df59b0768184028257f913843Evan Cheng/// around inside the function. 586a8e2989ece6dc46df59b0768184028257f913843Evan Chengunsigned ARMConstantIslands::GetOffsetOf(MachineInstr *MI) const { 587a8e2989ece6dc46df59b0768184028257f913843Evan Cheng MachineBasicBlock *MBB = MI->getParent(); 5888494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 589a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // The offset is composed of two things: the sum of the sizes of all MBB's 590a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // before this instruction's block, and the offset from the start of the block 591a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // it is in. 59299c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen unsigned Offset = BBOffsets[MBB->getNumber()]; 593a8e2989ece6dc46df59b0768184028257f913843Evan Cheng 5948593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // If we're looking for a CONSTPOOL_ENTRY in Thumb, see if this block has 5958593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // alignment padding, and compensate if so. 5968494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson if (isThumb && 5978494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson MI->getOpcode() == ARM::CONSTPOOL_ENTRY && 5988593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen Offset%4 != 0) 5998593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen Offset += 2; 6008593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen 601a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // Sum instructions before MI in MBB. 602a8e2989ece6dc46df59b0768184028257f913843Evan Cheng for (MachineBasicBlock::iterator I = MBB->begin(); ; ++I) { 603a8e2989ece6dc46df59b0768184028257f913843Evan Cheng assert(I != MBB->end() && "Didn't find MI in its own basic block?"); 604a8e2989ece6dc46df59b0768184028257f913843Evan Cheng if (&*I == MI) return Offset; 60552e724ad7e679ee590f4bd763d55280586a8f1bcNicolas Geoffray Offset += TII->GetInstSizeInBytes(I); 606a8e2989ece6dc46df59b0768184028257f913843Evan Cheng } 607a8e2989ece6dc46df59b0768184028257f913843Evan Cheng} 608a8e2989ece6dc46df59b0768184028257f913843Evan Cheng 609a8e2989ece6dc46df59b0768184028257f913843Evan Cheng/// CompareMBBNumbers - Little predicate function to sort the WaterList by MBB 610a8e2989ece6dc46df59b0768184028257f913843Evan Cheng/// ID. 611a8e2989ece6dc46df59b0768184028257f913843Evan Chengstatic bool CompareMBBNumbers(const MachineBasicBlock *LHS, 612a8e2989ece6dc46df59b0768184028257f913843Evan Cheng const MachineBasicBlock *RHS) { 613a8e2989ece6dc46df59b0768184028257f913843Evan Cheng return LHS->getNumber() < RHS->getNumber(); 614a8e2989ece6dc46df59b0768184028257f913843Evan Cheng} 615a8e2989ece6dc46df59b0768184028257f913843Evan Cheng 616a8e2989ece6dc46df59b0768184028257f913843Evan Cheng/// UpdateForInsertedWaterBlock - When a block is newly inserted into the 617a8e2989ece6dc46df59b0768184028257f913843Evan Cheng/// machine function, it upsets all of the block numbers. Renumber the blocks 618a8e2989ece6dc46df59b0768184028257f913843Evan Cheng/// and update the arrays that parallel this numbering. 619a8e2989ece6dc46df59b0768184028257f913843Evan Chengvoid ARMConstantIslands::UpdateForInsertedWaterBlock(MachineBasicBlock *NewBB) { 620a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // Renumber the MBB's to keep them consequtive. 621a8e2989ece6dc46df59b0768184028257f913843Evan Cheng NewBB->getParent()->RenumberBlocks(NewBB); 6228494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 623a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // Insert a size into BBSizes to align it properly with the (newly 624a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // renumbered) block numbers. 625a8e2989ece6dc46df59b0768184028257f913843Evan Cheng BBSizes.insert(BBSizes.begin()+NewBB->getNumber(), 0); 62699c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen 62799c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen // Likewise for BBOffsets. 62899c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen BBOffsets.insert(BBOffsets.begin()+NewBB->getNumber(), 0); 6298494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 6308494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson // Next, update WaterList. Specifically, we need to add NewMBB as having 631a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // available water after it. 632034de5f65f9139954cb01d94eaebbaefd294946eBob Wilson water_iterator IP = 633a8e2989ece6dc46df59b0768184028257f913843Evan Cheng std::lower_bound(WaterList.begin(), WaterList.end(), NewBB, 634a8e2989ece6dc46df59b0768184028257f913843Evan Cheng CompareMBBNumbers); 635a8e2989ece6dc46df59b0768184028257f913843Evan Cheng WaterList.insert(IP, NewBB); 636a8e2989ece6dc46df59b0768184028257f913843Evan Cheng} 637a8e2989ece6dc46df59b0768184028257f913843Evan Cheng 638a8e2989ece6dc46df59b0768184028257f913843Evan Cheng 639a8e2989ece6dc46df59b0768184028257f913843Evan Cheng/// Split the basic block containing MI into two blocks, which are joined by 640b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson/// an unconditional branch. Update data structures and renumber blocks to 6410c61584d05894a5543f690803191a8b0da05b8fcEvan Cheng/// account for this change and returns the newly created block. 6420c61584d05894a5543f690803191a8b0da05b8fcEvan ChengMachineBasicBlock *ARMConstantIslands::SplitBlockBeforeInstr(MachineInstr *MI) { 643a8e2989ece6dc46df59b0768184028257f913843Evan Cheng MachineBasicBlock *OrigBB = MI->getParent(); 6448e5f2c6f65841542e2a7092553fe42a00048e4c7Dan Gohman MachineFunction &MF = *OrigBB->getParent(); 645a8e2989ece6dc46df59b0768184028257f913843Evan Cheng 646a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // Create a new MBB for the code after the OrigBB. 6478494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson MachineBasicBlock *NewBB = 6488494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson MF.CreateMachineBasicBlock(OrigBB->getBasicBlock()); 649a8e2989ece6dc46df59b0768184028257f913843Evan Cheng MachineFunction::iterator MBBI = OrigBB; ++MBBI; 6508e5f2c6f65841542e2a7092553fe42a00048e4c7Dan Gohman MF.insert(MBBI, NewBB); 6518494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 652a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // Splice the instructions starting with MI over to NewBB. 653a8e2989ece6dc46df59b0768184028257f913843Evan Cheng NewBB->splice(NewBB->end(), OrigBB, MI, OrigBB->end()); 6548494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 655a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // Add an unconditional branch from OrigBB to NewBB. 656a9b8b8d62c67e96bc4dc2ed25298c539102f8638Evan Cheng // Note the new unconditional branch is not being recorded. 657b67284057ee130114055309eabe0bcd1af13777dDale Johannesen // There doesn't seem to be meaningful DebugInfo available; this doesn't 658b67284057ee130114055309eabe0bcd1af13777dDale Johannesen // correspond to anything in the source. 65958541fd62707b6856beee3db9e254b0110607bb1Evan Cheng unsigned Opc = isThumb ? (isThumb2 ? ARM::t2B : ARM::tB) : ARM::B; 66058541fd62707b6856beee3db9e254b0110607bb1Evan Cheng BuildMI(OrigBB, DebugLoc::getUnknownLoc(), TII->get(Opc)).addMBB(NewBB); 661a8e2989ece6dc46df59b0768184028257f913843Evan Cheng NumSplit++; 6628494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 663a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // Update the CFG. All succs of OrigBB are now succs of NewBB. 664a8e2989ece6dc46df59b0768184028257f913843Evan Cheng while (!OrigBB->succ_empty()) { 665a8e2989ece6dc46df59b0768184028257f913843Evan Cheng MachineBasicBlock *Succ = *OrigBB->succ_begin(); 666a8e2989ece6dc46df59b0768184028257f913843Evan Cheng OrigBB->removeSuccessor(Succ); 667a8e2989ece6dc46df59b0768184028257f913843Evan Cheng NewBB->addSuccessor(Succ); 6688494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 669a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // This pass should be run after register allocation, so there should be no 670a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // PHI nodes to update. 671a8e2989ece6dc46df59b0768184028257f913843Evan Cheng assert((Succ->empty() || Succ->begin()->getOpcode() != TargetInstrInfo::PHI) 672a8e2989ece6dc46df59b0768184028257f913843Evan Cheng && "PHI nodes should be eliminated by now!"); 673a8e2989ece6dc46df59b0768184028257f913843Evan Cheng } 6748494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 675a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // OrigBB branches to NewBB. 676a8e2989ece6dc46df59b0768184028257f913843Evan Cheng OrigBB->addSuccessor(NewBB); 6778494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 678a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // Update internal data structures to account for the newly inserted MBB. 67988e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen // This is almost the same as UpdateForInsertedWaterBlock, except that 68088e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen // the Water goes after OrigBB, not NewBB. 6818e5f2c6f65841542e2a7092553fe42a00048e4c7Dan Gohman MF.RenumberBlocks(NewBB); 6828494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 68388e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen // Insert a size into BBSizes to align it properly with the (newly 68488e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen // renumbered) block numbers. 68588e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen BBSizes.insert(BBSizes.begin()+NewBB->getNumber(), 0); 6868494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 68799c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen // Likewise for BBOffsets. 68899c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen BBOffsets.insert(BBOffsets.begin()+NewBB->getNumber(), 0); 68999c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen 6908494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson // Next, update WaterList. Specifically, we need to add OrigMBB as having 69188e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen // available water after it (but not if it's already there, which happens 69288e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen // when splitting before a conditional branch that is followed by an 69388e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen // unconditional branch - in that case we want to insert NewBB). 694034de5f65f9139954cb01d94eaebbaefd294946eBob Wilson water_iterator IP = 69588e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen std::lower_bound(WaterList.begin(), WaterList.end(), OrigBB, 69688e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen CompareMBBNumbers); 69788e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen MachineBasicBlock* WaterBB = *IP; 69888e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen if (WaterBB == OrigBB) 69988e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen WaterList.insert(next(IP), NewBB); 70088e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen else 70188e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen WaterList.insert(IP, OrigBB); 702b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson NewWaterList.insert(OrigBB); 70388e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen 7048593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // Figure out how large the first NewMBB is. (It cannot 7058593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // contain a constpool_entry or tablejump.) 706a8e2989ece6dc46df59b0768184028257f913843Evan Cheng unsigned NewBBSize = 0; 707a8e2989ece6dc46df59b0768184028257f913843Evan Cheng for (MachineBasicBlock::iterator I = NewBB->begin(), E = NewBB->end(); 708a8e2989ece6dc46df59b0768184028257f913843Evan Cheng I != E; ++I) 70952e724ad7e679ee590f4bd763d55280586a8f1bcNicolas Geoffray NewBBSize += TII->GetInstSizeInBytes(I); 7108494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 71199c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen unsigned OrigBBI = OrigBB->getNumber(); 71299c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen unsigned NewBBI = NewBB->getNumber(); 713a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // Set the size of NewBB in BBSizes. 71499c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen BBSizes[NewBBI] = NewBBSize; 7158494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 716a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // We removed instructions from UserMBB, subtract that off from its size. 717af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng // Add 2 or 4 to the block to count the unconditional branch we added to it. 71825f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng int delta = isThumb1 ? 2 : 4; 71999c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen BBSizes[OrigBBI] -= NewBBSize - delta; 72099c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen 72199c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen // ...and adjust BBOffsets for NewBB accordingly. 72299c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen BBOffsets[NewBBI] = BBOffsets[OrigBBI] + BBSizes[OrigBBI]; 72399c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen 72499c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen // All BBOffsets following these blocks must be modified. 72599c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen AdjustBBOffsetsAfter(NewBB, delta); 7260c61584d05894a5543f690803191a8b0da05b8fcEvan Cheng 7270c61584d05894a5543f690803191a8b0da05b8fcEvan Cheng return NewBB; 728a8e2989ece6dc46df59b0768184028257f913843Evan Cheng} 729a8e2989ece6dc46df59b0768184028257f913843Evan Cheng 7308593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen/// OffsetIsInRange - Checks whether UserOffset (the location of a constant pool 7318494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson/// reference) is within MaxDisp of TrialOffset (a proposed location of a 7328593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen/// constant pool entry). 7338494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilsonbool ARMConstantIslands::OffsetIsInRange(unsigned UserOffset, 734d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng unsigned TrialOffset, unsigned MaxDisp, 735d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng bool NegativeOK, bool IsSoImm) { 7368494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson // On Thumb offsets==2 mod 4 are rounded down by the hardware for 7378494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson // purposes of the displacement computation; compensate for that here. 7388593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // Effectively, the valid range of displacements is 2 bytes smaller for such 7398593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // references. 74031b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng unsigned TotalAdj = 0; 74131b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng if (isThumb && UserOffset%4 !=0) { 7428593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen UserOffset -= 2; 74331b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng TotalAdj = 2; 74431b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng } 7458593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // CPEs will be rounded up to a multiple of 4. 74631b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng if (isThumb && TrialOffset%4 != 0) { 7478593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen TrialOffset += 2; 74831b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng TotalAdj += 2; 74931b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng } 75031b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng 75131b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng // In Thumb2 mode, later branch adjustments can shift instructions up and 75231b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng // cause alignment change. In the worst case scenario this can cause the 75331b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng // user's effective address to be subtracted by 2 and the CPE's address to 75431b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng // be plus 2. 75531b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng if (isThumb2 && TotalAdj != 4) 75631b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng MaxDisp -= (4 - TotalAdj); 7578593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen 75899c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen if (UserOffset <= TrialOffset) { 75999c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen // User before the Trial. 760d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng if (TrialOffset - UserOffset <= MaxDisp) 761d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng return true; 76240efc251cd7a52dd2375ec95ee38b1be4572178fEvan Cheng // FIXME: Make use full range of soimm values. 76399c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen } else if (NegativeOK) { 764d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng if (UserOffset - TrialOffset <= MaxDisp) 765d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng return true; 76640efc251cd7a52dd2375ec95ee38b1be4572178fEvan Cheng // FIXME: Make use full range of soimm values. 76799c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen } 76899c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen return false; 76999c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen} 77099c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen 77188e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen/// WaterIsInRange - Returns true if a CPE placed after the specified 77288e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen/// Water (a basic block) will be in range for the specific MI. 77388e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen 77488e37ae36652546c8e409cab69a1777af63cf095Dale Johannesenbool ARMConstantIslands::WaterIsInRange(unsigned UserOffset, 7755d8f1cae76e4e424bf3b4392eddb3f4dbf38662aEvan Cheng MachineBasicBlock* Water, CPUser &U) { 7765d9c4b60204d741c213456e21b87e9af6a3dc627Dale Johannesen unsigned MaxDisp = U.MaxDisp; 7778494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson unsigned CPEOffset = BBOffsets[Water->getNumber()] + 77888e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen BBSizes[Water->getNumber()]; 77988e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen 780d959aa421a8d14fc5aad29141f816db8f4362c7fDale Johannesen // If the CPE is to be inserted before the instruction, that will raise 781af4b7352193e4a024d4a4e87cac1ba1589e4de57Bob Wilson // the offset of the instruction. 782d959aa421a8d14fc5aad29141f816db8f4362c7fDale Johannesen if (CPEOffset < UserOffset) 7835d9c4b60204d741c213456e21b87e9af6a3dc627Dale Johannesen UserOffset += U.CPEMI->getOperand(2).getImm(); 784d959aa421a8d14fc5aad29141f816db8f4362c7fDale Johannesen 785d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng return OffsetIsInRange(UserOffset, CPEOffset, MaxDisp, U.NegOk, U.IsSoImm); 78688e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen} 78788e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen 78888e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen/// CPEIsInRange - Returns true if the distance between specific MI and 789c0dbec7e1038ee60b8525eb1e8e3eaa6a839bd5bEvan Cheng/// specific ConstPool entry instruction can fit in MI's displacement field. 79088e37ae36652546c8e409cab69a1777af63cf095Dale Johannesenbool ARMConstantIslands::CPEIsInRange(MachineInstr *MI, unsigned UserOffset, 7915d8f1cae76e4e424bf3b4392eddb3f4dbf38662aEvan Cheng MachineInstr *CPEMI, unsigned MaxDisp, 7925d8f1cae76e4e424bf3b4392eddb3f4dbf38662aEvan Cheng bool NegOk, bool DoDump) { 7938593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen unsigned CPEOffset = GetOffsetOf(CPEMI); 7948593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen assert(CPEOffset%4 == 0 && "Misaligned CPE"); 7952021abe154e3cac523755b74fc5e62a2c9dad1fcEvan Cheng 79688e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen if (DoDump) { 797705e07f578e2b3af47ddab610feb4e7f2d3063a5Chris Lattner DEBUG(errs() << "User of CPE#" << CPEMI->getOperand(0).getImm() 798705e07f578e2b3af47ddab610feb4e7f2d3063a5Chris Lattner << " max delta=" << MaxDisp 799705e07f578e2b3af47ddab610feb4e7f2d3063a5Chris Lattner << " insn address=" << UserOffset 800705e07f578e2b3af47ddab610feb4e7f2d3063a5Chris Lattner << " CPE address=" << CPEOffset 801705e07f578e2b3af47ddab610feb4e7f2d3063a5Chris Lattner << " offset=" << int(CPEOffset-UserOffset) << "\t" << *MI); 80288e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen } 803a8e2989ece6dc46df59b0768184028257f913843Evan Cheng 8045d8f1cae76e4e424bf3b4392eddb3f4dbf38662aEvan Cheng return OffsetIsInRange(UserOffset, CPEOffset, MaxDisp, NegOk); 805c0dbec7e1038ee60b8525eb1e8e3eaa6a839bd5bEvan Cheng} 806c0dbec7e1038ee60b8525eb1e8e3eaa6a839bd5bEvan Cheng 807d1e7d9a88b5f4fa5e9a85affc4599c650c591ffbEvan Cheng#ifndef NDEBUG 808c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng/// BBIsJumpedOver - Return true of the specified basic block's only predecessor 809c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng/// unconditionally branches to its only successor. 810c99ef085b90b32952b484e8843fb66ad65215b61Evan Chengstatic bool BBIsJumpedOver(MachineBasicBlock *MBB) { 811c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng if (MBB->pred_size() != 1 || MBB->succ_size() != 1) 812c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng return false; 813c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng 814c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng MachineBasicBlock *Succ = *MBB->succ_begin(); 815c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng MachineBasicBlock *Pred = *MBB->pred_begin(); 816c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng MachineInstr *PredMI = &Pred->back(); 8175e47a9a6e46bd271eba058fb831da1a1edf8707cDavid Goodwin if (PredMI->getOpcode() == ARM::B || PredMI->getOpcode() == ARM::tB 8185e47a9a6e46bd271eba058fb831da1a1edf8707cDavid Goodwin || PredMI->getOpcode() == ARM::t2B) 819c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng return PredMI->getOperand(0).getMBB() == Succ; 820c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng return false; 821c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng} 822d1e7d9a88b5f4fa5e9a85affc4599c650c591ffbEvan Cheng#endif // NDEBUG 823c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng 8248494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilsonvoid ARMConstantIslands::AdjustBBOffsetsAfter(MachineBasicBlock *BB, 8258593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen int delta) { 8268593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen MachineFunction::iterator MBBI = BB; MBBI = next(MBBI); 827d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng for(unsigned i = BB->getNumber()+1, e = BB->getParent()->getNumBlockIDs(); 828d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng i < e; ++i) { 82999c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen BBOffsets[i] += delta; 8308593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // If some existing blocks have padding, adjust the padding as needed, a 8318593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // bit tricky. delta can be negative so don't use % on that. 832d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng if (!isThumb) 833d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng continue; 834d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng MachineBasicBlock *MBB = MBBI; 835d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng if (!MBB->empty()) { 836d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng // Constant pool entries require padding. 837d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng if (MBB->begin()->getOpcode() == ARM::CONSTPOOL_ENTRY) { 8384a8ea215e69e9ca19c8acf1c236b73860188a023Evan Cheng unsigned OldOffset = BBOffsets[i] - delta; 8394a8ea215e69e9ca19c8acf1c236b73860188a023Evan Cheng if ((OldOffset%4) == 0 && (BBOffsets[i]%4) != 0) { 840d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng // add new padding 841d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng BBSizes[i] += 2; 842d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng delta += 2; 8434a8ea215e69e9ca19c8acf1c236b73860188a023Evan Cheng } else if ((OldOffset%4) != 0 && (BBOffsets[i]%4) == 0) { 844d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng // remove existing padding 8454a8ea215e69e9ca19c8acf1c236b73860188a023Evan Cheng BBSizes[i] -= 2; 846d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng delta -= 2; 8478593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen } 848d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng } 849d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng // Thumb1 jump tables require padding. They should be at the end; 850d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng // following unconditional branches are removed by AnalyzeBranch. 851789476240d6b6f8ad9366cadf790a82bd41bb0b3Evan Cheng MachineInstr *ThumbJTMI = prior(MBB->end()); 85266ac53165e17b7c76b8c69e57bde623d44ec492eEvan Cheng if (ThumbJTMI->getOpcode() == ARM::tBR_JTr) { 8534a8ea215e69e9ca19c8acf1c236b73860188a023Evan Cheng unsigned NewMIOffset = GetOffsetOf(ThumbJTMI); 8544a8ea215e69e9ca19c8acf1c236b73860188a023Evan Cheng unsigned OldMIOffset = NewMIOffset - delta; 8554a8ea215e69e9ca19c8acf1c236b73860188a023Evan Cheng if ((OldMIOffset%4) == 0 && (NewMIOffset%4) != 0) { 856d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng // remove existing padding 857d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng BBSizes[i] -= 2; 858d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng delta -= 2; 8594a8ea215e69e9ca19c8acf1c236b73860188a023Evan Cheng } else if ((OldMIOffset%4) != 0 && (NewMIOffset%4) == 0) { 860d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng // add new padding 861d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng BBSizes[i] += 2; 862d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng delta += 2; 8638593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen } 8648593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen } 865d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng if (delta==0) 866d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng return; 8678593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen } 868d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng MBBI = next(MBBI); 8698593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen } 87099c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen} 87199c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen 87288e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen/// DecrementOldEntry - find the constant pool entry with index CPI 87388e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen/// and instruction CPEMI, and decrement its refcount. If the refcount 8748494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson/// becomes 0 remove the entry and instruction. Returns true if we removed 87588e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen/// the entry, false if we didn't. 876b43216ee4a418257ce5530c02601b77efe86c354Evan Cheng 877ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Chengbool ARMConstantIslands::DecrementOldEntry(unsigned CPI, MachineInstr *CPEMI) { 878c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng // Find the old entry. Eliminate it if it is no longer used. 879ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng CPEntry *CPE = findConstPoolEntry(CPI, CPEMI); 880ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng assert(CPE && "Unexpected!"); 881ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng if (--CPE->RefCount == 0) { 882ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng RemoveDeadCPEMI(CPEMI); 883ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng CPE->CPEMI = NULL; 884c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng NumCPEs--; 88588e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen return true; 88688e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen } 88788e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen return false; 88888e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen} 88988e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen 89088e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen/// LookForCPEntryInRange - see if the currently referenced CPE is in range; 89188e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen/// if not, see if an in-range clone of the CPE is in range, and if so, 89288e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen/// change the data structures so the user references the clone. Returns: 89388e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen/// 0 = no existing entry found 89488e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen/// 1 = entry found, and there were no code insertions or deletions 89588e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen/// 2 = entry found, and there were code insertions or deletions 89688e37ae36652546c8e409cab69a1777af63cf095Dale Johannesenint ARMConstantIslands::LookForExistingCPEntry(CPUser& U, unsigned UserOffset) 89788e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen{ 89888e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen MachineInstr *UserMI = U.MI; 89988e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen MachineInstr *CPEMI = U.CPEMI; 90088e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen 90188e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen // Check to see if the CPE is already in-range. 9025d8f1cae76e4e424bf3b4392eddb3f4dbf38662aEvan Cheng if (CPEIsInRange(UserMI, UserOffset, CPEMI, U.MaxDisp, U.NegOk, true)) { 903893e1c90a03a53cf13f73849324e83612688428aChris Lattner DEBUG(errs() << "In range\n"); 90488e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen return 1; 905c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng } 906c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng 90788e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen // No. Look for previously created clones of the CPE that are in range. 9088aa797aa51cd4ea1ec6f46f4891a6897944b75b2Chris Lattner unsigned CPI = CPEMI->getOperand(1).getIndex(); 90988e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen std::vector<CPEntry> &CPEs = CPEntries[CPI]; 91088e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen for (unsigned i = 0, e = CPEs.size(); i != e; ++i) { 91188e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen // We already tried this one 91288e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen if (CPEs[i].CPEMI == CPEMI) 91388e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen continue; 91488e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen // Removing CPEs can leave empty entries, skip 91588e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen if (CPEs[i].CPEMI == NULL) 91688e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen continue; 9175d8f1cae76e4e424bf3b4392eddb3f4dbf38662aEvan Cheng if (CPEIsInRange(UserMI, UserOffset, CPEs[i].CPEMI, U.MaxDisp, U.NegOk)) { 918893e1c90a03a53cf13f73849324e83612688428aChris Lattner DEBUG(errs() << "Replacing CPE#" << CPI << " with CPE#" 919893e1c90a03a53cf13f73849324e83612688428aChris Lattner << CPEs[i].CPI << "\n"); 92088e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen // Point the CPUser node to the replacement 92188e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen U.CPEMI = CPEs[i].CPEMI; 92288e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen // Change the CPI in the instruction operand to refer to the clone. 92388e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen for (unsigned j = 0, e = UserMI->getNumOperands(); j != e; ++j) 924d735b8019b0f297d7c14b55adcd887af24d8e602Dan Gohman if (UserMI->getOperand(j).isCPI()) { 9258aa797aa51cd4ea1ec6f46f4891a6897944b75b2Chris Lattner UserMI->getOperand(j).setIndex(CPEs[i].CPI); 92688e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen break; 92788e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen } 92888e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen // Adjust the refcount of the clone... 92988e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen CPEs[i].RefCount++; 93088e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen // ...and the original. If we didn't remove the old entry, none of the 93188e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen // addresses changed, so we don't need another pass. 932ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng return DecrementOldEntry(CPI, CPEMI) ? 2 : 1; 93388e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen } 93488e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen } 93588e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen return 0; 93688e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen} 93788e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen 938f1b214d3ca12f2d85f0d092b4920172bcc797bacDale Johannesen/// getUnconditionalBrDisp - Returns the maximum displacement that can fit in 939f1b214d3ca12f2d85f0d092b4920172bcc797bacDale Johannesen/// the specific unconditional branch instruction. 940f1b214d3ca12f2d85f0d092b4920172bcc797bacDale Johannesenstatic inline unsigned getUnconditionalBrDisp(int Opc) { 9415e47a9a6e46bd271eba058fb831da1a1edf8707cDavid Goodwin switch (Opc) { 9425e47a9a6e46bd271eba058fb831da1a1edf8707cDavid Goodwin case ARM::tB: 9435e47a9a6e46bd271eba058fb831da1a1edf8707cDavid Goodwin return ((1<<10)-1)*2; 9445e47a9a6e46bd271eba058fb831da1a1edf8707cDavid Goodwin case ARM::t2B: 9455e47a9a6e46bd271eba058fb831da1a1edf8707cDavid Goodwin return ((1<<23)-1)*2; 9465e47a9a6e46bd271eba058fb831da1a1edf8707cDavid Goodwin default: 9475e47a9a6e46bd271eba058fb831da1a1edf8707cDavid Goodwin break; 9485e47a9a6e46bd271eba058fb831da1a1edf8707cDavid Goodwin } 949764ab52dd80310a205c9888bf166d09dab858f90Jim Grosbach 9505e47a9a6e46bd271eba058fb831da1a1edf8707cDavid Goodwin return ((1<<23)-1)*4; 951f1b214d3ca12f2d85f0d092b4920172bcc797bacDale Johannesen} 952f1b214d3ca12f2d85f0d092b4920172bcc797bacDale Johannesen 953b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson/// LookForWater - Look for an existing entry in the WaterList in which 954b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen/// we can place the CPE referenced from U so it's within range of U's MI. 955b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson/// Returns true if found, false if not. If it returns true, WaterIter 956f98032ef64a777fe63d390539f901d7d6d4e868cBob Wilson/// is set to the WaterList entry. For Thumb, prefer water that will not 957f98032ef64a777fe63d390539f901d7d6d4e868cBob Wilson/// introduce padding to water that will. To ensure that this pass 958f98032ef64a777fe63d390539f901d7d6d4e868cBob Wilson/// terminates, the CPE location for a particular CPUser is only allowed to 959f98032ef64a777fe63d390539f901d7d6d4e868cBob Wilson/// move to a lower address, so search backward from the end of the list and 960f98032ef64a777fe63d390539f901d7d6d4e868cBob Wilson/// prefer the first water that is in range. 961b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesenbool ARMConstantIslands::LookForWater(CPUser &U, unsigned UserOffset, 962b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson water_iterator &WaterIter) { 9633b7573517ccd0f8f9e4bc64cf1923bae68e40d3fBob Wilson if (WaterList.empty()) 9643b7573517ccd0f8f9e4bc64cf1923bae68e40d3fBob Wilson return false; 9653b7573517ccd0f8f9e4bc64cf1923bae68e40d3fBob Wilson 96632c50e8f9920bb7835eb42926945c9a1e6385de5Bob Wilson bool FoundWaterThatWouldPad = false; 96732c50e8f9920bb7835eb42926945c9a1e6385de5Bob Wilson water_iterator IPThatWouldPad; 9683b7573517ccd0f8f9e4bc64cf1923bae68e40d3fBob Wilson for (water_iterator IP = prior(WaterList.end()), 9693b7573517ccd0f8f9e4bc64cf1923bae68e40d3fBob Wilson B = WaterList.begin();; --IP) { 9703b7573517ccd0f8f9e4bc64cf1923bae68e40d3fBob Wilson MachineBasicBlock* WaterBB = *IP; 971b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson // Check if water is in range and is either at a lower address than the 972b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson // current "high water mark" or a new water block that was created since 973b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson // the previous iteration by inserting an unconditional branch. In the 974b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson // latter case, we want to allow resetting the high water mark back to 975b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson // this new water since we haven't seen it before. Inserting branches 976b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson // should be relatively uncommon and when it does happen, we want to be 977b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson // sure to take advantage of it for all the CPEs near that block, so that 978b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson // we don't insert more branches than necessary. 979b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson if (WaterIsInRange(UserOffset, WaterBB, U) && 980b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson (WaterBB->getNumber() < U.HighWaterMark->getNumber() || 981b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson NewWaterList.count(WaterBB))) { 9823b7573517ccd0f8f9e4bc64cf1923bae68e40d3fBob Wilson unsigned WBBId = WaterBB->getNumber(); 9833b7573517ccd0f8f9e4bc64cf1923bae68e40d3fBob Wilson if (isThumb && 9843b7573517ccd0f8f9e4bc64cf1923bae68e40d3fBob Wilson (BBOffsets[WBBId] + BBSizes[WBBId])%4 != 0) { 9853b7573517ccd0f8f9e4bc64cf1923bae68e40d3fBob Wilson // This is valid Water, but would introduce padding. Remember 9863b7573517ccd0f8f9e4bc64cf1923bae68e40d3fBob Wilson // it in case we don't find any Water that doesn't do this. 98732c50e8f9920bb7835eb42926945c9a1e6385de5Bob Wilson if (!FoundWaterThatWouldPad) { 98832c50e8f9920bb7835eb42926945c9a1e6385de5Bob Wilson FoundWaterThatWouldPad = true; 9893b7573517ccd0f8f9e4bc64cf1923bae68e40d3fBob Wilson IPThatWouldPad = IP; 990f1b214d3ca12f2d85f0d092b4920172bcc797bacDale Johannesen } 9913b7573517ccd0f8f9e4bc64cf1923bae68e40d3fBob Wilson } else { 992b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson WaterIter = IP; 9933b7573517ccd0f8f9e4bc64cf1923bae68e40d3fBob Wilson return true; 994d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng } 99588e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen } 9963b7573517ccd0f8f9e4bc64cf1923bae68e40d3fBob Wilson if (IP == B) 9973b7573517ccd0f8f9e4bc64cf1923bae68e40d3fBob Wilson break; 99888e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen } 99932c50e8f9920bb7835eb42926945c9a1e6385de5Bob Wilson if (FoundWaterThatWouldPad) { 1000b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson WaterIter = IPThatWouldPad; 10018593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen return true; 10028593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen } 1003b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen return false; 1004b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen} 100588e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen 10068494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson/// CreateNewWater - No existing WaterList entry will work for 1007b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen/// CPUsers[CPUserIndex], so create a place to put the CPE. The end of the 1008b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen/// block is used if in range, and the conditional branch munged so control 1009b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen/// flow is correct. Otherwise the block is split to create a hole with an 1010757652c5ba820bbea75d8713d7bf3749e4113778Bob Wilson/// unconditional branch around it. In either case NewMBB is set to a 1011b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen/// block following which the new island can be inserted (the WaterList 1012b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen/// is not adjusted). 10138494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilsonvoid ARMConstantIslands::CreateNewWater(unsigned CPUserIndex, 1014757652c5ba820bbea75d8713d7bf3749e4113778Bob Wilson unsigned UserOffset, 1015757652c5ba820bbea75d8713d7bf3749e4113778Bob Wilson MachineBasicBlock *&NewMBB) { 1016b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen CPUser &U = CPUsers[CPUserIndex]; 1017b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen MachineInstr *UserMI = U.MI; 1018b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen MachineInstr *CPEMI = U.CPEMI; 1019b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen MachineBasicBlock *UserMBB = UserMI->getParent(); 10208494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson unsigned OffsetOfNextBlock = BBOffsets[UserMBB->getNumber()] + 1021b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen BBSizes[UserMBB->getNumber()]; 10228593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen assert(OffsetOfNextBlock== BBOffsets[UserMBB->getNumber()+1]); 1023b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen 102436fa5321bacf351f47d6193f56c464e6ab93b934Bob Wilson // If the block does not end in an unconditional branch already, and if the 102536fa5321bacf351f47d6193f56c464e6ab93b934Bob Wilson // end of the block is within range, make new water there. (The addition 102636fa5321bacf351f47d6193f56c464e6ab93b934Bob Wilson // below is for the unconditional branch we will be adding: 4 bytes on ARM + 102736fa5321bacf351f47d6193f56c464e6ab93b934Bob Wilson // Thumb2, 2 on Thumb1. Possible Thumb1 alignment padding is allowed for 10288593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // inside OffsetIsInRange. 102936fa5321bacf351f47d6193f56c464e6ab93b934Bob Wilson if (BBHasFallthrough(UserMBB) && 1030d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng OffsetIsInRange(UserOffset, OffsetOfNextBlock + (isThumb1 ? 2: 4), 1031d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng U.MaxDisp, U.NegOk, U.IsSoImm)) { 1032893e1c90a03a53cf13f73849324e83612688428aChris Lattner DEBUG(errs() << "Split at end of block\n"); 1033b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen if (&UserMBB->back() == UserMI) 1034b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen assert(BBHasFallthrough(UserMBB) && "Expected a fallthrough BB!"); 1035757652c5ba820bbea75d8713d7bf3749e4113778Bob Wilson NewMBB = next(MachineFunction::iterator(UserMBB)); 1036b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen // Add an unconditional branch from UserMBB to fallthrough block. 1037b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen // Record it for branch lengthening; this new branch will not get out of 1038b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen // range, but if the preceding conditional branch is out of range, the 1039b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen // targets will be exchanged, and the altered branch may be out of 1040b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen // range, so the machinery has to know about it. 10415e47a9a6e46bd271eba058fb831da1a1edf8707cDavid Goodwin int UncondBr = isThumb ? ((isThumb2) ? ARM::t2B : ARM::tB) : ARM::B; 1042b67284057ee130114055309eabe0bcd1af13777dDale Johannesen BuildMI(UserMBB, DebugLoc::getUnknownLoc(), 1043757652c5ba820bbea75d8713d7bf3749e4113778Bob Wilson TII->get(UncondBr)).addMBB(NewMBB); 1044b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen unsigned MaxDisp = getUnconditionalBrDisp(UncondBr); 10458494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson ImmBranches.push_back(ImmBranch(&UserMBB->back(), 1046b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen MaxDisp, false, UncondBr)); 1047d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng int delta = isThumb1 ? 2 : 4; 1048b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen BBSizes[UserMBB->getNumber()] += delta; 1049b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen AdjustBBOffsetsAfter(UserMBB, delta); 1050b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen } else { 1051b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen // What a big block. Find a place within the block to split it. 1052d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng // This is a little tricky on Thumb1 since instructions are 2 bytes 1053b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen // and constant pool entries are 4 bytes: if instruction I references 1054b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen // island CPE, and instruction I+1 references CPE', it will 1055b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen // not work well to put CPE as far forward as possible, since then 1056b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen // CPE' cannot immediately follow it (that location is 2 bytes 1057b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen // farther away from I+1 than CPE was from I) and we'd need to create 10588593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // a new island. So, we make a first guess, then walk through the 10598593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // instructions between the one currently being looked at and the 10608593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // possible insertion point, and make sure any other instructions 10618593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // that reference CPEs will be able to use the same island area; 10628593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // if not, we back up the insertion point. 10638593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen 1064b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen // The 4 in the following is for the unconditional branch we'll be 1065d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng // inserting (allows for long branch on Thumb1). Alignment of the 10668593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // island is handled inside OffsetIsInRange. 10678593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen unsigned BaseInsertOffset = UserOffset + U.MaxDisp -4; 1068b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen // This could point off the end of the block if we've already got 1069b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen // constant pool entries following this block; only the last one is 1070b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen // in the water list. Back past any possible branches (allow for a 1071b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen // conditional and a maximally long unconditional). 1072b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen if (BaseInsertOffset >= BBOffsets[UserMBB->getNumber()+1]) 10738494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson BaseInsertOffset = BBOffsets[UserMBB->getNumber()+1] - 1074d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng (isThumb1 ? 6 : 8); 1075b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen unsigned EndInsertOffset = BaseInsertOffset + 1076b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen CPEMI->getOperand(2).getImm(); 1077b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen MachineBasicBlock::iterator MI = UserMI; 1078b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen ++MI; 1079b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen unsigned CPUIndex = CPUserIndex+1; 108052e724ad7e679ee590f4bd763d55280586a8f1bcNicolas Geoffray for (unsigned Offset = UserOffset+TII->GetInstSizeInBytes(UserMI); 1081b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen Offset < BaseInsertOffset; 108252e724ad7e679ee590f4bd763d55280586a8f1bcNicolas Geoffray Offset += TII->GetInstSizeInBytes(MI), 1083b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen MI = next(MI)) { 1084b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen if (CPUIndex < CPUsers.size() && CPUsers[CPUIndex].MI == MI) { 1085d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng CPUser &U = CPUsers[CPUIndex]; 10868494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson if (!OffsetIsInRange(Offset, EndInsertOffset, 1087d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng U.MaxDisp, U.NegOk, U.IsSoImm)) { 1088d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng BaseInsertOffset -= (isThumb1 ? 2 : 4); 1089d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng EndInsertOffset -= (isThumb1 ? 2 : 4); 1090f1b214d3ca12f2d85f0d092b4920172bcc797bacDale Johannesen } 1091b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen // This is overly conservative, as we don't account for CPEMIs 1092b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen // being reused within the block, but it doesn't matter much. 1093b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen EndInsertOffset += CPUsers[CPUIndex].CPEMI->getOperand(2).getImm(); 1094b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen CPUIndex++; 1095f1b214d3ca12f2d85f0d092b4920172bcc797bacDale Johannesen } 109688e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen } 1097893e1c90a03a53cf13f73849324e83612688428aChris Lattner DEBUG(errs() << "Split in middle of big block\n"); 1098757652c5ba820bbea75d8713d7bf3749e4113778Bob Wilson NewMBB = SplitBlockBeforeInstr(prior(MI)); 1099b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen } 1100b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen} 1101b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen 1102b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen/// HandleConstantPoolUser - Analyze the specified user, checking to see if it 110339bf051ec2865cd715c41473d2a9fc34ff252534Bob Wilson/// is out-of-range. If so, pick up the constant pool value and move it some 1104b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen/// place in-range. Return true if we changed any addresses (thus must run 1105b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen/// another pass of branch lengthening), false otherwise. 11065657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Chengbool ARMConstantIslands::HandleConstantPoolUser(MachineFunction &MF, 11078494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson unsigned CPUserIndex) { 1108b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen CPUser &U = CPUsers[CPUserIndex]; 1109b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen MachineInstr *UserMI = U.MI; 1110b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen MachineInstr *CPEMI = U.CPEMI; 11118aa797aa51cd4ea1ec6f46f4891a6897944b75b2Chris Lattner unsigned CPI = CPEMI->getOperand(1).getIndex(); 1112b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen unsigned Size = CPEMI->getOperand(2).getImm(); 11138593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // Compute this only once, it's expensive. The 4 or 8 is the value the 1114a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng // hardware keeps in the PC. 1115b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen unsigned UserOffset = GetOffsetOf(UserMI) + (isThumb ? 4 : 8); 1116768c9f725bda048b3406b6289beb586ff6e933dfEvan Cheng 1117b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen // See if the current entry is within range, or there is a clone of it 1118b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen // in range. 1119b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen int result = LookForExistingCPEntry(U, UserOffset); 1120b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen if (result==1) return false; 1121b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen else if (result==2) return true; 1122b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen 1123b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen // No existing clone of this CPE is within range. 1124b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen // We will be generating a new clone. Get a UID for it. 112539bf051ec2865cd715c41473d2a9fc34ff252534Bob Wilson unsigned ID = AFI->createConstPoolEntryUId(); 1126b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen 1127f98032ef64a777fe63d390539f901d7d6d4e868cBob Wilson // Look for water where we can place this CPE. 1128b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson MachineBasicBlock *NewIsland = MF.CreateMachineBasicBlock(); 1129b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson MachineBasicBlock *NewMBB; 1130b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson water_iterator IP; 1131b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson if (LookForWater(U, UserOffset, IP)) { 1132b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson DEBUG(errs() << "found water in range\n"); 1133b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson MachineBasicBlock *WaterBB = *IP; 1134b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson 1135b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson // If the original WaterList entry was "new water" on this iteration, 1136b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson // propagate that to the new island. This is just keeping NewWaterList 1137b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson // updated to match the WaterList, which will be updated below. 1138b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson if (NewWaterList.count(WaterBB)) { 1139b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson NewWaterList.erase(WaterBB); 1140b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson NewWaterList.insert(NewIsland); 1141b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson } 1142b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson // The new CPE goes before the following block (NewMBB). 1143b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson NewMBB = next(MachineFunction::iterator(WaterBB)); 1144b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson 1145b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson } else { 1146b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen // No water found. 1147893e1c90a03a53cf13f73849324e83612688428aChris Lattner DEBUG(errs() << "No water found\n"); 1148757652c5ba820bbea75d8713d7bf3749e4113778Bob Wilson CreateNewWater(CPUserIndex, UserOffset, NewMBB); 1149b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson 1150b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson // SplitBlockBeforeInstr adds to WaterList, which is important when it is 1151b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson // called while handling branches so that the water will be seen on the 1152b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson // next iteration for constant pools, but in this context, we don't want 1153b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson // it. Check for this so it will be removed from the WaterList. 1154b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson // Also remove any entry from NewWaterList. 1155b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson MachineBasicBlock *WaterBB = prior(MachineFunction::iterator(NewMBB)); 1156b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson IP = std::find(WaterList.begin(), WaterList.end(), WaterBB); 1157b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson if (IP != WaterList.end()) 1158b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson NewWaterList.erase(WaterBB); 1159b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson 1160b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson // We are adding new water. Update NewWaterList. 1161b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson NewWaterList.insert(NewIsland); 116288e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen } 116388e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen 1164b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson // Remove the original WaterList entry; we want subsequent insertions in 1165b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson // this vicinity to go after the one we're about to insert. This 1166b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson // considerably reduces the number of times we have to move the same CPE 1167b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson // more than once and is also important to ensure the algorithm terminates. 1168b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson if (IP != WaterList.end()) 1169b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson WaterList.erase(IP); 1170b923953733ee6b0f477cd767dcc16f94a0966158Bob Wilson 117188e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen // Okay, we know we can put an island before NewMBB now, do it! 11725657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng MF.insert(NewMBB, NewIsland); 117388e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen 117488e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen // Update internal data structures to account for the newly inserted MBB. 117588e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen UpdateForInsertedWaterBlock(NewIsland); 117688e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen 117788e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen // Decrement the old entry, and remove it if refcount becomes 0. 1178ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng DecrementOldEntry(CPI, CPEMI); 117988e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen 118088e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen // Now that we have an island to add the CPE to, clone the original CPE and 118188e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen // add it to the island. 1182549dda9d82a5ec0a0cbf429a18d33a8e66062424Bob Wilson U.HighWaterMark = NewIsland; 1183b67284057ee130114055309eabe0bcd1af13777dDale Johannesen U.CPEMI = BuildMI(NewIsland, DebugLoc::getUnknownLoc(), 1184b67284057ee130114055309eabe0bcd1af13777dDale Johannesen TII->get(ARM::CONSTPOOL_ENTRY)) 1185a8e2989ece6dc46df59b0768184028257f913843Evan Cheng .addImm(ID).addConstantPoolIndex(CPI).addImm(Size); 118688e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen CPEntries[CPI].push_back(CPEntry(U.CPEMI, ID, 1)); 1187c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng NumCPEs++; 1188c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng 11898593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen BBOffsets[NewIsland->getNumber()] = BBOffsets[NewMBB->getNumber()]; 1190b43216ee4a418257ce5530c02601b77efe86c354Evan Cheng // Compensate for .align 2 in thumb mode. 11918494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson if (isThumb && BBOffsets[NewIsland->getNumber()]%4 != 0) 11928593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen Size += 2; 1193a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // Increase the size of the island block to account for the new entry. 1194a8e2989ece6dc46df59b0768184028257f913843Evan Cheng BBSizes[NewIsland->getNumber()] += Size; 119599c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen AdjustBBOffsetsAfter(NewIsland, Size); 11968494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 1197a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // Finally, change the CPI in the instruction operand to be ID. 1198a8e2989ece6dc46df59b0768184028257f913843Evan Cheng for (unsigned i = 0, e = UserMI->getNumOperands(); i != e; ++i) 1199d735b8019b0f297d7c14b55adcd887af24d8e602Dan Gohman if (UserMI->getOperand(i).isCPI()) { 12008aa797aa51cd4ea1ec6f46f4891a6897944b75b2Chris Lattner UserMI->getOperand(i).setIndex(ID); 1201a8e2989ece6dc46df59b0768184028257f913843Evan Cheng break; 1202a8e2989ece6dc46df59b0768184028257f913843Evan Cheng } 12038494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 1204705e07f578e2b3af47ddab610feb4e7f2d3063a5Chris Lattner DEBUG(errs() << " Moved CPE to #" << ID << " CPI=" << CPI 1205705e07f578e2b3af47ddab610feb4e7f2d3063a5Chris Lattner << '\t' << *UserMI); 12068494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 1207a8e2989ece6dc46df59b0768184028257f913843Evan Cheng return true; 1208a8e2989ece6dc46df59b0768184028257f913843Evan Cheng} 1209a8e2989ece6dc46df59b0768184028257f913843Evan Cheng 1210ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng/// RemoveDeadCPEMI - Remove a dead constant pool entry instruction. Update 1211ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng/// sizes and offsets of impacted basic blocks. 1212ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Chengvoid ARMConstantIslands::RemoveDeadCPEMI(MachineInstr *CPEMI) { 1213ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng MachineBasicBlock *CPEBB = CPEMI->getParent(); 12148593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen unsigned Size = CPEMI->getOperand(2).getImm(); 12158593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen CPEMI->eraseFromParent(); 12168593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen BBSizes[CPEBB->getNumber()] -= Size; 12178593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // All succeeding offsets have the current size value added in, fix this. 1218ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng if (CPEBB->empty()) { 1219d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng // In thumb1 mode, the size of island may be padded by two to compensate for 12208593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // the alignment requirement. Then it will now be 2 when the block is 1221ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng // empty, so fix this. 1222ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng // All succeeding offsets have the current size value added in, fix this. 1223ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng if (BBSizes[CPEBB->getNumber()] != 0) { 12248593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen Size += BBSizes[CPEBB->getNumber()]; 1225ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng BBSizes[CPEBB->getNumber()] = 0; 1226ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng } 1227ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng } 12288593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen AdjustBBOffsetsAfter(CPEBB, -Size); 12298593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // An island has only one predecessor BB and one successor BB. Check if 12308593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // this BB's predecessor jumps directly to this BB's successor. This 12318593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // shouldn't happen currently. 12328593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen assert(!BBIsJumpedOver(CPEBB) && "How did this happen?"); 12338593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // FIXME: remove the empty blocks after all the work is done? 1234ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng} 1235ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng 1236ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng/// RemoveUnusedCPEntries - Remove constant pool entries whose refcounts 1237ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng/// are zero. 1238ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Chengbool ARMConstantIslands::RemoveUnusedCPEntries() { 1239ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng unsigned MadeChange = false; 1240ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng for (unsigned i = 0, e = CPEntries.size(); i != e; ++i) { 1241ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng std::vector<CPEntry> &CPEs = CPEntries[i]; 1242ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng for (unsigned j = 0, ee = CPEs.size(); j != ee; ++j) { 1243ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng if (CPEs[j].RefCount == 0 && CPEs[j].CPEMI) { 1244ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng RemoveDeadCPEMI(CPEs[j].CPEMI); 1245ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng CPEs[j].CPEMI = NULL; 1246ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng MadeChange = true; 1247ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng } 1248ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng } 12498494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson } 1250ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng return MadeChange; 1251ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng} 1252ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng 125388e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen/// BBIsInRange - Returns true if the distance between specific MI and 125443aeab68a69e443c528092b4424a498d813f96b7Evan Cheng/// specific BB can fit in MI's displacement field. 1255c0dbec7e1038ee60b8525eb1e8e3eaa6a839bd5bEvan Chengbool ARMConstantIslands::BBIsInRange(MachineInstr *MI,MachineBasicBlock *DestBB, 1256c0dbec7e1038ee60b8525eb1e8e3eaa6a839bd5bEvan Cheng unsigned MaxDisp) { 1257b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen unsigned PCAdj = isThumb ? 4 : 8; 1258c0dbec7e1038ee60b8525eb1e8e3eaa6a839bd5bEvan Cheng unsigned BrOffset = GetOffsetOf(MI) + PCAdj; 125999c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen unsigned DestOffset = BBOffsets[DestBB->getNumber()]; 126043aeab68a69e443c528092b4424a498d813f96b7Evan Cheng 1261705e07f578e2b3af47ddab610feb4e7f2d3063a5Chris Lattner DEBUG(errs() << "Branch of destination BB#" << DestBB->getNumber() 1262705e07f578e2b3af47ddab610feb4e7f2d3063a5Chris Lattner << " from BB#" << MI->getParent()->getNumber() 1263705e07f578e2b3af47ddab610feb4e7f2d3063a5Chris Lattner << " max delta=" << MaxDisp 1264705e07f578e2b3af47ddab610feb4e7f2d3063a5Chris Lattner << " from " << GetOffsetOf(MI) << " to " << DestOffset 1265705e07f578e2b3af47ddab610feb4e7f2d3063a5Chris Lattner << " offset " << int(DestOffset-BrOffset) << "\t" << *MI); 1266c0dbec7e1038ee60b8525eb1e8e3eaa6a839bd5bEvan Cheng 12678593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen if (BrOffset <= DestOffset) { 12688593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // Branch before the Dest. 12698593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen if (DestOffset-BrOffset <= MaxDisp) 12708593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen return true; 12718593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen } else { 12728593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen if (BrOffset-DestOffset <= MaxDisp) 12738593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen return true; 12748593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen } 12758593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen return false; 127643aeab68a69e443c528092b4424a498d813f96b7Evan Cheng} 127743aeab68a69e443c528092b4424a498d813f96b7Evan Cheng 1278d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng/// FixUpImmediateBr - Fix up an immediate branch whose destination is too far 1279d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng/// away to fit in its displacement field. 12805657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Chengbool ARMConstantIslands::FixUpImmediateBr(MachineFunction &MF, ImmBranch &Br) { 1281d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng MachineInstr *MI = Br.MI; 12828aa797aa51cd4ea1ec6f46f4891a6897944b75b2Chris Lattner MachineBasicBlock *DestBB = MI->getOperand(0).getMBB(); 1283d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng 1284c0dbec7e1038ee60b8525eb1e8e3eaa6a839bd5bEvan Cheng // Check to see if the DestBB is already in-range. 1285c0dbec7e1038ee60b8525eb1e8e3eaa6a839bd5bEvan Cheng if (BBIsInRange(MI, DestBB, Br.MaxDisp)) 1286d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng return false; 1287d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng 1288d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng if (!Br.isCond) 12895657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng return FixUpUnconditionalBr(MF, Br); 12905657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng return FixUpConditionalBr(MF, Br); 1291d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng} 1292d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng 129388e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen/// FixUpUnconditionalBr - Fix up an unconditional branch whose destination is 129488e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen/// too far away to fit in its displacement field. If the LR register has been 1295d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng/// spilled in the epilogue, then we can use BL to implement a far jump. 129639bf051ec2865cd715c41473d2a9fc34ff252534Bob Wilson/// Otherwise, add an intermediate branch instruction to a branch. 1297d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Chengbool 12985657c01949dca6c012ac60d242d1a8d2ffdf5603Evan ChengARMConstantIslands::FixUpUnconditionalBr(MachineFunction &MF, ImmBranch &Br) { 1299d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng MachineInstr *MI = Br.MI; 1300d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng MachineBasicBlock *MBB = MI->getParent(); 130153c67c0218d8420234dd71bf2d9df3388909af77Evan Cheng if (!isThumb1) 130253c67c0218d8420234dd71bf2d9df3388909af77Evan Cheng llvm_unreachable("FixUpUnconditionalBr is Thumb1 only!"); 1303d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng 1304d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng // Use BL to implement far jump. 1305d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng Br.MaxDisp = (1 << 21) * 2; 13065080f4d9919d39b367891dc51e739c571a66036cChris Lattner MI->setDesc(TII->get(ARM::tBfar)); 1307d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng BBSizes[MBB->getNumber()] += 2; 130899c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen AdjustBBOffsetsAfter(MBB, 2); 1309d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng HasFarJump = true; 1310d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng NumUBrFixed++; 1311bd5d3dbdbe46c7325545a7cb8c891c0347375451Evan Cheng 1312705e07f578e2b3af47ddab610feb4e7f2d3063a5Chris Lattner DEBUG(errs() << " Changed B to long jump " << *MI); 1313bd5d3dbdbe46c7325545a7cb8c891c0347375451Evan Cheng 1314d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng return true; 1315d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng} 1316d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng 131788e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen/// FixUpConditionalBr - Fix up a conditional branch whose destination is too 1318d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng/// far away to fit in its displacement field. It is converted to an inverse 1319d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng/// conditional branch + an unconditional branch to the destination. 1320af5cbcb809bdbd30ebacab942994721c134d16a2Evan Chengbool 13215657c01949dca6c012ac60d242d1a8d2ffdf5603Evan ChengARMConstantIslands::FixUpConditionalBr(MachineFunction &MF, ImmBranch &Br) { 1322af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng MachineInstr *MI = Br.MI; 13238aa797aa51cd4ea1ec6f46f4891a6897944b75b2Chris Lattner MachineBasicBlock *DestBB = MI->getOperand(0).getMBB(); 1324af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng 132539bf051ec2865cd715c41473d2a9fc34ff252534Bob Wilson // Add an unconditional branch to the destination and invert the branch 1326d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng // condition to jump over it: 1327af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng // blt L1 1328af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng // => 1329af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng // bge L2 1330af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng // b L1 1331af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng // L2: 13329a1ceaedc282f0cae31f2723f4d6c00c7b88fe90Chris Lattner ARMCC::CondCodes CC = (ARMCC::CondCodes)MI->getOperand(1).getImm(); 1333af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng CC = ARMCC::getOppositeCondition(CC); 13340e1d37904abbf7e8c4c478408253dd995f3040f4Evan Cheng unsigned CCReg = MI->getOperand(2).getReg(); 1335af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng 1336af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng // If the branch is at the end of its MBB and that has a fall-through block, 1337af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng // direct the updated conditional branch to the fall-through block. Otherwise, 1338af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng // split the MBB before the next instruction. 1339af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng MachineBasicBlock *MBB = MI->getParent(); 1340bd5d3dbdbe46c7325545a7cb8c891c0347375451Evan Cheng MachineInstr *BMI = &MBB->back(); 1341bd5d3dbdbe46c7325545a7cb8c891c0347375451Evan Cheng bool NeedSplit = (BMI != MI) || !BBHasFallthrough(MBB); 134243aeab68a69e443c528092b4424a498d813f96b7Evan Cheng 1343d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng NumCBrFixed++; 1344bd5d3dbdbe46c7325545a7cb8c891c0347375451Evan Cheng if (BMI != MI) { 13458e5f2c6f65841542e2a7092553fe42a00048e4c7Dan Gohman if (next(MachineBasicBlock::iterator(MI)) == prior(MBB->end()) && 1346bd5d3dbdbe46c7325545a7cb8c891c0347375451Evan Cheng BMI->getOpcode() == Br.UncondBr) { 134739bf051ec2865cd715c41473d2a9fc34ff252534Bob Wilson // Last MI in the BB is an unconditional branch. Can we simply invert the 134843aeab68a69e443c528092b4424a498d813f96b7Evan Cheng // condition and swap destinations: 134943aeab68a69e443c528092b4424a498d813f96b7Evan Cheng // beq L1 135043aeab68a69e443c528092b4424a498d813f96b7Evan Cheng // b L2 135143aeab68a69e443c528092b4424a498d813f96b7Evan Cheng // => 135243aeab68a69e443c528092b4424a498d813f96b7Evan Cheng // bne L2 135343aeab68a69e443c528092b4424a498d813f96b7Evan Cheng // b L1 13548aa797aa51cd4ea1ec6f46f4891a6897944b75b2Chris Lattner MachineBasicBlock *NewDest = BMI->getOperand(0).getMBB(); 1355c0dbec7e1038ee60b8525eb1e8e3eaa6a839bd5bEvan Cheng if (BBIsInRange(MI, NewDest, Br.MaxDisp)) { 1356705e07f578e2b3af47ddab610feb4e7f2d3063a5Chris Lattner DEBUG(errs() << " Invert Bcc condition and swap its destination with " 1357705e07f578e2b3af47ddab610feb4e7f2d3063a5Chris Lattner << *BMI); 13588aa797aa51cd4ea1ec6f46f4891a6897944b75b2Chris Lattner BMI->getOperand(0).setMBB(DestBB); 13598aa797aa51cd4ea1ec6f46f4891a6897944b75b2Chris Lattner MI->getOperand(0).setMBB(NewDest); 136043aeab68a69e443c528092b4424a498d813f96b7Evan Cheng MI->getOperand(1).setImm(CC); 136143aeab68a69e443c528092b4424a498d813f96b7Evan Cheng return true; 136243aeab68a69e443c528092b4424a498d813f96b7Evan Cheng } 136343aeab68a69e443c528092b4424a498d813f96b7Evan Cheng } 136443aeab68a69e443c528092b4424a498d813f96b7Evan Cheng } 136543aeab68a69e443c528092b4424a498d813f96b7Evan Cheng 136643aeab68a69e443c528092b4424a498d813f96b7Evan Cheng if (NeedSplit) { 1367af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng SplitBlockBeforeInstr(MI); 136839bf051ec2865cd715c41473d2a9fc34ff252534Bob Wilson // No need for the branch to the next block. We're adding an unconditional 1369dd353b8ad747a8731a191848ff5db978a70bd0fbEvan Cheng // branch to the destination. 137052e724ad7e679ee590f4bd763d55280586a8f1bcNicolas Geoffray int delta = TII->GetInstSizeInBytes(&MBB->back()); 137156c42ef3e43f8eb75c435e781d0ac8251c7588a1Dale Johannesen BBSizes[MBB->getNumber()] -= delta; 13728593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen MachineBasicBlock* SplitBB = next(MachineFunction::iterator(MBB)); 13738593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen AdjustBBOffsetsAfter(SplitBB, -delta); 1374dd353b8ad747a8731a191848ff5db978a70bd0fbEvan Cheng MBB->back().eraseFromParent(); 13758593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // BBOffsets[SplitBB] is wrong temporarily, fixed below 1376dd353b8ad747a8731a191848ff5db978a70bd0fbEvan Cheng } 1377af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng MachineBasicBlock *NextBB = next(MachineFunction::iterator(MBB)); 13788494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 1379893e1c90a03a53cf13f73849324e83612688428aChris Lattner DEBUG(errs() << " Insert B to BB#" << DestBB->getNumber() 1380893e1c90a03a53cf13f73849324e83612688428aChris Lattner << " also invert condition and change dest. to BB#" 1381893e1c90a03a53cf13f73849324e83612688428aChris Lattner << NextBB->getNumber() << "\n"); 1382af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng 138356c42ef3e43f8eb75c435e781d0ac8251c7588a1Dale Johannesen // Insert a new conditional branch and a new unconditional branch. 1384af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng // Also update the ImmBranch as well as adding a new entry for the new branch. 1385b67284057ee130114055309eabe0bcd1af13777dDale Johannesen BuildMI(MBB, DebugLoc::getUnknownLoc(), 1386b67284057ee130114055309eabe0bcd1af13777dDale Johannesen TII->get(MI->getOpcode())) 1387b67284057ee130114055309eabe0bcd1af13777dDale Johannesen .addMBB(NextBB).addImm(CC).addReg(CCReg); 1388af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng Br.MI = &MBB->back(); 138952e724ad7e679ee590f4bd763d55280586a8f1bcNicolas Geoffray BBSizes[MBB->getNumber()] += TII->GetInstSizeInBytes(&MBB->back()); 1390b67284057ee130114055309eabe0bcd1af13777dDale Johannesen BuildMI(MBB, DebugLoc::getUnknownLoc(), TII->get(Br.UncondBr)).addMBB(DestBB); 139152e724ad7e679ee590f4bd763d55280586a8f1bcNicolas Geoffray BBSizes[MBB->getNumber()] += TII->GetInstSizeInBytes(&MBB->back()); 1392a9b8b8d62c67e96bc4dc2ed25298c539102f8638Evan Cheng unsigned MaxDisp = getUnconditionalBrDisp(Br.UncondBr); 1393a0bf794eb60b6795a121efcb9ff759e9e0955772Evan Cheng ImmBranches.push_back(ImmBranch(&MBB->back(), MaxDisp, false, Br.UncondBr)); 139456c42ef3e43f8eb75c435e781d0ac8251c7588a1Dale Johannesen 139556c42ef3e43f8eb75c435e781d0ac8251c7588a1Dale Johannesen // Remove the old conditional branch. It may or may not still be in MBB. 139652e724ad7e679ee590f4bd763d55280586a8f1bcNicolas Geoffray BBSizes[MI->getParent()->getNumber()] -= TII->GetInstSizeInBytes(MI); 1397af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng MI->eraseFromParent(); 1398af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng 139956c42ef3e43f8eb75c435e781d0ac8251c7588a1Dale Johannesen // The net size change is an addition of one unconditional branch. 140052e724ad7e679ee590f4bd763d55280586a8f1bcNicolas Geoffray int delta = TII->GetInstSizeInBytes(&MBB->back()); 140199c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen AdjustBBOffsetsAfter(MBB, delta); 1402af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng return true; 1403af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng} 1404d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng 1405d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng/// UndoLRSpillRestore - Remove Thumb push / pop instructions that only spills 14064b322e58b77d16f103d88a3af3a4ebd2675245a0Evan Cheng/// LR / restores LR to pc. FIXME: This is done here because it's only possible 14074b322e58b77d16f103d88a3af3a4ebd2675245a0Evan Cheng/// to do this if tBfar is not used. 1408d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Chengbool ARMConstantIslands::UndoLRSpillRestore() { 1409d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng bool MadeChange = false; 1410d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng for (unsigned i = 0, e = PushPopMIs.size(); i != e; ++i) { 1411d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng MachineInstr *MI = PushPopMIs[i]; 141210469f8e48e007989b0469e677d4000a1311ecd2Evan Cheng // First two operands are predicates, the third is a zero since there 141310469f8e48e007989b0469e677d4000a1311ecd2Evan Cheng // is no writeback. 141444bec52b1b7e9a3ac1efbae90db240b8c1ca2ad4Evan Cheng if (MI->getOpcode() == ARM::tPOP_RET && 141510469f8e48e007989b0469e677d4000a1311ecd2Evan Cheng MI->getOperand(3).getReg() == ARM::PC && 141610469f8e48e007989b0469e677d4000a1311ecd2Evan Cheng MI->getNumExplicitOperands() == 4) { 1417b67284057ee130114055309eabe0bcd1af13777dDale Johannesen BuildMI(MI->getParent(), MI->getDebugLoc(), TII->get(ARM::tBX_RET)); 141844bec52b1b7e9a3ac1efbae90db240b8c1ca2ad4Evan Cheng MI->eraseFromParent(); 141944bec52b1b7e9a3ac1efbae90db240b8c1ca2ad4Evan Cheng MadeChange = true; 1420d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng } 1421d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng } 1422d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng return MadeChange; 1423d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng} 14245657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng 1425a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Chengbool ARMConstantIslands::OptimizeThumb2Instructions(MachineFunction &MF) { 1426a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng bool MadeChange = false; 1427a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng 1428a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng // Shrink ADR and LDR from constantpool. 1429a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng for (unsigned i = 0, e = CPUsers.size(); i != e; ++i) { 1430a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng CPUser &U = CPUsers[i]; 1431a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng unsigned Opcode = U.MI->getOpcode(); 1432a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng unsigned NewOpc = 0; 1433a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng unsigned Scale = 1; 1434a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng unsigned Bits = 0; 1435a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng switch (Opcode) { 1436a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng default: break; 1437a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng case ARM::t2LEApcrel: 1438a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng if (isARMLowRegister(U.MI->getOperand(0).getReg())) { 1439a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng NewOpc = ARM::tLEApcrel; 1440a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng Bits = 8; 1441a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng Scale = 4; 1442a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng } 1443a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng break; 1444a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng case ARM::t2LDRpci: 1445a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng if (isARMLowRegister(U.MI->getOperand(0).getReg())) { 1446a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng NewOpc = ARM::tLDRpci; 1447a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng Bits = 8; 1448a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng Scale = 4; 1449a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng } 1450a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng break; 1451a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng } 1452a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng 1453a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng if (!NewOpc) 1454a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng continue; 1455a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng 1456a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng unsigned UserOffset = GetOffsetOf(U.MI) + 4; 1457a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng unsigned MaxOffs = ((1 << Bits) - 1) * Scale; 1458a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng // FIXME: Check if offset is multiple of scale if scale is not 4. 1459a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng if (CPEIsInRange(U.MI, UserOffset, U.CPEMI, MaxOffs, false, true)) { 1460a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng U.MI->setDesc(TII->get(NewOpc)); 1461a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng MachineBasicBlock *MBB = U.MI->getParent(); 1462a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng BBSizes[MBB->getNumber()] -= 2; 1463a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng AdjustBBOffsetsAfter(MBB, -2); 1464a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng ++NumT2CPShrunk; 1465a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng MadeChange = true; 1466a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng } 1467a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng } 1468a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng 1469a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng MadeChange |= OptimizeThumb2Branches(MF); 147031b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng MadeChange |= OptimizeThumb2JumpTables(MF); 1471a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng return MadeChange; 1472a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng} 1473a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng 1474a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Chengbool ARMConstantIslands::OptimizeThumb2Branches(MachineFunction &MF) { 147531b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng bool MadeChange = false; 147631b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng 147731b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng for (unsigned i = 0, e = ImmBranches.size(); i != e; ++i) { 147831b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng ImmBranch &Br = ImmBranches[i]; 147931b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng unsigned Opcode = Br.MI->getOpcode(); 148031b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng unsigned NewOpc = 0; 148131b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng unsigned Scale = 1; 148231b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng unsigned Bits = 0; 148331b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng switch (Opcode) { 148431b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng default: break; 148531b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng case ARM::t2B: 148631b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng NewOpc = ARM::tB; 148731b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng Bits = 11; 148831b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng Scale = 2; 148931b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng break; 1490de17fb6e4dd8f169f707d58d4e124c8d4d2c7dbaEvan Cheng case ARM::t2Bcc: { 149131b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng NewOpc = ARM::tBcc; 149231b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng Bits = 8; 1493de17fb6e4dd8f169f707d58d4e124c8d4d2c7dbaEvan Cheng Scale = 2; 149431b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng break; 149531b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng } 1496de17fb6e4dd8f169f707d58d4e124c8d4d2c7dbaEvan Cheng } 1497de17fb6e4dd8f169f707d58d4e124c8d4d2c7dbaEvan Cheng if (NewOpc) { 1498de17fb6e4dd8f169f707d58d4e124c8d4d2c7dbaEvan Cheng unsigned MaxOffs = ((1 << (Bits-1))-1) * Scale; 1499de17fb6e4dd8f169f707d58d4e124c8d4d2c7dbaEvan Cheng MachineBasicBlock *DestBB = Br.MI->getOperand(0).getMBB(); 1500de17fb6e4dd8f169f707d58d4e124c8d4d2c7dbaEvan Cheng if (BBIsInRange(Br.MI, DestBB, MaxOffs)) { 1501de17fb6e4dd8f169f707d58d4e124c8d4d2c7dbaEvan Cheng Br.MI->setDesc(TII->get(NewOpc)); 1502de17fb6e4dd8f169f707d58d4e124c8d4d2c7dbaEvan Cheng MachineBasicBlock *MBB = Br.MI->getParent(); 1503de17fb6e4dd8f169f707d58d4e124c8d4d2c7dbaEvan Cheng BBSizes[MBB->getNumber()] -= 2; 1504de17fb6e4dd8f169f707d58d4e124c8d4d2c7dbaEvan Cheng AdjustBBOffsetsAfter(MBB, -2); 1505de17fb6e4dd8f169f707d58d4e124c8d4d2c7dbaEvan Cheng ++NumT2BrShrunk; 1506de17fb6e4dd8f169f707d58d4e124c8d4d2c7dbaEvan Cheng MadeChange = true; 1507de17fb6e4dd8f169f707d58d4e124c8d4d2c7dbaEvan Cheng } 1508de17fb6e4dd8f169f707d58d4e124c8d4d2c7dbaEvan Cheng } 1509de17fb6e4dd8f169f707d58d4e124c8d4d2c7dbaEvan Cheng 1510de17fb6e4dd8f169f707d58d4e124c8d4d2c7dbaEvan Cheng Opcode = Br.MI->getOpcode(); 1511de17fb6e4dd8f169f707d58d4e124c8d4d2c7dbaEvan Cheng if (Opcode != ARM::tBcc) 151231b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng continue; 151331b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng 1514de17fb6e4dd8f169f707d58d4e124c8d4d2c7dbaEvan Cheng NewOpc = 0; 1515de17fb6e4dd8f169f707d58d4e124c8d4d2c7dbaEvan Cheng unsigned PredReg = 0; 1516de17fb6e4dd8f169f707d58d4e124c8d4d2c7dbaEvan Cheng ARMCC::CondCodes Pred = llvm::getInstrPredicate(Br.MI, PredReg); 1517de17fb6e4dd8f169f707d58d4e124c8d4d2c7dbaEvan Cheng if (Pred == ARMCC::EQ) 1518de17fb6e4dd8f169f707d58d4e124c8d4d2c7dbaEvan Cheng NewOpc = ARM::tCBZ; 1519de17fb6e4dd8f169f707d58d4e124c8d4d2c7dbaEvan Cheng else if (Pred == ARMCC::NE) 1520de17fb6e4dd8f169f707d58d4e124c8d4d2c7dbaEvan Cheng NewOpc = ARM::tCBNZ; 1521de17fb6e4dd8f169f707d58d4e124c8d4d2c7dbaEvan Cheng if (!NewOpc) 1522de17fb6e4dd8f169f707d58d4e124c8d4d2c7dbaEvan Cheng continue; 152331b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng MachineBasicBlock *DestBB = Br.MI->getOperand(0).getMBB(); 1524de17fb6e4dd8f169f707d58d4e124c8d4d2c7dbaEvan Cheng // Check if the distance is within 126. Subtract starting offset by 2 1525de17fb6e4dd8f169f707d58d4e124c8d4d2c7dbaEvan Cheng // because the cmp will be eliminated. 1526de17fb6e4dd8f169f707d58d4e124c8d4d2c7dbaEvan Cheng unsigned BrOffset = GetOffsetOf(Br.MI) + 4 - 2; 1527de17fb6e4dd8f169f707d58d4e124c8d4d2c7dbaEvan Cheng unsigned DestOffset = BBOffsets[DestBB->getNumber()]; 1528de17fb6e4dd8f169f707d58d4e124c8d4d2c7dbaEvan Cheng if (BrOffset < DestOffset && (DestOffset - BrOffset) <= 126) { 1529de17fb6e4dd8f169f707d58d4e124c8d4d2c7dbaEvan Cheng MachineBasicBlock::iterator CmpMI = Br.MI; --CmpMI; 1530de17fb6e4dd8f169f707d58d4e124c8d4d2c7dbaEvan Cheng if (CmpMI->getOpcode() == ARM::tCMPzi8) { 1531de17fb6e4dd8f169f707d58d4e124c8d4d2c7dbaEvan Cheng unsigned Reg = CmpMI->getOperand(0).getReg(); 1532de17fb6e4dd8f169f707d58d4e124c8d4d2c7dbaEvan Cheng Pred = llvm::getInstrPredicate(CmpMI, PredReg); 1533de17fb6e4dd8f169f707d58d4e124c8d4d2c7dbaEvan Cheng if (Pred == ARMCC::AL && 1534de17fb6e4dd8f169f707d58d4e124c8d4d2c7dbaEvan Cheng CmpMI->getOperand(1).getImm() == 0 && 1535de17fb6e4dd8f169f707d58d4e124c8d4d2c7dbaEvan Cheng isARMLowRegister(Reg)) { 1536de17fb6e4dd8f169f707d58d4e124c8d4d2c7dbaEvan Cheng MachineBasicBlock *MBB = Br.MI->getParent(); 1537de17fb6e4dd8f169f707d58d4e124c8d4d2c7dbaEvan Cheng MachineInstr *NewBR = 1538de17fb6e4dd8f169f707d58d4e124c8d4d2c7dbaEvan Cheng BuildMI(*MBB, CmpMI, Br.MI->getDebugLoc(), TII->get(NewOpc)) 1539de17fb6e4dd8f169f707d58d4e124c8d4d2c7dbaEvan Cheng .addReg(Reg).addMBB(DestBB, Br.MI->getOperand(0).getTargetFlags()); 1540de17fb6e4dd8f169f707d58d4e124c8d4d2c7dbaEvan Cheng CmpMI->eraseFromParent(); 1541de17fb6e4dd8f169f707d58d4e124c8d4d2c7dbaEvan Cheng Br.MI->eraseFromParent(); 1542de17fb6e4dd8f169f707d58d4e124c8d4d2c7dbaEvan Cheng Br.MI = NewBR; 1543de17fb6e4dd8f169f707d58d4e124c8d4d2c7dbaEvan Cheng BBSizes[MBB->getNumber()] -= 2; 1544de17fb6e4dd8f169f707d58d4e124c8d4d2c7dbaEvan Cheng AdjustBBOffsetsAfter(MBB, -2); 1545de17fb6e4dd8f169f707d58d4e124c8d4d2c7dbaEvan Cheng ++NumCBZ; 1546de17fb6e4dd8f169f707d58d4e124c8d4d2c7dbaEvan Cheng MadeChange = true; 1547de17fb6e4dd8f169f707d58d4e124c8d4d2c7dbaEvan Cheng } 1548de17fb6e4dd8f169f707d58d4e124c8d4d2c7dbaEvan Cheng } 154931b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng } 155031b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng } 155131b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng 155231b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng return MadeChange; 1553a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng} 1554a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng 1555a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng 1556a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng/// OptimizeThumb2JumpTables - Use tbb / tbh instructions to generate smaller 1557a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng/// jumptables when it's possible. 15585657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Chengbool ARMConstantIslands::OptimizeThumb2JumpTables(MachineFunction &MF) { 15595657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng bool MadeChange = false; 15605657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng 15615657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng // FIXME: After the tables are shrunk, can we get rid some of the 15625657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng // constantpool tables? 15635657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng const MachineJumpTableInfo *MJTI = MF.getJumpTableInfo(); 15645657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables(); 15655657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng for (unsigned i = 0, e = T2JumpTables.size(); i != e; ++i) { 15665657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng MachineInstr *MI = T2JumpTables[i]; 15675657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng const TargetInstrDesc &TID = MI->getDesc(); 15685657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng unsigned NumOps = TID.getNumOperands(); 15695657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng unsigned JTOpIdx = NumOps - (TID.isPredicable() ? 3 : 2); 15705657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng MachineOperand JTOP = MI->getOperand(JTOpIdx); 15715657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng unsigned JTI = JTOP.getIndex(); 15725657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng assert(JTI < JT.size()); 15735657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng 15745657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng bool ByteOk = true; 15755657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng bool HalfWordOk = true; 15765657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng unsigned JTOffset = GetOffsetOf(MI) + 4; 15775657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs; 15785657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng for (unsigned j = 0, ee = JTBBs.size(); j != ee; ++j) { 15795657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng MachineBasicBlock *MBB = JTBBs[j]; 15805657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng unsigned DstOffset = BBOffsets[MBB->getNumber()]; 15818770f747a98194056805f1b7cbcb0b75a7633b87Evan Cheng // Negative offset is not ok. FIXME: We should change BB layout to make 15828770f747a98194056805f1b7cbcb0b75a7633b87Evan Cheng // sure all the branches are forward. 1583d26b14c34cbcee1448b86b524578fc51cc979023Evan Cheng if (ByteOk && (DstOffset - JTOffset) > ((1<<8)-1)*2) 15845657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng ByteOk = false; 158525f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng unsigned TBHLimit = ((1<<16)-1)*2; 158625f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng if (HalfWordOk && (DstOffset - JTOffset) > TBHLimit) 15875657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng HalfWordOk = false; 15885657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng if (!ByteOk && !HalfWordOk) 15895657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng break; 15905657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng } 15915657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng 15925657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng if (ByteOk || HalfWordOk) { 15935657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng MachineBasicBlock *MBB = MI->getParent(); 15945657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng unsigned BaseReg = MI->getOperand(0).getReg(); 15955657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng bool BaseRegKill = MI->getOperand(0).isKill(); 15965657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng if (!BaseRegKill) 15975657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng continue; 15985657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng unsigned IdxReg = MI->getOperand(1).getReg(); 15995657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng bool IdxRegKill = MI->getOperand(1).isKill(); 16005657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng MachineBasicBlock::iterator PrevI = MI; 16015657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng if (PrevI == MBB->begin()) 16025657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng continue; 16035657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng 16045657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng MachineInstr *AddrMI = --PrevI; 16055657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng bool OptOk = true; 16065657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng // Examine the instruction that calculate the jumptable entry address. 16075657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng // If it's not the one just before the t2BR_JT, we won't delete it, then 16085657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng // it's not worth doing the optimization. 16095657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng for (unsigned k = 0, eee = AddrMI->getNumOperands(); k != eee; ++k) { 16105657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng const MachineOperand &MO = AddrMI->getOperand(k); 16115657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng if (!MO.isReg() || !MO.getReg()) 16125657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng continue; 16135657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng if (MO.isDef() && MO.getReg() != BaseReg) { 16145657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng OptOk = false; 16155657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng break; 16165657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng } 16175657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng if (MO.isUse() && !MO.isKill() && MO.getReg() != IdxReg) { 16185657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng OptOk = false; 16195657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng break; 16205657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng } 16215657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng } 16225657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng if (!OptOk) 16235657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng continue; 16245657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng 1625a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng // The previous instruction should be a tLEApcrel or t2LEApcrelJT, we want 1626a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng // to delete it as well. 16275657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng MachineInstr *LeaMI = --PrevI; 1628a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng if ((LeaMI->getOpcode() != ARM::tLEApcrelJT && 1629a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng LeaMI->getOpcode() != ARM::t2LEApcrelJT) || 16305657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng LeaMI->getOperand(0).getReg() != BaseReg) 163125f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng OptOk = false; 163225f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng 163325f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng if (!OptOk) 163425f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng continue; 163525f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng 163625f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng unsigned Opc = ByteOk ? ARM::t2TBB : ARM::t2TBH; 163725f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng MachineInstr *NewJTMI = BuildMI(MBB, MI->getDebugLoc(), TII->get(Opc)) 163825f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng .addReg(IdxReg, getKillRegState(IdxRegKill)) 163925f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng .addJumpTableIndex(JTI, JTOP.getTargetFlags()) 164025f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng .addImm(MI->getOperand(JTOpIdx+1).getImm()); 164125f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng // FIXME: Insert an "ALIGN" instruction to ensure the next instruction 164225f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng // is 2-byte aligned. For now, asm printer will fix it up. 164325f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng unsigned NewSize = TII->GetInstSizeInBytes(NewJTMI); 164425f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng unsigned OrigSize = TII->GetInstSizeInBytes(AddrMI); 164525f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng OrigSize += TII->GetInstSizeInBytes(LeaMI); 164625f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng OrigSize += TII->GetInstSizeInBytes(MI); 164725f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng 164825f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng AddrMI->eraseFromParent(); 164925f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng LeaMI->eraseFromParent(); 165025f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng MI->eraseFromParent(); 165125f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng 165225f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng int delta = OrigSize - NewSize; 165325f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng BBSizes[MBB->getNumber()] -= delta; 165425f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng AdjustBBOffsetsAfter(MBB, -delta); 165525f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng 165625f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng ++NumTBs; 165725f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng MadeChange = true; 16585657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng } 16595657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng } 16605657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng 16615657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng return MadeChange; 16625657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng} 1663