ARMConstantIslandPass.cpp revision 705e07f578e2b3af47ddab610feb4e7f2d3063a5
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/Compiler.h" 28a8e2989ece6dc46df59b0768184028257f913843Evan Cheng#include "llvm/Support/Debug.h" 29c25e7581b9b8088910da31702d4ca21c4734c6d7Torok Edwin#include "llvm/Support/ErrorHandling.h" 30705e07f578e2b3af47ddab610feb4e7f2d3063a5Chris Lattner#include "llvm/Support/raw_ostream.h" 31c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng#include "llvm/ADT/SmallVector.h" 32a8e2989ece6dc46df59b0768184028257f913843Evan Cheng#include "llvm/ADT/STLExtras.h" 33a8e2989ece6dc46df59b0768184028257f913843Evan Cheng#include "llvm/ADT/Statistic.h" 34a8e2989ece6dc46df59b0768184028257f913843Evan Chengusing namespace llvm; 35a8e2989ece6dc46df59b0768184028257f913843Evan Cheng 36a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan ChengSTATISTIC(NumCPEs, "Number of constpool entries"); 37a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan ChengSTATISTIC(NumSplit, "Number of uncond branches inserted"); 38a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan ChengSTATISTIC(NumCBrFixed, "Number of cond branches fixed"); 39a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan ChengSTATISTIC(NumUBrFixed, "Number of uncond branches fixed"); 40a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan ChengSTATISTIC(NumTBs, "Number of table branches generated"); 41a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan ChengSTATISTIC(NumT2CPShrunk, "Number of Thumb2 constantpool instructions shrunk"); 4231b99dd76035067b1c3cc6c7e9d663b7b0210938Evan ChengSTATISTIC(NumT2BrShrunk, "Number of Thumb2 immediate branches shrunk"); 43a8e2989ece6dc46df59b0768184028257f913843Evan Cheng 44a8e2989ece6dc46df59b0768184028257f913843Evan Chengnamespace { 4588e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen /// ARMConstantIslands - Due to limited PC-relative displacements, ARM 46a8e2989ece6dc46df59b0768184028257f913843Evan Cheng /// requires constant pool entries to be scattered among the instructions 47a8e2989ece6dc46df59b0768184028257f913843Evan Cheng /// inside a function. To do this, it completely ignores the normal LLVM 4888e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen /// constant pool; instead, it places constants wherever it feels like with 49a8e2989ece6dc46df59b0768184028257f913843Evan Cheng /// special instructions. 50a8e2989ece6dc46df59b0768184028257f913843Evan Cheng /// 51a8e2989ece6dc46df59b0768184028257f913843Evan Cheng /// The terminology used in this pass includes: 52a8e2989ece6dc46df59b0768184028257f913843Evan Cheng /// Islands - Clumps of constants placed in the function. 53a8e2989ece6dc46df59b0768184028257f913843Evan Cheng /// Water - Potential places where an island could be formed. 54a8e2989ece6dc46df59b0768184028257f913843Evan Cheng /// CPE - A constant pool entry that has been placed somewhere, which 55a8e2989ece6dc46df59b0768184028257f913843Evan Cheng /// tracks a list of users. 56a8e2989ece6dc46df59b0768184028257f913843Evan Cheng class VISIBILITY_HIDDEN ARMConstantIslands : public MachineFunctionPass { 57a8e2989ece6dc46df59b0768184028257f913843Evan Cheng /// BBSizes - The size of each MachineBasicBlock in bytes of code, indexed 588593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen /// by MBB Number. The two-byte pads required for Thumb alignment are 598593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen /// counted as part of the following block (i.e., the offset and size for 608593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen /// a padded block will both be ==2 mod 4). 61e03cff6812ac41598e2bca7854985dc821a07f44Evan Cheng std::vector<unsigned> BBSizes; 628494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 6399c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen /// BBOffsets - the offset of each MBB in bytes, starting from 0. 648593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen /// The two-byte pads required for Thumb alignment are counted as part of 658593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen /// the following block. 6699c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen std::vector<unsigned> BBOffsets; 6799c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen 68a8e2989ece6dc46df59b0768184028257f913843Evan Cheng /// WaterList - A sorted list of basic blocks where islands could be placed 69a8e2989ece6dc46df59b0768184028257f913843Evan Cheng /// (i.e. blocks that don't fall through to the following block, due 70a8e2989ece6dc46df59b0768184028257f913843Evan Cheng /// to a return, unreachable, or unconditional branch). 71e03cff6812ac41598e2bca7854985dc821a07f44Evan Cheng std::vector<MachineBasicBlock*> WaterList; 72c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng 73a8e2989ece6dc46df59b0768184028257f913843Evan Cheng /// CPUser - One user of a constant pool, keeping the machine instruction 74a8e2989ece6dc46df59b0768184028257f913843Evan Cheng /// pointer, the constant pool being referenced, and the max displacement 75a8e2989ece6dc46df59b0768184028257f913843Evan Cheng /// allowed from the instruction to the CP. 76a8e2989ece6dc46df59b0768184028257f913843Evan Cheng struct CPUser { 77a8e2989ece6dc46df59b0768184028257f913843Evan Cheng MachineInstr *MI; 78a8e2989ece6dc46df59b0768184028257f913843Evan Cheng MachineInstr *CPEMI; 79a8e2989ece6dc46df59b0768184028257f913843Evan Cheng unsigned MaxDisp; 805d8f1cae76e4e424bf3b4392eddb3f4dbf38662aEvan Cheng bool NegOk; 81d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng bool IsSoImm; 82d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng CPUser(MachineInstr *mi, MachineInstr *cpemi, unsigned maxdisp, 83d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng bool neg, bool soimm) 84d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng : MI(mi), CPEMI(cpemi), MaxDisp(maxdisp), NegOk(neg), IsSoImm(soimm) {} 85a8e2989ece6dc46df59b0768184028257f913843Evan Cheng }; 868494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 87a8e2989ece6dc46df59b0768184028257f913843Evan Cheng /// CPUsers - Keep track of all of the machine instructions that use various 88a8e2989ece6dc46df59b0768184028257f913843Evan Cheng /// constant pools and their max displacement. 89e03cff6812ac41598e2bca7854985dc821a07f44Evan Cheng std::vector<CPUser> CPUsers; 908494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 91c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng /// CPEntry - One per constant pool entry, keeping the machine instruction 92c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng /// pointer, the constpool index, and the number of CPUser's which 93c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng /// reference this entry. 94c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng struct CPEntry { 95c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng MachineInstr *CPEMI; 96c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng unsigned CPI; 97c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng unsigned RefCount; 98c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng CPEntry(MachineInstr *cpemi, unsigned cpi, unsigned rc = 0) 99c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng : CPEMI(cpemi), CPI(cpi), RefCount(rc) {} 100c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng }; 101c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng 102c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng /// CPEntries - Keep track of all of the constant pool entry machine 10388e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen /// instructions. For each original constpool index (i.e. those that 10488e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen /// existed upon entry to this pass), it keeps a vector of entries. 10588e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen /// Original elements are cloned as we go along; the clones are 10688e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen /// put in the vector of the original element, but have distinct CPIs. 107c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng std::vector<std::vector<CPEntry> > CPEntries; 1088494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 109af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng /// ImmBranch - One per immediate branch, keeping the machine instruction 110af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng /// pointer, conditional or unconditional, the max displacement, 111af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng /// and (if isCond is true) the corresponding unconditional branch 112af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng /// opcode. 113af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng struct ImmBranch { 114af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng MachineInstr *MI; 115c285414988ba026d01e5d8acc07a21cd06fd5732Evan Cheng unsigned MaxDisp : 31; 116c285414988ba026d01e5d8acc07a21cd06fd5732Evan Cheng bool isCond : 1; 117af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng int UncondBr; 118c285414988ba026d01e5d8acc07a21cd06fd5732Evan Cheng ImmBranch(MachineInstr *mi, unsigned maxdisp, bool cond, int ubr) 119c285414988ba026d01e5d8acc07a21cd06fd5732Evan Cheng : MI(mi), MaxDisp(maxdisp), isCond(cond), UncondBr(ubr) {} 120af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng }; 121af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng 1222706f9771de8e90ee6379e70afedd91892bb9c8cEvan Cheng /// ImmBranches - Keep track of all the immediate branch instructions. 123af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng /// 124e03cff6812ac41598e2bca7854985dc821a07f44Evan Cheng std::vector<ImmBranch> ImmBranches; 125af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng 126d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng /// PushPopMIs - Keep track of all the Thumb push / pop instructions. 127d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng /// 128c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng SmallVector<MachineInstr*, 4> PushPopMIs; 129d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng 1305657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng /// T2JumpTables - Keep track of all the Thumb2 jumptable instructions. 1315657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng SmallVector<MachineInstr*, 4> T2JumpTables; 1325657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng 133d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng /// HasFarJump - True if any far jump instruction has been emitted during 134d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng /// the branch fix up pass. 135d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng bool HasFarJump; 136d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng 137a8e2989ece6dc46df59b0768184028257f913843Evan Cheng const TargetInstrInfo *TII; 13825f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng const ARMSubtarget *STI; 1398593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen ARMFunctionInfo *AFI; 140b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen bool isThumb; 141d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng bool isThumb1; 1425e47a9a6e46bd271eba058fb831da1a1edf8707cDavid Goodwin bool isThumb2; 143a8e2989ece6dc46df59b0768184028257f913843Evan Cheng public: 1441997473cf72957d0e70322e2fe6fe2ab141c58a6Devang Patel static char ID; 145ae73dc1448d25b02cabc7c64c86c64371453dda8Dan Gohman ARMConstantIslands() : MachineFunctionPass(&ID) {} 146794fd75c67a2cdc128d67342c6d88a504d186896Devang Patel 1475657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng virtual bool runOnMachineFunction(MachineFunction &MF); 148a8e2989ece6dc46df59b0768184028257f913843Evan Cheng 149a8e2989ece6dc46df59b0768184028257f913843Evan Cheng virtual const char *getPassName() const { 150af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng return "ARM constant island placement and branch shortening pass"; 151a8e2989ece6dc46df59b0768184028257f913843Evan Cheng } 1528494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 153a8e2989ece6dc46df59b0768184028257f913843Evan Cheng private: 1545657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng void DoInitialPlacement(MachineFunction &MF, 155e03cff6812ac41598e2bca7854985dc821a07f44Evan Cheng std::vector<MachineInstr*> &CPEMIs); 156c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng CPEntry *findConstPoolEntry(unsigned CPI, const MachineInstr *CPEMI); 1575657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng void InitialFunctionScan(MachineFunction &MF, 158e03cff6812ac41598e2bca7854985dc821a07f44Evan Cheng const std::vector<MachineInstr*> &CPEMIs); 1590c61584d05894a5543f690803191a8b0da05b8fcEvan Cheng MachineBasicBlock *SplitBlockBeforeInstr(MachineInstr *MI); 160a8e2989ece6dc46df59b0768184028257f913843Evan Cheng void UpdateForInsertedWaterBlock(MachineBasicBlock *NewBB); 16199c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen void AdjustBBOffsetsAfter(MachineBasicBlock *BB, int delta); 162ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng bool DecrementOldEntry(unsigned CPI, MachineInstr* CPEMI); 16388e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen int LookForExistingCPEntry(CPUser& U, unsigned UserOffset); 1648494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson bool LookForWater(CPUser&U, unsigned UserOffset, 165b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen MachineBasicBlock** NewMBB); 1668494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson MachineBasicBlock* AcceptWater(MachineBasicBlock *WaterBB, 1678593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen std::vector<MachineBasicBlock*>::iterator IP); 168b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen void CreateNewWater(unsigned CPUserIndex, unsigned UserOffset, 169b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen MachineBasicBlock** NewMBB); 1705657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng bool HandleConstantPoolUser(MachineFunction &MF, unsigned CPUserIndex); 171ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng void RemoveDeadCPEMI(MachineInstr *CPEMI); 172ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng bool RemoveUnusedCPEntries(); 1738494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson bool CPEIsInRange(MachineInstr *MI, unsigned UserOffset, 1745d8f1cae76e4e424bf3b4392eddb3f4dbf38662aEvan Cheng MachineInstr *CPEMI, unsigned Disp, bool NegOk, 1755d8f1cae76e4e424bf3b4392eddb3f4dbf38662aEvan Cheng bool DoDump = false); 17699c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen bool WaterIsInRange(unsigned UserOffset, MachineBasicBlock *Water, 1775d9c4b60204d741c213456e21b87e9af6a3dc627Dale Johannesen CPUser &U); 17899c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen bool OffsetIsInRange(unsigned UserOffset, unsigned TrialOffset, 179d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng unsigned Disp, bool NegativeOK, bool IsSoImm = false); 180c0dbec7e1038ee60b8525eb1e8e3eaa6a839bd5bEvan Cheng bool BBIsInRange(MachineInstr *MI, MachineBasicBlock *BB, unsigned Disp); 1815657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng bool FixUpImmediateBr(MachineFunction &MF, ImmBranch &Br); 1825657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng bool FixUpConditionalBr(MachineFunction &MF, ImmBranch &Br); 1835657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng bool FixUpUnconditionalBr(MachineFunction &MF, ImmBranch &Br); 184d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng bool UndoLRSpillRestore(); 185a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng bool OptimizeThumb2Instructions(MachineFunction &MF); 186a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng bool OptimizeThumb2Branches(MachineFunction &MF); 1875657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng bool OptimizeThumb2JumpTables(MachineFunction &MF); 188a8e2989ece6dc46df59b0768184028257f913843Evan Cheng 189a8e2989ece6dc46df59b0768184028257f913843Evan Cheng unsigned GetOffsetOf(MachineInstr *MI) const; 1908593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen void dumpBBs(); 1915657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng void verify(MachineFunction &MF); 192a8e2989ece6dc46df59b0768184028257f913843Evan Cheng }; 1931997473cf72957d0e70322e2fe6fe2ab141c58a6Devang Patel char ARMConstantIslands::ID = 0; 194a8e2989ece6dc46df59b0768184028257f913843Evan Cheng} 195a8e2989ece6dc46df59b0768184028257f913843Evan Cheng 1968593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen/// verify - check BBOffsets, BBSizes, alignment of islands 1975657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Chengvoid ARMConstantIslands::verify(MachineFunction &MF) { 1988593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen assert(BBOffsets.size() == BBSizes.size()); 1998593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen for (unsigned i = 1, e = BBOffsets.size(); i != e; ++i) 2008593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen assert(BBOffsets[i-1]+BBSizes[i-1] == BBOffsets[i]); 201d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng if (!isThumb) 202d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng return; 203d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng#ifndef NDEBUG 2045657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng for (MachineFunction::iterator MBBI = MF.begin(), E = MF.end(); 205d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng MBBI != E; ++MBBI) { 206d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng MachineBasicBlock *MBB = MBBI; 207d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng if (!MBB->empty() && 208d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng MBB->begin()->getOpcode() == ARM::CONSTPOOL_ENTRY) { 209d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng unsigned MBBId = MBB->getNumber(); 210d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng assert((BBOffsets[MBBId]%4 == 0 && BBSizes[MBBId]%4 == 0) || 211d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng (BBOffsets[MBBId]%4 != 0 && BBSizes[MBBId]%4 != 0)); 2128593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen } 2138593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen } 214d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng#endif 2158593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen} 2168593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen 2178593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen/// print block size and offset information - debugging 2188593e418555fdae21a070357fd8734b4069c17d0Dale Johannesenvoid ARMConstantIslands::dumpBBs() { 2198593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen for (unsigned J = 0, E = BBOffsets.size(); J !=E; ++J) { 2208494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson DOUT << "block " << J << " offset " << BBOffsets[J] << 2215d9c4b60204d741c213456e21b87e9af6a3dc627Dale Johannesen " size " << BBSizes[J] << "\n"; 2228593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen } 2238593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen} 2248593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen 225af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng/// createARMConstantIslandPass - returns an instance of the constpool 226af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng/// island pass. 227a8e2989ece6dc46df59b0768184028257f913843Evan ChengFunctionPass *llvm::createARMConstantIslandPass() { 228a8e2989ece6dc46df59b0768184028257f913843Evan Cheng return new ARMConstantIslands(); 229a8e2989ece6dc46df59b0768184028257f913843Evan Cheng} 230a8e2989ece6dc46df59b0768184028257f913843Evan Cheng 2315657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Chengbool ARMConstantIslands::runOnMachineFunction(MachineFunction &MF) { 2325657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng MachineConstantPool &MCP = *MF.getConstantPool(); 2338494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 2345657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng TII = MF.getTarget().getInstrInfo(); 2355657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng AFI = MF.getInfo<ARMFunctionInfo>(); 23625f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng STI = &MF.getTarget().getSubtarget<ARMSubtarget>(); 23725f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng 238b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen isThumb = AFI->isThumbFunction(); 239d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng isThumb1 = AFI->isThumb1OnlyFunction(); 2405e47a9a6e46bd271eba058fb831da1a1edf8707cDavid Goodwin isThumb2 = AFI->isThumb2Function(); 241d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng 242d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng HasFarJump = false; 243d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng 244a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // Renumber all of the machine basic blocks in the function, guaranteeing that 245a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // the numbers agree with the position of the block in the function. 2465657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng MF.RenumberBlocks(); 247a8e2989ece6dc46df59b0768184028257f913843Evan Cheng 248d26b14c34cbcee1448b86b524578fc51cc979023Evan Cheng // Thumb1 functions containing constant pools get 4-byte alignment. 249d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng // This is so we can keep exact track of where the alignment padding goes. 250d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng 251d26b14c34cbcee1448b86b524578fc51cc979023Evan Cheng // Set default. Thumb1 function is 2-byte aligned, ARM and Thumb2 are 4-byte 252d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng // aligned. 253d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng AFI->setAlign(isThumb1 ? 1U : 2U); 25456c42ef3e43f8eb75c435e781d0ac8251c7588a1Dale Johannesen 255a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // Perform the initial placement of the constant pool entries. To start with, 256a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // we put them all at the end of the function. 257e03cff6812ac41598e2bca7854985dc821a07f44Evan Cheng std::vector<MachineInstr*> CPEMIs; 25856c42ef3e43f8eb75c435e781d0ac8251c7588a1Dale Johannesen if (!MCP.isEmpty()) { 2595657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng DoInitialPlacement(MF, CPEMIs); 260d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng if (isThumb1) 26156c42ef3e43f8eb75c435e781d0ac8251c7588a1Dale Johannesen AFI->setAlign(2U); 26256c42ef3e43f8eb75c435e781d0ac8251c7588a1Dale Johannesen } 2638494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 264a8e2989ece6dc46df59b0768184028257f913843Evan Cheng /// The next UID to take is the first unused one. 265f1bbb9577a42cf7dc3079412f1dd7683e3a03665Evan Cheng AFI->initConstPoolEntryUId(CPEMIs.size()); 2668494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 267a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // Do the initial scan of the function, building up information about the 268a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // sizes of each block, the location of all the water, and finding all of the 269a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // constant pool users. 2705657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng InitialFunctionScan(MF, CPEMIs); 271a8e2989ece6dc46df59b0768184028257f913843Evan Cheng CPEMIs.clear(); 2728494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 273ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng /// Remove dead constant pool entries. 274ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng RemoveUnusedCPEntries(); 275ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng 276d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng // Iteratively place constant pool entries and fix up branches until there 277d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng // is no change. 278d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng bool MadeChange = false; 279b6879b2b84df2f642cd39f5bf58584c4a39f8080Evan Cheng unsigned NoCPIters = 0, NoBRIters = 0; 280d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng while (true) { 281b6879b2b84df2f642cd39f5bf58584c4a39f8080Evan Cheng bool CPChange = false; 282a8e2989ece6dc46df59b0768184028257f913843Evan Cheng for (unsigned i = 0, e = CPUsers.size(); i != e; ++i) 283b6879b2b84df2f642cd39f5bf58584c4a39f8080Evan Cheng CPChange |= HandleConstantPoolUser(MF, i); 284b6879b2b84df2f642cd39f5bf58584c4a39f8080Evan Cheng if (CPChange && ++NoCPIters > 30) 285b6879b2b84df2f642cd39f5bf58584c4a39f8080Evan Cheng llvm_unreachable("Constant Island pass failed to converge!"); 2868202010364e1bfe6111f1ce62f154499b80877fbEvan Cheng DEBUG(dumpBBs()); 287b6879b2b84df2f642cd39f5bf58584c4a39f8080Evan Cheng 288b6879b2b84df2f642cd39f5bf58584c4a39f8080Evan Cheng bool BRChange = false; 289af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng for (unsigned i = 0, e = ImmBranches.size(); i != e; ++i) 290b6879b2b84df2f642cd39f5bf58584c4a39f8080Evan Cheng BRChange |= FixUpImmediateBr(MF, ImmBranches[i]); 291b6879b2b84df2f642cd39f5bf58584c4a39f8080Evan Cheng if (BRChange && ++NoBRIters > 30) 292b6879b2b84df2f642cd39f5bf58584c4a39f8080Evan Cheng llvm_unreachable("Branch Fix Up pass failed to converge!"); 2938202010364e1bfe6111f1ce62f154499b80877fbEvan Cheng DEBUG(dumpBBs()); 294b6879b2b84df2f642cd39f5bf58584c4a39f8080Evan Cheng 295b6879b2b84df2f642cd39f5bf58584c4a39f8080Evan Cheng if (!CPChange && !BRChange) 296d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng break; 297d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng MadeChange = true; 298d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng } 299ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng 300a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng // Shrink 32-bit Thumb2 branch, load, and store instructions. 301a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng if (isThumb2) 302a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng MadeChange |= OptimizeThumb2Instructions(MF); 30325f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng 3048593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // After a while, this might be made debug-only, but it is not expensive. 3055657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng verify(MF); 3068593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen 307d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng // If LR has been forced spilled and no far jumps (i.e. BL) has been issued. 308d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng // Undo the spill / restore of LR if possible. 3095657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng if (isThumb && !HasFarJump && AFI->isLRSpilledForFarJump()) 310d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng MadeChange |= UndoLRSpillRestore(); 311d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng 312a8e2989ece6dc46df59b0768184028257f913843Evan Cheng BBSizes.clear(); 31399c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen BBOffsets.clear(); 314a8e2989ece6dc46df59b0768184028257f913843Evan Cheng WaterList.clear(); 315a8e2989ece6dc46df59b0768184028257f913843Evan Cheng CPUsers.clear(); 316c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng CPEntries.clear(); 317af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng ImmBranches.clear(); 318c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng PushPopMIs.clear(); 3195657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng T2JumpTables.clear(); 320d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng 321d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng return MadeChange; 322a8e2989ece6dc46df59b0768184028257f913843Evan Cheng} 323a8e2989ece6dc46df59b0768184028257f913843Evan Cheng 324a8e2989ece6dc46df59b0768184028257f913843Evan Cheng/// DoInitialPlacement - Perform the initial placement of the constant pool 325a8e2989ece6dc46df59b0768184028257f913843Evan Cheng/// entries. To start with, we put them all at the end of the function. 3265657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Chengvoid ARMConstantIslands::DoInitialPlacement(MachineFunction &MF, 3278494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson std::vector<MachineInstr*> &CPEMIs) { 328a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // Create the basic block to hold the CPE's. 3295657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng MachineBasicBlock *BB = MF.CreateMachineBasicBlock(); 3305657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng MF.push_back(BB); 3318494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 332a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // Add all of the constants from the constant pool to the end block, use an 333a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // identity mapping of CPI's to CPE's. 334a8e2989ece6dc46df59b0768184028257f913843Evan Cheng const std::vector<MachineConstantPoolEntry> &CPs = 3355657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng MF.getConstantPool()->getConstants(); 3368494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 3375657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng const TargetData &TD = *MF.getTarget().getTargetData(); 338a8e2989ece6dc46df59b0768184028257f913843Evan Cheng for (unsigned i = 0, e = CPs.size(); i != e; ++i) { 339777d2306b36816a53bc1ae1244c0dc7d998ae691Duncan Sands unsigned Size = TD.getTypeAllocSize(CPs[i].getType()); 340a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // Verify that all constant pool entries are a multiple of 4 bytes. If not, 341a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // we would have to pad them out or something so that instructions stay 342a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // aligned. 343a8e2989ece6dc46df59b0768184028257f913843Evan Cheng assert((Size & 3) == 0 && "CP Entry not multiple of 4 bytes!"); 344a8e2989ece6dc46df59b0768184028257f913843Evan Cheng MachineInstr *CPEMI = 345b67284057ee130114055309eabe0bcd1af13777dDale Johannesen BuildMI(BB, DebugLoc::getUnknownLoc(), TII->get(ARM::CONSTPOOL_ENTRY)) 346a8e2989ece6dc46df59b0768184028257f913843Evan Cheng .addImm(i).addConstantPoolIndex(i).addImm(Size); 347a8e2989ece6dc46df59b0768184028257f913843Evan Cheng CPEMIs.push_back(CPEMI); 348c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng 349c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng // Add a new CPEntry, but no corresponding CPUser yet. 350c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng std::vector<CPEntry> CPEs; 351c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng CPEs.push_back(CPEntry(CPEMI, i)); 352c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng CPEntries.push_back(CPEs); 353c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng NumCPEs++; 354c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng DOUT << "Moved CPI#" << i << " to end of function as #" << i << "\n"; 355a8e2989ece6dc46df59b0768184028257f913843Evan Cheng } 356a8e2989ece6dc46df59b0768184028257f913843Evan Cheng} 357a8e2989ece6dc46df59b0768184028257f913843Evan Cheng 35888e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen/// BBHasFallthrough - Return true if the specified basic block can fallthrough 359a8e2989ece6dc46df59b0768184028257f913843Evan Cheng/// into the block immediately after it. 360a8e2989ece6dc46df59b0768184028257f913843Evan Chengstatic bool BBHasFallthrough(MachineBasicBlock *MBB) { 361a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // Get the next machine basic block in the function. 362a8e2989ece6dc46df59b0768184028257f913843Evan Cheng MachineFunction::iterator MBBI = MBB; 363a8e2989ece6dc46df59b0768184028257f913843Evan Cheng if (next(MBBI) == MBB->getParent()->end()) // Can't fall off end of function. 364a8e2989ece6dc46df59b0768184028257f913843Evan Cheng return false; 3658494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 366a8e2989ece6dc46df59b0768184028257f913843Evan Cheng MachineBasicBlock *NextBB = next(MBBI); 367a8e2989ece6dc46df59b0768184028257f913843Evan Cheng for (MachineBasicBlock::succ_iterator I = MBB->succ_begin(), 368a8e2989ece6dc46df59b0768184028257f913843Evan Cheng E = MBB->succ_end(); I != E; ++I) 369a8e2989ece6dc46df59b0768184028257f913843Evan Cheng if (*I == NextBB) 370a8e2989ece6dc46df59b0768184028257f913843Evan Cheng return true; 3718494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 372a8e2989ece6dc46df59b0768184028257f913843Evan Cheng return false; 373a8e2989ece6dc46df59b0768184028257f913843Evan Cheng} 374a8e2989ece6dc46df59b0768184028257f913843Evan Cheng 375c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng/// findConstPoolEntry - Given the constpool index and CONSTPOOL_ENTRY MI, 376c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng/// look up the corresponding CPEntry. 377c99ef085b90b32952b484e8843fb66ad65215b61Evan ChengARMConstantIslands::CPEntry 378c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng*ARMConstantIslands::findConstPoolEntry(unsigned CPI, 379c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng const MachineInstr *CPEMI) { 380c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng std::vector<CPEntry> &CPEs = CPEntries[CPI]; 381c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng // Number of entries per constpool index should be small, just do a 382c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng // linear search. 383c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng for (unsigned i = 0, e = CPEs.size(); i != e; ++i) { 384c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng if (CPEs[i].CPEMI == CPEMI) 385c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng return &CPEs[i]; 386c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng } 387c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng return NULL; 388c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng} 389c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng 390a8e2989ece6dc46df59b0768184028257f913843Evan Cheng/// InitialFunctionScan - Do the initial scan of the function, building up 391a8e2989ece6dc46df59b0768184028257f913843Evan Cheng/// information about the sizes of each block, the location of all the water, 392a8e2989ece6dc46df59b0768184028257f913843Evan Cheng/// and finding all of the constant pool users. 3935657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Chengvoid ARMConstantIslands::InitialFunctionScan(MachineFunction &MF, 394e03cff6812ac41598e2bca7854985dc821a07f44Evan Cheng const std::vector<MachineInstr*> &CPEMIs) { 39599c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen unsigned Offset = 0; 3965657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng for (MachineFunction::iterator MBBI = MF.begin(), E = MF.end(); 397a8e2989ece6dc46df59b0768184028257f913843Evan Cheng MBBI != E; ++MBBI) { 398a8e2989ece6dc46df59b0768184028257f913843Evan Cheng MachineBasicBlock &MBB = *MBBI; 3998494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 400a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // If this block doesn't fall through into the next MBB, then this is 401a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // 'water' that a constant pool island could be placed. 402a8e2989ece6dc46df59b0768184028257f913843Evan Cheng if (!BBHasFallthrough(&MBB)) 403a8e2989ece6dc46df59b0768184028257f913843Evan Cheng WaterList.push_back(&MBB); 4048494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 405a8e2989ece6dc46df59b0768184028257f913843Evan Cheng unsigned MBBSize = 0; 406a8e2989ece6dc46df59b0768184028257f913843Evan Cheng for (MachineBasicBlock::iterator I = MBB.begin(), E = MBB.end(); 407a8e2989ece6dc46df59b0768184028257f913843Evan Cheng I != E; ++I) { 408a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // Add instruction size to MBBSize. 40952e724ad7e679ee590f4bd763d55280586a8f1bcNicolas Geoffray MBBSize += TII->GetInstSizeInBytes(I); 410a8e2989ece6dc46df59b0768184028257f913843Evan Cheng 411af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng int Opc = I->getOpcode(); 412749c6f6b5ed301c84aac562e414486549d7b98ebChris Lattner if (I->getDesc().isBranch()) { 413af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng bool isCond = false; 414af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng unsigned Bits = 0; 415af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng unsigned Scale = 1; 416af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng int UOpc = Opc; 417af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng switch (Opc) { 4185657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng default: 4195657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng continue; // Ignore other JT branches 4208593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen case ARM::tBR_JTr: 42166ac53165e17b7c76b8c69e57bde623d44ec492eEvan Cheng // A Thumb1 table jump may involve padding; for the offsets to 4228593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // be right, functions containing these must be 4-byte aligned. 4238593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen AFI->setAlign(2U); 4248593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen if ((Offset+MBBSize)%4 != 0) 4255657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng // FIXME: Add a pseudo ALIGN instruction instead. 4268593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen MBBSize += 2; // padding 4278593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen continue; // Does not get an entry in ImmBranches 4285657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng case ARM::t2BR_JT: 4295657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng T2JumpTables.push_back(I); 4305657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng continue; // Does not get an entry in ImmBranches 431af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng case ARM::Bcc: 432af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng isCond = true; 433af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng UOpc = ARM::B; 434af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng // Fallthrough 435af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng case ARM::B: 436af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng Bits = 24; 437af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng Scale = 4; 438af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng break; 439af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng case ARM::tBcc: 440af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng isCond = true; 441af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng UOpc = ARM::tB; 442af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng Bits = 8; 443af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng Scale = 2; 444af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng break; 445af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng case ARM::tB: 446af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng Bits = 11; 447af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng Scale = 2; 448af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng break; 4495e47a9a6e46bd271eba058fb831da1a1edf8707cDavid Goodwin case ARM::t2Bcc: 4505e47a9a6e46bd271eba058fb831da1a1edf8707cDavid Goodwin isCond = true; 4515e47a9a6e46bd271eba058fb831da1a1edf8707cDavid Goodwin UOpc = ARM::t2B; 4525e47a9a6e46bd271eba058fb831da1a1edf8707cDavid Goodwin Bits = 20; 4535e47a9a6e46bd271eba058fb831da1a1edf8707cDavid Goodwin Scale = 2; 4545e47a9a6e46bd271eba058fb831da1a1edf8707cDavid Goodwin break; 4555e47a9a6e46bd271eba058fb831da1a1edf8707cDavid Goodwin case ARM::t2B: 4565e47a9a6e46bd271eba058fb831da1a1edf8707cDavid Goodwin Bits = 24; 4575e47a9a6e46bd271eba058fb831da1a1edf8707cDavid Goodwin Scale = 2; 4585e47a9a6e46bd271eba058fb831da1a1edf8707cDavid Goodwin break; 459af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng } 460b43216ee4a418257ce5530c02601b77efe86c354Evan Cheng 461b43216ee4a418257ce5530c02601b77efe86c354Evan Cheng // Record this immediate branch. 462bd5d3dbdbe46c7325545a7cb8c891c0347375451Evan Cheng unsigned MaxOffs = ((1 << (Bits-1))-1) * Scale; 463b43216ee4a418257ce5530c02601b77efe86c354Evan Cheng ImmBranches.push_back(ImmBranch(I, MaxOffs, isCond, UOpc)); 464af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng } 465af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng 466d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng if (Opc == ARM::tPUSH || Opc == ARM::tPOP_RET) 467d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng PushPopMIs.push_back(I); 468d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng 469d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng if (Opc == ARM::CONSTPOOL_ENTRY) 470d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng continue; 471d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng 472a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // Scan the instructions for constant pool operands. 473a8e2989ece6dc46df59b0768184028257f913843Evan Cheng for (unsigned op = 0, e = I->getNumOperands(); op != e; ++op) 474d735b8019b0f297d7c14b55adcd887af24d8e602Dan Gohman if (I->getOperand(op).isCPI()) { 475a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // We found one. The addressing mode tells us the max displacement 476a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // from the PC that this instruction permits. 4778494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 478a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // Basic size info comes from the TSFlags field. 479b43216ee4a418257ce5530c02601b77efe86c354Evan Cheng unsigned Bits = 0; 480b43216ee4a418257ce5530c02601b77efe86c354Evan Cheng unsigned Scale = 1; 4815d8f1cae76e4e424bf3b4392eddb3f4dbf38662aEvan Cheng bool NegOk = false; 482d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng bool IsSoImm = false; 483d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng 484d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng switch (Opc) { 4858494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson default: 486c23197a26f34f559ea9797de51e187087c039c42Torok Edwin llvm_unreachable("Unknown addressing mode for CP reference!"); 487a8e2989ece6dc46df59b0768184028257f913843Evan Cheng break; 488d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng 489d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng // Taking the address of a CP entry. 490d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng case ARM::LEApcrel: 491d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng // This takes a SoImm, which is 8 bit immediate rotated. We'll 492d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng // pretend the maximum offset is 255 * 4. Since each instruction 493d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng // 4 byte wide, this is always correct. We'llc heck for other 494d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng // displacements that fits in a SoImm as well. 495d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng Bits = 8; 496d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng Scale = 4; 4975d8f1cae76e4e424bf3b4392eddb3f4dbf38662aEvan Cheng NegOk = true; 498d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng IsSoImm = true; 499a8e2989ece6dc46df59b0768184028257f913843Evan Cheng break; 500d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng case ARM::t2LEApcrel: 501d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng Bits = 12; 5025d8f1cae76e4e424bf3b4392eddb3f4dbf38662aEvan Cheng NegOk = true; 503a8e2989ece6dc46df59b0768184028257f913843Evan Cheng break; 504d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng case ARM::tLEApcrel: 505b43216ee4a418257ce5530c02601b77efe86c354Evan Cheng Bits = 8; 506d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng Scale = 4; 507a8e2989ece6dc46df59b0768184028257f913843Evan Cheng break; 508d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng 509d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng case ARM::LDR: 510d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng case ARM::LDRcp: 511d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng case ARM::t2LDRpci: 512d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng Bits = 12; // +-offset_12 513d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng NegOk = true; 514a8e2989ece6dc46df59b0768184028257f913843Evan Cheng break; 515d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng 516d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng case ARM::tLDRpci: 517d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng case ARM::tLDRcp: 518b43216ee4a418257ce5530c02601b77efe86c354Evan Cheng Bits = 8; 519b43216ee4a418257ce5530c02601b77efe86c354Evan Cheng Scale = 4; // +(offset_8*4) 520012f2d97b78e4eb9128f1d491f2c177768dbe527Evan Cheng break; 521d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng 522d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng case ARM::FLDD: 523d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng case ARM::FLDS: 524d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng Bits = 8; 525d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng Scale = 4; // +-(offset_8*4) 526d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng NegOk = true; 527055b0310f862b91f33699037ce67d3ab8137c20cEvan Cheng break; 528a8e2989ece6dc46df59b0768184028257f913843Evan Cheng } 529b43216ee4a418257ce5530c02601b77efe86c354Evan Cheng 530a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // Remember that this is a user of a CP entry. 5318aa797aa51cd4ea1ec6f46f4891a6897944b75b2Chris Lattner unsigned CPI = I->getOperand(op).getIndex(); 532c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng MachineInstr *CPEMI = CPEMIs[CPI]; 53331b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng unsigned MaxOffs = ((1 << Bits)-1) * Scale; 534d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng CPUsers.push_back(CPUser(I, CPEMI, MaxOffs, NegOk, IsSoImm)); 535c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng 536c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng // Increment corresponding CPEntry reference count. 537c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng CPEntry *CPE = findConstPoolEntry(CPI, CPEMI); 538c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng assert(CPE && "Cannot find a corresponding CPEntry!"); 539c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng CPE->RefCount++; 5408494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 541a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // Instructions can only use one CP entry, don't bother scanning the 542a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // rest of the operands. 543a8e2989ece6dc46df59b0768184028257f913843Evan Cheng break; 544a8e2989ece6dc46df59b0768184028257f913843Evan Cheng } 545a8e2989ece6dc46df59b0768184028257f913843Evan Cheng } 5462021abe154e3cac523755b74fc5e62a2c9dad1fcEvan Cheng 5478593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // In thumb mode, if this block is a constpool island, we may need padding 5488593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // so it's aligned on 4 byte boundary. 549b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen if (isThumb && 55005cc424082f797c5820b19f29f398c9cce9b9928Evan Cheng !MBB.empty() && 5518593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen MBB.begin()->getOpcode() == ARM::CONSTPOOL_ENTRY && 5528593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen (Offset%4) != 0) 5532021abe154e3cac523755b74fc5e62a2c9dad1fcEvan Cheng MBBSize += 2; 5542021abe154e3cac523755b74fc5e62a2c9dad1fcEvan Cheng 555a8e2989ece6dc46df59b0768184028257f913843Evan Cheng BBSizes.push_back(MBBSize); 55699c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen BBOffsets.push_back(Offset); 55799c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen Offset += MBBSize; 558a8e2989ece6dc46df59b0768184028257f913843Evan Cheng } 559a8e2989ece6dc46df59b0768184028257f913843Evan Cheng} 560a8e2989ece6dc46df59b0768184028257f913843Evan Cheng 561a8e2989ece6dc46df59b0768184028257f913843Evan Cheng/// GetOffsetOf - Return the current offset of the specified machine instruction 562a8e2989ece6dc46df59b0768184028257f913843Evan Cheng/// from the start of the function. This offset changes as stuff is moved 563a8e2989ece6dc46df59b0768184028257f913843Evan Cheng/// around inside the function. 564a8e2989ece6dc46df59b0768184028257f913843Evan Chengunsigned ARMConstantIslands::GetOffsetOf(MachineInstr *MI) const { 565a8e2989ece6dc46df59b0768184028257f913843Evan Cheng MachineBasicBlock *MBB = MI->getParent(); 5668494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 567a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // The offset is composed of two things: the sum of the sizes of all MBB's 568a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // before this instruction's block, and the offset from the start of the block 569a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // it is in. 57099c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen unsigned Offset = BBOffsets[MBB->getNumber()]; 571a8e2989ece6dc46df59b0768184028257f913843Evan Cheng 5728593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // If we're looking for a CONSTPOOL_ENTRY in Thumb, see if this block has 5738593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // alignment padding, and compensate if so. 5748494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson if (isThumb && 5758494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson MI->getOpcode() == ARM::CONSTPOOL_ENTRY && 5768593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen Offset%4 != 0) 5778593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen Offset += 2; 5788593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen 579a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // Sum instructions before MI in MBB. 580a8e2989ece6dc46df59b0768184028257f913843Evan Cheng for (MachineBasicBlock::iterator I = MBB->begin(); ; ++I) { 581a8e2989ece6dc46df59b0768184028257f913843Evan Cheng assert(I != MBB->end() && "Didn't find MI in its own basic block?"); 582a8e2989ece6dc46df59b0768184028257f913843Evan Cheng if (&*I == MI) return Offset; 58352e724ad7e679ee590f4bd763d55280586a8f1bcNicolas Geoffray Offset += TII->GetInstSizeInBytes(I); 584a8e2989ece6dc46df59b0768184028257f913843Evan Cheng } 585a8e2989ece6dc46df59b0768184028257f913843Evan Cheng} 586a8e2989ece6dc46df59b0768184028257f913843Evan Cheng 587a8e2989ece6dc46df59b0768184028257f913843Evan Cheng/// CompareMBBNumbers - Little predicate function to sort the WaterList by MBB 588a8e2989ece6dc46df59b0768184028257f913843Evan Cheng/// ID. 589a8e2989ece6dc46df59b0768184028257f913843Evan Chengstatic bool CompareMBBNumbers(const MachineBasicBlock *LHS, 590a8e2989ece6dc46df59b0768184028257f913843Evan Cheng const MachineBasicBlock *RHS) { 591a8e2989ece6dc46df59b0768184028257f913843Evan Cheng return LHS->getNumber() < RHS->getNumber(); 592a8e2989ece6dc46df59b0768184028257f913843Evan Cheng} 593a8e2989ece6dc46df59b0768184028257f913843Evan Cheng 594a8e2989ece6dc46df59b0768184028257f913843Evan Cheng/// UpdateForInsertedWaterBlock - When a block is newly inserted into the 595a8e2989ece6dc46df59b0768184028257f913843Evan Cheng/// machine function, it upsets all of the block numbers. Renumber the blocks 596a8e2989ece6dc46df59b0768184028257f913843Evan Cheng/// and update the arrays that parallel this numbering. 597a8e2989ece6dc46df59b0768184028257f913843Evan Chengvoid ARMConstantIslands::UpdateForInsertedWaterBlock(MachineBasicBlock *NewBB) { 598a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // Renumber the MBB's to keep them consequtive. 599a8e2989ece6dc46df59b0768184028257f913843Evan Cheng NewBB->getParent()->RenumberBlocks(NewBB); 6008494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 601a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // Insert a size into BBSizes to align it properly with the (newly 602a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // renumbered) block numbers. 603a8e2989ece6dc46df59b0768184028257f913843Evan Cheng BBSizes.insert(BBSizes.begin()+NewBB->getNumber(), 0); 60499c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen 60599c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen // Likewise for BBOffsets. 60699c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen BBOffsets.insert(BBOffsets.begin()+NewBB->getNumber(), 0); 6078494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 6088494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson // Next, update WaterList. Specifically, we need to add NewMBB as having 609a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // available water after it. 610e03cff6812ac41598e2bca7854985dc821a07f44Evan Cheng std::vector<MachineBasicBlock*>::iterator IP = 611a8e2989ece6dc46df59b0768184028257f913843Evan Cheng std::lower_bound(WaterList.begin(), WaterList.end(), NewBB, 612a8e2989ece6dc46df59b0768184028257f913843Evan Cheng CompareMBBNumbers); 613a8e2989ece6dc46df59b0768184028257f913843Evan Cheng WaterList.insert(IP, NewBB); 614a8e2989ece6dc46df59b0768184028257f913843Evan Cheng} 615a8e2989ece6dc46df59b0768184028257f913843Evan Cheng 616a8e2989ece6dc46df59b0768184028257f913843Evan Cheng 617a8e2989ece6dc46df59b0768184028257f913843Evan Cheng/// Split the basic block containing MI into two blocks, which are joined by 618a8e2989ece6dc46df59b0768184028257f913843Evan Cheng/// an unconditional branch. Update datastructures and renumber blocks to 6190c61584d05894a5543f690803191a8b0da05b8fcEvan Cheng/// account for this change and returns the newly created block. 6200c61584d05894a5543f690803191a8b0da05b8fcEvan ChengMachineBasicBlock *ARMConstantIslands::SplitBlockBeforeInstr(MachineInstr *MI) { 621a8e2989ece6dc46df59b0768184028257f913843Evan Cheng MachineBasicBlock *OrigBB = MI->getParent(); 6228e5f2c6f65841542e2a7092553fe42a00048e4c7Dan Gohman MachineFunction &MF = *OrigBB->getParent(); 623a8e2989ece6dc46df59b0768184028257f913843Evan Cheng 624a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // Create a new MBB for the code after the OrigBB. 6258494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson MachineBasicBlock *NewBB = 6268494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson MF.CreateMachineBasicBlock(OrigBB->getBasicBlock()); 627a8e2989ece6dc46df59b0768184028257f913843Evan Cheng MachineFunction::iterator MBBI = OrigBB; ++MBBI; 6288e5f2c6f65841542e2a7092553fe42a00048e4c7Dan Gohman MF.insert(MBBI, NewBB); 6298494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 630a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // Splice the instructions starting with MI over to NewBB. 631a8e2989ece6dc46df59b0768184028257f913843Evan Cheng NewBB->splice(NewBB->end(), OrigBB, MI, OrigBB->end()); 6328494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 633a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // Add an unconditional branch from OrigBB to NewBB. 634a9b8b8d62c67e96bc4dc2ed25298c539102f8638Evan Cheng // Note the new unconditional branch is not being recorded. 635b67284057ee130114055309eabe0bcd1af13777dDale Johannesen // There doesn't seem to be meaningful DebugInfo available; this doesn't 636b67284057ee130114055309eabe0bcd1af13777dDale Johannesen // correspond to anything in the source. 63758541fd62707b6856beee3db9e254b0110607bb1Evan Cheng unsigned Opc = isThumb ? (isThumb2 ? ARM::t2B : ARM::tB) : ARM::B; 63858541fd62707b6856beee3db9e254b0110607bb1Evan Cheng BuildMI(OrigBB, DebugLoc::getUnknownLoc(), TII->get(Opc)).addMBB(NewBB); 639a8e2989ece6dc46df59b0768184028257f913843Evan Cheng NumSplit++; 6408494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 641a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // Update the CFG. All succs of OrigBB are now succs of NewBB. 642a8e2989ece6dc46df59b0768184028257f913843Evan Cheng while (!OrigBB->succ_empty()) { 643a8e2989ece6dc46df59b0768184028257f913843Evan Cheng MachineBasicBlock *Succ = *OrigBB->succ_begin(); 644a8e2989ece6dc46df59b0768184028257f913843Evan Cheng OrigBB->removeSuccessor(Succ); 645a8e2989ece6dc46df59b0768184028257f913843Evan Cheng NewBB->addSuccessor(Succ); 6468494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 647a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // This pass should be run after register allocation, so there should be no 648a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // PHI nodes to update. 649a8e2989ece6dc46df59b0768184028257f913843Evan Cheng assert((Succ->empty() || Succ->begin()->getOpcode() != TargetInstrInfo::PHI) 650a8e2989ece6dc46df59b0768184028257f913843Evan Cheng && "PHI nodes should be eliminated by now!"); 651a8e2989ece6dc46df59b0768184028257f913843Evan Cheng } 6528494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 653a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // OrigBB branches to NewBB. 654a8e2989ece6dc46df59b0768184028257f913843Evan Cheng OrigBB->addSuccessor(NewBB); 6558494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 656a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // Update internal data structures to account for the newly inserted MBB. 65788e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen // This is almost the same as UpdateForInsertedWaterBlock, except that 65888e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen // the Water goes after OrigBB, not NewBB. 6598e5f2c6f65841542e2a7092553fe42a00048e4c7Dan Gohman MF.RenumberBlocks(NewBB); 6608494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 66188e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen // Insert a size into BBSizes to align it properly with the (newly 66288e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen // renumbered) block numbers. 66388e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen BBSizes.insert(BBSizes.begin()+NewBB->getNumber(), 0); 6648494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 66599c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen // Likewise for BBOffsets. 66699c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen BBOffsets.insert(BBOffsets.begin()+NewBB->getNumber(), 0); 66799c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen 6688494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson // Next, update WaterList. Specifically, we need to add OrigMBB as having 66988e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen // available water after it (but not if it's already there, which happens 67088e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen // when splitting before a conditional branch that is followed by an 67188e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen // unconditional branch - in that case we want to insert NewBB). 67288e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen std::vector<MachineBasicBlock*>::iterator IP = 67388e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen std::lower_bound(WaterList.begin(), WaterList.end(), OrigBB, 67488e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen CompareMBBNumbers); 67588e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen MachineBasicBlock* WaterBB = *IP; 67688e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen if (WaterBB == OrigBB) 67788e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen WaterList.insert(next(IP), NewBB); 67888e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen else 67988e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen WaterList.insert(IP, OrigBB); 68088e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen 6818593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // Figure out how large the first NewMBB is. (It cannot 6828593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // contain a constpool_entry or tablejump.) 683a8e2989ece6dc46df59b0768184028257f913843Evan Cheng unsigned NewBBSize = 0; 684a8e2989ece6dc46df59b0768184028257f913843Evan Cheng for (MachineBasicBlock::iterator I = NewBB->begin(), E = NewBB->end(); 685a8e2989ece6dc46df59b0768184028257f913843Evan Cheng I != E; ++I) 68652e724ad7e679ee590f4bd763d55280586a8f1bcNicolas Geoffray NewBBSize += TII->GetInstSizeInBytes(I); 6878494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 68899c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen unsigned OrigBBI = OrigBB->getNumber(); 68999c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen unsigned NewBBI = NewBB->getNumber(); 690a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // Set the size of NewBB in BBSizes. 69199c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen BBSizes[NewBBI] = NewBBSize; 6928494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 693a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // We removed instructions from UserMBB, subtract that off from its size. 694af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng // Add 2 or 4 to the block to count the unconditional branch we added to it. 69525f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng int delta = isThumb1 ? 2 : 4; 69699c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen BBSizes[OrigBBI] -= NewBBSize - delta; 69799c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen 69899c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen // ...and adjust BBOffsets for NewBB accordingly. 69999c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen BBOffsets[NewBBI] = BBOffsets[OrigBBI] + BBSizes[OrigBBI]; 70099c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen 70199c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen // All BBOffsets following these blocks must be modified. 70299c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen AdjustBBOffsetsAfter(NewBB, delta); 7030c61584d05894a5543f690803191a8b0da05b8fcEvan Cheng 7040c61584d05894a5543f690803191a8b0da05b8fcEvan Cheng return NewBB; 705a8e2989ece6dc46df59b0768184028257f913843Evan Cheng} 706a8e2989ece6dc46df59b0768184028257f913843Evan Cheng 7078593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen/// OffsetIsInRange - Checks whether UserOffset (the location of a constant pool 7088494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson/// reference) is within MaxDisp of TrialOffset (a proposed location of a 7098593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen/// constant pool entry). 7108494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilsonbool ARMConstantIslands::OffsetIsInRange(unsigned UserOffset, 711d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng unsigned TrialOffset, unsigned MaxDisp, 712d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng bool NegativeOK, bool IsSoImm) { 7138494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson // On Thumb offsets==2 mod 4 are rounded down by the hardware for 7148494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson // purposes of the displacement computation; compensate for that here. 7158593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // Effectively, the valid range of displacements is 2 bytes smaller for such 7168593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // references. 71731b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng unsigned TotalAdj = 0; 71831b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng if (isThumb && UserOffset%4 !=0) { 7198593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen UserOffset -= 2; 72031b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng TotalAdj = 2; 72131b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng } 7228593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // CPEs will be rounded up to a multiple of 4. 72331b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng if (isThumb && TrialOffset%4 != 0) { 7248593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen TrialOffset += 2; 72531b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng TotalAdj += 2; 72631b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng } 72731b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng 72831b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng // In Thumb2 mode, later branch adjustments can shift instructions up and 72931b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng // cause alignment change. In the worst case scenario this can cause the 73031b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng // user's effective address to be subtracted by 2 and the CPE's address to 73131b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng // be plus 2. 73231b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng if (isThumb2 && TotalAdj != 4) 73331b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng MaxDisp -= (4 - TotalAdj); 7348593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen 73599c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen if (UserOffset <= TrialOffset) { 73699c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen // User before the Trial. 737d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng if (TrialOffset - UserOffset <= MaxDisp) 738d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng return true; 73940efc251cd7a52dd2375ec95ee38b1be4572178fEvan Cheng // FIXME: Make use full range of soimm values. 74099c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen } else if (NegativeOK) { 741d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng if (UserOffset - TrialOffset <= MaxDisp) 742d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng return true; 74340efc251cd7a52dd2375ec95ee38b1be4572178fEvan Cheng // FIXME: Make use full range of soimm values. 74499c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen } 74599c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen return false; 74699c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen} 74799c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen 74888e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen/// WaterIsInRange - Returns true if a CPE placed after the specified 74988e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen/// Water (a basic block) will be in range for the specific MI. 75088e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen 75188e37ae36652546c8e409cab69a1777af63cf095Dale Johannesenbool ARMConstantIslands::WaterIsInRange(unsigned UserOffset, 7525d8f1cae76e4e424bf3b4392eddb3f4dbf38662aEvan Cheng MachineBasicBlock* Water, CPUser &U) { 7535d9c4b60204d741c213456e21b87e9af6a3dc627Dale Johannesen unsigned MaxDisp = U.MaxDisp; 7548494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson unsigned CPEOffset = BBOffsets[Water->getNumber()] + 75588e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen BBSizes[Water->getNumber()]; 75688e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen 757d959aa421a8d14fc5aad29141f816db8f4362c7fDale Johannesen // If the CPE is to be inserted before the instruction, that will raise 7588593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // the offset of the instruction. (Currently applies only to ARM, so 7598593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // no alignment compensation attempted here.) 760d959aa421a8d14fc5aad29141f816db8f4362c7fDale Johannesen if (CPEOffset < UserOffset) 7615d9c4b60204d741c213456e21b87e9af6a3dc627Dale Johannesen UserOffset += U.CPEMI->getOperand(2).getImm(); 762d959aa421a8d14fc5aad29141f816db8f4362c7fDale Johannesen 763d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng return OffsetIsInRange(UserOffset, CPEOffset, MaxDisp, U.NegOk, U.IsSoImm); 76488e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen} 76588e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen 76688e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen/// CPEIsInRange - Returns true if the distance between specific MI and 767c0dbec7e1038ee60b8525eb1e8e3eaa6a839bd5bEvan Cheng/// specific ConstPool entry instruction can fit in MI's displacement field. 76888e37ae36652546c8e409cab69a1777af63cf095Dale Johannesenbool ARMConstantIslands::CPEIsInRange(MachineInstr *MI, unsigned UserOffset, 7695d8f1cae76e4e424bf3b4392eddb3f4dbf38662aEvan Cheng MachineInstr *CPEMI, unsigned MaxDisp, 7705d8f1cae76e4e424bf3b4392eddb3f4dbf38662aEvan Cheng bool NegOk, bool DoDump) { 7718593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen unsigned CPEOffset = GetOffsetOf(CPEMI); 7728593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen assert(CPEOffset%4 == 0 && "Misaligned CPE"); 7732021abe154e3cac523755b74fc5e62a2c9dad1fcEvan Cheng 77488e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen if (DoDump) { 775705e07f578e2b3af47ddab610feb4e7f2d3063a5Chris Lattner DEBUG(errs() << "User of CPE#" << CPEMI->getOperand(0).getImm() 776705e07f578e2b3af47ddab610feb4e7f2d3063a5Chris Lattner << " max delta=" << MaxDisp 777705e07f578e2b3af47ddab610feb4e7f2d3063a5Chris Lattner << " insn address=" << UserOffset 778705e07f578e2b3af47ddab610feb4e7f2d3063a5Chris Lattner << " CPE address=" << CPEOffset 779705e07f578e2b3af47ddab610feb4e7f2d3063a5Chris Lattner << " offset=" << int(CPEOffset-UserOffset) << "\t" << *MI); 78088e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen } 781a8e2989ece6dc46df59b0768184028257f913843Evan Cheng 7825d8f1cae76e4e424bf3b4392eddb3f4dbf38662aEvan Cheng return OffsetIsInRange(UserOffset, CPEOffset, MaxDisp, NegOk); 783c0dbec7e1038ee60b8525eb1e8e3eaa6a839bd5bEvan Cheng} 784c0dbec7e1038ee60b8525eb1e8e3eaa6a839bd5bEvan Cheng 785d1e7d9a88b5f4fa5e9a85affc4599c650c591ffbEvan Cheng#ifndef NDEBUG 786c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng/// BBIsJumpedOver - Return true of the specified basic block's only predecessor 787c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng/// unconditionally branches to its only successor. 788c99ef085b90b32952b484e8843fb66ad65215b61Evan Chengstatic bool BBIsJumpedOver(MachineBasicBlock *MBB) { 789c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng if (MBB->pred_size() != 1 || MBB->succ_size() != 1) 790c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng return false; 791c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng 792c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng MachineBasicBlock *Succ = *MBB->succ_begin(); 793c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng MachineBasicBlock *Pred = *MBB->pred_begin(); 794c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng MachineInstr *PredMI = &Pred->back(); 7955e47a9a6e46bd271eba058fb831da1a1edf8707cDavid Goodwin if (PredMI->getOpcode() == ARM::B || PredMI->getOpcode() == ARM::tB 7965e47a9a6e46bd271eba058fb831da1a1edf8707cDavid Goodwin || PredMI->getOpcode() == ARM::t2B) 797c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng return PredMI->getOperand(0).getMBB() == Succ; 798c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng return false; 799c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng} 800d1e7d9a88b5f4fa5e9a85affc4599c650c591ffbEvan Cheng#endif // NDEBUG 801c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng 8028494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilsonvoid ARMConstantIslands::AdjustBBOffsetsAfter(MachineBasicBlock *BB, 8038593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen int delta) { 8048593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen MachineFunction::iterator MBBI = BB; MBBI = next(MBBI); 805d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng for(unsigned i = BB->getNumber()+1, e = BB->getParent()->getNumBlockIDs(); 806d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng i < e; ++i) { 80799c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen BBOffsets[i] += delta; 8088593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // If some existing blocks have padding, adjust the padding as needed, a 8098593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // bit tricky. delta can be negative so don't use % on that. 810d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng if (!isThumb) 811d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng continue; 812d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng MachineBasicBlock *MBB = MBBI; 813d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng if (!MBB->empty()) { 814d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng // Constant pool entries require padding. 815d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng if (MBB->begin()->getOpcode() == ARM::CONSTPOOL_ENTRY) { 8164a8ea215e69e9ca19c8acf1c236b73860188a023Evan Cheng unsigned OldOffset = BBOffsets[i] - delta; 8174a8ea215e69e9ca19c8acf1c236b73860188a023Evan Cheng if ((OldOffset%4) == 0 && (BBOffsets[i]%4) != 0) { 818d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng // add new padding 819d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng BBSizes[i] += 2; 820d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng delta += 2; 8214a8ea215e69e9ca19c8acf1c236b73860188a023Evan Cheng } else if ((OldOffset%4) != 0 && (BBOffsets[i]%4) == 0) { 822d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng // remove existing padding 8234a8ea215e69e9ca19c8acf1c236b73860188a023Evan Cheng BBSizes[i] -= 2; 824d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng delta -= 2; 8258593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen } 826d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng } 827d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng // Thumb1 jump tables require padding. They should be at the end; 828d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng // following unconditional branches are removed by AnalyzeBranch. 829789476240d6b6f8ad9366cadf790a82bd41bb0b3Evan Cheng MachineInstr *ThumbJTMI = prior(MBB->end()); 83066ac53165e17b7c76b8c69e57bde623d44ec492eEvan Cheng if (ThumbJTMI->getOpcode() == ARM::tBR_JTr) { 8314a8ea215e69e9ca19c8acf1c236b73860188a023Evan Cheng unsigned NewMIOffset = GetOffsetOf(ThumbJTMI); 8324a8ea215e69e9ca19c8acf1c236b73860188a023Evan Cheng unsigned OldMIOffset = NewMIOffset - delta; 8334a8ea215e69e9ca19c8acf1c236b73860188a023Evan Cheng if ((OldMIOffset%4) == 0 && (NewMIOffset%4) != 0) { 834d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng // remove existing padding 835d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng BBSizes[i] -= 2; 836d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng delta -= 2; 8374a8ea215e69e9ca19c8acf1c236b73860188a023Evan Cheng } else if ((OldMIOffset%4) != 0 && (NewMIOffset%4) == 0) { 838d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng // add new padding 839d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng BBSizes[i] += 2; 840d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng delta += 2; 8418593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen } 8428593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen } 843d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng if (delta==0) 844d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng return; 8458593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen } 846d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng MBBI = next(MBBI); 8478593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen } 84899c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen} 84999c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen 85088e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen/// DecrementOldEntry - find the constant pool entry with index CPI 85188e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen/// and instruction CPEMI, and decrement its refcount. If the refcount 8528494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson/// becomes 0 remove the entry and instruction. Returns true if we removed 85388e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen/// the entry, false if we didn't. 854b43216ee4a418257ce5530c02601b77efe86c354Evan Cheng 855ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Chengbool ARMConstantIslands::DecrementOldEntry(unsigned CPI, MachineInstr *CPEMI) { 856c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng // Find the old entry. Eliminate it if it is no longer used. 857ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng CPEntry *CPE = findConstPoolEntry(CPI, CPEMI); 858ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng assert(CPE && "Unexpected!"); 859ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng if (--CPE->RefCount == 0) { 860ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng RemoveDeadCPEMI(CPEMI); 861ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng CPE->CPEMI = NULL; 862c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng NumCPEs--; 86388e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen return true; 86488e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen } 86588e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen return false; 86688e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen} 86788e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen 86888e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen/// LookForCPEntryInRange - see if the currently referenced CPE is in range; 86988e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen/// if not, see if an in-range clone of the CPE is in range, and if so, 87088e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen/// change the data structures so the user references the clone. Returns: 87188e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen/// 0 = no existing entry found 87288e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen/// 1 = entry found, and there were no code insertions or deletions 87388e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen/// 2 = entry found, and there were code insertions or deletions 87488e37ae36652546c8e409cab69a1777af63cf095Dale Johannesenint ARMConstantIslands::LookForExistingCPEntry(CPUser& U, unsigned UserOffset) 87588e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen{ 87688e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen MachineInstr *UserMI = U.MI; 87788e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen MachineInstr *CPEMI = U.CPEMI; 87888e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen 87988e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen // Check to see if the CPE is already in-range. 8805d8f1cae76e4e424bf3b4392eddb3f4dbf38662aEvan Cheng if (CPEIsInRange(UserMI, UserOffset, CPEMI, U.MaxDisp, U.NegOk, true)) { 8818202010364e1bfe6111f1ce62f154499b80877fbEvan Cheng DOUT << "In range\n"; 88288e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen return 1; 883c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng } 884c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng 88588e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen // No. Look for previously created clones of the CPE that are in range. 8868aa797aa51cd4ea1ec6f46f4891a6897944b75b2Chris Lattner unsigned CPI = CPEMI->getOperand(1).getIndex(); 88788e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen std::vector<CPEntry> &CPEs = CPEntries[CPI]; 88888e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen for (unsigned i = 0, e = CPEs.size(); i != e; ++i) { 88988e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen // We already tried this one 89088e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen if (CPEs[i].CPEMI == CPEMI) 89188e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen continue; 89288e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen // Removing CPEs can leave empty entries, skip 89388e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen if (CPEs[i].CPEMI == NULL) 89488e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen continue; 8955d8f1cae76e4e424bf3b4392eddb3f4dbf38662aEvan Cheng if (CPEIsInRange(UserMI, UserOffset, CPEs[i].CPEMI, U.MaxDisp, U.NegOk)) { 89688e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen DOUT << "Replacing CPE#" << CPI << " with CPE#" << CPEs[i].CPI << "\n"; 89788e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen // Point the CPUser node to the replacement 89888e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen U.CPEMI = CPEs[i].CPEMI; 89988e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen // Change the CPI in the instruction operand to refer to the clone. 90088e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen for (unsigned j = 0, e = UserMI->getNumOperands(); j != e; ++j) 901d735b8019b0f297d7c14b55adcd887af24d8e602Dan Gohman if (UserMI->getOperand(j).isCPI()) { 9028aa797aa51cd4ea1ec6f46f4891a6897944b75b2Chris Lattner UserMI->getOperand(j).setIndex(CPEs[i].CPI); 90388e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen break; 90488e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen } 90588e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen // Adjust the refcount of the clone... 90688e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen CPEs[i].RefCount++; 90788e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen // ...and the original. If we didn't remove the old entry, none of the 90888e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen // addresses changed, so we don't need another pass. 909ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng return DecrementOldEntry(CPI, CPEMI) ? 2 : 1; 91088e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen } 91188e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen } 91288e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen return 0; 91388e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen} 91488e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen 915f1b214d3ca12f2d85f0d092b4920172bcc797bacDale Johannesen/// getUnconditionalBrDisp - Returns the maximum displacement that can fit in 916f1b214d3ca12f2d85f0d092b4920172bcc797bacDale Johannesen/// the specific unconditional branch instruction. 917f1b214d3ca12f2d85f0d092b4920172bcc797bacDale Johannesenstatic inline unsigned getUnconditionalBrDisp(int Opc) { 9185e47a9a6e46bd271eba058fb831da1a1edf8707cDavid Goodwin switch (Opc) { 9195e47a9a6e46bd271eba058fb831da1a1edf8707cDavid Goodwin case ARM::tB: 9205e47a9a6e46bd271eba058fb831da1a1edf8707cDavid Goodwin return ((1<<10)-1)*2; 9215e47a9a6e46bd271eba058fb831da1a1edf8707cDavid Goodwin case ARM::t2B: 9225e47a9a6e46bd271eba058fb831da1a1edf8707cDavid Goodwin return ((1<<23)-1)*2; 9235e47a9a6e46bd271eba058fb831da1a1edf8707cDavid Goodwin default: 9245e47a9a6e46bd271eba058fb831da1a1edf8707cDavid Goodwin break; 9255e47a9a6e46bd271eba058fb831da1a1edf8707cDavid Goodwin } 926764ab52dd80310a205c9888bf166d09dab858f90Jim Grosbach 9275e47a9a6e46bd271eba058fb831da1a1edf8707cDavid Goodwin return ((1<<23)-1)*4; 928f1b214d3ca12f2d85f0d092b4920172bcc797bacDale Johannesen} 929f1b214d3ca12f2d85f0d092b4920172bcc797bacDale Johannesen 9308593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen/// AcceptWater - Small amount of common code factored out of the following. 9318593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen 9328494526a2396fd9cde027ab6ae11dd28b54ac90eBob WilsonMachineBasicBlock* ARMConstantIslands::AcceptWater(MachineBasicBlock *WaterBB, 9338593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen std::vector<MachineBasicBlock*>::iterator IP) { 9348593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen DOUT << "found water in range\n"; 9358593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // Remove the original WaterList entry; we want subsequent 9368593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // insertions in this vicinity to go after the one we're 9378593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // about to insert. This considerably reduces the number 9388593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // of times we have to move the same CPE more than once. 9398593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen WaterList.erase(IP); 9408593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // CPE goes before following block (NewMBB). 9418593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen return next(MachineFunction::iterator(WaterBB)); 9428593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen} 9438593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen 944b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen/// LookForWater - look for an existing entry in the WaterList in which 945b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen/// we can place the CPE referenced from U so it's within range of U's MI. 946b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen/// Returns true if found, false if not. If it returns true, *NewMBB 9478593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen/// is set to the WaterList entry. 948d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng/// For ARM, we prefer the water that's farthest away. For Thumb, prefer 9498593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen/// water that will not introduce padding to water that will; within each 9508593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen/// group, prefer the water that's farthest away. 951b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesenbool ARMConstantIslands::LookForWater(CPUser &U, unsigned UserOffset, 9528593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen MachineBasicBlock** NewMBB) { 9538593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen std::vector<MachineBasicBlock*>::iterator IPThatWouldPad; 9548593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen MachineBasicBlock* WaterBBThatWouldPad = NULL; 95588e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen if (!WaterList.empty()) { 95688e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen for (std::vector<MachineBasicBlock*>::iterator IP = prior(WaterList.end()), 957d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng B = WaterList.begin();; --IP) { 95888e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen MachineBasicBlock* WaterBB = *IP; 9595d9c4b60204d741c213456e21b87e9af6a3dc627Dale Johannesen if (WaterIsInRange(UserOffset, WaterBB, U)) { 960d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng unsigned WBBId = WaterBB->getNumber(); 9618593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen if (isThumb && 962d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng (BBOffsets[WBBId] + BBSizes[WBBId])%4 != 0) { 9638593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // This is valid Water, but would introduce padding. Remember 9648593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // it in case we don't find any Water that doesn't do this. 9658593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen if (!WaterBBThatWouldPad) { 9668593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen WaterBBThatWouldPad = WaterBB; 9678593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen IPThatWouldPad = IP; 9688593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen } 9698593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen } else { 9708593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen *NewMBB = AcceptWater(WaterBB, IP); 9718593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen return true; 972f1b214d3ca12f2d85f0d092b4920172bcc797bacDale Johannesen } 973d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng } 97488e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen if (IP == B) 97588e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen break; 97688e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen } 97788e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen } 9788593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen if (isThumb && WaterBBThatWouldPad) { 9798593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen *NewMBB = AcceptWater(WaterBBThatWouldPad, IPThatWouldPad); 9808593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen return true; 9818593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen } 982b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen return false; 983b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen} 98488e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen 9858494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson/// CreateNewWater - No existing WaterList entry will work for 986b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen/// CPUsers[CPUserIndex], so create a place to put the CPE. The end of the 987b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen/// block is used if in range, and the conditional branch munged so control 988b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen/// flow is correct. Otherwise the block is split to create a hole with an 989b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen/// unconditional branch around it. In either case *NewMBB is set to a 990b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen/// block following which the new island can be inserted (the WaterList 991b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen/// is not adjusted). 99288e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen 9938494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilsonvoid ARMConstantIslands::CreateNewWater(unsigned CPUserIndex, 994b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen unsigned UserOffset, MachineBasicBlock** NewMBB) { 995b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen CPUser &U = CPUsers[CPUserIndex]; 996b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen MachineInstr *UserMI = U.MI; 997b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen MachineInstr *CPEMI = U.CPEMI; 998b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen MachineBasicBlock *UserMBB = UserMI->getParent(); 9998494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson unsigned OffsetOfNextBlock = BBOffsets[UserMBB->getNumber()] + 1000b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen BBSizes[UserMBB->getNumber()]; 10018593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen assert(OffsetOfNextBlock== BBOffsets[UserMBB->getNumber()+1]); 1002b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen 1003b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen // If the use is at the end of the block, or the end of the block 10048593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // is within range, make new water there. (The addition below is 1005d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng // for the unconditional branch we will be adding: 4 bytes on ARM + Thumb2, 1006d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng // 2 on Thumb1. Possible Thumb1 alignment padding is allowed for 10078593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // inside OffsetIsInRange. 10088494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson // If the block ends in an unconditional branch already, it is water, 10098593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // and is known to be out of range, so we'll always be adding a branch.) 1010b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen if (&UserMBB->back() == UserMI || 1011d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng OffsetIsInRange(UserOffset, OffsetOfNextBlock + (isThumb1 ? 2: 4), 1012d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng U.MaxDisp, U.NegOk, U.IsSoImm)) { 1013b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen DOUT << "Split at end of block\n"; 1014b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen if (&UserMBB->back() == UserMI) 1015b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen assert(BBHasFallthrough(UserMBB) && "Expected a fallthrough BB!"); 1016b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen *NewMBB = next(MachineFunction::iterator(UserMBB)); 1017b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen // Add an unconditional branch from UserMBB to fallthrough block. 1018b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen // Record it for branch lengthening; this new branch will not get out of 1019b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen // range, but if the preceding conditional branch is out of range, the 1020b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen // targets will be exchanged, and the altered branch may be out of 1021b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen // range, so the machinery has to know about it. 10225e47a9a6e46bd271eba058fb831da1a1edf8707cDavid Goodwin int UncondBr = isThumb ? ((isThumb2) ? ARM::t2B : ARM::tB) : ARM::B; 1023b67284057ee130114055309eabe0bcd1af13777dDale Johannesen BuildMI(UserMBB, DebugLoc::getUnknownLoc(), 1024b67284057ee130114055309eabe0bcd1af13777dDale Johannesen TII->get(UncondBr)).addMBB(*NewMBB); 1025b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen unsigned MaxDisp = getUnconditionalBrDisp(UncondBr); 10268494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson ImmBranches.push_back(ImmBranch(&UserMBB->back(), 1027b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen MaxDisp, false, UncondBr)); 1028d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng int delta = isThumb1 ? 2 : 4; 1029b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen BBSizes[UserMBB->getNumber()] += delta; 1030b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen AdjustBBOffsetsAfter(UserMBB, delta); 1031b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen } else { 1032b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen // What a big block. Find a place within the block to split it. 1033d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng // This is a little tricky on Thumb1 since instructions are 2 bytes 1034b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen // and constant pool entries are 4 bytes: if instruction I references 1035b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen // island CPE, and instruction I+1 references CPE', it will 1036b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen // not work well to put CPE as far forward as possible, since then 1037b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen // CPE' cannot immediately follow it (that location is 2 bytes 1038b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen // farther away from I+1 than CPE was from I) and we'd need to create 10398593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // a new island. So, we make a first guess, then walk through the 10408593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // instructions between the one currently being looked at and the 10418593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // possible insertion point, and make sure any other instructions 10428593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // that reference CPEs will be able to use the same island area; 10438593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // if not, we back up the insertion point. 10448593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen 1045b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen // The 4 in the following is for the unconditional branch we'll be 1046d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng // inserting (allows for long branch on Thumb1). Alignment of the 10478593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // island is handled inside OffsetIsInRange. 10488593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen unsigned BaseInsertOffset = UserOffset + U.MaxDisp -4; 1049b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen // This could point off the end of the block if we've already got 1050b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen // constant pool entries following this block; only the last one is 1051b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen // in the water list. Back past any possible branches (allow for a 1052b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen // conditional and a maximally long unconditional). 1053b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen if (BaseInsertOffset >= BBOffsets[UserMBB->getNumber()+1]) 10548494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson BaseInsertOffset = BBOffsets[UserMBB->getNumber()+1] - 1055d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng (isThumb1 ? 6 : 8); 1056b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen unsigned EndInsertOffset = BaseInsertOffset + 1057b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen CPEMI->getOperand(2).getImm(); 1058b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen MachineBasicBlock::iterator MI = UserMI; 1059b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen ++MI; 1060b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen unsigned CPUIndex = CPUserIndex+1; 106152e724ad7e679ee590f4bd763d55280586a8f1bcNicolas Geoffray for (unsigned Offset = UserOffset+TII->GetInstSizeInBytes(UserMI); 1062b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen Offset < BaseInsertOffset; 106352e724ad7e679ee590f4bd763d55280586a8f1bcNicolas Geoffray Offset += TII->GetInstSizeInBytes(MI), 1064b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen MI = next(MI)) { 1065b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen if (CPUIndex < CPUsers.size() && CPUsers[CPUIndex].MI == MI) { 1066d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng CPUser &U = CPUsers[CPUIndex]; 10678494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson if (!OffsetIsInRange(Offset, EndInsertOffset, 1068d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng U.MaxDisp, U.NegOk, U.IsSoImm)) { 1069d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng BaseInsertOffset -= (isThumb1 ? 2 : 4); 1070d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng EndInsertOffset -= (isThumb1 ? 2 : 4); 1071f1b214d3ca12f2d85f0d092b4920172bcc797bacDale Johannesen } 1072b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen // This is overly conservative, as we don't account for CPEMIs 1073b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen // being reused within the block, but it doesn't matter much. 1074b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen EndInsertOffset += CPUsers[CPUIndex].CPEMI->getOperand(2).getImm(); 1075b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen CPUIndex++; 1076f1b214d3ca12f2d85f0d092b4920172bcc797bacDale Johannesen } 107788e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen } 1078b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen DOUT << "Split in middle of big block\n"; 1079b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen *NewMBB = SplitBlockBeforeInstr(prior(MI)); 1080b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen } 1081b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen} 1082b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen 1083b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen/// HandleConstantPoolUser - Analyze the specified user, checking to see if it 108439bf051ec2865cd715c41473d2a9fc34ff252534Bob Wilson/// is out-of-range. If so, pick up the constant pool value and move it some 1085b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen/// place in-range. Return true if we changed any addresses (thus must run 1086b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen/// another pass of branch lengthening), false otherwise. 10875657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Chengbool ARMConstantIslands::HandleConstantPoolUser(MachineFunction &MF, 10888494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson unsigned CPUserIndex) { 1089b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen CPUser &U = CPUsers[CPUserIndex]; 1090b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen MachineInstr *UserMI = U.MI; 1091b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen MachineInstr *CPEMI = U.CPEMI; 10928aa797aa51cd4ea1ec6f46f4891a6897944b75b2Chris Lattner unsigned CPI = CPEMI->getOperand(1).getIndex(); 1093b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen unsigned Size = CPEMI->getOperand(2).getImm(); 1094b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen MachineBasicBlock *NewMBB; 10958593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // Compute this only once, it's expensive. The 4 or 8 is the value the 1096a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng // hardware keeps in the PC. 1097b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen unsigned UserOffset = GetOffsetOf(UserMI) + (isThumb ? 4 : 8); 1098768c9f725bda048b3406b6289beb586ff6e933dfEvan Cheng 1099b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen // See if the current entry is within range, or there is a clone of it 1100b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen // in range. 1101b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen int result = LookForExistingCPEntry(U, UserOffset); 1102b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen if (result==1) return false; 1103b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen else if (result==2) return true; 1104b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen 1105b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen // No existing clone of this CPE is within range. 1106b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen // We will be generating a new clone. Get a UID for it. 110739bf051ec2865cd715c41473d2a9fc34ff252534Bob Wilson unsigned ID = AFI->createConstPoolEntryUId(); 1108b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen 1109b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen // Look for water where we can place this CPE. We look for the farthest one 1110b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen // away that will work. Forward references only for now (although later 1111b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen // we might find some that are backwards). 1112b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen 11138593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen if (!LookForWater(U, UserOffset, &NewMBB)) { 1114b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen // No water found. 1115b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen DOUT << "No water found\n"; 1116b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen CreateNewWater(CPUserIndex, UserOffset, &NewMBB); 111788e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen } 111888e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen 111988e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen // Okay, we know we can put an island before NewMBB now, do it! 11205657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng MachineBasicBlock *NewIsland = MF.CreateMachineBasicBlock(); 11215657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng MF.insert(NewMBB, NewIsland); 112288e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen 112388e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen // Update internal data structures to account for the newly inserted MBB. 112488e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen UpdateForInsertedWaterBlock(NewIsland); 112588e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen 112688e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen // Decrement the old entry, and remove it if refcount becomes 0. 1127ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng DecrementOldEntry(CPI, CPEMI); 112888e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen 112988e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen // Now that we have an island to add the CPE to, clone the original CPE and 113088e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen // add it to the island. 1131b67284057ee130114055309eabe0bcd1af13777dDale Johannesen U.CPEMI = BuildMI(NewIsland, DebugLoc::getUnknownLoc(), 1132b67284057ee130114055309eabe0bcd1af13777dDale Johannesen TII->get(ARM::CONSTPOOL_ENTRY)) 1133a8e2989ece6dc46df59b0768184028257f913843Evan Cheng .addImm(ID).addConstantPoolIndex(CPI).addImm(Size); 113488e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen CPEntries[CPI].push_back(CPEntry(U.CPEMI, ID, 1)); 1135c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng NumCPEs++; 1136c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng 11378593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen BBOffsets[NewIsland->getNumber()] = BBOffsets[NewMBB->getNumber()]; 1138b43216ee4a418257ce5530c02601b77efe86c354Evan Cheng // Compensate for .align 2 in thumb mode. 11398494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson if (isThumb && BBOffsets[NewIsland->getNumber()]%4 != 0) 11408593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen Size += 2; 1141a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // Increase the size of the island block to account for the new entry. 1142a8e2989ece6dc46df59b0768184028257f913843Evan Cheng BBSizes[NewIsland->getNumber()] += Size; 114399c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen AdjustBBOffsetsAfter(NewIsland, Size); 11448494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 1145a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // Finally, change the CPI in the instruction operand to be ID. 1146a8e2989ece6dc46df59b0768184028257f913843Evan Cheng for (unsigned i = 0, e = UserMI->getNumOperands(); i != e; ++i) 1147d735b8019b0f297d7c14b55adcd887af24d8e602Dan Gohman if (UserMI->getOperand(i).isCPI()) { 11488aa797aa51cd4ea1ec6f46f4891a6897944b75b2Chris Lattner UserMI->getOperand(i).setIndex(ID); 1149a8e2989ece6dc46df59b0768184028257f913843Evan Cheng break; 1150a8e2989ece6dc46df59b0768184028257f913843Evan Cheng } 11518494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 1152705e07f578e2b3af47ddab610feb4e7f2d3063a5Chris Lattner DEBUG(errs() << " Moved CPE to #" << ID << " CPI=" << CPI 1153705e07f578e2b3af47ddab610feb4e7f2d3063a5Chris Lattner << '\t' << *UserMI); 11548494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 1155a8e2989ece6dc46df59b0768184028257f913843Evan Cheng return true; 1156a8e2989ece6dc46df59b0768184028257f913843Evan Cheng} 1157a8e2989ece6dc46df59b0768184028257f913843Evan Cheng 1158ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng/// RemoveDeadCPEMI - Remove a dead constant pool entry instruction. Update 1159ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng/// sizes and offsets of impacted basic blocks. 1160ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Chengvoid ARMConstantIslands::RemoveDeadCPEMI(MachineInstr *CPEMI) { 1161ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng MachineBasicBlock *CPEBB = CPEMI->getParent(); 11628593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen unsigned Size = CPEMI->getOperand(2).getImm(); 11638593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen CPEMI->eraseFromParent(); 11648593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen BBSizes[CPEBB->getNumber()] -= Size; 11658593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // All succeeding offsets have the current size value added in, fix this. 1166ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng if (CPEBB->empty()) { 1167d3d9d66dd211d1267e764c7294876d9a227f04caEvan Cheng // In thumb1 mode, the size of island may be padded by two to compensate for 11688593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // the alignment requirement. Then it will now be 2 when the block is 1169ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng // empty, so fix this. 1170ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng // All succeeding offsets have the current size value added in, fix this. 1171ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng if (BBSizes[CPEBB->getNumber()] != 0) { 11728593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen Size += BBSizes[CPEBB->getNumber()]; 1173ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng BBSizes[CPEBB->getNumber()] = 0; 1174ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng } 1175ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng } 11768593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen AdjustBBOffsetsAfter(CPEBB, -Size); 11778593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // An island has only one predecessor BB and one successor BB. Check if 11788593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // this BB's predecessor jumps directly to this BB's successor. This 11798593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // shouldn't happen currently. 11808593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen assert(!BBIsJumpedOver(CPEBB) && "How did this happen?"); 11818593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // FIXME: remove the empty blocks after all the work is done? 1182ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng} 1183ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng 1184ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng/// RemoveUnusedCPEntries - Remove constant pool entries whose refcounts 1185ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng/// are zero. 1186ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Chengbool ARMConstantIslands::RemoveUnusedCPEntries() { 1187ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng unsigned MadeChange = false; 1188ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng for (unsigned i = 0, e = CPEntries.size(); i != e; ++i) { 1189ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng std::vector<CPEntry> &CPEs = CPEntries[i]; 1190ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng for (unsigned j = 0, ee = CPEs.size(); j != ee; ++j) { 1191ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng if (CPEs[j].RefCount == 0 && CPEs[j].CPEMI) { 1192ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng RemoveDeadCPEMI(CPEs[j].CPEMI); 1193ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng CPEs[j].CPEMI = NULL; 1194ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng MadeChange = true; 1195ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng } 1196ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng } 11978494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson } 1198ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng return MadeChange; 1199ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng} 1200ed884f3a2f7225a0ea40fc18964b6f949cac3680Evan Cheng 120188e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen/// BBIsInRange - Returns true if the distance between specific MI and 120243aeab68a69e443c528092b4424a498d813f96b7Evan Cheng/// specific BB can fit in MI's displacement field. 1203c0dbec7e1038ee60b8525eb1e8e3eaa6a839bd5bEvan Chengbool ARMConstantIslands::BBIsInRange(MachineInstr *MI,MachineBasicBlock *DestBB, 1204c0dbec7e1038ee60b8525eb1e8e3eaa6a839bd5bEvan Cheng unsigned MaxDisp) { 1205b71aa2b6ca801d407c702483c412a290ab4af3b2Dale Johannesen unsigned PCAdj = isThumb ? 4 : 8; 1206c0dbec7e1038ee60b8525eb1e8e3eaa6a839bd5bEvan Cheng unsigned BrOffset = GetOffsetOf(MI) + PCAdj; 120799c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen unsigned DestOffset = BBOffsets[DestBB->getNumber()]; 120843aeab68a69e443c528092b4424a498d813f96b7Evan Cheng 1209705e07f578e2b3af47ddab610feb4e7f2d3063a5Chris Lattner DEBUG(errs() << "Branch of destination BB#" << DestBB->getNumber() 1210705e07f578e2b3af47ddab610feb4e7f2d3063a5Chris Lattner << " from BB#" << MI->getParent()->getNumber() 1211705e07f578e2b3af47ddab610feb4e7f2d3063a5Chris Lattner << " max delta=" << MaxDisp 1212705e07f578e2b3af47ddab610feb4e7f2d3063a5Chris Lattner << " from " << GetOffsetOf(MI) << " to " << DestOffset 1213705e07f578e2b3af47ddab610feb4e7f2d3063a5Chris Lattner << " offset " << int(DestOffset-BrOffset) << "\t" << *MI); 1214c0dbec7e1038ee60b8525eb1e8e3eaa6a839bd5bEvan Cheng 12158593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen if (BrOffset <= DestOffset) { 12168593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // Branch before the Dest. 12178593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen if (DestOffset-BrOffset <= MaxDisp) 12188593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen return true; 12198593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen } else { 12208593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen if (BrOffset-DestOffset <= MaxDisp) 12218593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen return true; 12228593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen } 12238593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen return false; 122443aeab68a69e443c528092b4424a498d813f96b7Evan Cheng} 122543aeab68a69e443c528092b4424a498d813f96b7Evan Cheng 1226d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng/// FixUpImmediateBr - Fix up an immediate branch whose destination is too far 1227d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng/// away to fit in its displacement field. 12285657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Chengbool ARMConstantIslands::FixUpImmediateBr(MachineFunction &MF, ImmBranch &Br) { 1229d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng MachineInstr *MI = Br.MI; 12308aa797aa51cd4ea1ec6f46f4891a6897944b75b2Chris Lattner MachineBasicBlock *DestBB = MI->getOperand(0).getMBB(); 1231d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng 1232c0dbec7e1038ee60b8525eb1e8e3eaa6a839bd5bEvan Cheng // Check to see if the DestBB is already in-range. 1233c0dbec7e1038ee60b8525eb1e8e3eaa6a839bd5bEvan Cheng if (BBIsInRange(MI, DestBB, Br.MaxDisp)) 1234d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng return false; 1235d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng 1236d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng if (!Br.isCond) 12375657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng return FixUpUnconditionalBr(MF, Br); 12385657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng return FixUpConditionalBr(MF, Br); 1239d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng} 1240d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng 124188e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen/// FixUpUnconditionalBr - Fix up an unconditional branch whose destination is 124288e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen/// too far away to fit in its displacement field. If the LR register has been 1243d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng/// spilled in the epilogue, then we can use BL to implement a far jump. 124439bf051ec2865cd715c41473d2a9fc34ff252534Bob Wilson/// Otherwise, add an intermediate branch instruction to a branch. 1245d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Chengbool 12465657c01949dca6c012ac60d242d1a8d2ffdf5603Evan ChengARMConstantIslands::FixUpUnconditionalBr(MachineFunction &MF, ImmBranch &Br) { 1247d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng MachineInstr *MI = Br.MI; 1248d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng MachineBasicBlock *MBB = MI->getParent(); 124953c67c0218d8420234dd71bf2d9df3388909af77Evan Cheng if (!isThumb1) 125053c67c0218d8420234dd71bf2d9df3388909af77Evan Cheng llvm_unreachable("FixUpUnconditionalBr is Thumb1 only!"); 1251d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng 1252d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng // Use BL to implement far jump. 1253d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng Br.MaxDisp = (1 << 21) * 2; 12545080f4d9919d39b367891dc51e739c571a66036cChris Lattner MI->setDesc(TII->get(ARM::tBfar)); 1255d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng BBSizes[MBB->getNumber()] += 2; 125699c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen AdjustBBOffsetsAfter(MBB, 2); 1257d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng HasFarJump = true; 1258d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng NumUBrFixed++; 1259bd5d3dbdbe46c7325545a7cb8c891c0347375451Evan Cheng 1260705e07f578e2b3af47ddab610feb4e7f2d3063a5Chris Lattner DEBUG(errs() << " Changed B to long jump " << *MI); 1261bd5d3dbdbe46c7325545a7cb8c891c0347375451Evan Cheng 1262d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng return true; 1263d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng} 1264d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng 126588e37ae36652546c8e409cab69a1777af63cf095Dale Johannesen/// FixUpConditionalBr - Fix up a conditional branch whose destination is too 1266d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng/// far away to fit in its displacement field. It is converted to an inverse 1267d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng/// conditional branch + an unconditional branch to the destination. 1268af5cbcb809bdbd30ebacab942994721c134d16a2Evan Chengbool 12695657c01949dca6c012ac60d242d1a8d2ffdf5603Evan ChengARMConstantIslands::FixUpConditionalBr(MachineFunction &MF, ImmBranch &Br) { 1270af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng MachineInstr *MI = Br.MI; 12718aa797aa51cd4ea1ec6f46f4891a6897944b75b2Chris Lattner MachineBasicBlock *DestBB = MI->getOperand(0).getMBB(); 1272af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng 127339bf051ec2865cd715c41473d2a9fc34ff252534Bob Wilson // Add an unconditional branch to the destination and invert the branch 1274d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng // condition to jump over it: 1275af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng // blt L1 1276af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng // => 1277af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng // bge L2 1278af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng // b L1 1279af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng // L2: 12809a1ceaedc282f0cae31f2723f4d6c00c7b88fe90Chris Lattner ARMCC::CondCodes CC = (ARMCC::CondCodes)MI->getOperand(1).getImm(); 1281af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng CC = ARMCC::getOppositeCondition(CC); 12820e1d37904abbf7e8c4c478408253dd995f3040f4Evan Cheng unsigned CCReg = MI->getOperand(2).getReg(); 1283af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng 1284af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng // If the branch is at the end of its MBB and that has a fall-through block, 1285af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng // direct the updated conditional branch to the fall-through block. Otherwise, 1286af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng // split the MBB before the next instruction. 1287af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng MachineBasicBlock *MBB = MI->getParent(); 1288bd5d3dbdbe46c7325545a7cb8c891c0347375451Evan Cheng MachineInstr *BMI = &MBB->back(); 1289bd5d3dbdbe46c7325545a7cb8c891c0347375451Evan Cheng bool NeedSplit = (BMI != MI) || !BBHasFallthrough(MBB); 129043aeab68a69e443c528092b4424a498d813f96b7Evan Cheng 1291d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng NumCBrFixed++; 1292bd5d3dbdbe46c7325545a7cb8c891c0347375451Evan Cheng if (BMI != MI) { 12938e5f2c6f65841542e2a7092553fe42a00048e4c7Dan Gohman if (next(MachineBasicBlock::iterator(MI)) == prior(MBB->end()) && 1294bd5d3dbdbe46c7325545a7cb8c891c0347375451Evan Cheng BMI->getOpcode() == Br.UncondBr) { 129539bf051ec2865cd715c41473d2a9fc34ff252534Bob Wilson // Last MI in the BB is an unconditional branch. Can we simply invert the 129643aeab68a69e443c528092b4424a498d813f96b7Evan Cheng // condition and swap destinations: 129743aeab68a69e443c528092b4424a498d813f96b7Evan Cheng // beq L1 129843aeab68a69e443c528092b4424a498d813f96b7Evan Cheng // b L2 129943aeab68a69e443c528092b4424a498d813f96b7Evan Cheng // => 130043aeab68a69e443c528092b4424a498d813f96b7Evan Cheng // bne L2 130143aeab68a69e443c528092b4424a498d813f96b7Evan Cheng // b L1 13028aa797aa51cd4ea1ec6f46f4891a6897944b75b2Chris Lattner MachineBasicBlock *NewDest = BMI->getOperand(0).getMBB(); 1303c0dbec7e1038ee60b8525eb1e8e3eaa6a839bd5bEvan Cheng if (BBIsInRange(MI, NewDest, Br.MaxDisp)) { 1304705e07f578e2b3af47ddab610feb4e7f2d3063a5Chris Lattner DEBUG(errs() << " Invert Bcc condition and swap its destination with " 1305705e07f578e2b3af47ddab610feb4e7f2d3063a5Chris Lattner << *BMI); 13068aa797aa51cd4ea1ec6f46f4891a6897944b75b2Chris Lattner BMI->getOperand(0).setMBB(DestBB); 13078aa797aa51cd4ea1ec6f46f4891a6897944b75b2Chris Lattner MI->getOperand(0).setMBB(NewDest); 130843aeab68a69e443c528092b4424a498d813f96b7Evan Cheng MI->getOperand(1).setImm(CC); 130943aeab68a69e443c528092b4424a498d813f96b7Evan Cheng return true; 131043aeab68a69e443c528092b4424a498d813f96b7Evan Cheng } 131143aeab68a69e443c528092b4424a498d813f96b7Evan Cheng } 131243aeab68a69e443c528092b4424a498d813f96b7Evan Cheng } 131343aeab68a69e443c528092b4424a498d813f96b7Evan Cheng 131443aeab68a69e443c528092b4424a498d813f96b7Evan Cheng if (NeedSplit) { 1315af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng SplitBlockBeforeInstr(MI); 131639bf051ec2865cd715c41473d2a9fc34ff252534Bob Wilson // No need for the branch to the next block. We're adding an unconditional 1317dd353b8ad747a8731a191848ff5db978a70bd0fbEvan Cheng // branch to the destination. 131852e724ad7e679ee590f4bd763d55280586a8f1bcNicolas Geoffray int delta = TII->GetInstSizeInBytes(&MBB->back()); 131956c42ef3e43f8eb75c435e781d0ac8251c7588a1Dale Johannesen BBSizes[MBB->getNumber()] -= delta; 13208593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen MachineBasicBlock* SplitBB = next(MachineFunction::iterator(MBB)); 13218593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen AdjustBBOffsetsAfter(SplitBB, -delta); 1322dd353b8ad747a8731a191848ff5db978a70bd0fbEvan Cheng MBB->back().eraseFromParent(); 13238593e418555fdae21a070357fd8734b4069c17d0Dale Johannesen // BBOffsets[SplitBB] is wrong temporarily, fixed below 1324dd353b8ad747a8731a191848ff5db978a70bd0fbEvan Cheng } 1325af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng MachineBasicBlock *NextBB = next(MachineFunction::iterator(MBB)); 13268494526a2396fd9cde027ab6ae11dd28b54ac90eBob Wilson 1327c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng DOUT << " Insert B to BB#" << DestBB->getNumber() 1328c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng << " also invert condition and change dest. to BB#" 1329c99ef085b90b32952b484e8843fb66ad65215b61Evan Cheng << NextBB->getNumber() << "\n"; 1330af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng 133156c42ef3e43f8eb75c435e781d0ac8251c7588a1Dale Johannesen // Insert a new conditional branch and a new unconditional branch. 1332af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng // Also update the ImmBranch as well as adding a new entry for the new branch. 1333b67284057ee130114055309eabe0bcd1af13777dDale Johannesen BuildMI(MBB, DebugLoc::getUnknownLoc(), 1334b67284057ee130114055309eabe0bcd1af13777dDale Johannesen TII->get(MI->getOpcode())) 1335b67284057ee130114055309eabe0bcd1af13777dDale Johannesen .addMBB(NextBB).addImm(CC).addReg(CCReg); 1336af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng Br.MI = &MBB->back(); 133752e724ad7e679ee590f4bd763d55280586a8f1bcNicolas Geoffray BBSizes[MBB->getNumber()] += TII->GetInstSizeInBytes(&MBB->back()); 1338b67284057ee130114055309eabe0bcd1af13777dDale Johannesen BuildMI(MBB, DebugLoc::getUnknownLoc(), TII->get(Br.UncondBr)).addMBB(DestBB); 133952e724ad7e679ee590f4bd763d55280586a8f1bcNicolas Geoffray BBSizes[MBB->getNumber()] += TII->GetInstSizeInBytes(&MBB->back()); 1340a9b8b8d62c67e96bc4dc2ed25298c539102f8638Evan Cheng unsigned MaxDisp = getUnconditionalBrDisp(Br.UncondBr); 1341a0bf794eb60b6795a121efcb9ff759e9e0955772Evan Cheng ImmBranches.push_back(ImmBranch(&MBB->back(), MaxDisp, false, Br.UncondBr)); 134256c42ef3e43f8eb75c435e781d0ac8251c7588a1Dale Johannesen 134356c42ef3e43f8eb75c435e781d0ac8251c7588a1Dale Johannesen // Remove the old conditional branch. It may or may not still be in MBB. 134452e724ad7e679ee590f4bd763d55280586a8f1bcNicolas Geoffray BBSizes[MI->getParent()->getNumber()] -= TII->GetInstSizeInBytes(MI); 1345af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng MI->eraseFromParent(); 1346af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng 134756c42ef3e43f8eb75c435e781d0ac8251c7588a1Dale Johannesen // The net size change is an addition of one unconditional branch. 134852e724ad7e679ee590f4bd763d55280586a8f1bcNicolas Geoffray int delta = TII->GetInstSizeInBytes(&MBB->back()); 134999c49a4b94ffabdd22f55e8274c7f92892e25559Dale Johannesen AdjustBBOffsetsAfter(MBB, delta); 1350af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng return true; 1351af5cbcb809bdbd30ebacab942994721c134d16a2Evan Cheng} 1352d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng 1353d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng/// UndoLRSpillRestore - Remove Thumb push / pop instructions that only spills 13544b322e58b77d16f103d88a3af3a4ebd2675245a0Evan Cheng/// LR / restores LR to pc. FIXME: This is done here because it's only possible 13554b322e58b77d16f103d88a3af3a4ebd2675245a0Evan Cheng/// to do this if tBfar is not used. 1356d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Chengbool ARMConstantIslands::UndoLRSpillRestore() { 1357d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng bool MadeChange = false; 1358d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng for (unsigned i = 0, e = PushPopMIs.size(); i != e; ++i) { 1359d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng MachineInstr *MI = PushPopMIs[i]; 136044bec52b1b7e9a3ac1efbae90db240b8c1ca2ad4Evan Cheng if (MI->getOpcode() == ARM::tPOP_RET && 136148bd7e3bbc481cd9b99a981f7d8e06989774f9d2Evan Cheng MI->getOperand(2).getReg() == ARM::PC && 136248bd7e3bbc481cd9b99a981f7d8e06989774f9d2Evan Cheng MI->getNumExplicitOperands() == 3) { 1363b67284057ee130114055309eabe0bcd1af13777dDale Johannesen BuildMI(MI->getParent(), MI->getDebugLoc(), TII->get(ARM::tBX_RET)); 136444bec52b1b7e9a3ac1efbae90db240b8c1ca2ad4Evan Cheng MI->eraseFromParent(); 136544bec52b1b7e9a3ac1efbae90db240b8c1ca2ad4Evan Cheng MadeChange = true; 1366d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng } 1367d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng } 1368d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng return MadeChange; 1369d1b2c1e88fe4a7728ca9739b0f1c6fd90a19c5fdEvan Cheng} 13705657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng 1371a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Chengbool ARMConstantIslands::OptimizeThumb2Instructions(MachineFunction &MF) { 1372a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng bool MadeChange = false; 1373a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng 1374a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng // Shrink ADR and LDR from constantpool. 1375a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng for (unsigned i = 0, e = CPUsers.size(); i != e; ++i) { 1376a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng CPUser &U = CPUsers[i]; 1377a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng unsigned Opcode = U.MI->getOpcode(); 1378a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng unsigned NewOpc = 0; 1379a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng unsigned Scale = 1; 1380a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng unsigned Bits = 0; 1381a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng switch (Opcode) { 1382a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng default: break; 1383a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng case ARM::t2LEApcrel: 1384a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng if (isARMLowRegister(U.MI->getOperand(0).getReg())) { 1385a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng NewOpc = ARM::tLEApcrel; 1386a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng Bits = 8; 1387a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng Scale = 4; 1388a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng } 1389a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng break; 1390a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng case ARM::t2LDRpci: 1391a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng if (isARMLowRegister(U.MI->getOperand(0).getReg())) { 1392a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng NewOpc = ARM::tLDRpci; 1393a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng Bits = 8; 1394a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng Scale = 4; 1395a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng } 1396a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng break; 1397a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng } 1398a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng 1399a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng if (!NewOpc) 1400a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng continue; 1401a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng 1402a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng unsigned UserOffset = GetOffsetOf(U.MI) + 4; 1403a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng unsigned MaxOffs = ((1 << Bits) - 1) * Scale; 1404a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng // FIXME: Check if offset is multiple of scale if scale is not 4. 1405a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng if (CPEIsInRange(U.MI, UserOffset, U.CPEMI, MaxOffs, false, true)) { 1406a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng U.MI->setDesc(TII->get(NewOpc)); 1407a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng MachineBasicBlock *MBB = U.MI->getParent(); 1408a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng BBSizes[MBB->getNumber()] -= 2; 1409a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng AdjustBBOffsetsAfter(MBB, -2); 1410a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng ++NumT2CPShrunk; 1411a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng MadeChange = true; 1412a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng } 1413a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng } 1414a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng 1415a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng MadeChange |= OptimizeThumb2Branches(MF); 141631b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng MadeChange |= OptimizeThumb2JumpTables(MF); 1417a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng return MadeChange; 1418a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng} 1419a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng 1420a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Chengbool ARMConstantIslands::OptimizeThumb2Branches(MachineFunction &MF) { 142131b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng bool MadeChange = false; 142231b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng 142331b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng for (unsigned i = 0, e = ImmBranches.size(); i != e; ++i) { 142431b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng ImmBranch &Br = ImmBranches[i]; 142531b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng unsigned Opcode = Br.MI->getOpcode(); 142631b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng unsigned NewOpc = 0; 142731b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng unsigned Scale = 1; 142831b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng unsigned Bits = 0; 142931b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng switch (Opcode) { 143031b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng default: break; 143131b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng case ARM::t2B: 143231b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng NewOpc = ARM::tB; 143331b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng Bits = 11; 143431b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng Scale = 2; 143531b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng break; 143631b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng case ARM::t2Bcc: 143731b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng NewOpc = ARM::tBcc; 143831b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng Bits = 8; 143931b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng Scale = 2; 144031b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng break; 144131b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng } 144231b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng if (!NewOpc) 144331b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng continue; 144431b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng 144531b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng unsigned MaxOffs = ((1 << (Bits-1))-1) * Scale; 144631b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng MachineBasicBlock *DestBB = Br.MI->getOperand(0).getMBB(); 144731b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng if (BBIsInRange(Br.MI, DestBB, MaxOffs)) { 144831b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng Br.MI->setDesc(TII->get(NewOpc)); 144931b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng MachineBasicBlock *MBB = Br.MI->getParent(); 145031b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng BBSizes[MBB->getNumber()] -= 2; 145131b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng AdjustBBOffsetsAfter(MBB, -2); 145231b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng ++NumT2BrShrunk; 145331b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng MadeChange = true; 145431b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng } 145531b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng } 145631b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng 145731b99dd76035067b1c3cc6c7e9d663b7b0210938Evan Cheng return MadeChange; 1458a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng} 1459a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng 1460a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng 1461a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng/// OptimizeThumb2JumpTables - Use tbb / tbh instructions to generate smaller 1462a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng/// jumptables when it's possible. 14635657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Chengbool ARMConstantIslands::OptimizeThumb2JumpTables(MachineFunction &MF) { 14645657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng bool MadeChange = false; 14655657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng 14665657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng // FIXME: After the tables are shrunk, can we get rid some of the 14675657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng // constantpool tables? 14685657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng const MachineJumpTableInfo *MJTI = MF.getJumpTableInfo(); 14695657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables(); 14705657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng for (unsigned i = 0, e = T2JumpTables.size(); i != e; ++i) { 14715657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng MachineInstr *MI = T2JumpTables[i]; 14725657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng const TargetInstrDesc &TID = MI->getDesc(); 14735657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng unsigned NumOps = TID.getNumOperands(); 14745657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng unsigned JTOpIdx = NumOps - (TID.isPredicable() ? 3 : 2); 14755657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng MachineOperand JTOP = MI->getOperand(JTOpIdx); 14765657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng unsigned JTI = JTOP.getIndex(); 14775657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng assert(JTI < JT.size()); 14785657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng 14795657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng bool ByteOk = true; 14805657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng bool HalfWordOk = true; 14815657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng unsigned JTOffset = GetOffsetOf(MI) + 4; 14825657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs; 14835657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng for (unsigned j = 0, ee = JTBBs.size(); j != ee; ++j) { 14845657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng MachineBasicBlock *MBB = JTBBs[j]; 14855657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng unsigned DstOffset = BBOffsets[MBB->getNumber()]; 14868770f747a98194056805f1b7cbcb0b75a7633b87Evan Cheng // Negative offset is not ok. FIXME: We should change BB layout to make 14878770f747a98194056805f1b7cbcb0b75a7633b87Evan Cheng // sure all the branches are forward. 1488d26b14c34cbcee1448b86b524578fc51cc979023Evan Cheng if (ByteOk && (DstOffset - JTOffset) > ((1<<8)-1)*2) 14895657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng ByteOk = false; 149025f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng unsigned TBHLimit = ((1<<16)-1)*2; 149125f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng if (HalfWordOk && (DstOffset - JTOffset) > TBHLimit) 14925657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng HalfWordOk = false; 14935657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng if (!ByteOk && !HalfWordOk) 14945657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng break; 14955657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng } 14965657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng 14975657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng if (ByteOk || HalfWordOk) { 14985657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng MachineBasicBlock *MBB = MI->getParent(); 14995657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng unsigned BaseReg = MI->getOperand(0).getReg(); 15005657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng bool BaseRegKill = MI->getOperand(0).isKill(); 15015657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng if (!BaseRegKill) 15025657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng continue; 15035657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng unsigned IdxReg = MI->getOperand(1).getReg(); 15045657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng bool IdxRegKill = MI->getOperand(1).isKill(); 15055657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng MachineBasicBlock::iterator PrevI = MI; 15065657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng if (PrevI == MBB->begin()) 15075657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng continue; 15085657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng 15095657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng MachineInstr *AddrMI = --PrevI; 15105657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng bool OptOk = true; 15115657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng // Examine the instruction that calculate the jumptable entry address. 15125657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng // If it's not the one just before the t2BR_JT, we won't delete it, then 15135657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng // it's not worth doing the optimization. 15145657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng for (unsigned k = 0, eee = AddrMI->getNumOperands(); k != eee; ++k) { 15155657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng const MachineOperand &MO = AddrMI->getOperand(k); 15165657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng if (!MO.isReg() || !MO.getReg()) 15175657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng continue; 15185657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng if (MO.isDef() && MO.getReg() != BaseReg) { 15195657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng OptOk = false; 15205657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng break; 15215657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng } 15225657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng if (MO.isUse() && !MO.isKill() && MO.getReg() != IdxReg) { 15235657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng OptOk = false; 15245657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng break; 15255657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng } 15265657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng } 15275657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng if (!OptOk) 15285657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng continue; 15295657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng 1530a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng // The previous instruction should be a tLEApcrel or t2LEApcrelJT, we want 1531a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng // to delete it as well. 15325657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng MachineInstr *LeaMI = --PrevI; 1533a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng if ((LeaMI->getOpcode() != ARM::tLEApcrelJT && 1534a1efbbdbf3217598f334a6f39dab84ca06f5de41Evan Cheng LeaMI->getOpcode() != ARM::t2LEApcrelJT) || 15355657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng LeaMI->getOperand(0).getReg() != BaseReg) 153625f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng OptOk = false; 153725f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng 153825f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng if (!OptOk) 153925f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng continue; 154025f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng 154125f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng unsigned Opc = ByteOk ? ARM::t2TBB : ARM::t2TBH; 154225f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng MachineInstr *NewJTMI = BuildMI(MBB, MI->getDebugLoc(), TII->get(Opc)) 154325f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng .addReg(IdxReg, getKillRegState(IdxRegKill)) 154425f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng .addJumpTableIndex(JTI, JTOP.getTargetFlags()) 154525f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng .addImm(MI->getOperand(JTOpIdx+1).getImm()); 154625f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng // FIXME: Insert an "ALIGN" instruction to ensure the next instruction 154725f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng // is 2-byte aligned. For now, asm printer will fix it up. 154825f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng unsigned NewSize = TII->GetInstSizeInBytes(NewJTMI); 154925f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng unsigned OrigSize = TII->GetInstSizeInBytes(AddrMI); 155025f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng OrigSize += TII->GetInstSizeInBytes(LeaMI); 155125f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng OrigSize += TII->GetInstSizeInBytes(MI); 155225f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng 155325f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng AddrMI->eraseFromParent(); 155425f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng LeaMI->eraseFromParent(); 155525f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng MI->eraseFromParent(); 155625f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng 155725f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng int delta = OrigSize - NewSize; 155825f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng BBSizes[MBB->getNumber()] -= delta; 155925f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng AdjustBBOffsetsAfter(MBB, -delta); 156025f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng 156125f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng ++NumTBs; 156225f7cfc3cccba6f569f29f79ea533bae960b93c0Evan Cheng MadeChange = true; 15635657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng } 15645657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng } 15655657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng 15665657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng return MadeChange; 15675657c01949dca6c012ac60d242d1a8d2ffdf5603Evan Cheng} 1568