ARMSubtarget.cpp revision 87d21b92fc42f6b3bd8567a83fc5b5191c1205e5
1a8e2989ece6dc46df59b0768184028257f913843Evan Cheng//===-- ARMSubtarget.cpp - ARM Subtarget Information ------------*- 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 implements the ARM specific subclass of TargetSubtarget. 11a8e2989ece6dc46df59b0768184028257f913843Evan Cheng// 12a8e2989ece6dc46df59b0768184028257f913843Evan Cheng//===----------------------------------------------------------------------===// 13a8e2989ece6dc46df59b0768184028257f913843Evan Cheng 14a8e2989ece6dc46df59b0768184028257f913843Evan Cheng#include "ARMSubtarget.h" 15a8e2989ece6dc46df59b0768184028257f913843Evan Cheng#include "ARMGenSubtarget.inc" 16e4e4ed3b56f63e9343e01bf0b2ecd7c1f45d296cEvan Cheng#include "llvm/GlobalValue.h" 170eebf653a7b2978e7761f8d068b6fbec22aea0f6Anton Korobeynikov#include "llvm/Target/TargetOptions.h" 1854fc124d72512d65d62565cabcd85c7b07496513Bob Wilson#include "llvm/Support/CommandLine.h" 19c2e8a7e8d2ab156afaa8ab0d0317dd9ee3db7d30David Goodwin#include "llvm/ADT/SmallVector.h" 20a8e2989ece6dc46df59b0768184028257f913843Evan Chengusing namespace llvm; 21a8e2989ece6dc46df59b0768184028257f913843Evan Cheng 2254fc124d72512d65d62565cabcd85c7b07496513Bob Wilsonstatic cl::opt<bool> 2354fc124d72512d65d62565cabcd85c7b07496513Bob WilsonReserveR9("arm-reserve-r9", cl::Hidden, 2454fc124d72512d65d62565cabcd85c7b07496513Bob Wilson cl::desc("Reserve R9, making it unavailable as GPR")); 259843a93e830e76f96e9a997b3002624a28ca5aa6David Goodwinstatic cl::opt<bool> 269843a93e830e76f96e9a997b3002624a28ca5aa6David GoodwinUseNEONFP("arm-use-neon-fp", 279843a93e830e76f96e9a997b3002624a28ca5aa6David Goodwin cl::desc("Use NEON for single-precision FP"), 289843a93e830e76f96e9a997b3002624a28ca5aa6David Goodwin cl::init(false), cl::Hidden); 2954fc124d72512d65d62565cabcd85c7b07496513Bob Wilson 303be03406c9c3b2075d5ae416499af2f15f703d6fDaniel DunbarARMSubtarget::ARMSubtarget(const std::string &TT, const std::string &FS, 31d3dd50fec00fbbb76edbfaff4d613f1248d21c9eEvan Cheng bool isT) 321a3771e30e48b9cc21ccdc79fc9cf37ec4104b17Evan Cheng : ARMArchVersion(V4T) 336d7d2aa38a247426e2ccf53e3c6ad0315c9a4d8cAnton Korobeynikov , ARMFPUType(None) 349843a93e830e76f96e9a997b3002624a28ca5aa6David Goodwin , UseNEONForSinglePrecisionFP(UseNEONFP) 35d3dd50fec00fbbb76edbfaff4d613f1248d21c9eEvan Cheng , IsThumb(isT) 3670459bef9ccd73b3a2a44fdd62f2509861112745Anton Korobeynikov , ThumbMode(Thumb1) 370dad89fa94536284d51f60868326294b725a0c61David Goodwin , PostRAScheduler(false) 3854fc124d72512d65d62565cabcd85c7b07496513Bob Wilson , IsR9Reserved(ReserveR9) 393630e78db9268dbe81a9369a33e49b857804f2ecLauro Ramos Venancio , stackAlignment(4) 4041a024385f1220eadc48b48cb4c044a5fbc1b361Anton Korobeynikov , CPUString("generic") 413630e78db9268dbe81a9369a33e49b857804f2ecLauro Ramos Venancio , TargetType(isELF) // Default to ELF unless otherwise specified. 423630e78db9268dbe81a9369a33e49b857804f2ecLauro Ramos Venancio , TargetABI(ARM_ABI_APCS) { 430eebf653a7b2978e7761f8d068b6fbec22aea0f6Anton Korobeynikov // default to soft float ABI 440eebf653a7b2978e7761f8d068b6fbec22aea0f6Anton Korobeynikov if (FloatABIType == FloatABI::Default) 450eebf653a7b2978e7761f8d068b6fbec22aea0f6Anton Korobeynikov FloatABIType = FloatABI::Soft; 460eebf653a7b2978e7761f8d068b6fbec22aea0f6Anton Korobeynikov 47a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // Determine default and user specified characteristics 48a8e2989ece6dc46df59b0768184028257f913843Evan Cheng 49a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // Parse features string. 5041a024385f1220eadc48b48cb4c044a5fbc1b361Anton Korobeynikov CPUString = ParseSubtargetFeatures(FS, CPUString); 51a8e2989ece6dc46df59b0768184028257f913843Evan Cheng 52a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // Set the boolean corresponding to the current target triple, or the default 53a8e2989ece6dc46df59b0768184028257f913843Evan Cheng // if one cannot be determined, to true. 544b1747430a2d67702958b95d6776396734f184a0Evan Cheng unsigned Len = TT.length(); 558c6b991635ff589fbe4b8db013bcc1d2ef57a0e0Evan Cheng unsigned Idx = 0; 56d4022c3fbb0705abdc8eddc3ee4a5059f5ef8094Anton Korobeynikov 578c6b991635ff589fbe4b8db013bcc1d2ef57a0e0Evan Cheng if (Len >= 5 && TT.substr(0, 4) == "armv") 588c6b991635ff589fbe4b8db013bcc1d2ef57a0e0Evan Cheng Idx = 4; 599170ab6685fcd820c6274e761b8c3a71f25ae074Bob Wilson else if (Len >= 6 && TT.substr(0, 5) == "thumb") { 6070459bef9ccd73b3a2a44fdd62f2509861112745Anton Korobeynikov IsThumb = true; 618c6b991635ff589fbe4b8db013bcc1d2ef57a0e0Evan Cheng if (Len >= 7 && TT[5] == 'v') 628c6b991635ff589fbe4b8db013bcc1d2ef57a0e0Evan Cheng Idx = 6; 638c6b991635ff589fbe4b8db013bcc1d2ef57a0e0Evan Cheng } 648c6b991635ff589fbe4b8db013bcc1d2ef57a0e0Evan Cheng if (Idx) { 658c6b991635ff589fbe4b8db013bcc1d2ef57a0e0Evan Cheng unsigned SubVer = TT[Idx]; 668c6b991635ff589fbe4b8db013bcc1d2ef57a0e0Evan Cheng if (SubVer > '4' && SubVer <= '9') { 679170ab6685fcd820c6274e761b8c3a71f25ae074Bob Wilson if (SubVer >= '7') { 68d4022c3fbb0705abdc8eddc3ee4a5059f5ef8094Anton Korobeynikov ARMArchVersion = V7A; 699170ab6685fcd820c6274e761b8c3a71f25ae074Bob Wilson } else if (SubVer == '6') { 708c6b991635ff589fbe4b8db013bcc1d2ef57a0e0Evan Cheng ARMArchVersion = V6; 719170ab6685fcd820c6274e761b8c3a71f25ae074Bob Wilson if (Len >= Idx+3 && TT[Idx+1] == 't' && TT[Idx+2] == '2') 729170ab6685fcd820c6274e761b8c3a71f25ae074Bob Wilson ARMArchVersion = V6T2; 739170ab6685fcd820c6274e761b8c3a71f25ae074Bob Wilson } else if (SubVer == '5') { 748c6b991635ff589fbe4b8db013bcc1d2ef57a0e0Evan Cheng ARMArchVersion = V5T; 758c6b991635ff589fbe4b8db013bcc1d2ef57a0e0Evan Cheng if (Len >= Idx+3 && TT[Idx+1] == 't' && TT[Idx+2] == 'e') 768c6b991635ff589fbe4b8db013bcc1d2ef57a0e0Evan Cheng ARMArchVersion = V5TE; 774b1747430a2d67702958b95d6776396734f184a0Evan Cheng } 789170ab6685fcd820c6274e761b8c3a71f25ae074Bob Wilson if (ARMArchVersion >= V6T2) 799170ab6685fcd820c6274e761b8c3a71f25ae074Bob Wilson ThumbMode = Thumb2; 804b1747430a2d67702958b95d6776396734f184a0Evan Cheng } 814b1747430a2d67702958b95d6776396734f184a0Evan Cheng } 824b1747430a2d67702958b95d6776396734f184a0Evan Cheng 83b620724e614c6594e7b269b6ea7d8483947ea944Evan Cheng // Thumb2 implies at least V6T2. 84b620724e614c6594e7b269b6ea7d8483947ea944Evan Cheng if (ARMArchVersion < V6T2 && ThumbMode >= Thumb2) 85b620724e614c6594e7b269b6ea7d8483947ea944Evan Cheng ARMArchVersion = V6T2; 86b620724e614c6594e7b269b6ea7d8483947ea944Evan Cheng 878c6b991635ff589fbe4b8db013bcc1d2ef57a0e0Evan Cheng if (Len >= 10) { 881a3771e30e48b9cc21ccdc79fc9cf37ec4104b17Evan Cheng if (TT.find("-darwin") != std::string::npos) 898c6b991635ff589fbe4b8db013bcc1d2ef57a0e0Evan Cheng // arm-darwin 901a3771e30e48b9cc21ccdc79fc9cf37ec4104b17Evan Cheng TargetType = isDarwin; 91a8e2989ece6dc46df59b0768184028257f913843Evan Cheng } 92a8e2989ece6dc46df59b0768184028257f913843Evan Cheng 933630e78db9268dbe81a9369a33e49b857804f2ecLauro Ramos Venancio if (TT.find("eabi") != std::string::npos) 943630e78db9268dbe81a9369a33e49b857804f2ecLauro Ramos Venancio TargetABI = ARM_ABI_AAPCS; 953630e78db9268dbe81a9369a33e49b857804f2ecLauro Ramos Venancio 963630e78db9268dbe81a9369a33e49b857804f2ecLauro Ramos Venancio if (isAAPCS_ABI()) 973630e78db9268dbe81a9369a33e49b857804f2ecLauro Ramos Venancio stackAlignment = 8; 983630e78db9268dbe81a9369a33e49b857804f2ecLauro Ramos Venancio 99cd828618b8c6ec58df94aec0f5546f009f2fd0d5Evan Cheng if (isTargetDarwin()) 10054fc124d72512d65d62565cabcd85c7b07496513Bob Wilson IsR9Reserved = ReserveR9 | (ARMArchVersion < V6); 101471850ab84301dd47cab2bf8d694fcb5766c1169David Goodwin 102d3dd50fec00fbbb76edbfaff4d613f1248d21c9eEvan Cheng if (!isThumb() || hasThumb2()) 103d3dd50fec00fbbb76edbfaff4d613f1248d21c9eEvan Cheng PostRAScheduler = true; 104d3dd50fec00fbbb76edbfaff4d613f1248d21c9eEvan Cheng 105471850ab84301dd47cab2bf8d694fcb5766c1169David Goodwin // Set CPU specific features. 106471850ab84301dd47cab2bf8d694fcb5766c1169David Goodwin if (CPUString == "cortex-a8") { 107b46aea10324263dd63492fc5c1d54800e980c8f8Evan Cheng // On Cortex-a8, it's faster to perform some single-precision FP 108fee0c1074c68a61d15899fb8cb31f1902fa9e509Evan Cheng // operations with NEON instructions. 1099843a93e830e76f96e9a997b3002624a28ca5aa6David Goodwin if (UseNEONFP.getPosition() == 0) 1109843a93e830e76f96e9a997b3002624a28ca5aa6David Goodwin UseNEONForSinglePrecisionFP = true; 111471850ab84301dd47cab2bf8d694fcb5766c1169David Goodwin } 112a8e2989ece6dc46df59b0768184028257f913843Evan Cheng} 113e4e4ed3b56f63e9343e01bf0b2ecd7c1f45d296cEvan Cheng 114e4e4ed3b56f63e9343e01bf0b2ecd7c1f45d296cEvan Cheng/// GVIsIndirectSymbol - true if the GV will be accessed via an indirect symbol. 11563476a80404125e5196b6c09113c1d4796da0604Evan Chengbool 11663476a80404125e5196b6c09113c1d4796da0604Evan ChengARMSubtarget::GVIsIndirectSymbol(GlobalValue *GV, Reloc::Model RelocM) const { 11763476a80404125e5196b6c09113c1d4796da0604Evan Cheng if (RelocM == Reloc::Static) 118e4e4ed3b56f63e9343e01bf0b2ecd7c1f45d296cEvan Cheng return false; 11963476a80404125e5196b6c09113c1d4796da0604Evan Cheng 12063476a80404125e5196b6c09113c1d4796da0604Evan Cheng // GV with ghost linkage (in JIT lazy compilation mode) do not require an 12163476a80404125e5196b6c09113c1d4796da0604Evan Cheng // extra load from stub. 12263476a80404125e5196b6c09113c1d4796da0604Evan Cheng bool isDecl = GV->isDeclaration() && !GV->hasNotBeenReadFromBitcode(); 12363476a80404125e5196b6c09113c1d4796da0604Evan Cheng 12463476a80404125e5196b6c09113c1d4796da0604Evan Cheng if (!isTargetDarwin()) { 12563476a80404125e5196b6c09113c1d4796da0604Evan Cheng // Extra load is needed for all externally visible. 12663476a80404125e5196b6c09113c1d4796da0604Evan Cheng if (GV->hasLocalLinkage() || GV->hasHiddenVisibility()) 12763476a80404125e5196b6c09113c1d4796da0604Evan Cheng return false; 12863476a80404125e5196b6c09113c1d4796da0604Evan Cheng return true; 12963476a80404125e5196b6c09113c1d4796da0604Evan Cheng } else { 13063476a80404125e5196b6c09113c1d4796da0604Evan Cheng if (RelocM == Reloc::PIC_) { 13163476a80404125e5196b6c09113c1d4796da0604Evan Cheng // If this is a strong reference to a definition, it is definitely not 13263476a80404125e5196b6c09113c1d4796da0604Evan Cheng // through a stub. 13363476a80404125e5196b6c09113c1d4796da0604Evan Cheng if (!isDecl && !GV->isWeakForLinker()) 13463476a80404125e5196b6c09113c1d4796da0604Evan Cheng return false; 13563476a80404125e5196b6c09113c1d4796da0604Evan Cheng 13663476a80404125e5196b6c09113c1d4796da0604Evan Cheng // Unless we have a symbol with hidden visibility, we have to go through a 13763476a80404125e5196b6c09113c1d4796da0604Evan Cheng // normal $non_lazy_ptr stub because this symbol might be resolved late. 13863476a80404125e5196b6c09113c1d4796da0604Evan Cheng if (!GV->hasHiddenVisibility()) // Non-hidden $non_lazy_ptr reference. 13963476a80404125e5196b6c09113c1d4796da0604Evan Cheng return true; 14063476a80404125e5196b6c09113c1d4796da0604Evan Cheng 14163476a80404125e5196b6c09113c1d4796da0604Evan Cheng // If symbol visibility is hidden, we have a stub for common symbol 14263476a80404125e5196b6c09113c1d4796da0604Evan Cheng // references and external declarations. 14363476a80404125e5196b6c09113c1d4796da0604Evan Cheng if (isDecl || GV->hasCommonLinkage()) 14463476a80404125e5196b6c09113c1d4796da0604Evan Cheng // Hidden $non_lazy_ptr reference. 14563476a80404125e5196b6c09113c1d4796da0604Evan Cheng return true; 14663476a80404125e5196b6c09113c1d4796da0604Evan Cheng 14763476a80404125e5196b6c09113c1d4796da0604Evan Cheng return false; 14863476a80404125e5196b6c09113c1d4796da0604Evan Cheng } else { 14963476a80404125e5196b6c09113c1d4796da0604Evan Cheng // If this is a strong reference to a definition, it is definitely not 15063476a80404125e5196b6c09113c1d4796da0604Evan Cheng // through a stub. 15163476a80404125e5196b6c09113c1d4796da0604Evan Cheng if (!isDecl && !GV->isWeakForLinker()) 15263476a80404125e5196b6c09113c1d4796da0604Evan Cheng return false; 15363476a80404125e5196b6c09113c1d4796da0604Evan Cheng 15463476a80404125e5196b6c09113c1d4796da0604Evan Cheng // Unless we have a symbol with hidden visibility, we have to go through a 15563476a80404125e5196b6c09113c1d4796da0604Evan Cheng // normal $non_lazy_ptr stub because this symbol might be resolved late. 15663476a80404125e5196b6c09113c1d4796da0604Evan Cheng if (!GV->hasHiddenVisibility()) // Non-hidden $non_lazy_ptr reference. 15763476a80404125e5196b6c09113c1d4796da0604Evan Cheng return true; 15863476a80404125e5196b6c09113c1d4796da0604Evan Cheng } 15963476a80404125e5196b6c09113c1d4796da0604Evan Cheng } 16063476a80404125e5196b6c09113c1d4796da0604Evan Cheng 16163476a80404125e5196b6c09113c1d4796da0604Evan Cheng return false; 162e4e4ed3b56f63e9343e01bf0b2ecd7c1f45d296cEvan Cheng} 163c2e8a7e8d2ab156afaa8ab0d0317dd9ee3db7d30David Goodwin 164c2e8a7e8d2ab156afaa8ab0d0317dd9ee3db7d30David Goodwinbool ARMSubtarget::enablePostRAScheduler( 165c2e8a7e8d2ab156afaa8ab0d0317dd9ee3db7d30David Goodwin CodeGenOpt::Level OptLevel, 166c2e8a7e8d2ab156afaa8ab0d0317dd9ee3db7d30David Goodwin TargetSubtarget::AntiDepBreakMode& Mode, 16787d21b92fc42f6b3bd8567a83fc5b5191c1205e5David Goodwin RegClassVector& CriticalPathRCs) const { 168c2e8a7e8d2ab156afaa8ab0d0317dd9ee3db7d30David Goodwin Mode = TargetSubtarget::ANTIDEP_CRITICAL; 16987d21b92fc42f6b3bd8567a83fc5b5191c1205e5David Goodwin CriticalPathRCs.clear(); 17087d21b92fc42f6b3bd8567a83fc5b5191c1205e5David Goodwin CriticalPathRCs.push_back(&ARM::GPRRegClass); 171c2e8a7e8d2ab156afaa8ab0d0317dd9ee3db7d30David Goodwin return PostRAScheduler && OptLevel >= CodeGenOpt::Default; 172c2e8a7e8d2ab156afaa8ab0d0317dd9ee3db7d30David Goodwin} 173