1 //===- PowerPCSubtarget.cpp - PPC Subtarget Information -------------------===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // This file implements the PPC specific subclass of TargetSubtarget. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #include "PPCSubtarget.h" 15 #include "PPC.h" 16 #include "llvm/GlobalValue.h" 17 #include "llvm/Target/TargetMachine.h" 18 #include "PPCGenSubtarget.inc" 19 #include <cstdlib> 20 using namespace llvm; 21 22 #if defined(__APPLE__) 23 #include <mach/mach.h> 24 #include <mach/mach_host.h> 25 #include <mach/host_info.h> 26 #include <mach/machine.h> 27 28 /// GetCurrentPowerPCFeatures - Returns the current CPUs features. 29 static const char *GetCurrentPowerPCCPU() { 30 host_basic_info_data_t hostInfo; 31 mach_msg_type_number_t infoCount; 32 33 infoCount = HOST_BASIC_INFO_COUNT; 34 host_info(mach_host_self(), HOST_BASIC_INFO, (host_info_t)&hostInfo, 35 &infoCount); 36 37 if (hostInfo.cpu_type != CPU_TYPE_POWERPC) return "generic"; 38 39 switch(hostInfo.cpu_subtype) { 40 case CPU_SUBTYPE_POWERPC_601: return "601"; 41 case CPU_SUBTYPE_POWERPC_602: return "602"; 42 case CPU_SUBTYPE_POWERPC_603: return "603"; 43 case CPU_SUBTYPE_POWERPC_603e: return "603e"; 44 case CPU_SUBTYPE_POWERPC_603ev: return "603ev"; 45 case CPU_SUBTYPE_POWERPC_604: return "604"; 46 case CPU_SUBTYPE_POWERPC_604e: return "604e"; 47 case CPU_SUBTYPE_POWERPC_620: return "620"; 48 case CPU_SUBTYPE_POWERPC_750: return "750"; 49 case CPU_SUBTYPE_POWERPC_7400: return "7400"; 50 case CPU_SUBTYPE_POWERPC_7450: return "7450"; 51 case CPU_SUBTYPE_POWERPC_970: return "970"; 52 default: ; 53 } 54 55 return "generic"; 56 } 57 #endif 58 59 60 PPCSubtarget::PPCSubtarget(const std::string &TT, const std::string &FS, 61 bool is64Bit) 62 : StackAlignment(16) 63 , DarwinDirective(PPC::DIR_NONE) 64 , IsGigaProcessor(false) 65 , Has64BitSupport(false) 66 , Use64BitRegs(false) 67 , IsPPC64(is64Bit) 68 , HasAltivec(false) 69 , HasFSQRT(false) 70 , HasSTFIWX(false) 71 , HasLazyResolverStubs(false) 72 , IsJITCodeModel(false) 73 , DarwinVers(0) { 74 75 // Determine default and user specified characteristics 76 std::string CPU = "generic"; 77 #if defined(__APPLE__) 78 CPU = GetCurrentPowerPCCPU(); 79 #endif 80 81 // Parse features string. 82 ParseSubtargetFeatures(FS, CPU); 83 84 // If we are generating code for ppc64, verify that options make sense. 85 if (is64Bit) { 86 Has64BitSupport = true; 87 // Silently force 64-bit register use on ppc64. 88 Use64BitRegs = true; 89 } 90 91 // If the user requested use of 64-bit regs, but the cpu selected doesn't 92 // support it, ignore. 93 if (use64BitRegs() && !has64BitSupport()) 94 Use64BitRegs = false; 95 96 // Set the boolean corresponding to the current target triple, or the default 97 // if one cannot be determined, to true. 98 if (TT.length() > 7) { 99 // Determine which version of darwin this is. 100 size_t DarwinPos = TT.find("-darwin"); 101 if (DarwinPos != std::string::npos) { 102 if (isdigit(TT[DarwinPos+7])) 103 DarwinVers = atoi(&TT[DarwinPos+7]); 104 else 105 DarwinVers = 8; // Minimum supported darwin is Tiger. 106 } 107 } 108 109 // Set up darwin-specific properties. 110 if (isDarwin()) 111 HasLazyResolverStubs = true; 112 } 113 114 /// SetJITMode - This is called to inform the subtarget info that we are 115 /// producing code for the JIT. 116 void PPCSubtarget::SetJITMode() { 117 // JIT mode doesn't want lazy resolver stubs, it knows exactly where 118 // everything is. This matters for PPC64, which codegens in PIC mode without 119 // stubs. 120 HasLazyResolverStubs = false; 121 122 // Calls to external functions need to use indirect calls 123 IsJITCodeModel = true; 124 } 125 126 127 /// hasLazyResolverStub - Return true if accesses to the specified global have 128 /// to go through a dyld lazy resolution stub. This means that an extra load 129 /// is required to get the address of the global. 130 bool PPCSubtarget::hasLazyResolverStub(const GlobalValue *GV, 131 const TargetMachine &TM) const { 132 // We never have stubs if HasLazyResolverStubs=false or if in static mode. 133 if (!HasLazyResolverStubs || TM.getRelocationModel() == Reloc::Static) 134 return false; 135 // If symbol visibility is hidden, the extra load is not needed if 136 // the symbol is definitely defined in the current translation unit. 137 bool isDecl = GV->isDeclaration() && !GV->isMaterializable(); 138 if (GV->hasHiddenVisibility() && !isDecl && !GV->hasCommonLinkage()) 139 return false; 140 return GV->hasWeakLinkage() || GV->hasLinkOnceLinkage() || 141 GV->hasCommonLinkage() || isDecl; 142 } 143