1 //===--- X86.cpp - X86 Helpers for Tools ------------------------*- C++ -*-===//
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 #include "X86.h"
11 #include "ToolChains/CommonArgs.h"
12 #include "clang/Driver/Driver.h"
13 #include "clang/Driver/DriverDiagnostic.h"
14 #include "clang/Driver/Options.h"
15 #include "llvm/ADT/StringSwitch.h"
16 #include "llvm/Option/ArgList.h"
17 
18 using namespace clang::driver;
19 using namespace clang::driver::tools;
20 using namespace clang;
21 using namespace llvm::opt;
22 
23 const char *x86::getX86TargetCPU(const ArgList &Args,
24                                  const llvm::Triple &Triple) {
25   if (const Arg *A = Args.getLastArg(clang::driver::options::OPT_march_EQ)) {
26     if (StringRef(A->getValue()) != "native") {
27       if (Triple.isOSDarwin() && Triple.getArchName() == "x86_64h")
28         return "core-avx2";
29 
30       return A->getValue();
31     }
32 
33     // FIXME: Reject attempts to use -march=native unless the target matches
34     // the host.
35     //
36     // FIXME: We should also incorporate the detected target features for use
37     // with -native.
38     std::string CPU = llvm::sys::getHostCPUName();
39     if (!CPU.empty() && CPU != "generic")
40       return Args.MakeArgString(CPU);
41   }
42 
43   if (const Arg *A = Args.getLastArgNoClaim(options::OPT__SLASH_arch)) {
44     // Mapping built by looking at lib/Basic's X86TargetInfo::initFeatureMap().
45     StringRef Arch = A->getValue();
46     const char *CPU = nullptr;
47     if (Triple.getArch() == llvm::Triple::x86) {  // 32-bit-only /arch: flags.
48       CPU = llvm::StringSwitch<const char *>(Arch)
49                 .Case("IA32", "i386")
50                 .Case("SSE", "pentium3")
51                 .Case("SSE2", "pentium4")
52                 .Default(nullptr);
53     }
54     if (CPU == nullptr) {  // 32-bit and 64-bit /arch: flags.
55       CPU = llvm::StringSwitch<const char *>(Arch)
56                 .Case("AVX", "sandybridge")
57                 .Case("AVX2", "haswell")
58                 .Case("AVX512F", "knl")
59                 .Case("AVX512", "skylake-avx512")
60                 .Default(nullptr);
61     }
62     if (CPU) {
63       A->claim();
64       return CPU;
65     }
66   }
67 
68   // Select the default CPU if none was given (or detection failed).
69 
70   if (Triple.getArch() != llvm::Triple::x86_64 &&
71       Triple.getArch() != llvm::Triple::x86)
72     return nullptr; // This routine is only handling x86 targets.
73 
74   bool Is64Bit = Triple.getArch() == llvm::Triple::x86_64;
75 
76   // FIXME: Need target hooks.
77   if (Triple.isOSDarwin()) {
78     if (Triple.getArchName() == "x86_64h")
79       return "core-avx2";
80     // macosx10.12 drops support for all pre-Penryn Macs.
81     // Simulators can still run on 10.11 though, like Xcode.
82     if (Triple.isMacOSX() && !Triple.isOSVersionLT(10, 12))
83       return "penryn";
84     // The oldest x86_64 Macs have core2/Merom; the oldest x86 Macs have Yonah.
85     return Is64Bit ? "core2" : "yonah";
86   }
87 
88   // Set up default CPU name for PS4 compilers.
89   if (Triple.isPS4CPU())
90     return "btver2";
91 
92   // On Android use targets compatible with gcc
93   if (Triple.isAndroid())
94     return Is64Bit ? "x86-64" : "i686";
95 
96   // Everything else goes to x86-64 in 64-bit mode.
97   if (Is64Bit)
98     return "x86-64";
99 
100   switch (Triple.getOS()) {
101   case llvm::Triple::FreeBSD:
102   case llvm::Triple::NetBSD:
103   case llvm::Triple::OpenBSD:
104     return "i486";
105   case llvm::Triple::Haiku:
106     return "i586";
107   default:
108     // Fallback to p4.
109     return "pentium4";
110   }
111 }
112 
113 void x86::getX86TargetFeatures(const Driver &D, const llvm::Triple &Triple,
114                                const ArgList &Args,
115                                std::vector<StringRef> &Features) {
116   // If -march=native, autodetect the feature list.
117   if (const Arg *A = Args.getLastArg(clang::driver::options::OPT_march_EQ)) {
118     if (StringRef(A->getValue()) == "native") {
119       llvm::StringMap<bool> HostFeatures;
120       if (llvm::sys::getHostCPUFeatures(HostFeatures))
121         for (auto &F : HostFeatures)
122           Features.push_back(
123               Args.MakeArgString((F.second ? "+" : "-") + F.first()));
124     }
125   }
126 
127   if (Triple.getArchName() == "x86_64h") {
128     // x86_64h implies quite a few of the more modern subtarget features
129     // for Haswell class CPUs, but not all of them. Opt-out of a few.
130     Features.push_back("-rdrnd");
131     Features.push_back("-aes");
132     Features.push_back("-pclmul");
133     Features.push_back("-rtm");
134     Features.push_back("-fsgsbase");
135   }
136 
137   const llvm::Triple::ArchType ArchType = Triple.getArch();
138   // Add features to be compatible with gcc for Android.
139   if (Triple.isAndroid()) {
140     if (ArchType == llvm::Triple::x86_64) {
141       Features.push_back("+sse4.2");
142       Features.push_back("+popcnt");
143     } else
144       Features.push_back("+ssse3");
145   }
146 
147   // Now add any that the user explicitly requested on the command line,
148   // which may override the defaults.
149   handleTargetFeaturesGroup(Args, Features, options::OPT_m_x86_Features_Group);
150 }
151