1 //===--- X86.cpp - X86 Helpers for Tools ------------------------*- C++ -*-===//
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //===----------------------------------------------------------------------===//
10 #include "ToolChains/CommonArgs.h"
11 #include "clang/Driver/Driver.h"
12 #include "clang/Driver/DriverDiagnostic.h"
13 #include "clang/Driver/Options.h"
14 #include "llvm/ADT/StringSwitch.h"
15 #include "llvm/Option/ArgList.h"
17 using namespace clang::driver;
18 using namespace clang::driver::tools;
19 using namespace clang;
20 using namespace llvm::opt;
22 const char *x86::getX86TargetCPU(const ArgList &Args,
23 const llvm::Triple &Triple) {
24 if (const Arg *A = Args.getLastArg(clang::driver::options::OPT_march_EQ)) {
25 if (StringRef(A->getValue()) != "native")
28 // FIXME: Reject attempts to use -march=native unless the target matches
31 // FIXME: We should also incorporate the detected target features for use
33 std::string CPU = llvm::sys::getHostCPUName();
34 if (!CPU.empty() && CPU != "generic")
35 return Args.MakeArgString(CPU);
38 if (const Arg *A = Args.getLastArgNoClaim(options::OPT__SLASH_arch)) {
39 // Mapping built by looking at lib/Basic's X86TargetInfo::initFeatureMap().
40 StringRef Arch = A->getValue();
41 const char *CPU = nullptr;
42 if (Triple.getArch() == llvm::Triple::x86) { // 32-bit-only /arch: flags.
43 CPU = llvm::StringSwitch<const char *>(Arch)
45 .Case("SSE", "pentium3")
46 .Case("SSE2", "pentium4")
49 if (CPU == nullptr) { // 32-bit and 64-bit /arch: flags.
50 CPU = llvm::StringSwitch<const char *>(Arch)
51 .Case("AVX", "sandybridge")
52 .Case("AVX2", "haswell")
53 .Case("AVX512F", "knl")
54 .Case("AVX512", "skylake-avx512")
63 // Select the default CPU if none was given (or detection failed).
65 if (Triple.getArch() != llvm::Triple::x86_64 &&
66 Triple.getArch() != llvm::Triple::x86)
67 return nullptr; // This routine is only handling x86 targets.
69 bool Is64Bit = Triple.getArch() == llvm::Triple::x86_64;
71 // FIXME: Need target hooks.
72 if (Triple.isOSDarwin()) {
73 if (Triple.getArchName() == "x86_64h")
75 // macosx10.12 drops support for all pre-Penryn Macs.
76 // Simulators can still run on 10.11 though, like Xcode.
77 if (Triple.isMacOSX() && !Triple.isOSVersionLT(10, 12))
79 // The oldest x86_64 Macs have core2/Merom; the oldest x86 Macs have Yonah.
80 return Is64Bit ? "core2" : "yonah";
83 // Set up default CPU name for PS4 compilers.
84 if (Triple.isPS4CPU())
87 // On Android use targets compatible with gcc
88 if (Triple.isAndroid())
89 return Is64Bit ? "x86-64" : "i686";
91 // Everything else goes to x86-64 in 64-bit mode.
95 switch (Triple.getOS()) {
96 case llvm::Triple::FreeBSD:
98 case llvm::Triple::NetBSD:
99 case llvm::Triple::OpenBSD:
101 case llvm::Triple::Haiku:
109 void x86::getX86TargetFeatures(const Driver &D, const llvm::Triple &Triple,
111 std::vector<StringRef> &Features) {
112 // If -march=native, autodetect the feature list.
113 if (const Arg *A = Args.getLastArg(clang::driver::options::OPT_march_EQ)) {
114 if (StringRef(A->getValue()) == "native") {
115 llvm::StringMap<bool> HostFeatures;
116 if (llvm::sys::getHostCPUFeatures(HostFeatures))
117 for (auto &F : HostFeatures)
119 Args.MakeArgString((F.second ? "+" : "-") + F.first()));
123 if (Triple.getArchName() == "x86_64h") {
124 // x86_64h implies quite a few of the more modern subtarget features
125 // for Haswell class CPUs, but not all of them. Opt-out of a few.
126 Features.push_back("-rdrnd");
127 Features.push_back("-aes");
128 Features.push_back("-pclmul");
129 Features.push_back("-rtm");
130 Features.push_back("-fsgsbase");
133 const llvm::Triple::ArchType ArchType = Triple.getArch();
134 // Add features to be compatible with gcc for Android.
135 if (Triple.isAndroid()) {
136 if (ArchType == llvm::Triple::x86_64) {
137 Features.push_back("+sse4.2");
138 Features.push_back("+popcnt");
139 Features.push_back("+cx16");
141 Features.push_back("+ssse3");
144 // Translate the high level `-mretpoline` flag to the specific target feature
145 // flags. We also detect if the user asked for retpoline external thunks but
146 // failed to ask for retpolines themselves (through any of the different
147 // flags). This is a bit hacky but keeps existing usages working. We should
148 // consider deprecating this and instead warn if the user requests external
149 // retpoline thunks and *doesn't* request some form of retpolines.
150 if (Args.hasArgNoClaim(options::OPT_mretpoline, options::OPT_mno_retpoline,
151 options::OPT_mspeculative_load_hardening,
152 options::OPT_mno_speculative_load_hardening)) {
153 if (Args.hasFlag(options::OPT_mretpoline, options::OPT_mno_retpoline,
155 Features.push_back("+retpoline-indirect-calls");
156 Features.push_back("+retpoline-indirect-branches");
157 } else if (Args.hasFlag(options::OPT_mspeculative_load_hardening,
158 options::OPT_mno_speculative_load_hardening,
160 // On x86, speculative load hardening relies on at least using retpolines
161 // for indirect calls.
162 Features.push_back("+retpoline-indirect-calls");
164 } else if (Args.hasFlag(options::OPT_mretpoline_external_thunk,
165 options::OPT_mno_retpoline_external_thunk, false)) {
166 // FIXME: Add a warning about failing to specify `-mretpoline` and
167 // eventually switch to an error here.
168 Features.push_back("+retpoline-indirect-calls");
169 Features.push_back("+retpoline-indirect-branches");
172 // Now add any that the user explicitly requested on the command line,
173 // which may override the defaults.
174 handleTargetFeaturesGroup(Args, Features, options::OPT_m_x86_Features_Group);