1 //===-- X86Subtarget.cpp - X86 Subtarget Information ------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by Nate Begeman and is distributed under the
6 // University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements the X86 specific subclass of TargetSubtarget.
12 //===----------------------------------------------------------------------===//
14 #include "X86Subtarget.h"
15 #include "X86GenSubtarget.inc"
16 #include "llvm/Module.h"
17 #include "llvm/Support/CommandLine.h"
21 cl::opt<X86Subtarget::AsmWriterFlavorTy>
22 AsmWriterFlavor("x86-asm-syntax", cl::init(X86Subtarget::unset),
23 cl::desc("Choose style of code to emit from X86 backend:"),
25 clEnumValN(X86Subtarget::att, "att", " Emit AT&T-style assembly"),
26 clEnumValN(X86Subtarget::intel, "intel", " Emit Intel-style assembly"),
29 /// GetCpuIDAndInfo - Execute the specified cpuid and return the 4 values in the
30 /// specified arguments. If we can't run cpuid on the host, return true.
31 static bool GetCpuIDAndInfo(unsigned value, unsigned *rEAX, unsigned *rEBX,
32 unsigned *rECX, unsigned *rEDX) {
33 #if defined(__x86_64__)
34 asm ("pushq\t%%rbx\n\t"
36 "movl\t%%ebx, %%esi\n\t"
44 #elif defined(i386) || defined(__i386__) || defined(__x86__) || defined(_M_IX86)
46 asm ("pushl\t%%ebx\n\t"
48 "movl\t%%ebx, %%esi\n\t"
56 #elif defined(_MSC_VER)
61 mov dword ptr [esi],eax
63 mov dword ptr [esi],ebx
65 mov dword ptr [esi],ecx
67 mov dword ptr [esi],edx
75 static const char *GetCurrentX86CPU() {
76 unsigned EAX = 0, EBX = 0, ECX = 0, EDX = 0;
77 if (GetCpuIDAndInfo(0x1, &EAX, &EBX, &ECX, &EDX))
79 unsigned Family = (EAX & (0xffffffff >> (32 - 4)) << 8) >> 8; // Bits 8 - 11
80 unsigned Model = (EAX & (0xffffffff >> (32 - 4)) << 4) >> 4; // Bits 4 - 7
81 GetCpuIDAndInfo(0x80000001, &EAX, &EBX, &ECX, &EDX);
82 bool Em64T = EDX & (1 << 29);
89 GetCpuIDAndInfo(0, &EAX, text.u+0, text.u+2, text.u+1);
90 if (memcmp(text.c, "GenuineIntel", 12) == 0) {
98 case 4: return "pentium-mmx";
99 default: return "pentium";
103 case 1: return "pentiumpro";
106 case 6: return "pentium2";
110 case 11: return "pentium3";
112 case 13: return "pentium-m";
113 case 14: return "yonah";
114 case 15: return "core2";
115 default: return "i686";
121 return (Em64T) ? "nocona" : "prescott";
123 return (Em64T) ? "x86-64" : "pentium4";
130 } else if (memcmp(text.c, "AuthenticAMD", 12) == 0) {
131 // FIXME: this poorly matches the generated SubtargetFeatureKV table. There
132 // appears to be no way to generate the wide variety of AMD-specific targets
133 // from the information returned from CPUID.
141 case 8: return "k6-2";
143 case 13: return "k6-3";
144 default: return "pentium";
148 case 4: return "athlon-tbird";
151 case 8: return "athlon-mp";
152 case 10: return "athlon-xp";
153 default: return "athlon";
157 case 5: return "athlon-fx"; // also opteron
158 default: return "athlon64";
169 X86Subtarget::X86Subtarget(const Module &M, const std::string &FS, bool is64Bit)
170 : AsmFlavor(AsmWriterFlavor)
171 , X86SSELevel(NoMMXSSE)
172 , X863DNowLevel(NoThreeDNow)
175 // FIXME: this is a known good value for Yonah. How about others?
176 , MinRepStrSizeThreshold(128)
178 , TargetType(isELF) { // Default to ELF unless otherwise specified.
180 // Determine default and user specified characteristics
181 std::string CPU = GetCurrentX86CPU();
183 // Parse features string.
184 ParseSubtargetFeatures(FS, CPU);
186 if (Is64Bit && !HasX86_64) {
187 std::cerr << "Warning: Generation of 64-bit code for a 32-bit processor "
192 // Set the boolean corresponding to the current target triple, or the default
193 // if one cannot be determined, to true.
194 const std::string& TT = M.getTargetTriple();
195 if (TT.length() > 5) {
196 if (TT.find("cygwin") != std::string::npos ||
197 TT.find("mingw") != std::string::npos)
198 TargetType = isCygwin;
199 else if (TT.find("darwin") != std::string::npos)
200 TargetType = isDarwin;
201 else if (TT.find("win32") != std::string::npos)
202 TargetType = isWindows;
203 } else if (TT.empty()) {
204 #if defined(__CYGWIN__) || defined(__MINGW32__)
205 TargetType = isCygwin;
206 #elif defined(__APPLE__)
207 TargetType = isDarwin;
208 #elif defined(_WIN32)
209 TargetType = isWindows;
213 // If the asm syntax hasn't been overridden on the command line, use whatever
215 if (AsmFlavor == X86Subtarget::unset) {
216 if (TargetType == isWindows) {
217 AsmFlavor = X86Subtarget::intel;
219 AsmFlavor = X86Subtarget::att;
223 if (TargetType == isDarwin || TargetType == isCygwin)