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 "llvm/Module.h"
16 #include "llvm/Support/CommandLine.h"
17 #include "X86GenSubtarget.inc"
20 cl::opt<X86Subtarget::AsmWriterFlavorTy>
21 AsmWriterFlavor("x86-asm-syntax",
22 cl::desc("Choose style of code to emit from X86 backend:"),
24 clEnumValN(X86Subtarget::att, "att", " Emit AT&T-style assembly"),
25 clEnumValN(X86Subtarget::intel, "intel", " Emit Intel-style assembly"),
28 cl::init(X86Subtarget::intel)
30 cl::init(X86Subtarget::att)
34 /// GetCpuIDAndInfo - Execute the specified cpuid and return the 4 values in the
35 /// specified arguments. If we can't run cpuid on the host, return true.
36 static bool GetCpuIDAndInfo(unsigned value, unsigned *rEAX, unsigned *rEBX,
37 unsigned *rECX, unsigned *rEDX) {
38 #if defined(i386) || defined(__i386__) || defined(__x86__) || defined(_M_IX86)
40 asm ("pushl\t%%ebx\n\t"
42 "movl\t%%ebx, %%esi\n\t"
50 #elif defined(_MSC_VER)
55 mov dword ptr [esi],eax
57 mov dword ptr [esi],ebx
59 mov dword ptr [esi],ecx
61 mov dword ptr [esi],edx
69 static const char *GetCurrentX86CPU() {
70 unsigned EAX = 0, EBX = 0, ECX = 0, EDX = 0;
71 if (GetCpuIDAndInfo(0x1, &EAX, &EBX, &ECX, &EDX))
73 unsigned Family = (EAX & (0xffffffff >> (32 - 4)) << 8) >> 8; // Bits 8 - 11
74 unsigned Model = (EAX & (0xffffffff >> (32 - 4)) << 4) >> 4; // Bits 4 - 7
75 GetCpuIDAndInfo(0x80000001, &EAX, &EBX, &ECX, &EDX);
76 bool Em64T = EDX & (1 << 29);
83 GetCpuIDAndInfo(0, &EAX, text.u+0, text.u+2, text.u+1);
84 if (memcmp(text.c, "GenuineIntel", 12) == 0) {
92 case 4: return "pentium-mmx";
93 default: return "pentium";
97 case 1: return "pentiumpro";
100 case 6: return "pentium2";
104 case 11: return "pentium3";
106 case 13: return "pentium-m";
107 case 14: return "yonah";
109 return (Model > 14) ? "yonah" : "i686";
115 return (Em64T) ? "nocona" : "prescott";
117 return (Em64T) ? "x86-64" : "pentium4";
124 } else if (memcmp(text.c, "AuthenticAMD", 12) == 0) {
125 // FIXME: this poorly matches the generated SubtargetFeatureKV table. There
126 // appears to be no way to generate the wide variety of AMD-specific targets
127 // from the information returned from CPUID.
135 case 8: return "k6-2";
137 case 13: return "k6-3";
138 default: return "pentium";
142 case 4: return "athlon-tbird";
145 case 8: return "athlon-mp";
146 case 10: return "athlon-xp";
147 default: return "athlon";
151 case 5: return "athlon-fx"; // also opteron
152 default: return "athlon64";
163 X86Subtarget::X86Subtarget(const Module &M, const std::string &FS) {
165 // FIXME: this is a known good value for Yonah. Not sure about others.
166 MinRepStrSizeThreshold = 128;
167 X86SSELevel = NoMMXSSE;
168 X863DNowLevel = NoThreeDNow;
169 AsmFlavor = AsmWriterFlavor;
172 // Determine default and user specified characteristics
173 std::string CPU = GetCurrentX86CPU();
175 // Parse features string.
176 ParseSubtargetFeatures(FS, CPU);
178 // Default to ELF unless otherwise specified.
181 // Set the boolean corresponding to the current target triple, or the default
182 // if one cannot be determined, to true.
183 const std::string& TT = M.getTargetTriple();
184 if (TT.length() > 5) {
185 if (TT.find("cygwin") != std::string::npos ||
186 TT.find("mingw") != std::string::npos)
187 TargetType = isCygwin;
188 else if (TT.find("darwin") != std::string::npos)
189 TargetType = isDarwin;
190 else if (TT.find("win32") != std::string::npos)
191 TargetType = isWindows;
192 } else if (TT.empty()) {
193 #if defined(__CYGWIN__) || defined(__MINGW32__)
194 TargetType = isCygwin;
195 #elif defined(__APPLE__)
196 TargetType = isDarwin;
197 #elif defined(_WIN32)
198 TargetType = isWindows;
202 if (TargetType == isDarwin || TargetType == isCygwin)