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 "X86GenSubtarget.inc"
19 #include "llvm/Support/CommandLine.h"
21 cl::opt<bool> DisableSSE("disable-x86-sse", cl::Hidden,
22 cl::desc("Disable sse on X86"));
25 /// GetCpuIDAndInfo - Execute the specified cpuid and return the 4 values in the
26 /// specified arguments. If we can't run cpuid on the host, return true.
27 static bool GetCpuIDAndInfo(unsigned value, unsigned *rEAX, unsigned *rEBX,
28 unsigned *rECX, unsigned *rEDX) {
29 #if defined(i386) || defined(__i386__) || defined(__x86__) || defined(_M_IX86)
31 asm ("pushl\t%%ebx\n\t"
33 "movl\t%%ebx, %%esi\n\t"
41 #elif defined(_MSC_VER)
46 mov dword ptr [esi],eax
48 mov dword ptr [esi],ebx
50 mov dword ptr [esi],ecx
52 mov dword ptr [esi],edx
60 static const char *GetCurrentX86CPU() {
61 unsigned EAX = 0, EBX = 0, ECX = 0, EDX = 0;
62 if (GetCpuIDAndInfo(0x1, &EAX, &EBX, &ECX, &EDX))
64 unsigned Family = (EAX & (0xffffffff >> (32 - 4)) << 8) >> 8; // Bits 8 - 11
65 unsigned Model = (EAX & (0xffffffff >> (32 - 4)) << 4) >> 4; // Bits 4 - 7
66 GetCpuIDAndInfo(0x80000001, &EAX, &EBX, &ECX, &EDX);
67 bool Em64T = EDX & (1 << 29);
74 GetCpuIDAndInfo(0, &EAX, text.u+0, text.u+2, text.u+1);
75 if (memcmp(text.c, "GenuineIntel", 12) == 0) {
83 case 4: return "pentium-mmx";
84 default: return "pentium";
88 case 1: return "pentiumpro";
91 case 6: return "pentium2";
95 case 11: return "pentium3";
97 case 13: return "pentium-m";
98 case 14: return "yonah";
99 default: return "i686";
105 return (Em64T) ? "nocona" : "prescott";
107 return (Em64T) ? "x86-64" : "pentium4";
114 } else if (memcmp(text.c, "AuthenticAMD", 12) == 0) {
115 // FIXME: this poorly matches the generated SubtargetFeatureKV table. There
116 // appears to be no way to generate the wide variety of AMD-specific targets
117 // from the information returned from CPUID.
125 case 8: return "k6-2";
127 case 13: return "k6-3";
128 default: return "pentium";
132 case 4: return "athlon-tbird";
135 case 8: return "athlon-mp";
136 case 10: return "athlon-xp";
137 default: return "athlon";
141 case 5: return "athlon-fx"; // also opteron
142 default: return "athlon64";
153 X86Subtarget::X86Subtarget(const Module &M, const std::string &FS) {
155 indirectExternAndWeakGlobals = false;
156 X86SSELevel = NoMMXSSE;
157 X863DNowLevel = NoThreeDNow;
160 // Determine default and user specified characteristics
161 std::string CPU = GetCurrentX86CPU();
163 // Parse features string.
164 ParseSubtargetFeatures(FS, CPU);
166 // Default to ELF unless otherwise specified.
170 X86SSELevel = NoMMXSSE;
171 X863DNowLevel = NoThreeDNow;
174 // Set the boolean corresponding to the current target triple, or the default
175 // if one cannot be determined, to true.
176 const std::string& TT = M.getTargetTriple();
177 if (TT.length() > 5) {
178 if (TT.find("cygwin") != std::string::npos ||
179 TT.find("mingw") != std::string::npos)
180 TargetType = isCygwin;
181 else if (TT.find("darwin") != std::string::npos)
182 TargetType = isDarwin;
183 else if (TT.find("win32") != std::string::npos)
184 TargetType = isWindows;
185 } else if (TT.empty()) {
186 #if defined(__CYGWIN__) || defined(__MINGW32__)
187 TargetType = isCygwin;
188 #elif defined(__APPLE__)
189 TargetType = isDarwin;
190 #elif defined(_WIN32)
191 TargetType = isWindows;
195 if (TargetType == isDarwin) {
197 indirectExternAndWeakGlobals = true;