//
// The LLVM Compiler Infrastructure
//
-// This file was developed by Nate Begeman and is distributed under the
-// University of Illinois Open Source License. See LICENSE.TXT for details.
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
//
//===----------------------------------------------------------------------===//
+#define DEBUG_TYPE "subtarget"
#include "X86Subtarget.h"
#include "X86GenSubtarget.inc"
#include "llvm/Module.h"
#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/Debug.h"
#include "llvm/Target/TargetMachine.h"
+#include "llvm/Target/TargetOptions.h"
using namespace llvm;
-cl::opt<X86Subtarget::AsmWriterFlavorTy>
-AsmWriterFlavor("x86-asm-syntax", cl::init(X86Subtarget::unset),
+#if defined(_MSC_VER)
+ #include <intrin.h>
+#endif
+
+static cl::opt<X86Subtarget::AsmWriterFlavorTy>
+AsmWriterFlavor("x86-asm-syntax", cl::init(X86Subtarget::Unset),
cl::desc("Choose style of code to emit from X86 backend:"),
cl::values(
- clEnumValN(X86Subtarget::att, "att", " Emit AT&T-style assembly"),
- clEnumValN(X86Subtarget::intel, "intel", " Emit Intel-style assembly"),
+ clEnumValN(X86Subtarget::ATT, "att", "Emit AT&T-style assembly"),
+ clEnumValN(X86Subtarget::Intel, "intel", "Emit Intel-style assembly"),
clEnumValEnd));
const TargetMachine& TM,
bool isDirectCall) const
{
- if (TM.getRelocationModel() != Reloc::Static)
+ // FIXME: PIC
+ if (TM.getRelocationModel() != Reloc::Static &&
+ TM.getCodeModel() != CodeModel::Large) {
if (isTargetDarwin()) {
- return (!isDirectCall &&
- (GV->hasWeakLinkage() || GV->hasLinkOnceLinkage() ||
- (GV->isExternal() && !GV->hasNotBeenReadFromBytecode())));
- } else if (isTargetCygwin() || isTargetWindows()) {
+ if (isDirectCall)
+ return false;
+ bool isDecl = GV->isDeclaration() && !GV->hasNotBeenReadFromBitcode();
+ if (GV->hasHiddenVisibility() &&
+ (Is64Bit || (!isDecl && !GV->hasCommonLinkage())))
+ // If symbol visibility is hidden, the extra load is not needed if
+ // target is x86-64 or the symbol is definitely defined in the current
+ // translation unit.
+ return false;
+ return !isDirectCall && (isDecl || GV->isWeakForLinker());
+ } else if (isTargetELF()) {
+ // Extra load is needed for all externally visible.
+ if (isDirectCall)
+ return false;
+ if (GV->hasLocalLinkage() || GV->hasHiddenVisibility())
+ return false;
+ return true;
+ } else if (isTargetCygMing() || isTargetWindows()) {
return (GV->hasDLLImportLinkage());
}
-
+ }
return false;
}
+/// True if accessing the GV requires a register. This is a superset of the
+/// cases where GVRequiresExtraLoad is true. Some variations of PIC require
+/// a register, but not an extra load.
+bool X86Subtarget::GVRequiresRegister(const GlobalValue *GV,
+ const TargetMachine& TM,
+ bool isDirectCall) const
+{
+ if (GVRequiresExtraLoad(GV, TM, isDirectCall))
+ return true;
+ // Code below here need only consider cases where GVRequiresExtraLoad
+ // returns false.
+ if (TM.getRelocationModel() == Reloc::PIC_)
+ return !isDirectCall &&
+ (GV->hasLocalLinkage() || GV->hasExternalLinkage());
+ return false;
+}
+
+/// getBZeroEntry - This function returns the name of a function which has an
+/// interface like the non-standard bzero function, if such a function exists on
+/// the current subtarget and it is considered prefereable over memset with zero
+/// passed as the second argument. Otherwise it returns null.
+const char *X86Subtarget::getBZeroEntry() const {
+ // Darwin 10 has a __bzero entry point for this purpose.
+ if (getDarwinVers() >= 10)
+ return "__bzero";
+
+ return 0;
+}
+
+/// IsLegalToCallImmediateAddr - Return true if the subtarget allows calls
+/// to immediate address.
+bool X86Subtarget::IsLegalToCallImmediateAddr(const TargetMachine &TM) const {
+ if (Is64Bit)
+ return false;
+ return isTargetELF() || TM.getRelocationModel() == Reloc::Static;
+}
+
+/// getSpecialAddressLatency - For targets where it is beneficial to
+/// backschedule instructions that compute addresses, return a value
+/// indicating the number of scheduling cycles of backscheduling that
+/// should be attempted.
+unsigned X86Subtarget::getSpecialAddressLatency() const {
+ // For x86 out-of-order targets, back-schedule address computations so
+ // that loads and stores aren't blocked.
+ // This value was chosen arbitrarily.
+ return 200;
+}
+
/// GetCpuIDAndInfo - Execute the specified cpuid and return the 4 values in the
/// specified arguments. If we can't run cpuid on the host, return true.
bool X86::GetCpuIDAndInfo(unsigned value, unsigned *rEAX, unsigned *rEBX,
unsigned *rECX, unsigned *rEDX) {
-#if defined(__x86_64__)
- // gcc doesn't know cpuid would clobber ebx/rbx. Preseve it manually.
- asm ("movq\t%%rbx, %%rsi\n\t"
- "cpuid\n\t"
- "xchgq\t%%rbx, %%rsi\n\t"
- : "=a" (*rEAX),
- "=S" (*rEBX),
- "=c" (*rECX),
- "=d" (*rEDX)
- : "a" (value));
- return false;
+#if defined(__x86_64__) || defined(_M_AMD64)
+ #if defined(__GNUC__)
+ // gcc doesn't know cpuid would clobber ebx/rbx. Preseve it manually.
+ asm ("movq\t%%rbx, %%rsi\n\t"
+ "cpuid\n\t"
+ "xchgq\t%%rbx, %%rsi\n\t"
+ : "=a" (*rEAX),
+ "=S" (*rEBX),
+ "=c" (*rECX),
+ "=d" (*rEDX)
+ : "a" (value));
+ return false;
+ #elif defined(_MSC_VER)
+ int registers[4];
+ __cpuid(registers, value);
+ *rEAX = registers[0];
+ *rEBX = registers[1];
+ *rECX = registers[2];
+ *rEDX = registers[3];
+ return false;
+ #endif
#elif defined(i386) || defined(__i386__) || defined(__x86__) || defined(_M_IX86)
-#if defined(__GNUC__)
- asm ("movl\t%%ebx, %%esi\n\t"
- "cpuid\n\t"
- "xchgl\t%%ebx, %%esi\n\t"
- : "=a" (*rEAX),
- "=S" (*rEBX),
- "=c" (*rECX),
- "=d" (*rEDX)
- : "a" (value));
- return false;
-#elif defined(_MSC_VER)
- __asm {
- mov eax,value
- cpuid
- mov esi,rEAX
- mov dword ptr [esi],eax
- mov esi,rEBX
- mov dword ptr [esi],ebx
- mov esi,rECX
- mov dword ptr [esi],ecx
- mov esi,rEDX
- mov dword ptr [esi],edx
- }
- return false;
-#endif
+ #if defined(__GNUC__)
+ asm ("movl\t%%ebx, %%esi\n\t"
+ "cpuid\n\t"
+ "xchgl\t%%ebx, %%esi\n\t"
+ : "=a" (*rEAX),
+ "=S" (*rEBX),
+ "=c" (*rECX),
+ "=d" (*rEDX)
+ : "a" (value));
+ return false;
+ #elif defined(_MSC_VER)
+ __asm {
+ mov eax,value
+ cpuid
+ mov esi,rEAX
+ mov dword ptr [esi],eax
+ mov esi,rEBX
+ mov dword ptr [esi],ebx
+ mov esi,rECX
+ mov dword ptr [esi],ecx
+ mov esi,rEDX
+ mov dword ptr [esi],edx
+ }
+ return false;
+ #endif
#endif
return true;
}
+static void DetectFamilyModel(unsigned EAX, unsigned &Family, unsigned &Model) {
+ Family = (EAX >> 8) & 0xf; // Bits 8 - 11
+ Model = (EAX >> 4) & 0xf; // Bits 4 - 7
+ if (Family == 6 || Family == 0xf) {
+ if (Family == 0xf)
+ // Examine extended family ID if family ID is F.
+ Family += (EAX >> 20) & 0xff; // Bits 20 - 27
+ // Examine extended model ID if family ID is 6 or F.
+ Model += ((EAX >> 16) & 0xf) << 4; // Bits 16 - 19
+ }
+}
+
void X86Subtarget::AutoDetectSubtargetFeatures() {
unsigned EAX = 0, EBX = 0, ECX = 0, EDX = 0;
union {
if (X86::GetCpuIDAndInfo(0, &EAX, text.u+0, text.u+2, text.u+1))
return;
+
+ X86::GetCpuIDAndInfo(0x1, &EAX, &EBX, &ECX, &EDX);
- // FIXME: support for AMD family of processors.
- if (memcmp(text.c, "GenuineIntel", 12) == 0) {
- X86::GetCpuIDAndInfo(0x1, &EAX, &EBX, &ECX, &EDX);
+ if ((EDX >> 23) & 0x1) X86SSELevel = MMX;
+ if ((EDX >> 25) & 0x1) X86SSELevel = SSE1;
+ if ((EDX >> 26) & 0x1) X86SSELevel = SSE2;
+ if (ECX & 0x1) X86SSELevel = SSE3;
+ if ((ECX >> 9) & 0x1) X86SSELevel = SSSE3;
+ if ((ECX >> 19) & 0x1) X86SSELevel = SSE41;
+ if ((ECX >> 20) & 0x1) X86SSELevel = SSE42;
- if ((EDX >> 23) & 0x1) X86SSELevel = MMX;
- if ((EDX >> 25) & 0x1) X86SSELevel = SSE1;
- if ((EDX >> 26) & 0x1) X86SSELevel = SSE2;
- if (ECX & 0x1) X86SSELevel = SSE3;
+ bool IsIntel = memcmp(text.c, "GenuineIntel", 12) == 0;
+ bool IsAMD = !IsIntel && memcmp(text.c, "AuthenticAMD", 12) == 0;
+ if (IsIntel || IsAMD) {
+ // Determine if bit test memory instructions are slow.
+ unsigned Family = 0;
+ unsigned Model = 0;
+ DetectFamilyModel(EAX, Family, Model);
+ IsBTMemSlow = IsAMD || (Family == 6 && Model >= 13);
X86::GetCpuIDAndInfo(0x80000001, &EAX, &EBX, &ECX, &EDX);
HasX86_64 = (EDX >> 29) & 0x1;
+ HasSSE4A = IsAMD && ((ECX >> 6) & 0x1);
}
}
unsigned EAX = 0, EBX = 0, ECX = 0, EDX = 0;
if (X86::GetCpuIDAndInfo(0x1, &EAX, &EBX, &ECX, &EDX))
return "generic";
- unsigned Family = (EAX >> 8) & 0xf; // Bits 8 - 11
- unsigned Model = (EAX >> 4) & 0xf; // Bits 4 - 7
+ unsigned Family = 0;
+ unsigned Model = 0;
+ DetectFamilyModel(EAX, Family, Model);
+
X86::GetCpuIDAndInfo(0x80000001, &EAX, &EBX, &ECX, &EDX);
bool Em64T = (EDX >> 29) & 0x1;
+ bool HasSSE3 = (ECX & 0x1);
union {
unsigned u[3];
case 9:
case 13: return "pentium-m";
case 14: return "yonah";
- case 15: return "core2";
+ case 15:
+ case 22: // Celeron M 540
+ return "core2";
+ case 23: // 45nm: Penryn , Wolfdale, Yorkfield (XE)
+ return "penryn";
default: return "i686";
}
case 15: {
switch (Model) {
case 3:
case 4:
+ case 6: // same as 4, but 65nm
return (Em64T) ? "nocona" : "prescott";
+ case 26:
+ return "corei7";
+ case 28:
+ return "atom";
default:
return (Em64T) ? "x86-64" : "pentium4";
}
default: return "athlon";
}
case 15:
+ if (HasSSE3) {
+ switch (Model) {
+ default: return "k8-sse3";
+ }
+ } else {
+ switch (Model) {
+ case 1: return "opteron";
+ case 5: return "athlon-fx"; // also opteron
+ default: return "athlon64";
+ }
+ }
+ case 16:
switch (Model) {
- case 5: return "athlon-fx"; // also opteron
- default: return "athlon64";
+ default: return "amdfam10";
}
-
default:
return "generic";
}
X86Subtarget::X86Subtarget(const Module &M, const std::string &FS, bool is64Bit)
: AsmFlavor(AsmWriterFlavor)
+ , PICStyle(PICStyles::None)
, X86SSELevel(NoMMXSSE)
+ , X863DNowLevel(NoThreeDNow)
, HasX86_64(false)
+ , IsBTMemSlow(false)
+ , DarwinVers(0)
+ , IsLinux(false)
, stackAlignment(8)
// FIXME: this is a known good value for Yonah. How about others?
- , MinRepStrSizeThreshold(128)
+ , MaxInlineSizeThreshold(128)
, Is64Bit(is64Bit)
, TargetType(isELF) { // Default to ELF unless otherwise specified.
+ // default to hard float ABI
+ if (FloatABIType == FloatABI::Default)
+ FloatABIType = FloatABI::Hard;
+
// Determine default and user specified characteristics
if (!FS.empty()) {
// If feature string is not empty, parse features string.
std::string CPU = GetCurrentX86CPU();
ParseSubtargetFeatures(FS, CPU);
-
- if (Is64Bit && !HasX86_64)
- cerr << "Warning: Generation of 64-bit code for a 32-bit processor "
- << "requested.\n";
- if (Is64Bit && X86SSELevel < SSE2)
- cerr << "Warning: 64-bit processors all have at least SSE2.\n";
+ // All X86-64 CPUs also have SSE2, however user might request no SSE via
+ // -mattr, so don't force SSELevel here.
} else {
// Otherwise, use CPUID to auto-detect feature set.
AutoDetectSubtargetFeatures();
- }
-
- // If requesting codegen for X86-64, make sure that 64-bit and SSE2 features
- // are enabled. These are available on all x86-64 CPUs.
- if (Is64Bit) {
- HasX86_64 = true;
- if (X86SSELevel < SSE2)
+ // Make sure SSE2 is enabled; it is available on all X86-64 CPUs.
+ if (Is64Bit && X86SSELevel < SSE2)
X86SSELevel = SSE2;
}
+ // If requesting codegen for X86-64, make sure that 64-bit features
+ // are enabled.
+ if (Is64Bit)
+ HasX86_64 = true;
+
+ DOUT << "Subtarget features: SSELevel " << X86SSELevel
+ << ", 3DNowLevel " << X863DNowLevel
+ << ", 64bit " << HasX86_64 << "\n";
+ assert((!Is64Bit || HasX86_64) &&
+ "64-bit code requested on a subtarget that doesn't support it!");
+
// Set the boolean corresponding to the current target triple, or the default
// if one cannot be determined, to true.
const std::string& TT = M.getTargetTriple();
if (TT.length() > 5) {
- if (TT.find("cygwin") != std::string::npos ||
- TT.find("mingw") != std::string::npos)
- TargetType = isCygwin;
- else if (TT.find("darwin") != std::string::npos)
+ size_t Pos;
+ if ((Pos = TT.find("-darwin")) != std::string::npos) {
TargetType = isDarwin;
- else if (TT.find("win32") != std::string::npos)
+
+ // Compute the darwin version number.
+ if (isdigit(TT[Pos+7]))
+ DarwinVers = atoi(&TT[Pos+7]);
+ else
+ DarwinVers = 8; // Minimum supported darwin is Tiger.
+ } else if (TT.find("linux") != std::string::npos) {
+ // Linux doesn't imply ELF, but we don't currently support anything else.
+ TargetType = isELF;
+ IsLinux = true;
+ } else if (TT.find("cygwin") != std::string::npos) {
+ TargetType = isCygwin;
+ } else if (TT.find("mingw") != std::string::npos) {
+ TargetType = isMingw;
+ } else if (TT.find("win32") != std::string::npos) {
+ TargetType = isWindows;
+ } else if (TT.find("windows") != std::string::npos) {
TargetType = isWindows;
+ }
+ else if (TT.find("-cl") != std::string::npos) {
+ TargetType = isDarwin;
+ DarwinVers = 9;
+ }
} else if (TT.empty()) {
-#if defined(__CYGWIN__) || defined(__MINGW32__)
+#if defined(__CYGWIN__)
TargetType = isCygwin;
+#elif defined(__MINGW32__) || defined(__MINGW64__)
+ TargetType = isMingw;
#elif defined(__APPLE__)
TargetType = isDarwin;
-#elif defined(_WIN32)
+#if __APPLE_CC__ > 5400
+ DarwinVers = 9; // GCC 5400+ is Leopard.
+#else
+ DarwinVers = 8; // Minimum supported darwin is Tiger.
+#endif
+
+#elif defined(_WIN32) || defined(_WIN64)
TargetType = isWindows;
+#elif defined(__linux__)
+ // Linux doesn't imply ELF, but we don't currently support anything else.
+ TargetType = isELF;
+ IsLinux = true;
#endif
}
// If the asm syntax hasn't been overridden on the command line, use whatever
// the target wants.
- if (AsmFlavor == X86Subtarget::unset) {
- if (TargetType == isWindows) {
- AsmFlavor = X86Subtarget::intel;
- } else {
- AsmFlavor = X86Subtarget::att;
- }
+ if (AsmFlavor == X86Subtarget::Unset) {
+ AsmFlavor = (TargetType == isWindows)
+ ? X86Subtarget::Intel : X86Subtarget::ATT;
}
- if (TargetType == isDarwin ||
- TargetType == isCygwin ||
- (TargetType == isELF && Is64Bit))
+ // Stack alignment is 16 bytes on Darwin (both 32 and 64 bit) and for all 64
+ // bit targets.
+ if (TargetType == isDarwin || Is64Bit)
stackAlignment = 16;
+
+ if (StackAlignment)
+ stackAlignment = StackAlignment;
}