//
// 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 "llvm/Module.h"
+#include "X86InstrInfo.h"
#include "X86GenSubtarget.inc"
+#include "llvm/GlobalValue.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/System/Host.h"
+#include "llvm/Target/TargetMachine.h"
+#include "llvm/Target/TargetOptions.h"
+#include "llvm/ADT/SmallVector.h"
using namespace llvm;
+#if defined(_MSC_VER)
+#include <intrin.h>
+#endif
+
+/// ClassifyBlockAddressReference - Classify a blockaddress reference for the
+/// current subtarget according to how we should reference it in a non-pcrel
+/// context.
+unsigned char X86Subtarget::
+ClassifyBlockAddressReference() const {
+ if (isPICStyleGOT()) // 32-bit ELF targets.
+ return X86II::MO_GOTOFF;
+
+ if (isPICStyleStubPIC()) // Darwin/32 in PIC mode.
+ return X86II::MO_PIC_BASE_OFFSET;
+
+ // Direct static reference to label.
+ return X86II::MO_NO_FLAG;
+}
+
+/// ClassifyGlobalReference - Classify a global variable reference for the
+/// current subtarget according to how we should reference it in a non-pcrel
+/// context.
+unsigned char X86Subtarget::
+ClassifyGlobalReference(const GlobalValue *GV, const TargetMachine &TM) const {
+ // DLLImport only exists on windows, it is implemented as a load from a
+ // DLLIMPORT stub.
+ if (GV->hasDLLImportLinkage())
+ return X86II::MO_DLLIMPORT;
+
+ // Determine whether this is a reference to a definition or a declaration.
+ // Materializable GVs (in JIT lazy compilation mode) do not require an extra
+ // load from stub.
+ bool isDecl = GV->hasAvailableExternallyLinkage();
+ if (GV->isDeclaration() && !GV->isMaterializable())
+ isDecl = true;
+
+ // X86-64 in PIC mode.
+ if (isPICStyleRIPRel()) {
+ // Large model never uses stubs.
+ if (TM.getCodeModel() == CodeModel::Large)
+ return X86II::MO_NO_FLAG;
+
+ if (isTargetDarwin()) {
+ // 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.
+ if (GV->hasDefaultVisibility() &&
+ (isDecl || GV->isWeakForLinker()))
+ return X86II::MO_GOTPCREL;
+ } else if (!isTargetWin64()) {
+ assert(isTargetELF() && "Unknown rip-relative target");
+
+ // Extra load is needed for all externally visible.
+ if (!GV->hasLocalLinkage() && GV->hasDefaultVisibility())
+ return X86II::MO_GOTPCREL;
+ }
+
+ return X86II::MO_NO_FLAG;
+ }
+
+ if (isPICStyleGOT()) { // 32-bit ELF targets.
+ // Extra load is needed for all externally visible.
+ if (GV->hasLocalLinkage() || GV->hasHiddenVisibility())
+ return X86II::MO_GOTOFF;
+ return X86II::MO_GOT;
+ }
+
+ if (isPICStyleStubPIC()) { // Darwin/32 in PIC mode.
+ // Determine whether we have a stub reference and/or whether the reference
+ // is relative to the PIC base or not.
+
+ // If this is a strong reference to a definition, it is definitely not
+ // through a stub.
+ if (!isDecl && !GV->isWeakForLinker())
+ return X86II::MO_PIC_BASE_OFFSET;
+
+ // Unless we have a symbol with hidden visibility, we have to go through a
+ // normal $non_lazy_ptr stub because this symbol might be resolved late.
+ if (!GV->hasHiddenVisibility()) // Non-hidden $non_lazy_ptr reference.
+ return X86II::MO_DARWIN_NONLAZY_PIC_BASE;
+
+ // If symbol visibility is hidden, we have a stub for common symbol
+ // references and external declarations.
+ if (isDecl || GV->hasCommonLinkage()) {
+ // Hidden $non_lazy_ptr reference.
+ return X86II::MO_DARWIN_HIDDEN_NONLAZY_PIC_BASE;
+ }
+
+ // Otherwise, no stub.
+ return X86II::MO_PIC_BASE_OFFSET;
+ }
+
+ if (isPICStyleStubNoDynamic()) { // Darwin/32 in -mdynamic-no-pic mode.
+ // Determine whether we have a stub reference.
+
+ // If this is a strong reference to a definition, it is definitely not
+ // through a stub.
+ if (!isDecl && !GV->isWeakForLinker())
+ return X86II::MO_NO_FLAG;
+
+ // Unless we have a symbol with hidden visibility, we have to go through a
+ // normal $non_lazy_ptr stub because this symbol might be resolved late.
+ if (!GV->hasHiddenVisibility()) // Non-hidden $non_lazy_ptr reference.
+ return X86II::MO_DARWIN_NONLAZY;
+
+ // Otherwise, no stub.
+ return X86II::MO_NO_FLAG;
+ }
+
+ // Direct static reference to global.
+ return X86II::MO_NO_FLAG;
+}
+
+
+/// 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.
-static bool GetCpuIDAndInfo(unsigned value, unsigned *rEAX, unsigned *rEBX,
- unsigned *rECX, unsigned *rEDX) {
-#if defined(i386) || defined(__i386__) || defined(__x86__) || defined(_M_IX86)
-#if defined(__GNUC__)
- asm ("pushl\t%%ebx\n\t"
- "cpuid\n\t"
- "movl\t%%ebx, %%esi\n\t"
- "popl\t%%ebx"
- : "=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
+static bool GetCpuIDAndInfo(unsigned value, unsigned *rEAX,
+ unsigned *rEBX, unsigned *rECX, unsigned *rEDX) {
+#if defined(__x86_64__) || defined(_M_AMD64) || defined (_M_X64)
+ #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
#endif
return true;
}
-static const char *GetCurrentX86CPU() {
- unsigned EAX = 0, EBX = 0, ECX = 0, EDX = 0;
- if (GetCpuIDAndInfo(0x1, &EAX, &EBX, &ECX, &EDX))
- return "generic";
- unsigned Family = (EAX & (0xffffffff >> (32 - 4)) << 8) >> 8; // Bits 8 - 11
- unsigned Model = (EAX & (0xffffffff >> (32 - 4)) << 4) >> 4; // Bits 4 - 7
- GetCpuIDAndInfo(0x80000001, &EAX, &EBX, &ECX, &EDX);
- bool Em64T = EDX & (1 << 29);
+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 {
unsigned u[3];
char c[12];
} text;
+
+ if (GetCpuIDAndInfo(0, &EAX, text.u+0, text.u+2, text.u+1))
+ return;
- GetCpuIDAndInfo(0, &EAX, text.u+0, text.u+2, text.u+1);
- if (memcmp(text.c, "GenuineIntel", 12) == 0) {
- switch (Family) {
- case 3:
- return "i386";
- case 4:
- return "i486";
- case 5:
- switch (Model) {
- case 4: return "pentium-mmx";
- default: return "pentium";
- }
- case 6:
- switch (Model) {
- case 1: return "pentiumpro";
- case 3:
- case 5:
- case 6: return "pentium2";
- case 7:
- case 8:
- case 10:
- case 11: return "pentium3";
- case 9:
- case 13: return "pentium-m";
- case 14: return "yonah";
- default: return "i686";
- }
- case 15: {
- switch (Model) {
- case 3:
- case 4:
- return (Em64T) ? "nocona" : "prescott";
- default:
- return (Em64T) ? "x86-64" : "pentium4";
- }
- }
-
- default:
- return "generic";
- }
- } else if (memcmp(text.c, "AuthenticAMD", 12) == 0) {
- // FIXME: this poorly matches the generated SubtargetFeatureKV table. There
- // appears to be no way to generate the wide variety of AMD-specific targets
- // from the information returned from CPUID.
- switch (Family) {
- case 4:
- return "i486";
- case 5:
- switch (Model) {
- case 6:
- case 7: return "k6";
- case 8: return "k6-2";
- case 9:
- case 13: return "k6-3";
- default: return "pentium";
- }
- case 6:
- switch (Model) {
- case 4: return "athlon-tbird";
- case 6:
- case 7:
- case 8: return "athlon-mp";
- case 10: return "athlon-xp";
- default: return "athlon";
- }
- case 15:
- switch (Model) {
- case 5: return "athlon-fx"; // also opteron
- default: return "athlon64";
- }
-
- default:
- return "generic";
- }
- } else {
- return "generic";
+ GetCpuIDAndInfo(0x1, &EAX, &EBX, &ECX, &EDX);
+
+ if ((EDX >> 15) & 1) HasCMov = true;
+ if ((EDX >> 23) & 1) X86SSELevel = MMX;
+ if ((EDX >> 25) & 1) X86SSELevel = SSE1;
+ if ((EDX >> 26) & 1) X86SSELevel = SSE2;
+ if (ECX & 0x1) X86SSELevel = SSE3;
+ if ((ECX >> 9) & 1) X86SSELevel = SSSE3;
+ if ((ECX >> 19) & 1) X86SSELevel = SSE41;
+ if ((ECX >> 20) & 1) X86SSELevel = SSE42;
+
+ bool IsIntel = memcmp(text.c, "GenuineIntel", 12) == 0;
+ bool IsAMD = !IsIntel && memcmp(text.c, "AuthenticAMD", 12) == 0;
+
+ HasCLMUL = IsIntel && ((ECX >> 1) & 0x1);
+ HasFMA3 = IsIntel && ((ECX >> 12) & 0x1);
+ HasAVX = ((ECX >> 28) & 0x1);
+ HasAES = IsIntel && ((ECX >> 25) & 0x1);
+
+ 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);
+ // If it's Nehalem, unaligned memory access is fast.
+ if (Family == 15 && Model == 26)
+ IsUAMemFast = true;
+
+ GetCpuIDAndInfo(0x80000001, &EAX, &EBX, &ECX, &EDX);
+ HasX86_64 = (EDX >> 29) & 0x1;
+ HasSSE4A = IsAMD && ((ECX >> 6) & 0x1);
+ HasFMA4 = IsAMD && ((ECX >> 16) & 0x1);
}
}
-X86Subtarget::X86Subtarget(const Module &M, const std::string &FS) {
- stackAlignment = 8;
- indirectExternAndWeakGlobals = false;
- X86SSELevel = NoMMXSSE;
- X863DNowLevel = NoThreeDNow;
- Is64Bit = false;
+X86Subtarget::X86Subtarget(const std::string &TT, const std::string &FS,
+ bool is64Bit)
+ : PICStyle(PICStyles::None)
+ , X86SSELevel(NoMMXSSE)
+ , X863DNowLevel(NoThreeDNow)
+ , HasCMov(false)
+ , HasX86_64(false)
+ , HasSSE4A(false)
+ , HasAVX(false)
+ , HasAES(false)
+ , HasCLMUL(false)
+ , HasFMA3(false)
+ , HasFMA4(false)
+ , IsBTMemSlow(false)
+ , IsUAMemFast(false)
+ , HasVectorUAMem(false)
+ , stackAlignment(8)
+ // FIXME: this is a known good value for Yonah. How about others?
+ , MaxInlineSizeThreshold(128)
+ , TargetTriple(TT)
+ , Is64Bit(is64Bit) {
+ // default to hard float ABI
+ if (FloatABIType == FloatABI::Default)
+ FloatABIType = FloatABI::Hard;
+
// Determine default and user specified characteristics
- std::string CPU = GetCurrentX86CPU();
+ if (!FS.empty()) {
+ // If feature string is not empty, parse features string.
+ std::string CPU = sys::getHostCPUName();
+ ParseSubtargetFeatures(FS, CPU);
+ // 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();
+ // Make sure SSE2 is enabled; it is available on all X86-64 CPUs.
+ if (Is64Bit && X86SSELevel < SSE2)
+ X86SSELevel = SSE2;
+ }
- // Parse features string.
- ParseSubtargetFeatures(FS, CPU);
+ // If requesting codegen for X86-64, make sure that 64-bit features
+ // are enabled.
+ if (Is64Bit) {
+ HasX86_64 = true;
- // Default to ELF unless otherwise specified.
- TargetType = isELF;
-
- X86SSELevel = NoMMXSSE;
- X863DNowLevel = NoThreeDNow;
-
- // 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)
- TargetType = isDarwin;
- else if (TT.find("win32") != std::string::npos)
- TargetType = isWindows;
- } else if (TT.empty()) {
-#if defined(__CYGWIN__) || defined(__MINGW32__)
- TargetType = isCygwin;
-#elif defined(__APPLE__)
- TargetType = isDarwin;
-#elif defined(_WIN32)
- TargetType = isWindows;
-#endif
+ // All 64-bit cpus have cmov support.
+ HasCMov = true;
}
+
+ DEBUG(dbgs() << "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!");
- if (TargetType == isDarwin) {
+ // Stack alignment is 16 bytes on Darwin (both 32 and 64 bit) and for all 64
+ // bit targets.
+ if (isTargetDarwin() || Is64Bit)
stackAlignment = 16;
- indirectExternAndWeakGlobals = true;
+
+ if (StackAlignment)
+ stackAlignment = StackAlignment;
+}
+
+/// IsCalleePop - Determines whether the callee is required to pop its
+/// own arguments. Callee pop is necessary to support tail calls.
+bool X86Subtarget::IsCalleePop(bool IsVarArg,
+ CallingConv::ID CallingConv) const {
+ if (IsVarArg)
+ return false;
+
+ switch (CallingConv) {
+ default:
+ return false;
+ case CallingConv::X86_StdCall:
+ return !is64Bit();
+ case CallingConv::X86_FastCall:
+ return !is64Bit();
+ case CallingConv::X86_ThisCall:
+ return !is64Bit();
+ case CallingConv::Fast:
+ return GuaranteedTailCallOpt;
+ case CallingConv::GHC:
+ return GuaranteedTailCallOpt;
}
}
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