//
// 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 <iostream>
+#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),
+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));
+
+/// True if accessing the GV requires an extra load. For Windows, dllimported
+/// symbols are indirect, loading the value at address GV rather then the
+/// value of GV itself. This means that the GlobalAddress must be in the base
+/// or index register of the address, not the GV offset field.
+bool X86Subtarget::GVRequiresExtraLoad(const GlobalValue* GV,
+ const TargetMachine& TM,
+ bool isDirectCall) const
+{
+ // FIXME: PIC
+ if (TM.getRelocationModel() != Reloc::Static &&
+ TM.getCodeModel() != CodeModel::Large) {
+ if (isTargetDarwin()) {
+ 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->mayBeOverridden());
+ } 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;
+}
+
+/// 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 inline bool GetCpuIDAndInfo(unsigned value, unsigned *rEAX, unsigned *rEBX,
- unsigned *rECX, unsigned *rEDX) {
+bool X86::GetCpuIDAndInfo(unsigned value, unsigned *rEAX, unsigned *rEBX,
+ unsigned *rECX, unsigned *rEDX) {
#if defined(__x86_64__)
- asm ("pushq\t%%rbx\n\t"
+ // gcc doesn't know cpuid would clobber ebx/rbx. Preseve it manually.
+ asm ("movq\t%%rbx, %%rsi\n\t"
"cpuid\n\t"
- "movl\t%%ebx, %%esi\n\t"
- "popq\t%%rbx"
+ "xchgq\t%%rbx, %%rsi\n\t"
: "=a" (*rEAX),
"=S" (*rEBX),
"=c" (*rECX),
return false;
#elif defined(i386) || defined(__i386__) || defined(__x86__) || defined(_M_IX86)
#if defined(__GNUC__)
- asm ("pushl\t%%ebx\n\t"
+ asm ("movl\t%%ebx, %%esi\n\t"
"cpuid\n\t"
- "movl\t%%ebx, %%esi\n\t"
- "popl\t%%ebx"
+ "xchgl\t%%ebx, %%esi\n\t"
: "=a" (*rEAX),
"=S" (*rEBX),
"=c" (*rECX),
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 {
+ unsigned u[3];
+ char c[12];
+ } text;
+
+ if (X86::GetCpuIDAndInfo(0, &EAX, text.u+0, text.u+2, text.u+1))
+ return;
+
+ 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;
+
+ 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;
+ }
+}
+
static const char *GetCurrentX86CPU() {
unsigned EAX = 0, EBX = 0, ECX = 0, EDX = 0;
- if (GetCpuIDAndInfo(0x1, &EAX, &EBX, &ECX, &EDX))
+ 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
- GetCpuIDAndInfo(0x80000001, &EAX, &EBX, &ECX, &EDX);
- bool Em64T = EDX & (1 << 29);
+ unsigned Family = 0;
+ unsigned Model = 0;
+ DetectFamilyModel(EAX, Family, Model);
+
+ X86::GetCpuIDAndInfo(0x80000001, &EAX, &EBX, &ECX, &EDX);
+ bool Em64T = (EDX >> 29) & 0x1;
union {
unsigned u[3];
char c[12];
} text;
- GetCpuIDAndInfo(0, &EAX, text.u+0, text.u+2, text.u+1);
+ X86::GetCpuIDAndInfo(0, &EAX, text.u+0, text.u+2, text.u+1);
if (memcmp(text.c, "GenuineIntel", 12) == 0) {
switch (Family) {
case 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";
}
}
case 15:
switch (Model) {
+ case 1: return "opteron";
case 5: return "athlon-fx"; // also opteron
default: return "athlon64";
}
-
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.
-
+
// 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 = GetCurrentX86CPU();
+ 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;
- if (Is64Bit && !HasX86_64) {
- std::cerr << "Warning: Generation of 64-bit code for a 32-bit processor "
- "requested.\n";
- 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.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)
+ // 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;
}