[SDAG] Let the DAG combiner take care of dead nodes rather than manually
[oota-llvm.git] / lib / Target / TargetLibraryInfo.cpp
index e0a4eccc97e9ded95e94af2ea1d5cb445fc12fc5..616ff9067300706adf65999f7b3854f21dc6c44b 100644 (file)
@@ -24,136 +24,390 @@ void TargetLibraryInfo::anchor() { }
 
 const char* TargetLibraryInfo::StandardNames[LibFunc::NumLibFuncs] =
   {
+    "_IO_getc",
+    "_IO_putc",
+    "_ZdaPv",
+    "_ZdaPvRKSt9nothrow_t",
+    "_ZdlPv",
+    "_ZdlPvRKSt9nothrow_t",
+    "_Znaj",
+    "_ZnajRKSt9nothrow_t",
+    "_Znam",
+    "_ZnamRKSt9nothrow_t",
+    "_Znwj",
+    "_ZnwjRKSt9nothrow_t",
+    "_Znwm",
+    "_ZnwmRKSt9nothrow_t",
+    "__cospi",
+    "__cospif",
+    "__cxa_atexit",
+    "__cxa_guard_abort",
+    "__cxa_guard_acquire",
+    "__cxa_guard_release",
+    "__isoc99_scanf",
+    "__isoc99_sscanf",
+    "__memcpy_chk",
+    "__sincospi_stret",
+    "__sincospif_stret",
+    "__sinpi",
+    "__sinpif",
+    "__sqrt_finite",
+    "__sqrtf_finite",
+    "__sqrtl_finite",
+    "__strdup",
+    "__strndup",
+    "__strtok_r",
+    "abs",
+    "access",
     "acos",
-    "acosl",
     "acosf",
+    "acosh",
+    "acoshf",
+    "acoshl",
+    "acosl",
     "asin",
-    "asinl",
     "asinf",
+    "asinh",
+    "asinhf",
+    "asinhl",
+    "asinl",
     "atan",
-    "atanl",
-    "atanf",
     "atan2",
-    "atan2l",
     "atan2f",
+    "atan2l",
+    "atanf",
+    "atanh",
+    "atanhf",
+    "atanhl",
+    "atanl",
+    "atof",
+    "atoi",
+    "atol",
+    "atoll",
+    "bcmp",
+    "bcopy",
+    "bzero",
+    "calloc",
+    "cbrt",
+    "cbrtf",
+    "cbrtl",
     "ceil",
-    "ceill",
     "ceilf",
+    "ceill",
+    "chmod",
+    "chown",
+    "clearerr",
+    "closedir",
     "copysign",
     "copysignf",
     "copysignl",
     "cos",
-    "cosl",
     "cosf",
     "cosh",
-    "coshl",
     "coshf",
+    "coshl",
+    "cosl",
+    "ctermid",
     "exp",
-    "expl",
-    "expf",
+    "exp10",
+    "exp10f",
+    "exp10l",
     "exp2",
-    "exp2l",
     "exp2f",
+    "exp2l",
+    "expf",
+    "expl",
     "expm1",
-    "expm1l",
     "expm1f",
+    "expm1l",
     "fabs",
-    "fabsl",
     "fabsf",
+    "fabsl",
+    "fclose",
+    "fdopen",
+    "feof",
+    "ferror",
+    "fflush",
+    "ffs",
+    "ffsl",
+    "ffsll",
+    "fgetc",
+    "fgetpos",
+    "fgets",
+    "fileno",
+    "fiprintf",
+    "flockfile",
     "floor",
-    "floorl",
     "floorf",
-    "fiprintf",
+    "floorl",
+    "fmax",
+    "fmaxf",
+    "fmaxl",
+    "fmin",
+    "fminf",
+    "fminl",
     "fmod",
-    "fmodl",
     "fmodf",
+    "fmodl",
+    "fopen",
+    "fopen64",
+    "fprintf",
     "fputc",
     "fputs",
+    "fread",
+    "free",
+    "frexp",
+    "frexpf",
+    "frexpl",
+    "fscanf",
+    "fseek",
+    "fseeko",
+    "fseeko64",
+    "fsetpos",
+    "fstat",
+    "fstat64",
+    "fstatvfs",
+    "fstatvfs64",
+    "ftell",
+    "ftello",
+    "ftello64",
+    "ftrylockfile",
+    "funlockfile",
     "fwrite",
+    "getc",
+    "getc_unlocked",
+    "getchar",
+    "getenv",
+    "getitimer",
+    "getlogin_r",
+    "getpwnam",
+    "gets",
+    "gettimeofday",
+    "htonl",
+    "htons",
     "iprintf",
+    "isascii",
+    "isdigit",
+    "labs",
+    "lchown",
+    "ldexp",
+    "ldexpf",
+    "ldexpl",
+    "llabs",
     "log",
-    "logl",
-    "logf",
-    "log2",
-    "log2l",
-    "log2f",
     "log10",
-    "log10l",
     "log10f",
+    "log10l",
     "log1p",
-    "log1pl",
     "log1pf",
+    "log1pl",
+    "log2",
+    "log2f",
+    "log2l",
+    "logb",
+    "logbf",
+    "logbl",
+    "logf",
+    "logl",
+    "lstat",
+    "lstat64",
+    "malloc",
+    "memalign",
+    "memccpy",
     "memchr",
     "memcmp",
     "memcpy",
     "memmove",
+    "memrchr",
     "memset",
     "memset_pattern16",
+    "mkdir",
+    "mktime",
+    "modf",
+    "modff",
+    "modfl",
     "nearbyint",
     "nearbyintf",
     "nearbyintl",
+    "ntohl",
+    "ntohs",
+    "open",
+    "open64",
+    "opendir",
+    "pclose",
+    "perror",
+    "popen",
+    "posix_memalign",
     "pow",
     "powf",
     "powl",
+    "pread",
+    "printf",
+    "putc",
     "putchar",
     "puts",
+    "pwrite",
+    "qsort",
+    "read",
+    "readlink",
+    "realloc",
+    "reallocf",
+    "realpath",
+    "remove",
+    "rename",
+    "rewind",
     "rint",
     "rintf",
     "rintl",
+    "rmdir",
     "round",
     "roundf",
     "roundl",
+    "scanf",
+    "setbuf",
+    "setitimer",
+    "setvbuf",
     "sin",
-    "sinl",
     "sinf",
     "sinh",
-    "sinhl",
     "sinhf",
+    "sinhl",
+    "sinl",
     "siprintf",
+    "snprintf",
+    "sprintf",
     "sqrt",
-    "sqrtl",
     "sqrtf",
+    "sqrtl",
+    "sscanf",
+    "stat",
+    "stat64",
+    "statvfs",
+    "statvfs64",
+    "stpcpy",
+    "stpncpy",
+    "strcasecmp",
     "strcat",
     "strchr",
+    "strcmp",
+    "strcoll",
     "strcpy",
+    "strcspn",
+    "strdup",
     "strlen",
+    "strncasecmp",
     "strncat",
     "strncmp",
     "strncpy",
+    "strndup",
     "strnlen",
+    "strpbrk",
+    "strrchr",
+    "strspn",
+    "strstr",
+    "strtod",
+    "strtof",
+    "strtok",
+    "strtok_r",
+    "strtol",
+    "strtold",
+    "strtoll",
+    "strtoul",
+    "strtoull",
+    "strxfrm",
+    "system",
     "tan",
-    "tanl",
     "tanf",
     "tanh",
-    "tanhl",
     "tanhf",
+    "tanhl",
+    "tanl",
+    "times",
+    "tmpfile",
+    "tmpfile64",
+    "toascii",
     "trunc",
     "truncf",
     "truncl",
-    "__cxa_atexit",
-    "__cxa_guard_abort",
-    "__cxa_guard_acquire",
-    "__cxa_guard_release"
+    "uname",
+    "ungetc",
+    "unlink",
+    "unsetenv",
+    "utime",
+    "utimes",
+    "valloc",
+    "vfprintf",
+    "vfscanf",
+    "vprintf",
+    "vscanf",
+    "vsnprintf",
+    "vsprintf",
+    "vsscanf",
+    "write"
   };
 
+static bool hasSinCosPiStret(const Triple &T) {
+  // Only Darwin variants have _stret versions of combined trig functions.
+  if (!T.isMacOSX() && T.getOS() != Triple::IOS)
+    return false;
+
+  // The ABI is rather complicated on x86, so don't do anything special there.
+  if (T.getArch() == Triple::x86)
+    return false;
+
+  if (T.isMacOSX() && T.isMacOSXVersionLT(10, 9))
+    return false;
+
+  if (T.getOS() == Triple::IOS && T.isOSVersionLT(7, 0))
+    return false;
+
+  return true;
+}
+
 /// initialize - Initialize the set of available library functions based on the
 /// specified target triple.  This should be carefully written so that a missing
 /// target triple gets a sane set of defaults.
-static void initialize(TargetLibraryInfo &TLI, const Triple &T) {
+static void initialize(TargetLibraryInfo &TLI, const Triple &T,
+                       const char **StandardNames) {
   initializeTargetLibraryInfoPass(*PassRegistry::getPassRegistry());
 
-  
-  // memset_pattern16 is only available on iOS 3.0 and Mac OS/X 10.5 and later.
+#ifndef NDEBUG
+  // Verify that the StandardNames array is in alphabetical order.
+  for (unsigned F = 1; F < LibFunc::NumLibFuncs; ++F) {
+    if (strcmp(StandardNames[F-1], StandardNames[F]) >= 0)
+      llvm_unreachable("TargetLibraryInfo function names must be sorted");
+  }
+#endif // !NDEBUG
+
+  // There are no library implementations of mempcy and memset for r600 and
+  // these can be difficult to lower in the backend.
+  if (T.getArch() == Triple::r600) {
+    TLI.setUnavailable(LibFunc::memcpy);
+    TLI.setUnavailable(LibFunc::memset);
+    TLI.setUnavailable(LibFunc::memset_pattern16);
+    return;
+  }
+
+  // memset_pattern16 is only available on iOS 3.0 and Mac OS X 10.5 and later.
   if (T.isMacOSX()) {
     if (T.isMacOSXVersionLT(10, 5))
       TLI.setUnavailable(LibFunc::memset_pattern16);
-  } else if (T.getOS() == Triple::IOS) {
+  } else if (T.isiOS()) {
     if (T.isOSVersionLT(3, 0))
       TLI.setUnavailable(LibFunc::memset_pattern16);
   } else {
     TLI.setUnavailable(LibFunc::memset_pattern16);
   }
 
+  if (!hasSinCosPiStret(T)) {
+    TLI.setUnavailable(LibFunc::sinpi);
+    TLI.setUnavailable(LibFunc::sinpif);
+    TLI.setUnavailable(LibFunc::cospi);
+    TLI.setUnavailable(LibFunc::cospif);
+    TLI.setUnavailable(LibFunc::sincospi_stret);
+    TLI.setUnavailable(LibFunc::sincospif_stret);
+  }
+
   if (T.isMacOSX() && T.getArch() == Triple::x86 &&
       !T.isMacOSXVersionLT(10, 7)) {
     // x86-32 OSX has a scheme where fwrite and fputs (and some other functions
@@ -172,7 +426,7 @@ static void initialize(TargetLibraryInfo &TLI, const Triple &T) {
     TLI.setUnavailable(LibFunc::fiprintf);
   }
 
-  if (T.getOS() == Triple::Win32) {
+  if (T.isOSWindows() && !T.isOSCygMing()) {
     // Win32 does not support long double
     TLI.setUnavailable(LibFunc::acosl);
     TLI.setUnavailable(LibFunc::asinl);
@@ -186,8 +440,14 @@ static void initialize(TargetLibraryInfo &TLI, const Triple &T) {
     TLI.setUnavailable(LibFunc::fabsf); // Win32 and Win64 both lack fabsf
     TLI.setUnavailable(LibFunc::fabsl);
     TLI.setUnavailable(LibFunc::floorl);
+    TLI.setUnavailable(LibFunc::fmaxl);
+    TLI.setUnavailable(LibFunc::fminl);
     TLI.setUnavailable(LibFunc::fmodl);
+    TLI.setUnavailable(LibFunc::frexpl);
+    TLI.setUnavailable(LibFunc::ldexpf);
+    TLI.setUnavailable(LibFunc::ldexpl);
     TLI.setUnavailable(LibFunc::logl);
+    TLI.setUnavailable(LibFunc::modfl);
     TLI.setUnavailable(LibFunc::powl);
     TLI.setUnavailable(LibFunc::sinl);
     TLI.setUnavailable(LibFunc::sinhl);
@@ -196,6 +456,18 @@ static void initialize(TargetLibraryInfo &TLI, const Triple &T) {
     TLI.setUnavailable(LibFunc::tanhl);
 
     // Win32 only has C89 math
+    TLI.setUnavailable(LibFunc::acosh);
+    TLI.setUnavailable(LibFunc::acoshf);
+    TLI.setUnavailable(LibFunc::acoshl);
+    TLI.setUnavailable(LibFunc::asinh);
+    TLI.setUnavailable(LibFunc::asinhf);
+    TLI.setUnavailable(LibFunc::asinhl);
+    TLI.setUnavailable(LibFunc::atanh);
+    TLI.setUnavailable(LibFunc::atanhf);
+    TLI.setUnavailable(LibFunc::atanhl);
+    TLI.setUnavailable(LibFunc::cbrt);
+    TLI.setUnavailable(LibFunc::cbrtf);
+    TLI.setUnavailable(LibFunc::cbrtl);
     TLI.setUnavailable(LibFunc::exp2);
     TLI.setUnavailable(LibFunc::exp2f);
     TLI.setUnavailable(LibFunc::exp2l);
@@ -208,6 +480,9 @@ static void initialize(TargetLibraryInfo &TLI, const Triple &T) {
     TLI.setUnavailable(LibFunc::log1p);
     TLI.setUnavailable(LibFunc::log1pf);
     TLI.setUnavailable(LibFunc::log1pl);
+    TLI.setUnavailable(LibFunc::logb);
+    TLI.setUnavailable(LibFunc::logbf);
+    TLI.setUnavailable(LibFunc::logbl);
     TLI.setUnavailable(LibFunc::nearbyint);
     TLI.setUnavailable(LibFunc::nearbyintf);
     TLI.setUnavailable(LibFunc::nearbyintl);
@@ -236,6 +511,8 @@ static void initialize(TargetLibraryInfo &TLI, const Triple &T) {
       TLI.setUnavailable(LibFunc::coshf);
       TLI.setUnavailable(LibFunc::expf);
       TLI.setUnavailable(LibFunc::floorf);
+      TLI.setUnavailable(LibFunc::fminf);
+      TLI.setUnavailable(LibFunc::fmaxf);
       TLI.setUnavailable(LibFunc::fmodf);
       TLI.setUnavailable(LibFunc::logf);
       TLI.setUnavailable(LibFunc::powf);
@@ -245,6 +522,155 @@ static void initialize(TargetLibraryInfo &TLI, const Triple &T) {
       TLI.setUnavailable(LibFunc::tanf);
       TLI.setUnavailable(LibFunc::tanhf);
     }
+
+    // Win32 does *not* provide provide these functions, but they are
+    // generally available on POSIX-compliant systems:
+    TLI.setUnavailable(LibFunc::access);
+    TLI.setUnavailable(LibFunc::bcmp);
+    TLI.setUnavailable(LibFunc::bcopy);
+    TLI.setUnavailable(LibFunc::bzero);
+    TLI.setUnavailable(LibFunc::chmod);
+    TLI.setUnavailable(LibFunc::chown);
+    TLI.setUnavailable(LibFunc::closedir);
+    TLI.setUnavailable(LibFunc::ctermid);
+    TLI.setUnavailable(LibFunc::fdopen);
+    TLI.setUnavailable(LibFunc::ffs);
+    TLI.setUnavailable(LibFunc::fileno);
+    TLI.setUnavailable(LibFunc::flockfile);
+    TLI.setUnavailable(LibFunc::fseeko);
+    TLI.setUnavailable(LibFunc::fstat);
+    TLI.setUnavailable(LibFunc::fstatvfs);
+    TLI.setUnavailable(LibFunc::ftello);
+    TLI.setUnavailable(LibFunc::ftrylockfile);
+    TLI.setUnavailable(LibFunc::funlockfile);
+    TLI.setUnavailable(LibFunc::getc_unlocked);
+    TLI.setUnavailable(LibFunc::getitimer);
+    TLI.setUnavailable(LibFunc::getlogin_r);
+    TLI.setUnavailable(LibFunc::getpwnam);
+    TLI.setUnavailable(LibFunc::gettimeofday);
+    TLI.setUnavailable(LibFunc::htonl);
+    TLI.setUnavailable(LibFunc::htons);
+    TLI.setUnavailable(LibFunc::lchown);
+    TLI.setUnavailable(LibFunc::lstat);
+    TLI.setUnavailable(LibFunc::memccpy);
+    TLI.setUnavailable(LibFunc::mkdir);
+    TLI.setUnavailable(LibFunc::ntohl);
+    TLI.setUnavailable(LibFunc::ntohs);
+    TLI.setUnavailable(LibFunc::open);
+    TLI.setUnavailable(LibFunc::opendir);
+    TLI.setUnavailable(LibFunc::pclose);
+    TLI.setUnavailable(LibFunc::popen);
+    TLI.setUnavailable(LibFunc::pread);
+    TLI.setUnavailable(LibFunc::pwrite);
+    TLI.setUnavailable(LibFunc::read);
+    TLI.setUnavailable(LibFunc::readlink);
+    TLI.setUnavailable(LibFunc::realpath);
+    TLI.setUnavailable(LibFunc::rmdir);
+    TLI.setUnavailable(LibFunc::setitimer);
+    TLI.setUnavailable(LibFunc::stat);
+    TLI.setUnavailable(LibFunc::statvfs);
+    TLI.setUnavailable(LibFunc::stpcpy);
+    TLI.setUnavailable(LibFunc::stpncpy);
+    TLI.setUnavailable(LibFunc::strcasecmp);
+    TLI.setUnavailable(LibFunc::strncasecmp);
+    TLI.setUnavailable(LibFunc::times);
+    TLI.setUnavailable(LibFunc::uname);
+    TLI.setUnavailable(LibFunc::unlink);
+    TLI.setUnavailable(LibFunc::unsetenv);
+    TLI.setUnavailable(LibFunc::utime);
+    TLI.setUnavailable(LibFunc::utimes);
+    TLI.setUnavailable(LibFunc::write);
+
+    // Win32 does *not* provide provide these functions, but they are
+    // specified by C99:
+    TLI.setUnavailable(LibFunc::atoll);
+    TLI.setUnavailable(LibFunc::frexpf);
+    TLI.setUnavailable(LibFunc::llabs);
+  }
+
+  switch (T.getOS()) {
+  case Triple::MacOSX:
+    // exp10 and exp10f are not available on OS X until 10.9 and iOS until 7.0
+    // and their names are __exp10 and __exp10f. exp10l is not available on
+    // OS X or iOS.
+    TLI.setUnavailable(LibFunc::exp10l);
+    if (T.isMacOSXVersionLT(10, 9)) {
+      TLI.setUnavailable(LibFunc::exp10);
+      TLI.setUnavailable(LibFunc::exp10f);
+    } else {
+      TLI.setAvailableWithName(LibFunc::exp10, "__exp10");
+      TLI.setAvailableWithName(LibFunc::exp10f, "__exp10f");
+    }
+    break;
+  case Triple::IOS:
+    TLI.setUnavailable(LibFunc::exp10l);
+    if (T.isOSVersionLT(7, 0)) {
+      TLI.setUnavailable(LibFunc::exp10);
+      TLI.setUnavailable(LibFunc::exp10f);
+    } else {
+      TLI.setAvailableWithName(LibFunc::exp10, "__exp10");
+      TLI.setAvailableWithName(LibFunc::exp10f, "__exp10f");
+    }
+    break;
+  case Triple::Linux:
+    // exp10, exp10f, exp10l is available on Linux (GLIBC) but are extremely
+    // buggy prior to glibc version 2.18. Until this version is widely deployed
+    // or we have a reasonable detection strategy, we cannot use exp10 reliably
+    // on Linux.
+    //
+    // Fall through to disable all of them.
+  default:
+    TLI.setUnavailable(LibFunc::exp10);
+    TLI.setUnavailable(LibFunc::exp10f);
+    TLI.setUnavailable(LibFunc::exp10l);
+  }
+
+  // ffsl is available on at least Darwin, Mac OS X, iOS, FreeBSD, and
+  // Linux (GLIBC):
+  // http://developer.apple.com/library/mac/#documentation/Darwin/Reference/ManPages/man3/ffsl.3.html
+  // http://svn.freebsd.org/base/user/eri/pf45/head/lib/libc/string/ffsl.c
+  // http://www.gnu.org/software/gnulib/manual/html_node/ffsl.html
+  switch (T.getOS()) {
+  case Triple::Darwin:
+  case Triple::MacOSX:
+  case Triple::IOS:
+  case Triple::FreeBSD:
+  case Triple::Linux:
+    break;
+  default:
+    TLI.setUnavailable(LibFunc::ffsl);
+  }
+
+  // ffsll is available on at least FreeBSD and Linux (GLIBC):
+  // http://svn.freebsd.org/base/user/eri/pf45/head/lib/libc/string/ffsll.c
+  // http://www.gnu.org/software/gnulib/manual/html_node/ffsll.html
+  switch (T.getOS()) {
+  case Triple::FreeBSD:
+  case Triple::Linux:
+    break;
+  default:
+    TLI.setUnavailable(LibFunc::ffsll);
+  }
+
+  // The following functions are available on at least Linux:
+  if (!T.isOSLinux()) {
+    TLI.setUnavailable(LibFunc::dunder_strdup);
+    TLI.setUnavailable(LibFunc::dunder_strtok_r);
+    TLI.setUnavailable(LibFunc::dunder_isoc99_scanf);
+    TLI.setUnavailable(LibFunc::dunder_isoc99_sscanf);
+    TLI.setUnavailable(LibFunc::under_IO_getc);
+    TLI.setUnavailable(LibFunc::under_IO_putc);
+    TLI.setUnavailable(LibFunc::memalign);
+    TLI.setUnavailable(LibFunc::fopen64);
+    TLI.setUnavailable(LibFunc::fseeko64);
+    TLI.setUnavailable(LibFunc::fstat64);
+    TLI.setUnavailable(LibFunc::fstatvfs64);
+    TLI.setUnavailable(LibFunc::ftello64);
+    TLI.setUnavailable(LibFunc::lstat64);
+    TLI.setUnavailable(LibFunc::open64);
+    TLI.setUnavailable(LibFunc::stat64);
+    TLI.setUnavailable(LibFunc::statvfs64);
+    TLI.setUnavailable(LibFunc::tmpfile64);
   }
 }
 
@@ -253,14 +679,14 @@ TargetLibraryInfo::TargetLibraryInfo() : ImmutablePass(ID) {
   // Default to everything being available.
   memset(AvailableArray, -1, sizeof(AvailableArray));
 
-  initialize(*this, Triple());
+  initialize(*this, Triple(), StandardNames);
 }
 
 TargetLibraryInfo::TargetLibraryInfo(const Triple &T) : ImmutablePass(ID) {
   // Default to everything being available.
   memset(AvailableArray, -1, sizeof(AvailableArray));
   
-  initialize(*this, T);
+  initialize(*this, T, StandardNames);
 }
 
 TargetLibraryInfo::TargetLibraryInfo(const TargetLibraryInfo &TLI)
@@ -269,6 +695,46 @@ TargetLibraryInfo::TargetLibraryInfo(const TargetLibraryInfo &TLI)
   CustomNames = TLI.CustomNames;
 }
 
+namespace {
+struct StringComparator {
+  /// Compare two strings and return true if LHS is lexicographically less than
+  /// RHS. Requires that RHS doesn't contain any zero bytes.
+  bool operator()(const char *LHS, StringRef RHS) const {
+    // Compare prefixes with strncmp. If prefixes match we know that LHS is
+    // greater or equal to RHS as RHS can't contain any '\0'.
+    return std::strncmp(LHS, RHS.data(), RHS.size()) < 0;
+  }
+
+  // Provided for compatibility with MSVC's debug mode.
+  bool operator()(StringRef LHS, const char *RHS) const { return LHS < RHS; }
+  bool operator()(StringRef LHS, StringRef RHS) const { return LHS < RHS; }
+  bool operator()(const char *LHS, const char *RHS) const {
+    return std::strcmp(LHS, RHS) < 0;
+  }
+};
+}
+
+bool TargetLibraryInfo::getLibFunc(StringRef funcName,
+                                   LibFunc::Func &F) const {
+  const char **Start = &StandardNames[0];
+  const char **End = &StandardNames[LibFunc::NumLibFuncs];
+
+  // Filter out empty names and names containing null bytes, those can't be in
+  // our table.
+  if (funcName.empty() || funcName.find('\0') != StringRef::npos)
+    return false;
+
+  // Check for \01 prefix that is used to mangle __asm declarations and
+  // strip it if present.
+  if (funcName.front() == '\01')
+    funcName = funcName.substr(1);
+  const char **I = std::lower_bound(Start, End, funcName, StringComparator());
+  if (I != End && *I == funcName) {
+    F = (LibFunc::Func)(I - Start);
+    return true;
+  }
+  return false;
+}
 
 /// disableAllFunctions - This disables all builtins, which is used for options
 /// like -fno-builtin.