bool llvm::inferLibFuncAttributes()

in llvm/lib/Transforms/Utils/BuildLibCalls.cpp [235:1180]


bool llvm::inferLibFuncAttributes(Function &F, const TargetLibraryInfo &TLI) {
  LibFunc TheLibFunc;
  if (!(TLI.getLibFunc(F, TheLibFunc) && TLI.has(TheLibFunc)))
    return false;

  bool Changed = false;

  if(!isLibFreeFunction(&F, TheLibFunc) && !isReallocLikeFn(&F,  &TLI))
    Changed |= setDoesNotFreeMemory(F);

  if (F.getParent() != nullptr && F.getParent()->getRtLibUseGOT())
    Changed |= setNonLazyBind(F);

  switch (TheLibFunc) {
  case LibFunc_strlen:
  case LibFunc_strnlen:
  case LibFunc_wcslen:
    Changed |= setOnlyReadsMemory(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setOnlyAccessesArgMemory(F);
    Changed |= setWillReturn(F);
    Changed |= setDoesNotCapture(F, 0);
    return Changed;
  case LibFunc_strchr:
  case LibFunc_strrchr:
    Changed |= setOnlyAccessesArgMemory(F);
    Changed |= setOnlyReadsMemory(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setWillReturn(F);
    return Changed;
  case LibFunc_strtol:
  case LibFunc_strtod:
  case LibFunc_strtof:
  case LibFunc_strtoul:
  case LibFunc_strtoll:
  case LibFunc_strtold:
  case LibFunc_strtoull:
    Changed |= setDoesNotThrow(F);
    Changed |= setWillReturn(F);
    Changed |= setDoesNotCapture(F, 1);
    Changed |= setOnlyReadsMemory(F, 0);
    return Changed;
  case LibFunc_strcat:
  case LibFunc_strncat:
    Changed |= setOnlyAccessesArgMemory(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setWillReturn(F);
    Changed |= setReturnedArg(F, 0);
    Changed |= setDoesNotCapture(F, 1);
    Changed |= setOnlyReadsMemory(F, 1);
    Changed |= setDoesNotAlias(F, 0);
    Changed |= setDoesNotAlias(F, 1);
    return Changed;
  case LibFunc_strcpy:
  case LibFunc_strncpy:
    Changed |= setReturnedArg(F, 0);
    LLVM_FALLTHROUGH;
  case LibFunc_stpcpy:
  case LibFunc_stpncpy:
    Changed |= setOnlyAccessesArgMemory(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setWillReturn(F);
    Changed |= setDoesNotCapture(F, 1);
    Changed |= setOnlyWritesMemory(F, 0);
    Changed |= setOnlyReadsMemory(F, 1);
    Changed |= setDoesNotAlias(F, 0);
    Changed |= setDoesNotAlias(F, 1);
    return Changed;
  case LibFunc_strxfrm:
    Changed |= setDoesNotThrow(F);
    Changed |= setWillReturn(F);
    Changed |= setDoesNotCapture(F, 0);
    Changed |= setDoesNotCapture(F, 1);
    Changed |= setOnlyReadsMemory(F, 1);
    return Changed;
  case LibFunc_strcmp:      // 0,1
  case LibFunc_strspn:      // 0,1
  case LibFunc_strncmp:     // 0,1
  case LibFunc_strcspn:     // 0,1
    Changed |= setDoesNotThrow(F);
    Changed |= setOnlyAccessesArgMemory(F);
    Changed |= setWillReturn(F);
    Changed |= setOnlyReadsMemory(F);
    Changed |= setDoesNotCapture(F, 0);
    Changed |= setDoesNotCapture(F, 1);
    return Changed;
  case LibFunc_strcoll:
  case LibFunc_strcasecmp:  // 0,1
  case LibFunc_strncasecmp: //
    // Those functions may depend on the locale, which may be accessed through
    // global memory.
    Changed |= setOnlyReadsMemory(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setWillReturn(F);
    Changed |= setDoesNotCapture(F, 0);
    Changed |= setDoesNotCapture(F, 1);
    return Changed;
  case LibFunc_strstr:
  case LibFunc_strpbrk:
    Changed |= setOnlyAccessesArgMemory(F);
    Changed |= setOnlyReadsMemory(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setWillReturn(F);
    Changed |= setDoesNotCapture(F, 1);
    return Changed;
  case LibFunc_strtok:
  case LibFunc_strtok_r:
    Changed |= setDoesNotThrow(F);
    Changed |= setWillReturn(F);
    Changed |= setDoesNotCapture(F, 1);
    Changed |= setOnlyReadsMemory(F, 1);
    return Changed;
  case LibFunc_scanf:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setDoesNotCapture(F, 0);
    Changed |= setOnlyReadsMemory(F, 0);
    return Changed;
  case LibFunc_setbuf:
  case LibFunc_setvbuf:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setDoesNotCapture(F, 0);
    return Changed;
  case LibFunc_strndup:
    Changed |= setArgNoUndef(F, 1);
    LLVM_FALLTHROUGH;
  case LibFunc_strdup:
    Changed |= setOnlyAccessesInaccessibleMemOrArgMem(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setRetDoesNotAlias(F);
    Changed |= setWillReturn(F);
    Changed |= setDoesNotCapture(F, 0);
    Changed |= setOnlyReadsMemory(F, 0);
    return Changed;
  case LibFunc_stat:
  case LibFunc_statvfs:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setDoesNotCapture(F, 0);
    Changed |= setDoesNotCapture(F, 1);
    Changed |= setOnlyReadsMemory(F, 0);
    return Changed;
  case LibFunc_sscanf:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setDoesNotCapture(F, 0);
    Changed |= setDoesNotCapture(F, 1);
    Changed |= setOnlyReadsMemory(F, 0);
    Changed |= setOnlyReadsMemory(F, 1);
    return Changed;
  case LibFunc_sprintf:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setDoesNotCapture(F, 0);
    Changed |= setDoesNotAlias(F, 0);
    Changed |= setOnlyWritesMemory(F, 0);
    Changed |= setDoesNotCapture(F, 1);
    Changed |= setOnlyReadsMemory(F, 1);
    return Changed;
  case LibFunc_snprintf:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setDoesNotCapture(F, 0);
    Changed |= setDoesNotAlias(F, 0);
    Changed |= setOnlyWritesMemory(F, 0);
    Changed |= setDoesNotCapture(F, 2);
    Changed |= setOnlyReadsMemory(F, 2);
    return Changed;
  case LibFunc_setitimer:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setWillReturn(F);
    Changed |= setDoesNotCapture(F, 1);
    Changed |= setDoesNotCapture(F, 2);
    Changed |= setOnlyReadsMemory(F, 1);
    return Changed;
  case LibFunc_system:
    // May throw; "system" is a valid pthread cancellation point.
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotCapture(F, 0);
    Changed |= setOnlyReadsMemory(F, 0);
    return Changed;
  case LibFunc_aligned_alloc:
  case LibFunc_valloc:
  case LibFunc_malloc:
  case LibFunc_vec_malloc:
    Changed |= setOnlyAccessesInaccessibleMemory(F);
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setRetDoesNotAlias(F);
    Changed |= setWillReturn(F);
    return Changed;
  case LibFunc_memcmp:
    Changed |= setOnlyAccessesArgMemory(F);
    Changed |= setOnlyReadsMemory(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setWillReturn(F);
    Changed |= setDoesNotCapture(F, 0);
    Changed |= setDoesNotCapture(F, 1);
    return Changed;
  case LibFunc_memchr:
  case LibFunc_memrchr:
    Changed |= setDoesNotThrow(F);
    Changed |= setOnlyAccessesArgMemory(F);
    Changed |= setOnlyReadsMemory(F);
    Changed |= setWillReturn(F);
    return Changed;
  case LibFunc_modf:
  case LibFunc_modff:
  case LibFunc_modfl:
    Changed |= setDoesNotThrow(F);
    Changed |= setWillReturn(F);
    Changed |= setDoesNotCapture(F, 1);
    return Changed;
  case LibFunc_memcpy:
    Changed |= setDoesNotThrow(F);
    Changed |= setOnlyAccessesArgMemory(F);
    Changed |= setWillReturn(F);
    Changed |= setDoesNotAlias(F, 0);
    Changed |= setReturnedArg(F, 0);
    Changed |= setOnlyWritesMemory(F, 0);
    Changed |= setDoesNotAlias(F, 1);
    Changed |= setDoesNotCapture(F, 1);
    Changed |= setOnlyReadsMemory(F, 1);
    return Changed;
  case LibFunc_memmove:
    Changed |= setDoesNotThrow(F);
    Changed |= setOnlyAccessesArgMemory(F);
    Changed |= setWillReturn(F);
    Changed |= setReturnedArg(F, 0);
    Changed |= setOnlyWritesMemory(F, 0);
    Changed |= setDoesNotCapture(F, 1);
    Changed |= setOnlyReadsMemory(F, 1);
    return Changed;
  case LibFunc_mempcpy:
  case LibFunc_memccpy:
    Changed |= setWillReturn(F);
    LLVM_FALLTHROUGH;
  case LibFunc_memcpy_chk:
    Changed |= setDoesNotThrow(F);
    Changed |= setOnlyAccessesArgMemory(F);
    Changed |= setDoesNotAlias(F, 0);
    Changed |= setOnlyWritesMemory(F, 0);
    Changed |= setDoesNotAlias(F, 1);
    Changed |= setDoesNotCapture(F, 1);
    Changed |= setOnlyReadsMemory(F, 1);
    return Changed;
  case LibFunc_memalign:
    Changed |= setOnlyAccessesInaccessibleMemory(F);
    Changed |= setRetNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setRetDoesNotAlias(F);
    Changed |= setWillReturn(F);
    return Changed;
  case LibFunc_mkdir:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setDoesNotCapture(F, 0);
    Changed |= setOnlyReadsMemory(F, 0);
    return Changed;
  case LibFunc_mktime:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setWillReturn(F);
    Changed |= setDoesNotCapture(F, 0);
    return Changed;
  case LibFunc_realloc:
  case LibFunc_vec_realloc:
  case LibFunc_reallocf:
    Changed |= setOnlyAccessesInaccessibleMemOrArgMem(F);
    Changed |= setRetNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setRetDoesNotAlias(F);
    Changed |= setWillReturn(F);
    Changed |= setDoesNotCapture(F, 0);
    Changed |= setArgNoUndef(F, 1);
    return Changed;
  case LibFunc_read:
    // May throw; "read" is a valid pthread cancellation point.
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotCapture(F, 1);
    return Changed;
  case LibFunc_rewind:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setDoesNotCapture(F, 0);
    return Changed;
  case LibFunc_rmdir:
  case LibFunc_remove:
  case LibFunc_realpath:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setDoesNotCapture(F, 0);
    Changed |= setOnlyReadsMemory(F, 0);
    return Changed;
  case LibFunc_rename:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setDoesNotCapture(F, 0);
    Changed |= setDoesNotCapture(F, 1);
    Changed |= setOnlyReadsMemory(F, 0);
    Changed |= setOnlyReadsMemory(F, 1);
    return Changed;
  case LibFunc_readlink:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setDoesNotCapture(F, 0);
    Changed |= setDoesNotCapture(F, 1);
    Changed |= setOnlyReadsMemory(F, 0);
    return Changed;
  case LibFunc_write:
    // May throw; "write" is a valid pthread cancellation point.
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotCapture(F, 1);
    Changed |= setOnlyReadsMemory(F, 1);
    return Changed;
  case LibFunc_bcopy:
    Changed |= setDoesNotThrow(F);
    Changed |= setOnlyAccessesArgMemory(F);
    Changed |= setWillReturn(F);
    Changed |= setDoesNotCapture(F, 0);
    Changed |= setOnlyReadsMemory(F, 0);
    Changed |= setOnlyWritesMemory(F, 1);
    Changed |= setDoesNotCapture(F, 1);
    return Changed;
  case LibFunc_bcmp:
    Changed |= setDoesNotThrow(F);
    Changed |= setOnlyAccessesArgMemory(F);
    Changed |= setOnlyReadsMemory(F);
    Changed |= setWillReturn(F);
    Changed |= setDoesNotCapture(F, 0);
    Changed |= setDoesNotCapture(F, 1);
    return Changed;
  case LibFunc_bzero:
    Changed |= setDoesNotThrow(F);
    Changed |= setOnlyAccessesArgMemory(F);
    Changed |= setWillReturn(F);
    Changed |= setDoesNotCapture(F, 0);
    Changed |= setOnlyWritesMemory(F, 0);
    return Changed;
  case LibFunc_calloc:
  case LibFunc_vec_calloc:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setRetDoesNotAlias(F);
    Changed |= setWillReturn(F);
    return Changed;
  case LibFunc_chmod:
  case LibFunc_chown:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setDoesNotCapture(F, 0);
    Changed |= setOnlyReadsMemory(F, 0);
    return Changed;
  case LibFunc_ctermid:
  case LibFunc_clearerr:
  case LibFunc_closedir:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setDoesNotCapture(F, 0);
    return Changed;
  case LibFunc_atoi:
  case LibFunc_atol:
  case LibFunc_atof:
  case LibFunc_atoll:
    Changed |= setDoesNotThrow(F);
    Changed |= setOnlyReadsMemory(F);
    Changed |= setWillReturn(F);
    Changed |= setDoesNotCapture(F, 0);
    return Changed;
  case LibFunc_access:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setDoesNotCapture(F, 0);
    Changed |= setOnlyReadsMemory(F, 0);
    return Changed;
  case LibFunc_fopen:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setRetDoesNotAlias(F);
    Changed |= setDoesNotCapture(F, 0);
    Changed |= setDoesNotCapture(F, 1);
    Changed |= setOnlyReadsMemory(F, 0);
    Changed |= setOnlyReadsMemory(F, 1);
    return Changed;
  case LibFunc_fdopen:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setRetDoesNotAlias(F);
    Changed |= setDoesNotCapture(F, 1);
    Changed |= setOnlyReadsMemory(F, 1);
    return Changed;
  case LibFunc_feof:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setDoesNotCapture(F, 0);
    return Changed;
  case LibFunc_free:
  case LibFunc_vec_free:
    Changed |= setOnlyAccessesInaccessibleMemOrArgMem(F);
    Changed |= setArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setWillReturn(F);
    Changed |= setDoesNotCapture(F, 0);
    return Changed;
  case LibFunc_fseek:
  case LibFunc_ftell:
  case LibFunc_fgetc:
  case LibFunc_fgetc_unlocked:
  case LibFunc_fseeko:
  case LibFunc_ftello:
  case LibFunc_fileno:
  case LibFunc_fflush:
  case LibFunc_fclose:
  case LibFunc_fsetpos:
  case LibFunc_flockfile:
  case LibFunc_funlockfile:
  case LibFunc_ftrylockfile:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setDoesNotCapture(F, 0);
    return Changed;
  case LibFunc_ferror:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setDoesNotCapture(F, 0);
    Changed |= setOnlyReadsMemory(F);
    return Changed;
  case LibFunc_fputc:
  case LibFunc_fputc_unlocked:
  case LibFunc_fstat:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setDoesNotCapture(F, 1);
    return Changed;
  case LibFunc_frexp:
  case LibFunc_frexpf:
  case LibFunc_frexpl:
    Changed |= setDoesNotThrow(F);
    Changed |= setWillReturn(F);
    Changed |= setDoesNotCapture(F, 1);
    return Changed;
  case LibFunc_fstatvfs:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setDoesNotCapture(F, 1);
    return Changed;
  case LibFunc_fgets:
  case LibFunc_fgets_unlocked:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setDoesNotCapture(F, 2);
    return Changed;
  case LibFunc_fread:
  case LibFunc_fread_unlocked:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setDoesNotCapture(F, 0);
    Changed |= setDoesNotCapture(F, 3);
    return Changed;
  case LibFunc_fwrite:
  case LibFunc_fwrite_unlocked:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setDoesNotCapture(F, 0);
    Changed |= setDoesNotCapture(F, 3);
    // FIXME: readonly #1?
    return Changed;
  case LibFunc_fputs:
  case LibFunc_fputs_unlocked:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setDoesNotCapture(F, 0);
    Changed |= setDoesNotCapture(F, 1);
    Changed |= setOnlyReadsMemory(F, 0);
    return Changed;
  case LibFunc_fscanf:
  case LibFunc_fprintf:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setDoesNotCapture(F, 0);
    Changed |= setDoesNotCapture(F, 1);
    Changed |= setOnlyReadsMemory(F, 1);
    return Changed;
  case LibFunc_fgetpos:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setDoesNotCapture(F, 0);
    Changed |= setDoesNotCapture(F, 1);
    return Changed;
  case LibFunc_getc:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setDoesNotCapture(F, 0);
    return Changed;
  case LibFunc_getlogin_r:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setDoesNotCapture(F, 0);
    return Changed;
  case LibFunc_getc_unlocked:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setDoesNotCapture(F, 0);
    return Changed;
  case LibFunc_getenv:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setOnlyReadsMemory(F);
    Changed |= setDoesNotCapture(F, 0);
    return Changed;
  case LibFunc_gets:
  case LibFunc_getchar:
  case LibFunc_getchar_unlocked:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    return Changed;
  case LibFunc_getitimer:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setDoesNotCapture(F, 1);
    return Changed;
  case LibFunc_getpwnam:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setDoesNotCapture(F, 0);
    Changed |= setOnlyReadsMemory(F, 0);
    return Changed;
  case LibFunc_ungetc:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setDoesNotCapture(F, 1);
    return Changed;
  case LibFunc_uname:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setDoesNotCapture(F, 0);
    return Changed;
  case LibFunc_unlink:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setDoesNotCapture(F, 0);
    Changed |= setOnlyReadsMemory(F, 0);
    return Changed;
  case LibFunc_unsetenv:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setDoesNotCapture(F, 0);
    Changed |= setOnlyReadsMemory(F, 0);
    return Changed;
  case LibFunc_utime:
  case LibFunc_utimes:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setDoesNotCapture(F, 0);
    Changed |= setDoesNotCapture(F, 1);
    Changed |= setOnlyReadsMemory(F, 0);
    Changed |= setOnlyReadsMemory(F, 1);
    return Changed;
  case LibFunc_putc:
  case LibFunc_putc_unlocked:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setDoesNotCapture(F, 1);
    return Changed;
  case LibFunc_puts:
  case LibFunc_printf:
  case LibFunc_perror:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setDoesNotCapture(F, 0);
    Changed |= setOnlyReadsMemory(F, 0);
    return Changed;
  case LibFunc_pread:
    // May throw; "pread" is a valid pthread cancellation point.
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotCapture(F, 1);
    return Changed;
  case LibFunc_pwrite:
    // May throw; "pwrite" is a valid pthread cancellation point.
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotCapture(F, 1);
    Changed |= setOnlyReadsMemory(F, 1);
    return Changed;
  case LibFunc_putchar:
  case LibFunc_putchar_unlocked:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    return Changed;
  case LibFunc_popen:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setRetDoesNotAlias(F);
    Changed |= setDoesNotCapture(F, 0);
    Changed |= setDoesNotCapture(F, 1);
    Changed |= setOnlyReadsMemory(F, 0);
    Changed |= setOnlyReadsMemory(F, 1);
    return Changed;
  case LibFunc_pclose:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setDoesNotCapture(F, 0);
    return Changed;
  case LibFunc_vscanf:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setDoesNotCapture(F, 0);
    Changed |= setOnlyReadsMemory(F, 0);
    return Changed;
  case LibFunc_vsscanf:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setDoesNotCapture(F, 0);
    Changed |= setDoesNotCapture(F, 1);
    Changed |= setOnlyReadsMemory(F, 0);
    Changed |= setOnlyReadsMemory(F, 1);
    return Changed;
  case LibFunc_vfscanf:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setDoesNotCapture(F, 0);
    Changed |= setDoesNotCapture(F, 1);
    Changed |= setOnlyReadsMemory(F, 1);
    return Changed;
  case LibFunc_vprintf:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setDoesNotCapture(F, 0);
    Changed |= setOnlyReadsMemory(F, 0);
    return Changed;
  case LibFunc_vfprintf:
  case LibFunc_vsprintf:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setDoesNotCapture(F, 0);
    Changed |= setDoesNotCapture(F, 1);
    Changed |= setOnlyReadsMemory(F, 1);
    return Changed;
  case LibFunc_vsnprintf:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setDoesNotCapture(F, 0);
    Changed |= setDoesNotCapture(F, 2);
    Changed |= setOnlyReadsMemory(F, 2);
    return Changed;
  case LibFunc_open:
    // May throw; "open" is a valid pthread cancellation point.
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotCapture(F, 0);
    Changed |= setOnlyReadsMemory(F, 0);
    return Changed;
  case LibFunc_opendir:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setRetDoesNotAlias(F);
    Changed |= setDoesNotCapture(F, 0);
    Changed |= setOnlyReadsMemory(F, 0);
    return Changed;
  case LibFunc_tmpfile:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setRetDoesNotAlias(F);
    return Changed;
  case LibFunc_times:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setDoesNotCapture(F, 0);
    return Changed;
  case LibFunc_htonl:
  case LibFunc_htons:
  case LibFunc_ntohl:
  case LibFunc_ntohs:
    Changed |= setDoesNotThrow(F);
    Changed |= setDoesNotAccessMemory(F);
    return Changed;
  case LibFunc_lstat:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setDoesNotCapture(F, 0);
    Changed |= setDoesNotCapture(F, 1);
    Changed |= setOnlyReadsMemory(F, 0);
    return Changed;
  case LibFunc_lchown:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setDoesNotCapture(F, 0);
    Changed |= setOnlyReadsMemory(F, 0);
    return Changed;
  case LibFunc_qsort:
    // May throw; places call through function pointer.
    // Cannot give undef pointer/size
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotCapture(F, 3);
    return Changed;
  case LibFunc_dunder_strndup:
    Changed |= setArgNoUndef(F, 1);
    LLVM_FALLTHROUGH;
  case LibFunc_dunder_strdup:
    Changed |= setDoesNotThrow(F);
    Changed |= setRetDoesNotAlias(F);
    Changed |= setWillReturn(F);
    Changed |= setDoesNotCapture(F, 0);
    Changed |= setOnlyReadsMemory(F, 0);
    return Changed;
  case LibFunc_dunder_strtok_r:
    Changed |= setDoesNotThrow(F);
    Changed |= setDoesNotCapture(F, 1);
    Changed |= setOnlyReadsMemory(F, 1);
    return Changed;
  case LibFunc_under_IO_getc:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setDoesNotCapture(F, 0);
    return Changed;
  case LibFunc_under_IO_putc:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setDoesNotCapture(F, 1);
    return Changed;
  case LibFunc_dunder_isoc99_scanf:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setDoesNotCapture(F, 0);
    Changed |= setOnlyReadsMemory(F, 0);
    return Changed;
  case LibFunc_stat64:
  case LibFunc_lstat64:
  case LibFunc_statvfs64:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setDoesNotCapture(F, 0);
    Changed |= setDoesNotCapture(F, 1);
    Changed |= setOnlyReadsMemory(F, 0);
    return Changed;
  case LibFunc_dunder_isoc99_sscanf:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setDoesNotCapture(F, 0);
    Changed |= setDoesNotCapture(F, 1);
    Changed |= setOnlyReadsMemory(F, 0);
    Changed |= setOnlyReadsMemory(F, 1);
    return Changed;
  case LibFunc_fopen64:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setRetDoesNotAlias(F);
    Changed |= setDoesNotCapture(F, 0);
    Changed |= setDoesNotCapture(F, 1);
    Changed |= setOnlyReadsMemory(F, 0);
    Changed |= setOnlyReadsMemory(F, 1);
    return Changed;
  case LibFunc_fseeko64:
  case LibFunc_ftello64:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setDoesNotCapture(F, 0);
    return Changed;
  case LibFunc_tmpfile64:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setRetDoesNotAlias(F);
    return Changed;
  case LibFunc_fstat64:
  case LibFunc_fstatvfs64:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setDoesNotCapture(F, 1);
    return Changed;
  case LibFunc_open64:
    // May throw; "open" is a valid pthread cancellation point.
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotCapture(F, 0);
    Changed |= setOnlyReadsMemory(F, 0);
    return Changed;
  case LibFunc_gettimeofday:
    // Currently some platforms have the restrict keyword on the arguments to
    // gettimeofday. To be conservative, do not add noalias to gettimeofday's
    // arguments.
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotThrow(F);
    Changed |= setDoesNotCapture(F, 0);
    Changed |= setDoesNotCapture(F, 1);
    return Changed;
  case LibFunc_memset_pattern4:
  case LibFunc_memset_pattern8:
  case LibFunc_memset_pattern16:
    Changed |= setOnlyAccessesArgMemory(F);
    Changed |= setDoesNotCapture(F, 0);
    Changed |= setOnlyWritesMemory(F, 0);
    Changed |= setDoesNotCapture(F, 1);
    Changed |= setOnlyReadsMemory(F, 1);
    return Changed;
  case LibFunc_memset:
    Changed |= setWillReturn(F);
    LLVM_FALLTHROUGH;
  case LibFunc_memset_chk:
    Changed |= setOnlyAccessesArgMemory(F);
    Changed |= setOnlyWritesMemory(F, 0);
    Changed |= setDoesNotThrow(F);
    return Changed;
  // int __nvvm_reflect(const char *)
  case LibFunc_nvvm_reflect:
    Changed |= setRetAndArgsNoUndef(F);
    Changed |= setDoesNotAccessMemory(F);
    Changed |= setDoesNotThrow(F);
    return Changed;
  case LibFunc_ldexp:
  case LibFunc_ldexpf:
  case LibFunc_ldexpl:
    Changed |= setSignExtendedArg(F, 1);
    Changed |= setWillReturn(F);
    return Changed;
  case LibFunc_abs:
  case LibFunc_acos:
  case LibFunc_acosf:
  case LibFunc_acosh:
  case LibFunc_acoshf:
  case LibFunc_acoshl:
  case LibFunc_acosl:
  case LibFunc_asin:
  case LibFunc_asinf:
  case LibFunc_asinh:
  case LibFunc_asinhf:
  case LibFunc_asinhl:
  case LibFunc_asinl:
  case LibFunc_atan:
  case LibFunc_atan2:
  case LibFunc_atan2f:
  case LibFunc_atan2l:
  case LibFunc_atanf:
  case LibFunc_atanh:
  case LibFunc_atanhf:
  case LibFunc_atanhl:
  case LibFunc_atanl:
  case LibFunc_cbrt:
  case LibFunc_cbrtf:
  case LibFunc_cbrtl:
  case LibFunc_ceil:
  case LibFunc_ceilf:
  case LibFunc_ceill:
  case LibFunc_copysign:
  case LibFunc_copysignf:
  case LibFunc_copysignl:
  case LibFunc_cos:
  case LibFunc_cosh:
  case LibFunc_coshf:
  case LibFunc_coshl:
  case LibFunc_cosf:
  case LibFunc_cosl:
  case LibFunc_cospi:
  case LibFunc_cospif:
  case LibFunc_exp:
  case LibFunc_expf:
  case LibFunc_expl:
  case LibFunc_exp2:
  case LibFunc_exp2f:
  case LibFunc_exp2l:
  case LibFunc_expm1:
  case LibFunc_expm1f:
  case LibFunc_expm1l:
  case LibFunc_fabs:
  case LibFunc_fabsf:
  case LibFunc_fabsl:
  case LibFunc_ffs:
  case LibFunc_ffsl:
  case LibFunc_ffsll:
  case LibFunc_floor:
  case LibFunc_floorf:
  case LibFunc_floorl:
  case LibFunc_fls:
  case LibFunc_flsl:
  case LibFunc_flsll:
  case LibFunc_fmax:
  case LibFunc_fmaxf:
  case LibFunc_fmaxl:
  case LibFunc_fmin:
  case LibFunc_fminf:
  case LibFunc_fminl:
  case LibFunc_fmod:
  case LibFunc_fmodf:
  case LibFunc_fmodl:
  case LibFunc_isascii:
  case LibFunc_isdigit:
  case LibFunc_labs:
  case LibFunc_llabs:
  case LibFunc_log:
  case LibFunc_log10:
  case LibFunc_log10f:
  case LibFunc_log10l:
  case LibFunc_log1p:
  case LibFunc_log1pf:
  case LibFunc_log1pl:
  case LibFunc_log2:
  case LibFunc_log2f:
  case LibFunc_log2l:
  case LibFunc_logb:
  case LibFunc_logbf:
  case LibFunc_logbl:
  case LibFunc_logf:
  case LibFunc_logl:
  case LibFunc_nearbyint:
  case LibFunc_nearbyintf:
  case LibFunc_nearbyintl:
  case LibFunc_pow:
  case LibFunc_powf:
  case LibFunc_powl:
  case LibFunc_rint:
  case LibFunc_rintf:
  case LibFunc_rintl:
  case LibFunc_round:
  case LibFunc_roundf:
  case LibFunc_roundl:
  case LibFunc_sin:
  case LibFunc_sincospif_stret:
  case LibFunc_sinf:
  case LibFunc_sinh:
  case LibFunc_sinhf:
  case LibFunc_sinhl:
  case LibFunc_sinl:
  case LibFunc_sinpi:
  case LibFunc_sinpif:
  case LibFunc_sqrt:
  case LibFunc_sqrtf:
  case LibFunc_sqrtl:
  case LibFunc_tan:
  case LibFunc_tanf:
  case LibFunc_tanh:
  case LibFunc_tanhf:
  case LibFunc_tanhl:
  case LibFunc_tanl:
  case LibFunc_toascii:
  case LibFunc_trunc:
  case LibFunc_truncf:
  case LibFunc_truncl:
    Changed |= setDoesNotThrow(F);
    Changed |= setDoesNotFreeMemory(F);
    Changed |= setOnlyWritesMemory(F);
    Changed |= setWillReturn(F);
    return Changed;
  default:
    // FIXME: It'd be really nice to cover all the library functions we're
    // aware of here.
    return false;
  }
}