Improve support for popcount and counting trailing zeros.

Do this by using the Gnulib modules for this.
This should generate faster code on non-GCC, non-MSC platforms,
and make the code a bit more portable, at least in theory.
* admin/merge-gnulib (GNULIB_MODULES): Add count-one-bits
and count-trailing-zeros.
* lib/count-one-bits.c, lib/count-one-bits.h:
* lib/count-trailing-zeros.c, lib/count-trailing-zeros.h:
* m4/count-one-bits.m4, m4/count-trailing-zeros.m4:
New files, copied from gnulib.
* lib/gnulib.mk, m4/gnulib-comp.m4: Regenerate.
* nt/gnulib.mk: Merge changes from lib/gnulib.mk.
* src/data.c: Include <count-one-bits.h>, <count-trailing-zeros.h>.
(USE_MSC_POPCOUNT, POPCOUNT_STATIC_INLINE)
(NEED_GENERIC_POPCOUNT, popcount_size_t_generic)
(popcount_size_t_msc, popcount_size_t_gcc):
Remove; now done by Gnulib.
(popcount_size_t): Now a macro that defers to Gnulib.
(count_trailing_zero_bits): Return int, for consistency with
Gnulib and because Emacs prefers signed to unsigned int.
Don't assume that size_t is either unsigned int or unsigned long
or unsigned long long.
(size_t_to_host_endian): Do not assume that size_t is either
exactly 32 or exactly 64 bits wide.
* src/lisp.h (BITS_PER_SIZE_T): Define consistently with BITS_PER_LONG
etc., so that it's now an enum constant, not a macro.
No need to assume that it's either 32 or 64.

Fixes: debbugs:15550

3 files changed, 34 insertions, 0 deletions

diff --git a/m4/count-one-bits.m4 b/m4/count-one-bits.m4
new file mode 100644
index 00000000000..07289641d4a
--- /dev/null
+++ b/m4/count-one-bits.m4
@@ -0,0 +1,12 @@
+# count-one-bits.m4 serial 3
+dnl Copyright (C) 2007, 2009-2013 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+AC_DEFUN([gl_COUNT_ONE_BITS],
+[
+  dnl We don't need (and can't compile) count_one_bits_ll
+  dnl unless the type 'unsigned long long int' exists.
+  AC_REQUIRE([AC_TYPE_UNSIGNED_LONG_LONG_INT])
+])
diff --git a/m4/count-trailing-zeros.m4 b/m4/count-trailing-zeros.m4
new file mode 100644
index 00000000000..b4a13c14397
--- /dev/null
+++ b/m4/count-trailing-zeros.m4
@@ -0,0 +1,12 @@
+# count-trailing-zeros.m4
+dnl Copyright (C) 2013 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+AC_DEFUN([gl_COUNT_TRAILING_ZEROS],
+[
+  dnl We don't need (and can't compile) count_trailing_zeros_ll
+  dnl unless the type 'unsigned long long int' exists.
+  AC_REQUIRE([AC_TYPE_UNSIGNED_LONG_LONG_INT])
+])
diff --git a/m4/gnulib-comp.m4 b/m4/gnulib-comp.m4
index ff36981c8d0..534d56f5bac 100644
--- a/m4/gnulib-comp.m4
+++ b/m4/gnulib-comp.m4
@@ -48,6 +48,8 @@ AC_DEFUN([gl_EARLY],
   # Code from module careadlinkat:
   # Code from module clock-time:
   # Code from module close-stream:
+  # Code from module count-one-bits:
+  # Code from module count-trailing-zeros:
   # Code from module crypto/md5:
   # Code from module crypto/sha1:
   # Code from module crypto/sha256:
@@ -175,6 +177,8 @@ AC_DEFUN([gl_INIT],
   gl_CLOCK_TIME
   gl_CLOSE_STREAM
   gl_MODULE_INDICATOR([close-stream])
+  gl_COUNT_ONE_BITS
+  gl_COUNT_TRAILING_ZEROS
   gl_MD5
   gl_SHA1
   gl_SHA256
@@ -806,6 +810,10 @@ AC_DEFUN([gl_FILE_LIST], [
   lib/careadlinkat.h
   lib/close-stream.c
   lib/close-stream.h
+  lib/count-one-bits.c
+  lib/count-one-bits.h
+  lib/count-trailing-zeros.c
+  lib/count-trailing-zeros.h
   lib/dirent.in.h
   lib/dosname.h
   lib/dtoastr.c
@@ -919,6 +927,8 @@ AC_DEFUN([gl_FILE_LIST], [
   m4/c-strtod.m4
   m4/clock_time.m4
   m4/close-stream.m4
+  m4/count-one-bits.m4
+  m4/count-trailing-zeros.m4
   m4/dirent_h.m4
   m4/dup2.m4
   m4/environ.m4