gnulib: import count-one-bits module and use it

For a fix I intend to submit, I would need a function that counts the
number of set bits in a word.  There is  __builtin_popcount that is
supported by gcc and clang, but there is also a gnulib module that wraps
that and provides a fallback for other compilers, so I think it would be
good to use it.

I also noticed that there is a bitcount function in arch/arm.c, so I
thought that as a first step I would replace that one with the gnulib
count-one-bits module.  This is what this patch does.

The gnulib module provides multiple functions, with various parameter
length (unsigned int, unsigned long int, unsigned long long int), I
chose the one that made sense for each call site based on the argument
type.

gnulib/ChangeLog:

	* update-gnulib.sh (IMPORTED_GNULIB_MODULES): Import
	count-one-bits module.
	* configure: Re-generate.
	* aclocal.m4: Re-generate.
	* Makefile.in: Re-generate.
	* import/count-one-bits.c: New file.
	* import/count-one-bits.h: New file.
	* import/Makefile.am: Re-generate.
	* import/Makefile.in: Re-generate.
	* import/m4/gnulib-cache.m4: Re-generate.
	* import/m4/gnulib-comp.m4: Re-generate.
	* import/m4/count-one-bits.m4: New file.

gdb/ChangeLog:

	* arm-tdep.c: Include count-one-bits.h.
	(cleanup_block_store_pc): Use count_one_bits.
	(cleanup_block_load_pc): Use count_one_bits.
	(arm_copy_block_xfer): Use count_one_bits.
	(thumb2_copy_block_xfer): Use count_one_bits.
	(thumb_copy_pop_pc_16bit): Use count_one_bits.
	* arch/arm-get-next-pcs.c: Include count-one-bits.h.
	(thumb_get_next_pcs_raw): Use count_one_bits.
	(arm_get_next_pcs_raw): Use count_one_bits_l.
	* arch/arm.c (bitcount): Remove.
	* arch/arm.h (bitcount): Remove.

7 files changed, 198 insertions, 23 deletions

diff --git a/gnulib/import/Makefile.am b/gnulib/import/Makefile.am
index 4ddaf4f..0944473 100644
--- a/gnulib/import/Makefile.am
+++ b/gnulib/import/Makefile.am
@@ -35,6 +35,7 @@
 #  --no-vc-files \
 #  alloca \
 #  canonicalize-lgpl \
+#  count-one-bits \
 #  dirent \
 #  dirfd \
 #  errno \
@@ -236,6 +237,14 @@ EXTRA_libgnu_a_SOURCES += closedir.c
 
 ## end   gnulib module closedir
 
+## begin gnulib module count-one-bits
+
+libgnu_a_SOURCES += count-one-bits.c
+
+EXTRA_DIST += count-one-bits.h
+
+## end   gnulib module count-one-bits
+
 ## begin gnulib module dirent
 
 BUILT_SOURCES += dirent.h
diff --git a/gnulib/import/Makefile.in b/gnulib/import/Makefile.in
index 7059d4c..f5ad783 100644
--- a/gnulib/import/Makefile.in
+++ b/gnulib/import/Makefile.in
@@ -49,6 +49,7 @@
 #  --no-vc-files \
 #  alloca \
 #  canonicalize-lgpl \
+#  count-one-bits \
 #  dirent \
 #  dirfd \
 #  errno \
@@ -178,6 +179,7 @@ am__aclocal_m4_deps = $(top_srcdir)/../config/depstand.m4 \
 	$(top_srcdir)/import/m4/close.m4 \
 	$(top_srcdir)/import/m4/closedir.m4 \
 	$(top_srcdir)/import/m4/codeset.m4 \
+	$(top_srcdir)/import/m4/count-one-bits.m4 \
 	$(top_srcdir)/import/m4/d-ino.m4 \
 	$(top_srcdir)/import/m4/d-type.m4 \
 	$(top_srcdir)/import/m4/dirent_h.m4 \
@@ -326,14 +328,15 @@ am__v_AR_1 =
 libgnu_a_AR = $(AR) $(ARFLAGS)
 am__DEPENDENCIES_1 =
 am__dirstamp = $(am__leading_dot)dirstamp
-am_libgnu_a_OBJECTS = cloexec.$(OBJEXT) dirname-lgpl.$(OBJEXT) \
-	basename-lgpl.$(OBJEXT) stripslash.$(OBJEXT) \
-	exitfail.$(OBJEXT) fd-hook.$(OBJEXT) fd-safer-flag.$(OBJEXT) \
-	dup-safer-flag.$(OBJEXT) filenamecat-lgpl.$(OBJEXT) \
-	getprogname.$(OBJEXT) hard-locale.$(OBJEXT) \
-	localcharset.$(OBJEXT) glthread/lock.$(OBJEXT) \
-	malloca.$(OBJEXT) math.$(OBJEXT) openat-die.$(OBJEXT) \
-	save-cwd.$(OBJEXT) malloc/scratch_buffer_grow.$(OBJEXT) \
+am_libgnu_a_OBJECTS = cloexec.$(OBJEXT) count-one-bits.$(OBJEXT) \
+	dirname-lgpl.$(OBJEXT) basename-lgpl.$(OBJEXT) \
+	stripslash.$(OBJEXT) exitfail.$(OBJEXT) fd-hook.$(OBJEXT) \
+	fd-safer-flag.$(OBJEXT) dup-safer-flag.$(OBJEXT) \
+	filenamecat-lgpl.$(OBJEXT) getprogname.$(OBJEXT) \
+	hard-locale.$(OBJEXT) localcharset.$(OBJEXT) \
+	glthread/lock.$(OBJEXT) malloca.$(OBJEXT) math.$(OBJEXT) \
+	openat-die.$(OBJEXT) save-cwd.$(OBJEXT) \
+	malloc/scratch_buffer_grow.$(OBJEXT) \
 	malloc/scratch_buffer_grow_preserve.$(OBJEXT) \
 	malloc/scratch_buffer_set_array_size.$(OBJEXT) \
 	stat-time.$(OBJEXT) strnlen1.$(OBJEXT) sys_socket.$(OBJEXT) \
@@ -1620,15 +1623,15 @@ noinst_LTLIBRARIES =
 EXTRA_DIST = m4/gnulib-cache.m4 alloca.c alloca.in.h arpa_inet.in.h \
 	assure.h openat-priv.h openat-proc.c canonicalize-lgpl.c \
 	chdir-long.c chdir-long.h cloexec.h close.c closedir.c \
-	dirent-private.h dirent.in.h dirfd.c dirname.h dosname.h dup.c \
-	dup2.c errno.in.h error.c error.h exitfail.h fchdir.c fcntl.c \
-	fcntl.in.h fd-hook.h fdopendir.c filename.h filenamecat.h \
-	flexmember.h float.c float.in.h itold.c fnmatch.c \
-	fnmatch_loop.c fnmatch.in.h fpucw.h frexp.c frexp.c frexpl.c \
-	fstat.c stat-w32.c stat-w32.h at-func.c fstatat.c getcwd.c \
-	getcwd-lgpl.c getdtablesize.c getlogin_r.c gettimeofday.c \
-	glob.c glob_internal.h glob_pattern_p.c globfree.c glob-libc.h \
-	glob.in.h hard-locale.h \
+	dirent-private.h count-one-bits.h dirent.in.h dirfd.c \
+	dirname.h dosname.h dup.c dup2.c errno.in.h error.c error.h \
+	exitfail.h fchdir.c fcntl.c fcntl.in.h fd-hook.h fdopendir.c \
+	filename.h filenamecat.h flexmember.h float.c float.in.h \
+	itold.c fnmatch.c fnmatch_loop.c fnmatch.in.h fpucw.h frexp.c \
+	frexp.c frexpl.c fstat.c stat-w32.c stat-w32.h at-func.c \
+	fstatat.c getcwd.c getcwd-lgpl.c getdtablesize.c getlogin_r.c \
+	gettimeofday.c glob.c glob_internal.h glob_pattern_p.c \
+	globfree.c glob-libc.h glob.in.h hard-locale.h \
 	$(top_srcdir)/import/extra/config.rpath inet_ntop.c intprops.h \
 	inttypes.in.h float+.h isnan.c isnand-nolibm.h isnand.c \
 	float+.h isnan.c isnanl-nolibm.h isnanl.c cdefs.h \
@@ -1682,12 +1685,12 @@ DISTCLEANFILES =
 MAINTAINERCLEANFILES = 
 AM_CPPFLAGS = 
 AM_CFLAGS = 
-libgnu_a_SOURCES = cloexec.c dirname-lgpl.c basename-lgpl.c \
-	stripslash.c exitfail.c fd-hook.c fd-safer-flag.c \
-	dup-safer-flag.c filenamecat-lgpl.c getprogname.h \
-	getprogname.c gettext.h hard-locale.c localcharset.c \
-	glthread/lock.h glthread/lock.c malloca.c math.c openat-die.c \
-	save-cwd.c malloc/scratch_buffer_grow.c \
+libgnu_a_SOURCES = cloexec.c count-one-bits.c dirname-lgpl.c \
+	basename-lgpl.c stripslash.c exitfail.c fd-hook.c \
+	fd-safer-flag.c dup-safer-flag.c filenamecat-lgpl.c \
+	getprogname.h getprogname.c gettext.h hard-locale.c \
+	localcharset.c glthread/lock.h glthread/lock.c malloca.c \
+	math.c openat-die.c save-cwd.c malloc/scratch_buffer_grow.c \
 	malloc/scratch_buffer_grow_preserve.c \
 	malloc/scratch_buffer_set_array_size.c stat-time.c strnlen1.h \
 	strnlen1.c sys_socket.c tempname.c glthread/threadlib.c \
@@ -1827,6 +1830,7 @@ distclean-compile:
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/cloexec.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/close.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/closedir.Po@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/count-one-bits.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/dirfd.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/dirname-lgpl.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/dup-safer-flag.Po@am__quote@
diff --git a/gnulib/import/count-one-bits.c b/gnulib/import/count-one-bits.c
new file mode 100644
index 0000000..66341d7
--- /dev/null
+++ b/gnulib/import/count-one-bits.c
@@ -0,0 +1,7 @@
+#include <config.h>
+#define COUNT_ONE_BITS_INLINE _GL_EXTERN_INLINE
+#include "count-one-bits.h"
+
+#if 1500 <= _MSC_VER && (defined _M_IX86 || defined _M_X64)
+int popcount_support = -1;
+#endif
diff --git a/gnulib/import/count-one-bits.h b/gnulib/import/count-one-bits.h
new file mode 100644
index 0000000..0056994
--- /dev/null
+++ b/gnulib/import/count-one-bits.h
@@ -0,0 +1,136 @@
+/* count-one-bits.h -- counts the number of 1-bits in a word.
+   Copyright (C) 2007-2019 Free Software Foundation, Inc.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
+
+/* Written by Ben Pfaff.  */
+
+#ifndef COUNT_ONE_BITS_H
+#define COUNT_ONE_BITS_H 1
+
+#include <limits.h>
+#include <stdlib.h>
+
+#ifndef _GL_INLINE_HEADER_BEGIN
+ #error "Please include config.h first."
+#endif
+_GL_INLINE_HEADER_BEGIN
+#ifndef COUNT_ONE_BITS_INLINE
+# define COUNT_ONE_BITS_INLINE _GL_INLINE
+#endif
+
+/* Expand to code that computes the number of 1-bits of the local
+   variable 'x' of type TYPE (an unsigned integer type) and return it
+   from the current function.  */
+#define COUNT_ONE_BITS_GENERIC(TYPE)                                   \
+    do                                                                  \
+      {                                                                 \
+        int count = 0;                                                  \
+        int bits;                                                       \
+        for (bits = 0; bits < sizeof (TYPE) * CHAR_BIT; bits += 32)     \
+          {                                                             \
+            count += count_one_bits_32 (x);                             \
+            x = x >> 31 >> 1;                                           \
+          }                                                             \
+        return count;                                                   \
+      }                                                                 \
+    while (0)
+
+/* Assuming the GCC builtin is BUILTIN and the MSC builtin is MSC_BUILTIN,
+   expand to code that computes the number of 1-bits of the local
+   variable 'x' of type TYPE (an unsigned integer type) and return it
+   from the current function.  */
+#if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4)
+# define COUNT_ONE_BITS(BUILTIN, MSC_BUILTIN, TYPE) return BUILTIN (x)
+#else
+
+/* Compute and return the number of 1-bits set in the least
+   significant 32 bits of X. */
+COUNT_ONE_BITS_INLINE int
+count_one_bits_32 (unsigned int x)
+{
+  x = ((x & 0xaaaaaaaaU) >> 1) + (x & 0x55555555U);
+  x = ((x & 0xccccccccU) >> 2) + (x & 0x33333333U);
+  x = (x >> 16) + (x & 0xffff);
+  x = ((x & 0xf0f0) >> 4) + (x & 0x0f0f);
+  return (x >> 8) + (x & 0x00ff);
+}
+
+# if 1500 <= _MSC_VER && (defined _M_IX86 || defined _M_X64)
+
+/* While gcc falls back to its own generic code if the machine
+   on which it's running doesn't support popcount, with Microsoft's
+   compiler we need to detect and fallback ourselves.  */
+#  pragma intrinsic __cpuid
+#  pragma intrinsic __popcnt
+#  pragma intrinsic __popcnt64
+
+/* Return nonzero if popcount is supported.  */
+
+/* 1 if supported, 0 if not supported, -1 if unknown.  */
+extern int popcount_support;
+
+COUNT_ONE_BITS_INLINE int
+popcount_supported (void)
+{
+  if (popcount_support < 0)
+    {
+      int cpu_info[4];
+      __cpuid (cpu_info, 1);
+      popcount_support = (cpu_info[2] >> 23) & 1;  /* See MSDN.  */
+    }
+  return popcount_support;
+}
+
+#  define COUNT_ONE_BITS(BUILTIN, MSC_BUILTIN, TYPE)    \
+     do                                                 \
+       {                                                \
+         if (popcount_supported ())                     \
+           return MSC_BUILTIN (x);                      \
+         else                                           \
+           COUNT_ONE_BITS_GENERIC (TYPE);               \
+       }                                                \
+     while (0)
+# else
+#  define COUNT_ONE_BITS(BUILTIN, MSC_BUILTIN, TYPE)	\
+     COUNT_ONE_BITS_GENERIC (TYPE)
+# endif
+#endif
+
+/* Compute and return the number of 1-bits set in X. */
+COUNT_ONE_BITS_INLINE int
+count_one_bits (unsigned int x)
+{
+  COUNT_ONE_BITS (__builtin_popcount, __popcnt, unsigned int);
+}
+
+/* Compute and return the number of 1-bits set in X. */
+COUNT_ONE_BITS_INLINE int
+count_one_bits_l (unsigned long int x)
+{
+  COUNT_ONE_BITS (__builtin_popcountl, __popcnt, unsigned long int);
+}
+
+#if HAVE_UNSIGNED_LONG_LONG_INT
+/* Compute and return the number of 1-bits set in X. */
+COUNT_ONE_BITS_INLINE int
+count_one_bits_ll (unsigned long long int x)
+{
+  COUNT_ONE_BITS (__builtin_popcountll, __popcnt64, unsigned long long int);
+}
+#endif
+
+_GL_INLINE_HEADER_END
+
+#endif /* COUNT_ONE_BITS_H */
diff --git a/gnulib/import/m4/count-one-bits.m4 b/gnulib/import/m4/count-one-bits.m4
new file mode 100644
index 0000000..b4721b5
--- /dev/null
+++ b/gnulib/import/m4/count-one-bits.m4
@@ -0,0 +1,12 @@
+# count-one-bits.m4 serial 3
+dnl Copyright (C) 2007, 2009-2019 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/gnulib/import/m4/gnulib-cache.m4 b/gnulib/import/m4/gnulib-cache.m4
index 428f5c9..03101b6 100644
--- a/gnulib/import/m4/gnulib-cache.m4
+++ b/gnulib/import/m4/gnulib-cache.m4
@@ -40,6 +40,7 @@
 #  --no-vc-files \
 #  alloca \
 #  canonicalize-lgpl \
+#  count-one-bits \
 #  dirent \
 #  dirfd \
 #  errno \
@@ -79,6 +80,7 @@ gl_LOCAL_DIR([])
 gl_MODULES([
   alloca
   canonicalize-lgpl
+  count-one-bits
   dirent
   dirfd
   errno
diff --git a/gnulib/import/m4/gnulib-comp.m4 b/gnulib/import/m4/gnulib-comp.m4
index be1fd39..fe1da67 100644
--- a/gnulib/import/m4/gnulib-comp.m4
+++ b/gnulib/import/m4/gnulib-comp.m4
@@ -57,6 +57,7 @@ AC_DEFUN([gl_EARLY],
   # Code from module cloexec:
   # Code from module close:
   # Code from module closedir:
+  # Code from module count-one-bits:
   # Code from module d-ino:
   # Code from module d-type:
   # Code from module dirent:
@@ -250,6 +251,7 @@ AC_DEFUN([gl_INIT],
     AC_LIBOBJ([closedir])
   fi
   gl_DIRENT_MODULE_INDICATOR([closedir])
+  gl_COUNT_ONE_BITS
   gl_CHECK_TYPE_STRUCT_DIRENT_D_INO
   gl_CHECK_TYPE_STRUCT_DIRENT_D_TYPE
   gl_DIRENT_H
@@ -855,6 +857,8 @@ AC_DEFUN([gl_FILE_LIST], [
   lib/cloexec.h
   lib/close.c
   lib/closedir.c
+  lib/count-one-bits.c
+  lib/count-one-bits.h
   lib/dirent-private.h
   lib/dirent.in.h
   lib/dirfd.c
@@ -1045,6 +1049,7 @@ AC_DEFUN([gl_FILE_LIST], [
   m4/close.m4
   m4/closedir.m4
   m4/codeset.m4
+  m4/count-one-bits.m4
   m4/d-ino.m4
   m4/d-type.m4
   m4/dirent_h.m4