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authorAdhemerval Zanella <azanella@linux.vnet.ibm.com>2013-06-20 19:40:55 -0500
committerAdhemerval Zanella <azanella@linux.vnet.ibm.com>2013-06-20 19:42:05 -0500
commit85c2e6110c9a01ec817c30f1b7e20549d7229987 (patch)
tree9b044403d906f9aaa6930484ae6d60dc687ecc19
parentb8c792af85fe3ff65c0cd68e2f291072a60cd953 (diff)
downloadglibc-85c2e6110c9a01ec817c30f1b7e20549d7229987.tar.gz
Fix loop construction to functions calls
Check wheter the compiler has the option -fno-tree-loop-distribute-patterns to inhibit loop transformation to library calls and uses it on memset and memmove default implementation to avoid recursive calls.
-rw-r--r--ChangeLog16
-rw-r--r--benchtests/bench-memmove.c1
-rw-r--r--benchtests/bench-memset.c1
-rw-r--r--config.h.in3
-rwxr-xr-xconfigure33
-rw-r--r--configure.in18
-rw-r--r--include/libc-symbols.h10
-rw-r--r--string/memmove.c1
-rw-r--r--string/memset.c1
-rw-r--r--string/test-memmove.c1
-rw-r--r--string/test-memset.c1
11 files changed, 86 insertions, 0 deletions
diff --git a/ChangeLog b/ChangeLog
index 314a563e6a..6c65453eb4 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,19 @@
+2013-06-20 Adhemerval Zanella <azanella@linux.vnet.ibm.com>
+
+ * config.h.in (HAVE_CC_INHIBIT_LOOP_TO_LIBCALL): New define.
+ * configure.in (libc_cv_cc_loop_to_function): Check if compiler
+ accepts -fno-tree-loop-distribute-patterns.
+ * include/libc-symbols.h (inhibit_loop_to_libcall): New macro.
+ * string/memmove.c (MEMMOVE): Disable loop transformation to avoid
+ recursive call.
+ * string/memset.c (memset): Likewise.
+ * string/test-memmove.c (simple_memmove): Disable loop transformation
+ to library calls.
+ * string/test-memset.c (simple_memset): Likewise.
+ * benchtests/bench-memmove.c (simple_memmove): Likewise.
+ * benchtests/bench-memset.c (simple_memset): Likewise.
+ * configure: Regenerated.
+
2013-06-20 Joseph Myers <joseph@codesourcery.com>
* math/test-misc.c (main): Ignore fesetround failure when failures
diff --git a/benchtests/bench-memmove.c b/benchtests/bench-memmove.c
index dccde5d14e..8925606af8 100644
--- a/benchtests/bench-memmove.c
+++ b/benchtests/bench-memmove.c
@@ -46,6 +46,7 @@ IMPL (memmove, 1)
#endif
char *
+inhibit_loop_to_libcall
simple_memmove (char *dst, const char *src, size_t n)
{
char *ret = dst;
diff --git a/benchtests/bench-memset.c b/benchtests/bench-memset.c
index 92e34f0d61..ea29cf37fc 100644
--- a/benchtests/bench-memset.c
+++ b/benchtests/bench-memset.c
@@ -63,6 +63,7 @@ builtin_memset (char *s, int c, size_t n)
#endif
char *
+inhibit_loop_to_libcall
simple_memset (char *s, int c, size_t n)
{
char *r = s, *end = s + n;
diff --git a/config.h.in b/config.h.in
index 8c2479ef48..b5c6f163a7 100644
--- a/config.h.in
+++ b/config.h.in
@@ -69,6 +69,9 @@
/* Define if the compiler supports __builtin_memset. */
#undef HAVE_BUILTIN_MEMSET
+/* Define if compiler accepts -ftree-loop-distribute-patterns. */
+#undef HAVE_CC_INHIBIT_LOOP_TO_LIBCALL
+
/* Define if the regparm attribute shall be used for local functions
(gcc on ix86 only). */
#undef USE_REGPARMS
diff --git a/configure b/configure
index 09d8336f10..14bff72a3d 100755
--- a/configure
+++ b/configure
@@ -598,6 +598,7 @@ have_selinux
have_libcap
have_libaudit
LIBGD
+libc_cv_cc_loop_to_function
libc_cv_cc_submachine
libc_cv_cc_nofma
exceptions
@@ -6933,6 +6934,38 @@ $as_echo "$libc_cv_cc_submachine" >&6; }
fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking if $CC accepts -fno-tree-loop-distribute-patterns with \
+__attribute__ ((__optimize__))" >&5
+$as_echo_n "checking if $CC accepts -fno-tree-loop-distribute-patterns with \
+__attribute__ ((__optimize__))... " >&6; }
+if ${libc_cv_cc_loop_to_function+:} false; then :
+ $as_echo_n "(cached) " >&6
+else
+ cat > conftest.c <<EOF
+void
+__attribute__ ((__optimize__ ("-fno-tree-loop-distribute-patterns")))
+foo (void) {}
+EOF
+libc_cv_cc_loop_to_function=no
+if { ac_try='${CC-cc} $CFLAGS $CPPFLAGS -c conftest.c'
+ { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
+ (eval $ac_try) 2>&5
+ ac_status=$?
+ $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+ test $ac_status = 0; }; }
+then
+ libc_cv_cc_loop_to_function=yes
+fi
+rm -f conftest*
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $libc_cv_cc_loop_to_function" >&5
+$as_echo "$libc_cv_cc_loop_to_function" >&6; }
+if test $libc_cv_cc_loop_to_function = yes; then
+ $as_echo "#define HAVE_CC_INHIBIT_LOOP_TO_LIBCALL 1" >>confdefs.h
+
+fi
+
+
{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for libgd" >&5
$as_echo_n "checking for libgd... " >&6; }
if test "$with_gd" != "no"; then
diff --git a/configure.in b/configure.in
index 8b110817bc..56cd61c171 100644
--- a/configure.in
+++ b/configure.in
@@ -1964,6 +1964,24 @@ if test -n "$submachine"; then
fi
AC_SUBST(libc_cv_cc_submachine)
+AC_CACHE_CHECK(if $CC accepts -fno-tree-loop-distribute-patterns with \
+__attribute__ ((__optimize__)), libc_cv_cc_loop_to_function, [dnl
+cat > conftest.c <<EOF
+void
+__attribute__ ((__optimize__ ("-fno-tree-loop-distribute-patterns")))
+foo (void) {}
+EOF
+libc_cv_cc_loop_to_function=no
+if AC_TRY_COMMAND([${CC-cc} $CFLAGS $CPPFLAGS -c conftest.c])
+then
+ libc_cv_cc_loop_to_function=yes
+fi
+rm -f conftest*])
+if test $libc_cv_cc_loop_to_function = yes; then
+ AC_DEFINE(HAVE_CC_INHIBIT_LOOP_TO_LIBCALL)
+fi
+AC_SUBST(libc_cv_cc_loop_to_function)
+
dnl Check whether we have the gd library available.
AC_MSG_CHECKING(for libgd)
if test "$with_gd" != "no"; then
diff --git a/include/libc-symbols.h b/include/libc-symbols.h
index f043ce0850..a3b6274bad 100644
--- a/include/libc-symbols.h
+++ b/include/libc-symbols.h
@@ -782,4 +782,14 @@ for linking")
#define libc_ifunc_hidden_def(name) \
libc_ifunc_hidden_def1 (__GI_##name, name)
+/* Add the compiler optimization to inhibit loop transformation to library
+ calls. This is used to avoid recursive calls in memset and memmove
+ default implementations. */
+#ifdef HAVE_CC_INHIBIT_LOOP_TO_LIBCALL
+# define inhibit_loop_to_libcall \
+ __attribute__ ((__optimize__ ("-fno-tree-loop-distribute-patterns")))
+#else
+# define inhibit_loop_to_libcall
+#endif
+
#endif /* libc-symbols.h */
diff --git a/string/memmove.c b/string/memmove.c
index 9dcd2f1f68..ec61e28c60 100644
--- a/string/memmove.c
+++ b/string/memmove.c
@@ -41,6 +41,7 @@
#endif
rettype
+inhibit_loop_to_libcall
MEMMOVE (a1, a2, len)
a1const void *a1;
a2const void *a2;
diff --git a/string/memset.c b/string/memset.c
index 868be53bf9..74b5409218 100644
--- a/string/memset.c
+++ b/string/memset.c
@@ -21,6 +21,7 @@
#undef memset
void *
+inhibit_loop_to_libcall
memset (dstpp, c, len)
void *dstpp;
int c;
diff --git a/string/test-memmove.c b/string/test-memmove.c
index 4ec55b2fcc..94576a299b 100644
--- a/string/test-memmove.c
+++ b/string/test-memmove.c
@@ -47,6 +47,7 @@ IMPL (memmove, 1)
#endif
char *
+inhibit_loop_to_libcall
simple_memmove (char *dst, const char *src, size_t n)
{
char *ret = dst;
diff --git a/string/test-memset.c b/string/test-memset.c
index 9981fcef46..72a390e7d9 100644
--- a/string/test-memset.c
+++ b/string/test-memset.c
@@ -64,6 +64,7 @@ builtin_memset (char *s, int c, size_t n)
#endif
char *
+inhibit_loop_to_libcall
simple_memset (char *s, int c, size_t n)
{
char *r = s, *end = s + n;