Hi Richard,
> This description is too brief for me. Could you say in detail how the
> new scheme works? E.g. the description doesn't explain:
>
> -if ARCH_AARCH64_HAVE_LSE128
> -AM_CPPFLAGS = -DHAVE_FEAT_LSE128
> -endif
That is not needed because we can include auto-config.h in atomic_16.S. I needed
this for HAVE_IFUNC, but then we redefine HAVE_FEAT_LSE128...
> And what's the purpose of ARCH_AARCH64_HAVE_LSE128 after this change?
None. I've removed the makefile leftovers in v2.
> Is the indirection via ALIAS2 necessary? Couldn't ENTRY just define
> the __atomic_* symbols directly, as non-hidden, if we remove the
> libat_ prefix? That would make it easier to ensure that the lists
> are kept up-to-date.
Yes, we need both the libat_ symbol as well as the __atomic_ variant in this
case. One is for internal calls, the other for external. I have a separate
cleanup
patch which hides the extra alias in ENTRY and removes all the libat prefixes.
However while trivial, that feels more like a stage 1 patch.
> Shouldn't we skip the ENTRY_FEAT functions and existing aliases
> if !HAVE_IFUNC?
Yes, that's relatively easy, I've added HAVE_FEAT_LSE2 for that. Also we skip
the
aliases at the end.
> I think it'd be worth (as a prepatch) splitting the file into two
> #included subfiles, one that contains the base AArch64 routines and one
> that contains the optimised versions. The former would then be #included
> for all builds while the latter would be specific to HAVE_IFUNC.
That sounds like a complete rewrite. We might as well emit our own ifuncs at
that
point and avoid all of the workarounds needed to fit in the framework of
libatomic.
So for v2 I have kept things simple and just focus on fixing the bug.
Cheers,
Wilco
v2:
Fix libatomic build to support --disable-gnu-indirect-function on AArch64.
Always build atomic_16.S, add aliases to the __atomic_ functions if
!HAVE_IFUNC.
Include auto-config.h in atomic_16.S to avoid having to pass defines via
makefiles.
Fix build if HWCAP_ATOMICS/CPUID are not defined.
Passes regress and bootstrap, OK for commit?
libatomic:
PR target/113986
* Makefile.in: Regenerated.
* Makefile.am: Make atomic_16.S not depend on HAVE_IFUNC.
Remove predefine of HAVE_FEAT_LSE128.
* acinclude.m4: Remove ARCH_AARCH64_HAVE_LSE128.
* configure: Regenerated.
* config/linux/aarch64/atomic_16.S: Add __atomic_ aliases if
!HAVE_IFUNC.
* config/linux/aarch64/host-config.h: Correctly handle !HAVE_IFUNC. Add
defines for HWCAP_ATOMICS and HWCAP_CPUID.
---
diff --git a/libatomic/Makefile.am b/libatomic/Makefile.am
index
d49c44c7d5fbe83061fddd1f8ef4813a39eb1b8b..980677f353345c050f6cef2d57090360216c56cf
100644
--- a/libatomic/Makefile.am
+++ b/libatomic/Makefile.am
@@ -130,12 +130,8 @@ libatomic_la_LIBADD = $(foreach s,$(SIZES),$(addsuffix
_$(s)_.lo,$(SIZEOBJS)))
## On a target-specific basis, include alternates to be selected by IFUNC.
if HAVE_IFUNC
if ARCH_AARCH64_LINUX
-if ARCH_AARCH64_HAVE_LSE128
-AM_CPPFLAGS = -DHAVE_FEAT_LSE128
-endif
IFUNC_OPTIONS = -march=armv8-a+lse
libatomic_la_LIBADD += $(foreach s,$(SIZES),$(addsuffix
_$(s)_1_.lo,$(SIZEOBJS)))
-libatomic_la_SOURCES += atomic_16.S
endif
if ARCH_ARM_LINUX
@@ -155,6 +151,10 @@ libatomic_la_LIBADD += $(addsuffix _16_1_.lo,$(SIZEOBJS)) \
endif
endif
+if ARCH_AARCH64_LINUX
+libatomic_la_SOURCES += atomic_16.S
+endif
+
libatomic_convenience_la_SOURCES = $(libatomic_la_SOURCES)
libatomic_convenience_la_LIBADD = $(libatomic_la_LIBADD)
diff --git a/libatomic/Makefile.in b/libatomic/Makefile.in
index
11c8ec7ba15ba7da5ef55e90bd836317bc270061..d9d529bc502d4ce7b9997640d5f40f5d5cc1232c
100644
--- a/libatomic/Makefile.in
+++ b/libatomic/Makefile.in
@@ -90,17 +90,17 @@ build_triplet = @build@
host_triplet = @host@
target_triplet = @target@
@ARCH_AARCH64_LINUX_TRUE@@HAVE_IFUNC_TRUE@am__append_1 = $(foreach
s,$(SIZES),$(addsuffix _$(s)_1_.lo,$(SIZEOBJS)))
-@ARCH_AARCH64_LINUX_TRUE@@HAVE_IFUNC_TRUE@am__append_2 = atomic_16.S
-@ARCH_ARM_LINUX_TRUE@@HAVE_IFUNC_TRUE@am__append_3 = $(foreach \
+@ARCH_ARM_LINUX_TRUE@@HAVE_IFUNC_TRUE@am__append_2 = $(foreach \
@ARCH_ARM_LINUX_TRUE@@HAVE_IFUNC_TRUE@ s,$(SIZES),$(addsuffix \
@ARCH_ARM_LINUX_TRUE@@HAVE_IFUNC_TRUE@ _$(s)_1_.lo,$(SIZEOBJS))) \
@ARCH_ARM_LINUX_TRUE@@HAVE_IFUNC_TRUE@ $(addsuffix \
@ARCH_ARM_LINUX_TRUE@@HAVE_IFUNC_TRUE@ _8_2_.lo,$(SIZEOBJS)) \
@ARCH_ARM_LINUX_TRUE@@HAVE_IFUNC_TRUE@ tas_1_2_.lo
-@ARCH_I386_TRUE@@HAVE_IFUNC_TRUE@am__append_4 = $(addsuffix
_8_1_.lo,$(SIZEOBJS))
-@ARCH_X86_64_TRUE@@HAVE_IFUNC_TRUE@am__append_5 = $(addsuffix
_16_1_.lo,$(SIZEOBJS)) \
+@ARCH_I386_TRUE@@HAVE_IFUNC_TRUE@am__append_3 = $(addsuffix
_8_1_.lo,$(SIZEOBJS))
+@ARCH_X86_64_TRUE@@HAVE_IFUNC_TRUE@am__append_4 = $(addsuffix
_16_1_.lo,$(SIZEOBJS)) \
@ARCH_X86_64_TRUE@@HAVE_IFUNC_TRUE@ $(addsuffix
_16_2_.lo,$(SIZEOBJS))
+@ARCH_AARCH64_LINUX_TRUE@am__append_5 = atomic_16.S
subdir = .
ACLOCAL_M4 = $(top_srcdir)/aclocal.m4
am__aclocal_m4_deps = $(top_srcdir)/../config/acx.m4 \
@@ -156,8 +156,7 @@ am__uninstall_files_from_dir = { \
}
am__installdirs = "$(DESTDIR)$(toolexeclibdir)"
LTLIBRARIES = $(noinst_LTLIBRARIES) $(toolexeclib_LTLIBRARIES)
-@ARCH_AARCH64_LINUX_TRUE@@HAVE_IFUNC_TRUE@am__objects_1 = \
-@ARCH_AARCH64_LINUX_TRUE@@HAVE_IFUNC_TRUE@ atomic_16.lo
+@ARCH_AARCH64_LINUX_TRUE@am__objects_1 = atomic_16.lo
am_libatomic_la_OBJECTS = gload.lo gstore.lo gcas.lo gexch.lo \
glfree.lo lock.lo init.lo fenv.lo fence.lo flag.lo \
$(am__objects_1)
@@ -425,7 +424,7 @@ libatomic_la_LDFLAGS = $(libatomic_version_info)
$(libatomic_version_script) \
$(lt_host_flags) $(libatomic_darwin_rpath)
libatomic_la_SOURCES = gload.c gstore.c gcas.c gexch.c glfree.c lock.c \
- init.c fenv.c fence.c flag.c $(am__append_2)
+ init.c fenv.c fence.c flag.c $(am__append_5)
SIZEOBJS = load store cas exch fadd fsub fand fior fxor fnand tas
EXTRA_libatomic_la_SOURCES = $(addsuffix _n.c,$(SIZEOBJS))
libatomic_la_DEPENDENCIES = $(libatomic_la_LIBADD) $(libatomic_version_dep)
@@ -451,9 +450,8 @@ all_c_files := $(foreach dir,$(search_path),$(wildcard
$(dir)/*.c))
# Then sort through them to find the one we want, and select the first.
M_SRC = $(firstword $(filter %/$(M_FILE), $(all_c_files)))
libatomic_la_LIBADD = $(foreach s,$(SIZES),$(addsuffix \
- _$(s)_.lo,$(SIZEOBJS))) $(am__append_1) $(am__append_3) \
- $(am__append_4) $(am__append_5)
-@ARCH_AARCH64_HAVE_LSE128_TRUE@@ARCH_AARCH64_LINUX_TRUE@@HAVE_IFUNC_TRUE@AM_CPPFLAGS
= -DHAVE_FEAT_LSE128
+ _$(s)_.lo,$(SIZEOBJS))) $(am__append_1) $(am__append_2) \
+ $(am__append_3) $(am__append_4)
@ARCH_AARCH64_LINUX_TRUE@@HAVE_IFUNC_TRUE@IFUNC_OPTIONS = -march=armv8-a+lse
@ARCH_ARM_LINUX_TRUE@@HAVE_IFUNC_TRUE@IFUNC_OPTIONS = -march=armv7-a+fp
-DHAVE_KERNEL64
@ARCH_I386_TRUE@@HAVE_IFUNC_TRUE@IFUNC_OPTIONS = -march=i586
diff --git a/libatomic/acinclude.m4 b/libatomic/acinclude.m4
index
d4f13174e2c92c4fffb86c106840dd26745fb600..6d2e0b1c355c470e4417696412864d20a6c1c62c
100644
--- a/libatomic/acinclude.m4
+++ b/libatomic/acinclude.m4
@@ -99,7 +99,6 @@ AC_DEFUN([LIBAT_TEST_FEAT_AARCH64_LSE128],[
])
LIBAT_DEFINE_YESNO([HAVE_FEAT_LSE128], [$libat_cv_have_feat_lse128],
[Have LSE128 support for 16 byte integers.])
- AM_CONDITIONAL([ARCH_AARCH64_HAVE_LSE128], [test x$libat_cv_have_feat_lse128
= xyes])
])
dnl
diff --git a/libatomic/config/linux/aarch64/atomic_16.S
b/libatomic/config/linux/aarch64/atomic_16.S
index
d4a360a6f7812351249d0a0ad7f60373b7f8c35a..4e3fa870b0338da4cfcdb0879ab8bed8d041a0a3
100644
--- a/libatomic/config/linux/aarch64/atomic_16.S
+++ b/libatomic/config/linux/aarch64/atomic_16.S
@@ -38,6 +38,15 @@
The libat_<op>_16_i1 entry points are used when LSE128 is available.
The libat_<op>_16_i2 entry points are used when LSE2 is available. */
+#include "auto-config.h"
+
+#if !HAVE_IFUNC
+# undef HAVE_FEAT_LSE128
+# define HAVE_FEAT_LSE128 0
+#endif
+
+#define HAVE_FEAT_LSE2 HAVE_IFUNC
+
#if HAVE_FEAT_LSE128
.arch armv9-a+lse128
#else
@@ -67,8 +76,8 @@ NAME: \
.cfi_endproc; \
.size NAME, .-NAME;
-#define ALIAS(NAME, FROM, TO) \
- ALIAS1 (FROM (NAME),TO (NAME))
+#define ALIAS(NAME, FROM, TO) ALIAS1 (FROM (NAME),TO (NAME))
+#define ALIAS2(NAME) ALIAS1 (__atomic_##NAME, libat_##NAME)
#define ALIAS1(ALIAS, NAME) \
.global ALIAS; \
@@ -125,6 +134,7 @@ ENTRY (libat_load_16)
END (libat_load_16)
+#if HAVE_FEAT_LSE2
ENTRY_FEAT (libat_load_16, LSE2)
cbnz w1, 1f
@@ -146,6 +156,7 @@ ENTRY_FEAT (libat_load_16, LSE2)
dmb ishld
ret
END_FEAT (libat_load_16, LSE2)
+#endif
ENTRY (libat_store_16)
@@ -165,6 +176,7 @@ ENTRY (libat_store_16)
END (libat_store_16)
+#if HAVE_FEAT_LSE2
ENTRY_FEAT (libat_store_16, LSE2)
cbnz w4, 1f
@@ -178,6 +190,7 @@ ENTRY_FEAT (libat_store_16, LSE2)
cbnz w4, 1b
ret
END_FEAT (libat_store_16, LSE2)
+#endif
ENTRY (libat_exchange_16)
@@ -279,6 +292,7 @@ ENTRY (libat_compare_exchange_16)
END (libat_compare_exchange_16)
+#if HAVE_FEAT_LSE2
ENTRY_FEAT (libat_compare_exchange_16, LSE2)
ldp exp0, exp1, [x1]
mov tmp0, exp0
@@ -313,6 +327,7 @@ ENTRY_FEAT (libat_compare_exchange_16, LSE2)
4: caspal exp0, exp1, in0, in1, [x0]
b 0b
END_FEAT (libat_compare_exchange_16, LSE2)
+#endif
ENTRY (libat_fetch_add_16)
@@ -710,13 +725,14 @@ END (libat_test_and_set_16)
/* Alias entry points which are the same in LSE2 and LSE128. */
-#if !HAVE_FEAT_LSE128
+#if HAVE_IFUNC
+# if !HAVE_FEAT_LSE128
ALIAS (libat_exchange_16, LSE128, LSE2)
ALIAS (libat_fetch_or_16, LSE128, LSE2)
ALIAS (libat_fetch_and_16, LSE128, LSE2)
ALIAS (libat_or_fetch_16, LSE128, LSE2)
ALIAS (libat_and_fetch_16, LSE128, LSE2)
-#endif
+# endif
ALIAS (libat_load_16, LSE128, LSE2)
ALIAS (libat_store_16, LSE128, LSE2)
ALIAS (libat_compare_exchange_16, LSE128, LSE2)
@@ -747,6 +763,29 @@ ALIAS (libat_fetch_nand_16, LSE2, CORE)
ALIAS (libat_nand_fetch_16, LSE2, CORE)
ALIAS (libat_test_and_set_16, LSE2, CORE)
+#else
+
+/* Emit __atomic_* entrypoints if no ifuncs. */
+
+ALIAS2 (load_16)
+ALIAS2 (store_16)
+ALIAS2 (compare_exchange_16)
+ALIAS2 (exchange_16)
+ALIAS2 (fetch_add_16)
+ALIAS2 (add_fetch_16)
+ALIAS2 (fetch_sub_16)
+ALIAS2 (sub_fetch_16)
+ALIAS2 (fetch_or_16)
+ALIAS2 (or_fetch_16)
+ALIAS2 (fetch_and_16)
+ALIAS2 (and_fetch_16)
+ALIAS2 (fetch_xor_16)
+ALIAS2 (xor_fetch_16)
+ALIAS2 (fetch_nand_16)
+ALIAS2 (nand_fetch_16)
+ALIAS2 (test_and_set_16)
+#endif
+
/* GNU_PROPERTY_AARCH64_* macros from elf.h for use in asm code. */
#define FEATURE_1_AND 0xc0000000
#define FEATURE_1_BTI 1
diff --git a/libatomic/config/linux/aarch64/host-config.h
b/libatomic/config/linux/aarch64/host-config.h
index
4e3541240633dc26de4a57c506b7e4b0c50185c2..d28449109a5e8beef650972e5a8c215671f4a01b
100644
--- a/libatomic/config/linux/aarch64/host-config.h
+++ b/libatomic/config/linux/aarch64/host-config.h
@@ -24,6 +24,19 @@
#if HAVE_IFUNC
#include <sys/auxv.h>
+#ifndef HWCAP_ATOMICS
+# define HWCAP_ATOMICS (1 << 8)
+#endif
+#ifndef HWCAP_CPUID
+# define HWCAP_CPUID (1 << 11)
+#endif
+#ifndef HWCAP_USCAT
+# define HWCAP_USCAT (1 << 25)
+#endif
+#ifndef HWCAP2_LSE128
+# define HWCAP2_LSE128 (1UL << 47)
+#endif
+
#if __has_include(<sys/ifunc.h>)
# include <sys/ifunc.h>
#else
@@ -35,7 +48,6 @@ typedef struct __ifunc_arg_t {
# define _IFUNC_ARG_HWCAP (1ULL << 62)
#endif
-#ifdef HWCAP_USCAT
# if N == 16
# define IFUNC_COND_1 (has_lse128 (hwcap, features))
# define IFUNC_COND_2 (has_lse2 (hwcap, features))
@@ -44,19 +56,6 @@ typedef struct __ifunc_arg_t {
# define IFUNC_COND_1 (hwcap & HWCAP_ATOMICS)
# define IFUNC_NCOND(N) 1
# endif
-#else
-# define IFUNC_COND_1 (false)
-# define IFUNC_NCOND(N) 1
-#endif
-
-#endif /* HAVE_IFUNC */
-
-/* All 128-bit atomic functions are defined in aarch64/atomic_16.S. */
-#if N == 16
-# define DONE 1
-#endif
-
-#ifdef HWCAP_USCAT
#define MIDR_IMPLEMENTOR(midr) (((midr) >> 24) & 255)
#define MIDR_PARTNUM(midr) (((midr) >> 4) & 0xfff)
@@ -89,11 +88,6 @@ has_lse2 (unsigned long hwcap, const __ifunc_arg_t *features)
#define AT_FEAT_FIELD(isar0) (((isar0) >> 20) & 15)
-/* Ensure backwards compatibility with glibc <= 2.38. */
-#ifndef HWCAP2_LSE128
-#define HWCAP2_LSE128 (1UL << 47)
-#endif
-
static inline bool
has_lse128 (unsigned long hwcap, const __ifunc_arg_t *features)
{
@@ -116,6 +110,14 @@ has_lse128 (unsigned long hwcap, const __ifunc_arg_t
*features)
return false;
}
+#endif /* HAVE_IFUNC */
+
+/* All 128-bit atomic functions are defined in aarch64/atomic_16.S. */
+#if N == 16
+# define DONE 1
+# if !HAVE_IFUNC
+# define IFUNC_ALT 1
+# endif
#endif
#include_next <host-config.h>
diff --git a/libatomic/configure b/libatomic/configure
index
8ab730d80828199caaf16d4aa9e1e36eeef280db..8ca72f08dfd21660e105c0ec3ad684c9b6aedb73
100755
--- a/libatomic/configure
+++ b/libatomic/configure
@@ -656,8 +656,6 @@ LIBAT_BUILD_VERSIONED_SHLIB_FALSE
LIBAT_BUILD_VERSIONED_SHLIB_TRUE
OPT_LDFLAGS
SECTION_LDFLAGS
-ARCH_AARCH64_HAVE_LSE128_FALSE
-ARCH_AARCH64_HAVE_LSE128_TRUE
SYSROOT_CFLAGS_FOR_TARGET
enable_aarch64_lse
libtool_VERSION
@@ -14740,15 +14738,6 @@ cat >>confdefs.h <<_ACEOF
_ACEOF
- if test x$libat_cv_have_feat_lse128 = xyes; then
- ARCH_AARCH64_HAVE_LSE128_TRUE=
- ARCH_AARCH64_HAVE_LSE128_FALSE='#'
-else
- ARCH_AARCH64_HAVE_LSE128_TRUE='#'
- ARCH_AARCH64_HAVE_LSE128_FALSE=
-fi
-
-
{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether byte ordering is
bigendian" >&5
$as_echo_n "checking whether byte ordering is bigendian... " >&6; }
@@ -16042,11 +16031,6 @@ if test -z "${ENABLE_DARWIN_AT_RPATH_TRUE}" && test -z
"${ENABLE_DARWIN_AT_RPATH
as_fn_error $? "conditional \"ENABLE_DARWIN_AT_RPATH\" was never defined.
Usually this means the macro was only invoked conditionally." "$LINENO" 5
fi
-if test -z "${ARCH_AARCH64_HAVE_LSE128_TRUE}" && test -z
"${ARCH_AARCH64_HAVE_LSE128_FALSE}"; then
- as_fn_error $? "conditional \"ARCH_AARCH64_HAVE_LSE128\" was never defined.
-Usually this means the macro was only invoked conditionally." "$LINENO" 5
-fi
-
if test -z "${LIBAT_BUILD_VERSIONED_SHLIB_TRUE}" && test -z
"${LIBAT_BUILD_VERSIONED_SHLIB_FALSE}"; then
as_fn_error $? "conditional \"LIBAT_BUILD_VERSIONED_SHLIB\" was never
defined.
Usually this means the macro was only invoked conditionally." "$LINENO" 5
