Patchwork [BZ,#19058] Better workaround for aliases of *_finite symbols in vector math library

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Submitter Andrew Senkevich
Date Nov. 26, 2015, 4:17 p.m.
Message ID <CAMXFM3uVghLzryBppyfCny2vxkhW4tORyFU=PM-O4=4+qp5yEw@mail.gmail.com>
Download mbox | patch
Permalink /patch/9833/
State New
Headers show

Comments

Andrew Senkevich - Nov. 26, 2015, 4:17 p.m.
Hi,

BZ #19058 shows that current workaround based on assembly aliases can
lead to link fail with -fopenmp and -flto options.
This patch makes workaround in another way to avoid such linker fails.

2015-11-26  Andrew Senkevich  <andrew.senkevich@intel.com>

       [BZ #19058]
       * math/Makefile ($(inst_libdir)/libm.so): Added libmvec_nonshared.a to
       AS_NEEDED.
       * sysdeps/x86/fpu/bits/math-vector.h: Removed code with old
       workaround.
       * sysdeps/x86_64/fpu/Makefile (libmvec-support,
       libmvec-static-only-routines): Added new file.
       * sysdeps/x86_64/fpu/svml_finite_alias.S: New file.



Is it OK for trunk and 2.22 branch (with mention in NEWS for branch)?


--
WBR,
Andrew
Joseph Myers - Nov. 26, 2015, 5:25 p.m.
On Thu, 26 Nov 2015, Andrew Senkevich wrote:

> Hi,
> 
> BZ #19058 shows that current workaround based on assembly aliases can
> lead to link fail with -fopenmp and -flto options.
> This patch makes workaround in another way to avoid such linker fails.
> 
> 2015-11-26  Andrew Senkevich  <andrew.senkevich@intel.com>
> 
>        [BZ #19058]
>        * math/Makefile ($(inst_libdir)/libm.so): Added libmvec_nonshared.a to
>        AS_NEEDED.
>        * sysdeps/x86/fpu/bits/math-vector.h: Removed code with old
>        workaround.
>        * sysdeps/x86_64/fpu/Makefile (libmvec-support,
>        libmvec-static-only-routines): Added new file.
>        * sysdeps/x86_64/fpu/svml_finite_alias.S: New file.

OK, but you need to take a more active lead in the gcc list discussion in 
seeking consensus for an appropriate solution for controlling what 
assembler name the names for vector variants are based on and then getting 
that implemented.
Aurelien Jarno - Dec. 2, 2015, 8:37 p.m.
On 2015-11-26 19:17, Andrew Senkevich wrote:
> Hi,
> 
> BZ #19058 shows that current workaround based on assembly aliases can
> lead to link fail with -fopenmp and -flto options.
> This patch makes workaround in another way to avoid such linker fails.
> 
> 2015-11-26  Andrew Senkevich  <andrew.senkevich@intel.com>
> 
>        [BZ #19058]
>        * math/Makefile ($(inst_libdir)/libm.so): Added libmvec_nonshared.a to
>        AS_NEEDED.
>        * sysdeps/x86/fpu/bits/math-vector.h: Removed code with old
>        workaround.
>        * sysdeps/x86_64/fpu/Makefile (libmvec-support,
>        libmvec-static-only-routines): Added new file.
>        * sysdeps/x86_64/fpu/svml_finite_alias.S: New file.
> 
> diff --git a/math/Makefile b/math/Makefile
> index 0ff3baa..6a926e9 100644
> --- a/math/Makefile
> +++ b/math/Makefile
> @@ -99,7 +99,7 @@ $(inst_libdir)/libm.so: $(common-objpfx)format.lds \
>         (echo '/* GNU ld script'; echo '*/';\
>          cat $<; \
>          echo 'GROUP ( $(slibdir)/libm.so$(libm.so-version) ' \
> -             'AS_NEEDED ( $(slibdir)/libmvec.so$(libmvec.so-version) ) )' \
> +             'AS_NEEDED ( $(slibdir)/libmvec_nonshared.a
> $(slibdir)/libmvec.so$(libmvec.so-version) ) )' \
>         ) > $@
>  endif

This is wrong. libmvec_nonshared.a is installed in $(libdir) and not in
$(slibdir). Thus linking fails.

Patch

diff --git a/math/Makefile b/math/Makefile
index 0ff3baa..6a926e9 100644
--- a/math/Makefile
+++ b/math/Makefile
@@ -99,7 +99,7 @@  $(inst_libdir)/libm.so: $(common-objpfx)format.lds \
        (echo '/* GNU ld script'; echo '*/';\
         cat $<; \
         echo 'GROUP ( $(slibdir)/libm.so$(libm.so-version) ' \
-             'AS_NEEDED ( $(slibdir)/libmvec.so$(libmvec.so-version) ) )' \
+             'AS_NEEDED ( $(slibdir)/libmvec_nonshared.a
$(slibdir)/libmvec.so$(libmvec.so-version) ) )' \
        ) > $@
 endif

diff --git a/sysdeps/x86/fpu/bits/math-vector.h
b/sysdeps/x86/fpu/bits/math-vector.h
index f9e798b..f3bfb86 100644
--- a/sysdeps/x86/fpu/bits/math-vector.h
+++ b/sysdeps/x86/fpu/bits/math-vector.h
@@ -53,34 +53,5 @@ 
 #  undef __DECL_SIMD_powf
 #  define __DECL_SIMD_powf __DECL_SIMD_x86_64

-/* Workaround to exclude unnecessary symbol aliases in libmvec
-   while GCC creates the vector names based on scalar asm name.
-   Corresponding discussion started at
-   <https://gcc.gnu.org/ml/gcc/2015-06/msg00173.html>.  */
-__asm__ ("_ZGVbN2v___log_finite = _ZGVbN2v_log");
-__asm__ ("_ZGVcN4v___log_finite = _ZGVcN4v_log");
-__asm__ ("_ZGVdN4v___log_finite = _ZGVdN4v_log");
-__asm__ ("_ZGVeN8v___log_finite = _ZGVeN8v_log");
-__asm__ ("_ZGVbN4v___logf_finite = _ZGVbN4v_logf");
-__asm__ ("_ZGVcN8v___logf_finite = _ZGVcN8v_logf");
-__asm__ ("_ZGVdN8v___logf_finite = _ZGVdN8v_logf");
-__asm__ ("_ZGVeN16v___logf_finite = _ZGVeN16v_logf");
-__asm__ ("_ZGVbN2v___exp_finite = _ZGVbN2v_exp");
-__asm__ ("_ZGVcN4v___exp_finite = _ZGVcN4v_exp");
-__asm__ ("_ZGVdN4v___exp_finite = _ZGVdN4v_exp");
-__asm__ ("_ZGVeN8v___exp_finite = _ZGVeN8v_exp");
-__asm__ ("_ZGVbN4v___expf_finite = _ZGVbN4v_expf");
-__asm__ ("_ZGVcN8v___expf_finite = _ZGVcN8v_expf");
-__asm__ ("_ZGVdN8v___expf_finite = _ZGVdN8v_expf");
-__asm__ ("_ZGVeN16v___expf_finite = _ZGVeN16v_expf");
-__asm__ ("_ZGVbN2vv___pow_finite = _ZGVbN2vv_pow");
-__asm__ ("_ZGVcN4vv___pow_finite = _ZGVcN4vv_pow");
-__asm__ ("_ZGVdN4vv___pow_finite = _ZGVdN4vv_pow");
-__asm__ ("_ZGVeN8vv___pow_finite = _ZGVeN8vv_pow");
-__asm__ ("_ZGVbN4vv___powf_finite = _ZGVbN4vv_powf");
-__asm__ ("_ZGVcN8vv___powf_finite = _ZGVcN8vv_powf");
-__asm__ ("_ZGVdN8vv___powf_finite = _ZGVdN8vv_powf");
-__asm__ ("_ZGVeN16vv___powf_finite = _ZGVeN16vv_powf");
-
 # endif
 #endif
diff --git a/sysdeps/x86_64/fpu/Makefile b/sysdeps/x86_64/fpu/Makefile
index f98f6cf..88742fa 100644
--- a/sysdeps/x86_64/fpu/Makefile
+++ b/sysdeps/x86_64/fpu/Makefile
@@ -20,7 +20,9 @@  libmvec-support += svml_d_cos2_core svml_d_cos4_core_avx \
                   svml_d_pow_data svml_s_powf4_core svml_s_powf8_core_avx \
                   svml_s_powf8_core svml_s_powf16_core svml_s_powf_data \
                   svml_s_sincosf4_core svml_s_sincosf8_core_avx \
-                  svml_s_sincosf8_core svml_s_sincosf16_core
+                  svml_s_sincosf8_core svml_s_sincosf16_core svml_finite_alias
+
+libmvec-static-only-routines = svml_finite_alias
 endif

 # Variables for libmvec tests.
diff --git a/sysdeps/x86_64/fpu/svml_finite_alias.S
b/sysdeps/x86_64/fpu/svml_finite_alias.S
new file mode 100644
index 0000000..f8bcfeb
--- /dev/null
+++ b/sysdeps/x86_64/fpu/svml_finite_alias.S
@@ -0,0 +1,59 @@ 
+/* These aliases added as workaround to exclude unnecessary symbol
+   aliases in libmvec.so while compiler creates the vector names
+   based on scalar asm name.  Corresponding discussion is at
+   <https://gcc.gnu.org/ml/gcc/2015-06/msg00173.html>.
+   Copyright (C) 2015 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <sysdep.h>
+
+#define ALIAS_IMPL(alias, target) \
+ENTRY (alias); \
+       call target; \
+       ret; \
+END (alias)
+
+       .text
+ALIAS_IMPL (_ZGVbN2v___log_finite, _ZGVbN2v_log)
+ALIAS_IMPL (_ZGVcN4v___log_finite, _ZGVcN4v_log)
+ALIAS_IMPL (_ZGVdN4v___log_finite, _ZGVdN4v_log)
+ALIAS_IMPL (_ZGVeN8v___log_finite, _ZGVeN8v_log)
+
+ALIAS_IMPL (_ZGVbN4v___logf_finite, _ZGVbN4v_logf)
+ALIAS_IMPL (_ZGVcN8v___logf_finite, _ZGVcN8v_logf)
+ALIAS_IMPL (_ZGVdN8v___logf_finite, _ZGVdN8v_logf)
+ALIAS_IMPL (_ZGVeN16v___logf_finite, _ZGVeN16v_logf)
+
+ALIAS_IMPL (_ZGVbN2v___exp_finite, _ZGVbN2v_exp)
+ALIAS_IMPL (_ZGVcN4v___exp_finite, _ZGVcN4v_exp)
+ALIAS_IMPL (_ZGVdN4v___exp_finite, _ZGVdN4v_exp)
+ALIAS_IMPL (_ZGVeN8v___exp_finite, _ZGVeN8v_exp)
+
+ALIAS_IMPL (_ZGVbN4v___expf_finite, _ZGVbN4v_expf)
+ALIAS_IMPL (_ZGVcN8v___expf_finite, _ZGVcN8v_expf)
+ALIAS_IMPL (_ZGVdN8v___expf_finite, _ZGVdN8v_expf)
+ALIAS_IMPL (_ZGVeN16v___expf_finite, _ZGVeN16v_expf)
+
+ALIAS_IMPL (_ZGVbN2vv___pow_finite, _ZGVbN2vv_pow)
+ALIAS_IMPL (_ZGVcN4vv___pow_finite, _ZGVcN4vv_pow)
+ALIAS_IMPL (_ZGVdN4vv___pow_finite, _ZGVdN4vv_pow)
+ALIAS_IMPL (_ZGVeN8vv___pow_finite, _ZGVeN8vv_pow)
+
+ALIAS_IMPL (_ZGVbN4vv___powf_finite, _ZGVbN4vv_powf)
+ALIAS_IMPL (_ZGVcN8vv___powf_finite, _ZGVcN8vv_powf)
+ALIAS_IMPL (_ZGVdN8vv___powf_finite, _ZGVdN8vv_powf)
+ALIAS_IMPL (_ZGVeN16vv___powf_finite, _ZGVeN16vv_powf)