Commit Graph

466 Commits

Author SHA1 Message Date
Stefan Liebler
970449311d S390: Refactor stpcpy ifunc handling.
The ifunc handling for stpcpy is adjusted in order to omit ifunc
variants if those will never be used as the minimum architecture level
already supports newer CPUs by default.
Glibc internal calls will then also use the "newer" ifunc variant.

ChangeLog:

	* sysdeps/s390/multiarch/Makefile
	(sysdep_routines): Remove stpcpy variants.
	* sysdeps/s390/Makefile (sysdep_routines): Add stpcpy variants.
	* sysdeps/s390/multiarch/ifunc-impl-list.c
	(__libc_ifunc_impl_list): Refactor ifunc handling for stpcpy.
	* sysdeps/s390/multiarch/stpcpy-c.c: Move to ...
	* sysdeps/s390/stpcpy-c.c: ... here and adjust ifunc handling.
	* sysdeps/s390/multiarch/stpcpy-vx.S: Move to ...
	* sysdeps/s390/stpcpy-vx.S: ... here and adjust ifunc handling.
	* sysdeps/s390/multiarch/stpcpy.c: Move to ...
	* sysdeps/s390/stpcpy.c: ... here and adjust ifunc handling.
	* sysdeps/s390/ifunc-stpcpy.h: New file.
2018-12-18 13:57:11 +01:00
Stefan Liebler
914a4e0557 S390: Refactor strcpy ifunc handling.
The ifunc handling for strcpy is adjusted in order to omit ifunc
variants if those will never be used as the minimum architecture level
already supports newer CPUs by default.
Glibc internal calls will then also use the "newer" ifunc variant.

Note: The fallback s390-32/s390-64 ifunc variants with mvst instruction
are now moved to the unified strcpy-z900.S file which can be used for
31/64bit. The s390-32/s390-64 files multiarch/strcpy.c and strcpy.S
are deleted.

ChangeLog:

	* sysdeps/s390/multiarch/Makefile
	(sysdep_routines): Remove strcpy variants.
	* sysdeps/s390/Makefile (sysdep_routines): Add strcpy variants.
	* sysdeps/s390/multiarch/ifunc-impl-list.c
	(__libc_ifunc_impl_list): Refactor ifunc handling for strcpy.
	* sysdeps/s390/multiarch/strcpy-vx.S: Move to ...
	* sysdeps/s390/strcpy-vx.S: ... here and adjust ifunc handling.
	* sysdeps/s390/multiarch/strcpy.c: Move to ...
	* sysdeps/s390/strcpy.c: ... here and adjust ifunc handling.
	* sysdeps/s390/ifunc-strcpy.h: New file.
	* sysdeps/s390/s390-64/strcpy.S: Move to ...
	* sysdeps/s390/strcpy-z900.S: ... here and adjust to be usable
	for 31/64bit and ifunc handling.
	* sysdeps/s390/s390-32/multiarch/strcpy.c: Delete file.
	* sysdeps/s390/s390-64/multiarch/strcpy.c: Likewise.
	* sysdeps/s390/s390-32/strcpy.S: Likewise.
2018-12-18 13:57:10 +01:00
Stefan Liebler
de10e44dda S390: Refactor strnlen ifunc handling.
The ifunc handling for strnlen is adjusted in order to omit ifunc
variants if those will never be used as the minimum architecture level
already supports newer CPUs by default.
Glibc internal calls will then also use the "newer" ifunc variant.

ChangeLog:

	* sysdeps/s390/multiarch/Makefile
	(sysdep_routines): Remove strnlen variants.
	* sysdeps/s390/Makefile (sysdep_routines): Add strnlen variants.
	* sysdeps/s390/multiarch/ifunc-impl-list.c
	(__libc_ifunc_impl_list): Refactor ifunc handling for strnlen.
	* sysdeps/s390/multiarch/strnlen-c.c: Move to ...
	* sysdeps/s390/strnlen-c.c: ... here and adjust ifunc handling.
	* sysdeps/s390/multiarch/strnlen-vx.S: Move to ...
	* sysdeps/s390/strnlen-vx.S: ... here and adjust ifunc handling.
	* sysdeps/s390/multiarch/strnlen.c: Move to ...
	* sysdeps/s390/strnlen.c: ... here and adjust ifunc handling.
	* sysdeps/s390/ifunc-strnlen.h: New file.
2018-12-18 13:57:10 +01:00
Stefan Liebler
ff3ca3743a S390: Refactor strlen ifunc handling.
The ifunc handling for strlen is adjusted in order to omit ifunc
variants if those will never be used as the minimum architecture level
already supports newer CPUs by default.
Glibc internal calls will then also use the "newer" ifunc variant.

ChangeLog:

	* sysdeps/s390/multiarch/Makefile
	(sysdep_routines): Remove strlen variants.
	* sysdeps/s390/Makefile (sysdep_routines): Add strlen variants.
	* sysdeps/s390/multiarch/ifunc-impl-list.c
	(__libc_ifunc_impl_list): Refactor ifunc handling for strlen.
	* sysdeps/s390/multiarch/strlen-c.c: Move to ...
	* sysdeps/s390/strlen-c.c: ... here and adjust ifunc handling.
	* sysdeps/s390/multiarch/strlen-vx.S: Move to ...
	* sysdeps/s390/strlen-vx.S: ... here and adjust ifunc handling.
	* sysdeps/s390/multiarch/strlen.c: Move to ...
	* sysdeps/s390/strlen.c: ... here and adjust ifunc handling.
	* sysdeps/s390/ifunc-strlen.h: New file.
2018-12-18 13:57:10 +01:00
Stefan Liebler
d2c4c403fe S390: Add z13 memmem ifunc variant.
The new vector variant of memmem is using the common code
implementation, but instead of calling the default
mem* functions, the vector variants are called.

ChangeLog:

	* sysdeps/s390/Makefile (sysdep_routines): Add memmem variants.
	* sysdeps/s390/multiarch/ifunc-impl-list.c
	(__libc_ifunc_impl_list): Add ifunc variants for memmem.
	* sysdeps/s390/ifunc-memmem.h: New file.
	* sysdeps/s390/memmem.c: Likewise.
	* sysdeps/s390/memmem-c.c: Likewise.
	* sysdeps/s390/memmem-vx.c: Likewise.
2018-12-18 13:57:09 +01:00
Stefan Liebler
8c25dddd2e S390: Add z13 strstr ifunc variant.
The new vector variant of strstr is using the common code
implementation, but instead of calling the default
str* / mem* functions, the vector variants are called.

ChangeLog:

	* sysdeps/s390/Makefile (sysdep_routines): Add strstr variants.
	* sysdeps/s390/multiarch/ifunc-impl-list.c
	(__libc_ifunc_impl_list): Add ifunc variants for strstr.
	* sysdeps/s390/ifunc-strstr.h: New file.
	* sysdeps/s390/strstr.c: Likewise.
	* sysdeps/s390/strstr-c.c: Likewise.
	* sysdeps/s390/strstr-vx.c: Likewise.
2018-12-18 13:57:09 +01:00
Stefan Liebler
cdd927d98c S390: Add z13 memmove ifunc variant.
This patch introduces a z13 specific ifunc variant for memmove.
As the common code implementation, it checks if we can copy from
the beginning to the end - with z196 memcpy implementation - or
if we have to copy from the end to the beginning.
The latter case is done by using vector load/store instructions.

If vector instructions are not available, the common-code is
used as fallback.  Therefore it is implemented in memmove-c with
a different name.
Furthermore the ifunc logic decides if we need the common-code
implementation at all.  If vector instructions are supported
due to the minimum architecture level set we can skip the
common-code ifunc variant.

ChangeLog:

	* sysdeps/s390/Makefile (sysdep_routines): Add memmove-c.
	* sysdeps/s390/ifunc-memcpy.h (HAVE_MEMMOVE_IFUNC,
	HAVE_MEMMOVE_IFUNC_AND_VX_SUPPORT, MEMMOVE_DEFAULT,
	HAVE_MEMMOVE_C, MEMMOVE_C,  HAVE_MEMMOVE_Z13, MEMMOVE_Z13):
	New defines.
	* sysdeps/s390/memcpy-z900.S: Add z13 memmove implementation.
	* sysdeps/s390/memmove-c.c: New file.
	* sysdeps/s390/memmove.c: Likewise.
	* sysdeps/s390/multiarch/ifunc-impl-list.c
	(__libc_ifunc_impl_list): Add ifunc variants for memmove.
2018-12-18 13:57:08 +01:00
Stefan Liebler
2ee1bc57ab S390: Add configure check to detect z13 as mininum architecture level set.
Add a configure check for z13 in the same way as done for z196.

ChangeLog:

	* config.h.in (HAVE_S390_MIN_Z13_ZARCH_ASM_SUPPORT): New undefine.
	* sysdeps/s390/configure.ac: Add check for z13 support.
	* sysdeps/s390/configure: Regenerated.
2018-12-18 13:57:08 +01:00
Stefan Liebler
d097d97626 S390: Use memcpy for forward cases in memmove.
The s390/s390x memcpy implementations are safe to be
used by memmove.  Starting with this commit, memmove is
using memcpy for the forward cases on s390.

ChangeLog:

	* sysdeps/s390/memcopy.h: New file.
2018-12-18 13:57:07 +01:00
Stefan Liebler
e099aab060 S390: Remove s390 specific implementation of bcopy.
Nowadays gcc is automatically replacing a call to bcopy
with a call to memmove.  Thus only old binaries will call
the s390 specific bcopy implementation.

The s390 specific implementation is using an own
implementation for memcpy in the forward case and is
relying on memmove in the backward case.

After removing the s390 specific bcopy, the common code
bcopy is used.  It just performs a tail call to memmove.

ChangeLog:
	* sysdeps/s390/s390-32/bcopy.S: Remove.
	* sysdeps/s390/s390-64/bcopy.S: Likewise.
2018-12-18 13:57:07 +01:00
Stefan Liebler
18eb862d45 S390: Refactor memcpy/mempcpy ifunc handling.
This patch moves all ifunc variants for memcpy/mempcpy
to sysdeps/s390/memcpy-z900.S. The configure-check/preprocessor logic
in sysdeps/s390/ifunc-memcpy.h decides if ifunc is needed at all
and which ifunc variants should be available.
E.g. if the compiler/assembler already supports z196 by default,
the older ifunc variants are not included.
If we only need the newest ifunc variant,
then we can skip ifunc at all.

Therefore the ifunc-resolvers and __libc_ifunc_impl_list are adjusted
in order to handle only the available ifunc variants.

ChangeLog:

	* sysdeps/s390/ifunc-memcpy.h: New File.
	* sysdeps/s390/memcpy.S: Move to ...
	* sysdeps/s390/memcpy-z900.S ... here.
	Move implementations from memcpy-s390x.s to here.
	* sysdeps/s390/multiarch/memcpy-s390x.S: Delete File.
	* sysdeps/s390/multiarch/Makefile (sysdep_routines):
	Remove memcpy/mempcpy variants.
	* sysdeps/s390/Makefile (sysdep_routines):
	Add memcpy/mempcpy variants.
	* sysdeps/s390/multiarch/ifunc-impl-list.c
	(__libc_ifunc_impl_list): Adjust ifunc variants for
	memcpy and mempcpy.
	* sysdeps/s390/multiarch/memcpy.c: Move ifunc resolver
	to ...
	* sysdeps/s390/memcpy.c: ... here.
	Adjust ifunc variants for memcpy.
	* sysdeps/s390/multiarch/mempcpy.c: Move to ...
	* sysdeps/s390/mempcpy.c: ... here.
	Adjust ifunc variants for mempcpy.
	* sysdeps/s390/mempcpy.S: Delete file.
2018-12-18 13:57:06 +01:00
Stefan Liebler
df3eb8de31 S390: Unify 31/64bit memcpy.
The implementation of memcpy/mempcpy for s390-32 (31bit)
and s390-64 (64bit) is nearly the same.
This patch unifies it for maintability reasons.

__mem[p]cpy_z10 and __mem[p]cpy_z196 differs between 31 and 64bit:
-31bit needs .machinemode "zarch_nohighgprs" and llgfr   %r4,%r4
-lr vs lgr; lgr can be also used on 31bit as this ifunc variant
is only called if we are on a zarch machine.

__mem[p]cpy_default differs between 31 and 64bit:
-Some 31bit vs 64bit instructions (e.g. ltr vs ltgr.
Solved with 31/64 specific instruction macros).
-The address of mvc instruction is setup in different ways
(larl vs bras). Solved with #if defined __s390x__.

__memcpy_mvcle differs between 31 and 64bit:
-lr vs lgr; ahi vs aghi;
Solved with 31/64bit specific instruction macros.

Otherwise 31/64bit implementation has the same structure of the code.

ChangeLog:

	* sysdeps/s390/s390-64/memcpy.S: Move to ...
	* sysdeps/s390/memcpy.S: ... here.
	Adjust to be usable for 31/64bit.
	* sysdeps/s390/s390-32/memcpy.S: Delete File.
	* sysdeps/s390/multiarch/Makefile (sysdep_routines): Add memcpy.
	* sysdeps/s390/s390-32/multiarch/Makefile: Delete file.
	* sysdeps/s390/s390-64/multiarch/Makefile: Likewise.
	* sysdeps/s390/s390-64/multiarch/memcpy-s390x.S: Move to ...
	* sysdeps/s390/multiarch/memcpy-s390x.S: ... here.
	Adjust to be usable for 31/64bit.
	* sysdeps/s390/s390-32/multiarch/memcpy-s390.S: Delete File.
	* sysdeps/s390/s390-64/multiarch/memcpy.c: Move to ...
	* sysdeps/s390/multiarch/memcpy.c: ... here.
	* sysdeps/s390/s390-32/multiarch/memcpy.c: Delete File.
2018-12-18 13:57:06 +01:00
Stefan Liebler
b7e024a838 S390: Refactor memcmp ifunc handling.
This patch moves all ifunc variants for memcmp
to sysdeps/s390/memcmp-z900.S. The configure-check/preprocessor logic
in sysdeps/s390/ifunc-memcmp.h decides if ifunc is needed at all
and which ifunc variants should be available.
E.g. if the compiler/assembler already supports z196 by default,
the older ifunc variants are not included.
If we only need the newest ifunc variant,
then we can skip ifunc at all.

Therefore the ifunc-resolvers and __libc_ifunc_impl_list are adjusted
in order to handle only the available ifunc variants.

ChangeLog:

	* sysdeps/s390/ifunc-memcmp.h: New File.
	* sysdeps/s390/memcmp.S: Move to ...
	* sysdeps/s390/memcmp-z900.S ... here.
	Move implementations from memcmp-s390x.s to here.
	* sysdeps/s390/multiarch/memcmp-s390x.S: Delete File.
	* sysdeps/s390/multiarch/Makefile (sysdep_routines):
	Remove memcmp variants.
	* sysdeps/s390/Makefile (sysdep_routines):
	Add memcmp variants.
	* sysdeps/s390/multiarch/ifunc-impl-list.c
	(__libc_ifunc_impl_list): Adjust ifunc variants for
	memcmp.
	* sysdeps/s390/multiarch/memcmp.c: Move ifunc resolver
	to ...
	* sysdeps/s390/memcmp.c: ... here.
	Adjust ifunc variants for memcmp.
2018-12-18 13:57:05 +01:00
Stefan Liebler
6c6b8c7470 S390: Unify 31/64bit memcmp.
The implementation of memcmp for s390-32 (31bit) and
s390-64 (64bit) is nearly the same.
This patch unifies it for maintability reasons.

__memcmp_z10 and __memcmp_z196 differs between 31 and 64bit:
-31bit needs .machinemode "zarch_nohighgprs" and llgfr   %r4,%r4
-lr vs lgr and some other instructions:
But lgr and co can be also used on 31bit as this ifunc variant
is only called if we are on a zarch machine.

__memcmp_default differs between 31 and 64bit:
-Some 31bit vs 64bit instructions (e.g. ltr vs ltgr.
Solved with 31/64 specific instruction macros).
-The address of mvc instruction is setup in different ways
(larl vs bras). Solved with #if defined __s390x__.

Otherwise 31/64bit implementation has the same structure of the code.

ChangeLog:

	* sysdeps/s390/s390-64/memcmp.S: Move to ...
	* sysdeps/s390/memcmp.S: ... here.
	Adjust to be usable for 31/64bit.
	* sysdeps/s390/s390-32/memcmp.S: Delete File.
	* sysdeps/s390/multiarch/Makefile (sysdep_routines): Add memcmp.
	* sysdeps/s390/s390-32/multiarch/Makefile (sysdep_routines):
	Remove memcmp.
	* sysdeps/s390/s390-64/multiarch/Makefile: Likewise.
	* sysdeps/s390/s390-64/multiarch/memcmp-s390x.S: Move to ...
	* sysdeps/s390/multiarch/memcmp-s390x.S: ... here.
	Adjust to be usable for 31/64bit.
	* sysdeps/s390/s390-32/multiarch/memcmp-s390.S: Delete File.
	* sysdeps/s390/s390-64/multiarch/memcmp.c: Move to ...
	* sysdeps/s390/multiarch/memcmp.c: ... here.
	* sysdeps/s390/s390-32/multiarch/memcmp.c: Delete File.
2018-12-18 13:57:05 +01:00
Stefan Liebler
07be392807 S390: Implement bzero with memset.
This patch removes the bzero s390 implementation with mvcle and
adds entry points for bzero in memset ifunc variants.
Therefore an ifunc resolver is implemented for bzero, too.

ChangeLog:

	* sysdeps/s390/s390-32/bzero.S: Delete file.
	* sysdeps/s390/s390-64/bzero.S: Likewise.
	* sysdeps/s390/Makefile (sysdep_routines): Add bzero.
	* sysdeps/s390/bzero.c: New file.
	* sysdeps/s390/memset-z900.S: Add bzero entry points.
	* sysdeps/s390/ifunc-memset.h: Add bzero function macros.
	* sysdeps/s390/multiarch/ifunc-impl-list.c
	(__libc_ifunc_impl_list): Add bzero ifunc variants.
2018-12-18 13:57:05 +01:00
Stefan Liebler
712a254a97 S390: Refactor memset ifunc handling.
This patch moves all ifunc variants for memset
to sysdeps/s390/memset-z900.S. The configure-check/preprocessor logic
in sysdeps/s390/ifunc-memset.h decides if ifunc is needed at all
and which ifunc variants should be available.
E.g. if the compiler/assembler already supports z196 by default,
the older ifunc variants are not included.
If we only need the newest ifunc variant,
then we can skip ifunc at all.

Therefore the ifunc-resolvers and __libc_ifunc_impl_list are adjusted
in order to handle only the available ifunc variants.

ChangeLog:

	* sysdeps/s390/ifunc-memset.h: New File.
	* sysdeps/s390/memset.S: Move to ...
	* sysdeps/s390/memset-z900.S ... here.
	Move implementations from memset-s390x.s to here.
	* sysdeps/s390/multiarch/memset-s390x.S: Delete File.
	* sysdeps/s390/multiarch/Makefile (sysdep_routines):
	Remove memset variants.
	* sysdeps/s390/Makefile (sysdep_routines):
	Add memset variants.
	* sysdeps/s390/multiarch/ifunc-impl-list.c
	(__libc_ifunc_impl_list): Adjust ifunc variants for
	memset.
	* sysdeps/s390/multiarch/memset.c: Move ifunc resolver
	to ...
	* sysdeps/s390/memset.c: ... here.
	Adjust ifunc variants for memset.
2018-12-18 13:57:04 +01:00
Stefan Liebler
5f1743d118 S390: Unify 31/64bit memset.
The implementation of memset for s390-32 (31bit) and
s390-64 (64bit) is nearly the same.
This patch unifies it for maintability reasons.

__memset_z10 and __memset_z196 differs between 31 and 64bit:
-31bit needs .machinemode "zarch_nohighgprs" and llgfr   %r4,%r4
-lr vs lgr and some other instructions:
But lgr and co can be also used on 31bit as this ifunc variant
is only called if we are on a zarch machine.

__memset_default differs between 31 and 64bit:
-Some 31bit vs 64bit instructions (e.g. ltr vs ltgr.
Solved with 31/64 specific instruction macros).
-The address of mvc instruction is setup in different ways
(larl vs bras). Solved with #if defined __s390x__.

Otherwise 31/64bit implementation has the same structure of the code.

ChangeLog:

	* sysdeps/s390/s390-64/memset.S: Move to ...
	* sysdeps/s390/memset.S: ... here.
	Adjust to be usable for 31/64bit.
	* sysdeps/s390/s390-32/memset.S: Delete File.
	* sysdeps/s390/multiarch/Makefile (sysdep_routines): Add memset.
	* sysdeps/s390/s390-32/multiarch/Makefile (sysdep_routines):
	Remove memset.
	* sysdeps/s390/s390-64/multiarch/Makefile: Likewise.
	* sysdeps/s390/s390-64/multiarch/memset-s390x.S: Move to ...
	* sysdeps/s390/multiarch/memset-s390x.S: ... here.
	Adjust to be usable for 31/64bit.
	* sysdeps/s390/s390-32/multiarch/memset-s390.S: Delete File.
	* sysdeps/s390/s390-64/multiarch/memset.c: Move to ...
	* sysdeps/s390/multiarch/memset.c: ... here.
	* sysdeps/s390/s390-32/multiarch/memset.c: Delete File.
2018-12-18 13:57:04 +01:00
Stefan Liebler
e8023f2685 S390: Use hwcap instead of dl_hwcap in ifunc-resolvers.
The renaming of hwcap arguments in ifunc-resolvers is needed
in order to prepare for further commits which refactors
ifunc handling for memset, memcmp, and memcpy.  Now you are able
to use s390_libc_ifunc_init which stores the stfle bits
within the expression for an ifunc-resolver generated by
s390_libc_ifunc_expr.

ChangeLog:

	* sysdeps/s390/multiarch/ifunc-resolve.h
	(s390_libc_ifunc_init, s390_libc_ifunc,
	s390_vx_libc_ifunc2_redirected): Use hwcap instead of dl_hwcap.
2018-12-18 13:57:03 +01:00
Stefan Liebler
b8686c0d70 S390: Add configure check to detect z10 as mininum architecture level set.
Add a configure check for z10 in the same way as done for z196.

ChangeLog:

	* config.h.in (HAVE_S390_MIN_Z10_ZARCH_ASM_SUPPORT): New undefine.
	* sysdeps/s390/configure.ac: Add check for z10 support.
	* sysdeps/s390/configure: Regenerated.
2018-12-18 13:57:03 +01:00
Stefan Liebler
9a0b697033 S390: Regenerate ULPs.
Regenerated ulps from scratch as builds with gcc 5.5 / 6.4
resulted in +1 ulps.

ChangeLog:

	* sysdeps/s390/fpu/libm-test-ulps: Regenerated.
2018-11-28 15:20:18 +01:00
Stefan Liebler
38245425a9 S390: Regenerate ULPs.
Regenerated ulps from scratch after recent changes.

ChangeLog:

	* sysdeps/s390/fpu/libm-test-ulps: Regenerated.
2018-09-06 14:29:01 +02:00
Paul Pluzhnikov
a6e8926f8d [BZ #20271] Add newlines in __libc_fatal calls. 2018-08-31 18:04:32 -07:00
Florian Weimer
86a6c75a29 math: Regenerate s390 ulps
Based on results on a s390x 2964 machine, with -march=z196 and
-mtune=zEC12, and separately with -march=z13 and -mtune=z14.
2018-08-17 16:39:13 +02:00
Ilya Leoshkevich
8f135efcad S390: Fix unwind in 32-bit _mcount
* Fix CFI offset for %r14.
* Fix unwound value of %r15 being off by 128 bytes.

ChangeLog:

	* sysdeps/s390/s390-32/s390-mcount.S (_mcount):
	Fix unwind.
2018-08-10 09:07:44 +02:00
Ilya Leoshkevich
71c01af52f S390: Implement 64-bit __fentry__
* Since __fentry__ is almost the same as _mcount, reuse the code by
  #including it twice with different #defines around.
* Remove LA usages - they are needed in 31-bit mode to clear the top
  bit, but in 64-bit they appear to do nothing.
* Add CFI rule for the nonstandard return register. This rule applies
  to the current function (binutils generates a new CIE - see
  gas/dw2gencfi.c:select_cie_for_fde()), so it is not necessary to put
  __fentry__ into a new file.
* Fix CFI offset for %r14.
* Add CFI rule for %r0.
* Fix unwound value of %r15 being off by 244 bytes.
* Unwinding in __fentry__@plt does not work, no plan to fix it - it
  would require asking linker to generate CFI for return address in
  %r0.  From functional perspective keeping it broken is fine, since
  the callee did not have a chance to do anything yet.  From
  convenience perspective it would be possible to enhance GDB in the
  future to treat __fentry__@plt in a special way.
* Fix whitespace.
* Fix offsets in comments, which were copied from 32-bit code.
* 32-bit version will not be implemented, since it's not compatible
  with the corresponding PLT stubs: they assume %r12 points to GOT,
  which is not the case for gcc-emitted __fentry__ stub, which runs
  before the prolog.

This patch adds the runtime support in glibc for the -mfentry
gcc feature introduced in [1] and [2].

[1] https://gcc.gnu.org/ml/gcc-patches/2018-07/msg00784.html
[2] https://gcc.gnu.org/ml/gcc-patches/2018-07/msg00912.html

ChangeLog:

	* sysdeps/s390/s390-64/Versions (__fentry__): Add.
	* sysdeps/s390/s390-64/s390x-mcount.S: Move the common
	code to s390x-mcount.h and #include it.
	* sysdeps/s390/s390-64/s390x-mcount.h: New file.
	* sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
	(__fentry__): Add.
2018-08-10 09:07:44 +02:00
Ilya Leoshkevich
69e2444ab1 S390: Test that lazy binding does not clobber R0
The following combinations need to be tested:
* 32- (g5, esa and zarch) and 64-bit
  * linux32 glibc/configure CC='gcc -m31 -march=g5'
  * linux32 glibc/configure CC='gcc -m31'
  * linux32 glibc/configure CC='gcc -m31 -mzarch'
* With and without VX:
  * glibc/configure libc_cv_asm_s390_vx=no
* With and without profiling (using LD_PROFILE)
* With and without pltexit (using LD_AUDIT)

ChangeLog:

	* sysdeps/s390/Makefile: Register the new tests.
	* sysdeps/s390/tst-dl-runtime-mod.S: New file.
	* sysdeps/s390/tst-dl-runtime-profile-audit.c: New file.
	* sysdeps/s390/tst-dl-runtime-profile-noaudit.c: New file.
	* sysdeps/s390/tst-dl-runtime-resolve-audit.c: New file.
	* sysdeps/s390/tst-dl-runtime-resolve-noaudit.c: New file.
	* sysdeps/s390/tst-dl-runtime.c: New file.
2018-08-10 09:07:43 +02:00
Ilya Leoshkevich
bde6320f39 S390: Do not clobber R0 in 64-bit _dl_runtime_profile
Preparation for the usage of R0 by __fentry__.

ChangeLog:

	* sysdeps/s390/s390-64/dl-trampoline.h (_dl_runtime_profile):
	Do not clobber R0.
2018-08-10 09:07:43 +02:00
Ilya Leoshkevich
5755f5e4cc S390: Do not clobber R0 in 64-bit _dl_runtime_resolve
Preparation for the usage of R0 by __fentry__.

ChangeLog:

	* sysdeps/s390/s390-64/dl-trampoline.h (_dl_runtime_resolve):
	Do not clobber R0.
2018-08-10 09:07:43 +02:00
Ilya Leoshkevich
c8ad85225b S390: Do not clobber R0 in 32-bit _dl_runtime_profile
Preparation for the usage of R0 by __fentry__.

ChangeLog:

	* sysdeps/s390/s390-32/dl-trampoline.h (_dl_runtime_profile):
	Do not clobber R0.
2018-08-10 09:07:43 +02:00
Ilya Leoshkevich
b215eee1e1 S390: Do not clobber R0 in 32-bit _dl_runtime_resolve
Preparation for the usage of R0 by __fentry__.

ChangeLog:

	* sysdeps/s390/s390-32/dl-trampoline.h (_dl_runtime_resolve):
	Do not clobber R0.
2018-08-10 09:07:42 +02:00
Ilya Leoshkevich
329c6fec8b S390: Use symbolic offsets for stack variables in 64-bit _dl_runtime_profile
Maintainability improvement.

ChangeLog:

	* sysdeps/s390/s390-64/dl-trampoline.h (_dl_runtime_profile):
	Use symbolic offsets for stack variables.
2018-08-10 09:07:42 +02:00
Ilya Leoshkevich
0fb7afa2f9 S390: Use symbolic offsets for stack variables in 64-bit _dl_runtime_resolve
Maintainability improvement.

ChangeLog:

	* sysdeps/s390/s390-64/dl-trampoline.h (_dl_runtime_resolve):
	Use symbolic offsets for stack variables.
2018-08-10 09:07:42 +02:00
Ilya Leoshkevich
6954059ad6 S390: Use symbolic offsets for stack variables in 32-bit _dl_runtime_profile
Maintainability improvement.

ChangeLog:

	* sysdeps/s390/s390-32/dl-trampoline.h (_dl_runtime_profile):
	Use symbolic offsets for stack variables.
2018-08-10 09:07:41 +02:00
Ilya Leoshkevich
c7099673aa S390: Use symbolic offsets for stack variables in 32-bit _dl_runtime_resolve
Maintainability improvement.

ChangeLog:

	* sysdeps/s390/s390-32/dl-trampoline.h (_dl_runtime_resolve):
	Use symbolic offsets for stack variables.
2018-08-10 09:07:41 +02:00
H.J. Lu
67c0579669 Mark _init and _fini as hidden [BZ #23145]
_init and _fini are special functions provided by glibc for linker to
define DT_INIT and DT_FINI in executable and shared library.  They
should never be put in dynamic symbol table.  This patch marks them as
hidden to remove them from dynamic symbol table.

Tested with build-many-glibcs.py.

	[BZ #23145]
	* elf/Makefile (tests-special): Add $(objpfx)check-initfini.out.
	($(all-built-dso:=.dynsym): New target.
	(common-generated): Add $(all-built-dso:$(common-objpfx)%=%.dynsym).
	($(objpfx)check-initfini.out): New target.
	(generated): Add check-initfini.out.
	* scripts/check-initfini.awk: New file.
	* sysdeps/aarch64/crti.S (_init): Mark as hidden.
	(_fini): Likewise.
	* sysdeps/alpha/crti.S (_init): Mark as hidden.
	(_fini): Likewise.
	* sysdeps/arm/crti.S (_init): Mark as hidden.
	(_fini): Likewise.
	* sysdeps/hppa/crti.S (_init): Mark as hidden.
	(_fini): Likewise.
	* sysdeps/i386/crti.S (_init): Mark as hidden.
	(_fini): Likewise.
	* sysdeps/ia64/crti.S (_init): Mark as hidden.
	(_fini): Likewise.
	* sysdeps/m68k/crti.S (_init): Mark as hidden.
	(_fini): Likewise.
	* sysdeps/microblaze/crti.S (_init): Mark as hidden.
	(_fini): Likewise.
	* sysdeps/mips/mips32/crti.S (_init): Mark as hidden.
	(_fini): Likewise.
	* sysdeps/mips/mips64/n32/crti.S (_init): Mark as hidden.
	(_fini): Likewise.
	* sysdeps/mips/mips64/n64/crti.S (_init): Mark as hidden.
	(_fini): Likewise.
	* sysdeps/nios2/crti.S (_init): Mark as hidden.
	(_fini): Likewise.
	* sysdeps/powerpc/powerpc32/crti.S (_init): Mark as hidden.
	(_fini): Likewise.
	* sysdeps/powerpc/powerpc64/crti.S (_init): Mark as hidden.
	(_fini): Likewise.
	* sysdeps/s390/s390-32/crti.S (_init): Mark as hidden.
	(_fini): Likewise.
	* sysdeps/s390/s390-64/crti.S (_init): Mark as hidden.
	(_fini): Likewise.
	* sysdeps/sh/crti.S (_init): Mark as hidden.
	(_fini): Likewise.
	* sysdeps/sparc/crti.S (_init): Mark as hidden.
	(_fini): Likewise.
	* sysdeps/x86_64/crti.S (_init): Mark as hidden.
	(_fini): Likewise.
2018-06-08 10:28:52 -07:00
H.J. Lu
0068c08588 nptl: Remove __ASSUME_PRIVATE_FUTEX
Since __ASSUME_PRIVATE_FUTEX is always defined, this patch removes the
!__ASSUME_PRIVATE_FUTEX paths.

Tested with build-many-glibcs.py.

	* nptl/allocatestack.c (allocate_stack): Remove the
	!__ASSUME_PRIVATE_FUTEX paths.
	* nptl/descr.h (header): Remove the !__ASSUME_PRIVATE_FUTEX path.
	* nptl/nptl-init.c (__pthread_initialize_minimal_internal):
	Likewise.
	* sysdeps/i386/nptl/tcb-offsets.sym (PRIVATE_FUTEX): Removed.
	* sysdeps/powerpc/nptl/tcb-offsets.sym (PRIVATE_FUTEX): Likewise.
	* sysdeps/sh/nptl/tcb-offsets.sym (PRIVATE_FUTEX): Likewise.
	* sysdeps/x86_64/nptl/tcb-offsets.sym (PRIVATE_FUTEX): Likewise.
	* sysdeps/i386/nptl/tls.h: (tcbhead_t): Remve the
	!__ASSUME_PRIVATE_FUTEX path.
	* sysdeps/s390/nptl/tls.h (tcbhead_t): Likewise.
	* sysdeps/sparc/nptl/tls.h (tcbhead_t): Likewise.
	* sysdeps/x86_64/nptl/tls.h (tcbhead_t): Likewise.
	* sysdeps/unix/sysv/linux/i386/lowlevellock.S: Remove the
	!__ASSUME_PRIVATE_FUTEX macros.
	* sysdeps/unix/sysv/linux/lowlevellock-futex.h: Likewise.
	* sysdeps/unix/sysv/linux/x86_64/cancellation.S: Likewise.
	* sysdeps/unix/sysv/linux/x86_64/lowlevellock.S: Likewise.
	* sysdeps/unix/sysv/linux/kernel-features.h
	(__ASSUME_PRIVATE_FUTEX): Removed.
2018-05-17 04:25:10 -07:00
Stefan Liebler
db9e55ff36 S390: Regenerate ULPs.
Updated ulps after recent commit
"[PATCH 1/7] sin/cos slow paths: avoid slow paths for small inputs"
(19a8b9a300).

ChangeLog:

	* sysdeps/s390/fpu/libm-test-ulps: Regenerated.
2018-04-05 16:24:06 +02:00
Samuel Thibault
08e92e2443 Revert "hurd: Avoid PLTs for longjmp & siglongjmp"
This reverts commit e5f9508a32.
2018-04-05 09:38:58 +02:00
Samuel Thibault
e5f9508a32 hurd: Avoid PLTs for longjmp & siglongjmp
* include/setjmp.h (longjmp, siglongjmp): Add hidden protos.
	* setjmp/longjmp.c (longjmp, siglongjmp): Add hidden defs.
	* sysdeps/s390/longjmp.c (longjmp, siglongjmp): Add hidden defs.
2018-04-04 23:19:18 +00:00
Maciej W. Rozycki
10a446ddcc elf: Unify symbol address run-time calculation [BZ #19818]
Wrap symbol address run-time calculation into a macro and use it
throughout, replacing inline calculations.

There are a couple of variants, most of them different in a functionally
insignificant way.  Most calculations are right following RESOLVE_MAP,
at which point either the map or the symbol returned can be checked for
validity as the macro sets either both or neither.  In some places both
the symbol and the map has to be checked however.

My initial implementation therefore always checked both, however that
resulted in code larger by as much as 0.3%, as many places know from
elsewhere that no check is needed.  I have decided the size growth was
unacceptable.

Having looked closer I realized that it's the map that is the culprit.
Therefore I have modified LOOKUP_VALUE_ADDRESS to accept an additional
boolean argument telling it to access the map without checking it for
validity.  This in turn has brought quite nice results, with new code
actually being smaller for i686, and MIPS o32, n32 and little-endian n64
targets, unchanged in size for x86-64 and, unusually, marginally larger
for big-endian MIPS n64, as follows:

i686:
   text    data     bss     dec     hex filename
 152255    4052     192  156499   26353 ld-2.27.9000-base.so
 152159    4052     192  156403   262f3 ld-2.27.9000-elf-symbol-value.so
MIPS/o32/el:
   text    data     bss     dec     hex filename
 142906    4396     260  147562   2406a ld-2.27.9000-base.so
 142890    4396     260  147546   2405a ld-2.27.9000-elf-symbol-value.so
MIPS/n32/el:
   text    data     bss     dec     hex filename
 142267    4404     260  146931   23df3 ld-2.27.9000-base.so
 142171    4404     260  146835   23d93 ld-2.27.9000-elf-symbol-value.so
MIPS/n64/el:
   text    data     bss     dec     hex filename
 149835    7376     408  157619   267b3 ld-2.27.9000-base.so
 149787    7376     408  157571   26783 ld-2.27.9000-elf-symbol-value.so
MIPS/o32/eb:
   text    data     bss     dec     hex filename
 142870    4396     260  147526   24046 ld-2.27.9000-base.so
 142854    4396     260  147510   24036 ld-2.27.9000-elf-symbol-value.so
MIPS/n32/eb:
   text    data     bss     dec     hex filename
 142019    4404     260  146683   23cfb ld-2.27.9000-base.so
 141923    4404     260  146587   23c9b ld-2.27.9000-elf-symbol-value.so
MIPS/n64/eb:
   text    data     bss     dec     hex filename
 149763    7376     408  157547   2676b ld-2.27.9000-base.so
 149779    7376     408  157563   2677b ld-2.27.9000-elf-symbol-value.so
x86-64:
   text    data     bss     dec     hex filename
 148462    6452     400  155314   25eb2 ld-2.27.9000-base.so
 148462    6452     400  155314   25eb2 ld-2.27.9000-elf-symbol-value.so

	[BZ #19818]
	* sysdeps/generic/ldsodefs.h (LOOKUP_VALUE_ADDRESS): Add `set'
	parameter.
	(SYMBOL_ADDRESS): New macro.
	[!ELF_FUNCTION_PTR_IS_SPECIAL] (DL_SYMBOL_ADDRESS): Use
	SYMBOL_ADDRESS for symbol address calculation.
	* elf/dl-runtime.c (_dl_fixup): Likewise.
	(_dl_profile_fixup): Likewise.
	* elf/dl-symaddr.c (_dl_symbol_address): Likewise.
	* elf/rtld.c (dl_main): Likewise.
	* sysdeps/aarch64/dl-machine.h (elf_machine_rela): Likewise.
	* sysdeps/alpha/dl-machine.h (elf_machine_rela): Likewise.
	* sysdeps/arm/dl-machine.h (elf_machine_rel): Likewise.
	(elf_machine_rela): Likewise.
	* sysdeps/hppa/dl-machine.h (elf_machine_rela): Likewise.
	* sysdeps/hppa/dl-symaddr.c (_dl_symbol_address): Likewise.
	* sysdeps/i386/dl-machine.h (elf_machine_rel): Likewise.
	(elf_machine_rela): Likewise.
	* sysdeps/ia64/dl-machine.h (elf_machine_rela): Likewise.
	* sysdeps/m68k/dl-machine.h (elf_machine_rela): Likewise.
	* sysdeps/microblaze/dl-machine.h (elf_machine_rela): Likewise.
	* sysdeps/mips/dl-machine.h (ELF_MACHINE_BEFORE_RTLD_RELOC):
	Likewise.
	(elf_machine_reloc): Likewise.
	(elf_machine_got_rel): Likewise.
	* sysdeps/mips/dl-trampoline.c (__dl_runtime_resolve): Likewise.
	* sysdeps/nios2/dl-machine.h (elf_machine_rela): Likewise.
	* sysdeps/powerpc/powerpc32/dl-machine.h (elf_machine_rela):
	Likewise.
	* sysdeps/powerpc/powerpc64/dl-machine.h (elf_machine_rela):
	Likewise.
	* sysdeps/riscv/dl-machine.h (elf_machine_rela): Likewise.
	* sysdeps/s390/s390-32/dl-machine.h (elf_machine_rela):
	Likewise.
	* sysdeps/s390/s390-64/dl-machine.h (elf_machine_rela):
	Likewise.
	* sysdeps/sh/dl-machine.h (elf_machine_rela): Likewise.
	* sysdeps/sparc/sparc32/dl-machine.h (elf_machine_rela):
	Likewise.
	* sysdeps/sparc/sparc64/dl-machine.h (elf_machine_rela):
	Likewise.
	* sysdeps/tile/dl-machine.h (elf_machine_rela): Likewise.
	* sysdeps/x86_64/dl-machine.h (elf_machine_rela): Likewise.

Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2018-04-04 23:09:37 +01:00
Samuel Thibault
51722f4dc7 Revert "s390x: Fix hidden aliases"
This reverts commit 811836a411.
2018-04-03 22:59:25 +02:00
Samuel Thibault
811836a411 s390x: Fix hidden aliases
* sysdeps/s390/longjmp.c (__libc_longjmp, __libc_siglongjmp): New
	hidden defs.
2018-04-03 13:52:29 +02:00
Wilco Dijkstra
700593fdd7 Remove all target specific __ieee754_sqrt(f/l) inlines
Remove the now unused target specific__ieee754_sqrt(f/l) inlines.
Also remove inlines of sqrt which are for really old GCC versions.
Removing these is desirable, under the general principle of leaving
such inlining to the compiler rather than trying to do it in installed
headers, especially when only very old compilers are affected.

Note that removing inlines for __ieee754_sqrt disables inlining in the
sqrt wrapper functions.  Given the sqrt function will typically only be
called for negative arguments, it doesn't matter whether the inlining
happens or not.

	* sysdeps/aarch64/fpu/math_private.h (__ieee754_sqrt): Remove.
	(__ieee754_sqrtf): Remove.
	* sysdeps/alpha/fpu/math_private.h (__ieee754_sqrt): Remove.
	(__ieee754_sqrtf): Remove.
	* sysdeps/generic/math-type-macros.h (M_SQRT): Use sqrt.
	* sysdeps/m68k/m680x0/fpu/mathimpl.h (__ieee754_sqrt): Remove.
	* sysdeps/powerpc/fpu/math_private.h (__ieee754_sqrt): Remove.
	(__ieee754_sqrtf): Remove.
	* sysdeps/s390/fpu/bits/mathinline.h: Remove file.
	* sysdeps/sparc/fpu/bits/mathinline.h (sqrt) Remove.
	(sqrtf): Remove.
	(sqrtl): Remove.
	(__ieee754_sqrt): Remove.
	(__ieee754_sqrtf): Remove.
	(__ieee754_sqrtl): Remove.
	* sysdeps/m68k/m680x0/fpu/mathimpl.h (__ieee754_sqrt): Remove.
	* sysdeps/x86/fpu/math_private.h (__ieee754_sqrt): Remove.
	* sysdeps/x86_64/fpu/math_private.h (__ieee754_sqrt): Remove.
	(__ieee754_sqrtf): Remove.
	(__ieee754_sqrtl): Remove.
2018-03-15 19:21:36 +00:00
Samuel Thibault
a5df0318ef hurd: add gscope support
* elf/dl-support.c [!THREAD_GSCOPE_IN_TCB] (_dl_thread_gscope_count):
Define variable.
* sysdeps/generic/ldsodefs.h [!THREAD_GSCOPE_IN_TCB] (struct
rtld_global): Add _dl_thread_gscope_count member.
* sysdeps/mach/hurd/tls.h: Include <atomic.h>.
[!defined __ASSEMBLER__] (THREAD_GSCOPE_GLOBAL, THREAD_GSCOPE_SET_FLAG,
THREAD_GSCOPE_RESET_FLAG, THREAD_GSCOPE_WAIT): Define macros.
* sysdeps/generic/tls.h: Document THREAD_GSCOPE_IN_TCB.
* sysdeps/aarch64/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1.
* sysdeps/alpha/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1.
* sysdeps/arm/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1.
* sysdeps/hppa/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1.
* sysdeps/i386/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1.
* sysdeps/ia64/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1.
* sysdeps/m68k/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1.
* sysdeps/microblaze/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1.
* sysdeps/mips/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1.
* sysdeps/nios2/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1.
* sysdeps/powerpc/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1.
* sysdeps/riscv/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1.
* sysdeps/s390/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1.
* sysdeps/sh/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1.
* sysdeps/sparc/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1.
* sysdeps/tile/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1.
* sysdeps/x86_64/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1.
2018-03-11 13:06:33 +01:00
H.J. Lu
6253bacdc0 Remove hidden __libc_longjmp
Since __libc_longjmp is a private interface for cancellation implementation
in libpthread, there is no need to provide hidden __libc_longjmp in libc.

Tested with build-many-glibcs.py.

	* include/setjmp.h (__libc_longjmp): Remove libc_hidden_proto.
	* setjmp/longjmp.c (__libc_longjmp): Remove libc_hidden_def.
	* sysdeps/s390/longjmp.c (__libc_longjmp): Likewise.
	* sysdeps/unix/sysv/linux/sparc/sparc64/longjmp.S (__libc_longjmp):
	Likewise.
2018-03-10 09:27:20 -08:00
Joseph Myers
6900d2ca74 Fix s390 -Os iconv build.
Building glibc for s390 with -Os (32-bit only, with GCC 7) fails with:

In file included from ../sysdeps/s390/multiarch/8bit-generic.c:370:0,
                 from ebcdic-at-de.c:28:
../iconv/loop.c: In function '__to_generic_vx':
../iconv/loop.c:264:22: error: 'ch' may be used uninitialized in this function [-Werror=maybe-uninitialized]
     if (((Character) >> 7) == (0xe0000 >> 7))          \
                      ^~
In file included from ebcdic-at-de.c:28:0:
../sysdeps/s390/multiarch/8bit-generic.c:340:15: note: 'ch' was declared here
      uint32_t ch;      \
               ^
../iconv/loop.c:325:7: note: in expansion of macro 'BODY'
       BODY
       ^~~~

It's fairly easy to see, looking at the (long) expansion of the BODY
macro, that this is a false positive and the relevant variable 'ch' is
always initialized before use, in one of two possible places.  As
such, disabling the warning for -Os with the DIAG_* macros is the
natural approach to fix this build failure.  However, because of the
location at which the warning is reported, the disabling needs to go
in iconv/loop.c, around the definition of UNICODE_TAG_HANDLER (not
inside the definition), as that macro definition is where the
uninitialized use is reported, whereas the code that needs to be
reasoned about to see that the warning is a false positive is in the
definition of BODY elsewhere.

Thus, the patch adds such disabling in iconv/loop.c, with a comment
pointing to the s390-specific code and a comment in the s390-specific
code pointing to the generic file to alert people to the possible need
to update one place when changing the other.  It would be possible if
desired to use #ifdef __s390__ around the disabling, though in general
we try to avoid that sort of thing in generic files.  (Or some
extremely specialized macros for "disable -Wmaybe-uninitialized in
this particular place" could be specified, defined to 0 in a lot of
different files that include iconv/loop.c and to 1 in that particular
s390 file.)

Tested that this fixed -Os compilation for s390-linux-gnu with
build-many-glibcs.py.

	* iconv/loop.c (UNICODE_TAG_HANDLER): Disable
	-Wmaybe-uninitialized for -Os.
	* sysdeps/s390/multiarch/8bit-generic.c (BODY): Add comment about
	this disabling.
2018-03-05 21:46:55 +00:00
Stefan Liebler
6e33647646 S390: Regenerate ULPs.
After regenerating ULPs from scratch in
commit 8e7196c875, I've missed
to test it with multiple gcc versions.  Hence, here is a further update.

ChangeLog:

	* sysdeps/s390/fpu/libm-test-ulps: Regenerated.
2018-02-22 09:19:49 +01:00
Stefan Liebler
8e7196c875 S390: Regenerate ULPs.
Regenerated ulps file from scratch due to recent pow changes.

ChangeLog:

	* sysdeps/s390/fpu/libm-test-ulps: Regenerated.
2018-02-15 09:06:18 +01:00
Joseph Myers
0d40d0ecba Unify and simplify bits/byteswap.h, bits/byteswap-16.h headers (bug 14508, bug 15512, bug 17082, bug 20530).
We have a general principle of preferring optimizations for library
facilities to use compiler built-in functions rather than being
located in library headers, where the compiler can reasonably optimize
code without needing to know glibc implementation details.

This patch applies this principle to bits/byteswap.h, eliminating all
the architecture-specific variants and bits/byteswap-16.h.  The
__bswap_16, __bswap_32 and __bswap_64 interfaces all become inline
functions, never macros, using the GCC built-in functions where
available and otherwise a single architecture-independent definition
using shifts and masking (which compilers may well be able to detect
and optimize; GCC has detection of various byte-swapping idioms).

The __bswap_constant_32 macro needs to stay around because of uses in
static initializers within glibc and its tests, and so for consistency
all __bswap_constant_* are kept rather than just being inlined into
the old-GCC-or-non-GCC parts of the __bswap_* inline function
definitions.

Various open bugs are addressed by this cleanup, with caveats about
exactly what is covered by those bugs and when the bugs applied at
all.

Bug 14508 reports -Wformat warnings building glibc because __bswap_*
sometimes returned the wrong types.  Obviously we already don't have
such warnings any more or the build would be failing, given -Werror,
and I suspect that bug was originally for wrong types for x86_64, as
fixed by commit d394eb742a (glibc 2.17).
The only case I saw removed by this patch where the types would still
have been wrong was the non-__GNUC__ case of __bswap_64 in the s390
header (using unsigned long long int, but uint64_t would be unsigned
long int for 64-bit).  In any case, the single header consistently
uses __uintN_t types after this patch, thereby eliminating all such
bugs.  The existing string/test-endian-types.c test already suffices
to verify that the types are correct with the compiler used to build
glibc and its tests.

Bug 15512 reports an error from __bswap_constant_16 with -Werror
-Wsign-conversion.  I am unable to reproduce this with any GCC version
supporting -Wsign-conversion - all seem to be able to avoid warning
for ((x) >> 8) & 0xffu, where x is uint16_t, which while it formally
does involve an implicit conversion from int to unsigned int, is also
a case where it should be easy for the compiler to see that the value
converted is never negative.  But in this patch __bswap_constant_16 is
changed to use signed 0xff so that no such implicit conversion occurs
at all, and a test with -Werror -Wsign-conversion is added.

Bug 17082 objects to the use of ({}) statement expressions in these
macros preventing use at file scope (in C, that's in sizeof etc.; in
C++, more generally in static initializers).  The particular case of
these interfaces is fixed by this patch as it changes them to inline
functions, eliminating all uses of ({}) in bits/byteswap.h, and a
corresponding testcase is added.  The bug tries to raise a more
general policy question about use of ({}) in macros in installed
headers, referring to "many other libc functions" (unspecified which
functions are being considered).

Since such policy questions belong on libc-alpha, and since there
*are* macros in installed headers which can't really avoid using ({})
(where they are type-generic, so can't use an inline function, but
need a temporary variable, and a few where the interface involves
returning memory from alloca so can't use an inline function either),
I propose to consider that bug fixed with this change.  That is
without prejudice to any other new bugs anyone wishes to file *for
precisely defined sets of macros* requesting moving away from ({})
*where it is clearly possible for those interfaces*.  Where ({}) can
be avoided, typically by use of an inline function, I think that's a
good idea - that inline functions are typically to be preferred to
({}) for header interfaces where such optimizations are useful but the
interface is suited to being defined using an inline function.

Bug 20530 requests use of __builtin_bswap16 when available (GCC 4.8
and later), which this patch implements.

Tested for x86_64, and with build-many-glibcs.py.  Also did an x86_64
test with the __GNUC_PREREQ conditionals changed to "#if 0" to verify
the old-GCC/non-GCC case in the headers.  (There are already existing
tests for correctness of results of these interfaces.)

	[BZ #14508]
	[BZ #15512]
	[BZ #17082]
	[BZ #20530]
	* bits/byteswap.h: Update file comment.  Do not include
	<bits/byteswap-16.h>.
	(__bswap_constant_16): Cast result to __uint16_t.  Use signed 0xff
	constant.
	(__bswap_16): Define as inline function.
	(__bswap_constant_32): Reformat definition.
	(__bswap_32): Always define as inline function, not macro, using
	__uint32_t.  Use __builtin_bswap32 if [__GNUC_PREREQ (4, 3)],
	otherwise __bswap_constant_32.
	(__bswap_constant_64): Reformat definition.  Do not use
	__extension__ here.
	(__bswap_64): Always define as inline function, not macro.  Use
	__extension__ on function definition.  Use __builtin_bswap64 if
	[__GNUC_PREREQ (4, 3)], otherwise __bswap_constant_64.
	* string/test-endian-file-scope.c: New file.
	* string/test-endian-sign-conversion.c: Likewise.
	* string/Makefile (headers): Remove bits/byteswap-16.h.
	(tests): Add test-endian-file-scope and
	test-endian-sign-conversion.
	(CFLAGS-test-endian-sign-conversion.c): New variable.
	* bits/byteswap-16.h: Remove file.
	* sysdeps/ia64/bits/byteswap-16.h: Likewise.
	* sysdeps/ia64/bits/byteswap.h: Likewise.
	* sysdeps/m68k/bits/byteswap.h: Likewise.
	* sysdeps/s390/bits/byteswap-16.h: Likewise.
	* sysdeps/s390/bits/byteswap.h: Likewise.
	* sysdeps/tile/bits/byteswap.h: Likewise.
	* sysdeps/x86/bits/byteswap-16.h: Likewise.
	* sysdeps/x86/bits/byteswap.h: Likewise.
2018-02-06 21:55:08 +00:00
Joseph Myers
c8924f1ff2 Fix s390 linknamespace fallout of bug 22702 patch.
My fix for bug 22702 introduced linknamespace test failures on
s390x-linux-gnu and s390-linux-gnu because it made remainder call
__feholdexcept, and the s390 __feholdexcept calls fegetenv, and
remainder is in Unix98 and XPG4.2 but fegetenv isn't.  This patch
makes __feholdexcept call __fegetenv instead to avoid that namespace
issue.

Tested (compilation) with build-many-glibcs.py for s390x-linux-gnu,
where it resolves the test failures.

	* sysdeps/s390/fpu/feholdexcpt.c (__feholdexcept): Call __fegetenv
	instead of fegetenv.
2018-01-12 00:12:57 +00:00