TS 18661-1 defines totalorder functions implementing the totalOrder
comparison operation from IEEE 754-2008. This patch implements these
functions for glibc, including the type-generic macro in <tgmath.h>.
(The totalordermag functions will be added in a separate patch.)
The description of the totalOrder operation is complicated. However,
for IEEE interchange binary formats and the preferred quiet NaN
convention, what that complicated description means is that you
interpret the representation as a sign-magnitude integer (with -0
coming before +0) and do a <= comparison on that interpretation. For
finite values and infinities the ordering of the sign-magnitude
integers is just the same as the ordering of floating-point values, so
this extends that to all representations. (Different representations
of the same floating-point value - which includes same quantum in the
decimal case - must still be considered equal by this operation, but
that issue doesn't arise for IEEE interchange binary formats.) So the
complications are:
* When MIPS quiet NaN conventions are in use, the representation of
NaNs needs adjusting before making such an integer comparison. This
patch does this adjustment only when both arguments are NaNs, as
there's no need for it if only one is a NaN, and as long as both are
NaNs you can just flip the relevant bits without any problems from
this turning a NaN into an infinity.
* For the m68k version of ldbl-96, where the high mantissa bit is
"don't care" for infinities and NaNs, representations where it
differs must compare the same. Note: although the testcase for this
compiles, I have not actually tested on m68k.
* For ldbl-128ibm, the low part must be ignored when the high part is
NaN, and low parts of +0 and -0 must be considered the same whatever
the high part.
The new tests in libm-test.inc are the first tests there specifying
particular payloads for input NaNs. Separate tests are also added for
the ldbl-96 and ldbl-128ibm special cases where there are different
representations of the same value that must compare equal (which can't
be covered in libm-test.inc as that only specifies values, not
representations).
Tested for x86_64, x86, mips64 and powerpc.
* math/bits/mathcalls.h [__GLIBC_USE (IEC_60559_BFP_EXT)]
(totalorder): New declaration.
* math/tgmath.h [__GLIBC_USE (IEC_60559_BFP_EXT)] (totalorder):
New macro.
* math/Versions (totalorder): New libm symbol at version
GLIBC_2.25.
(totalorderf): Likewise.
(totalorderl): Likewise.
* math/Makefile (libm-calls): Add s_totalorderF.
* math/gen-libm-test.pl (parse_args): Escape quotes in test name
string.
* math/libm-test.inc (PAYLOAD_DIG): New macro.
(qnan_value_pl): Likewise.
(snan_value_pl): Likewise.
(qnan_value): Define using qnan_value_pl.
(snan_value): Define using snan_value_pl.
(struct test_ff_i_data): Add comment about which tests use this
structure.
(RUN_TEST_ff_b): New macro.
(RUN_TEST_LOOP_ff_b): Likewise.
(totalorder_test_data): New array.
(totalorder_test): New function.
(main): Call totalorder_test.
* math/test-tgmath.c (NCALLS): Increase to 122.
(F(compile_test)): Call totalorder.
(F(totalorder)): New function.
* manual/arith.texi (FP Comparison Functions): Document
totalorder, totalorderf and totalorderl.
* manual/libm-err-tab.pl: Update comment on interfaces without
ulps tabulated.
* sysdeps/ieee754/dbl-64/s_totalorder.c: New file.
* sysdeps/ieee754/dbl-64/wordsize-64/s_totalorder.c: Likewise.
* sysdeps/ieee754/flt-32/s_totalorderf.c: Likewise.
* sysdeps/ieee754/ldbl-128/s_totalorderl.c: Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_totalorderl.c: Likewise.
* sysdeps/ieee754/ldbl-96/s_totalorderl.c: Likewise.
* sysdeps/ieee754/ldbl-opt/nldbl-totalorder.c: Likewise.
* sysdeps/ieee754/ldbl-opt/Makefile (libnldbl-calls): Add
totalorder.
(CFLAGS-nldbl-totalorder.c): New variable.
* sysdeps/ieee754/ldbl-128ibm/test-totalorderl-ldbl-128ibm.c: New
file.
* sysdeps/ieee754/ldbl-128ibm/Makefile [$(subdir) = math] (tests):
Add test-totalorderl-ldbl-128ibm.
* sysdeps/ieee754/ldbl-96/test-totalorderl-ldbl-96.c: New file.
* sysdeps/ieee754/ldbl-96/Makefile [$(subdir) = math] (tests): Add
test-totalorderl-ldbl-96.
* sysdeps/nacl/libm.abilist: Update.
* sysdeps/unix/sysv/linux/aarch64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/alpha/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/arm/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/hppa/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/i386/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/ia64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/m68k/coldfire/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/m68k/m680x0/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/microblaze/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips32/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/nios2/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libm-le.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/s390/s390-32/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/sh/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc32/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/tile/tilepro/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/x86_64/64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/x86_64/x32/libm.abilist: Likewise.
This patch consolidates all the sync_file_range implementation for Linux
in only one (sysdeps/unix/sysv/linux/sync_file_range.c). It also removes
the syscall from the auto-generation using assembly macros (except for
x86_64 due x32 [1]).
For current minimum supported kernel (2.6.32 for x86_64 and 3.2 for all
other architectures) either sync_file_range or sync_file_range2 is supported
and it is expected that any future Linux ABI will provide either of one
syscall. So the code path that returns ENOSYS in the case of missing
syscall is removed.
Checked on x86_64, i386, powerpc64le, aarch64, and armhf.
* sysdeps/unix/sysv/linux/Makefile (tests): Add tst-sync_file_range.
* sysdeps/unix/sysv/linux/mips/mips32/sync_file_range.c: Remove file.
* sysdeps/sysv/linux/powerpc/powerpc64/sync_file_range.c: Likewise.
* sysdeps/unix/sysv/linux/sync_file_range.c: New file.
* sysdeps/unix/sysv/linux/tst-sync_file_range.c (sync_file_range):
Consolidate all Linux implementations.
[1] https://patchwork.ozlabs.org/patch/659794/
Some libm complex functions have code that computes M_NAN + M_NAN.
This is nonsensical; it's just equivalent to M_NAN, since it's a quiet
NaN (and the comments suggesting this raises an exception are
similarly wrong). This patch changes the code just to use M_NAN (and
removes the bogus comments). (Preferably, code should either
propagate an input NaN or do a computation that raises "invalid" and
generates a default NaN at the same time. There are various cases,
however, that currently raise "invalid" even for NaN inputs; I think
those are cases where "invalid" is optional in ISO C so a change to
whether it's raised would be OK, but they would still need more
careful consideration than the cases where such issues do not arise.)
Tested for x86_64 and x86 (testsuite, and that installed stripped
shared libraries are unchanged by the patch).
* math/s_ccosh_template.c (M_DECL_FUNC (__ccosh)): Use M_NAN
instead of M_NAN + M_NAN.
* math/s_csinh_template.c (M_DECL_FUNC (__csinh)): Likewise.
iseqsig, like other type-generic comparison macros, should behave like
a comparison operator in not removing excess range and precision from
its arguments (see C11 F.10.11). This patch implements this by making
definitions of iseqsig appropriately conditional on
__FLT_EVAL_METHOD__ (including support for TS 18661-3 values of that
macro), with a corresponding testcase (that failed for 32-bit x86 in
the absence of the math.h changes) being added. (Of course the
definitions may need reworking when float128 support is added, just as
with other type-generic macros.)
Tested for x86_64 and x86.
* math/math.h [__GLIBC_USE (IEC_60559_BFP_EXT)] (iseqsig): Define
conditional on value of [__FLT_EVAL_METHOD__].
* math/test-iseqsig-excess-precision.c: New file.
* math/Makefile (tests): Add test-iseqsig-excess-precision.
Microblaze, nios2, and tile do not support FE_INVALID and thus
define feraiseexcept as a empty macro. Include math-private.h
to get such definition.
Checked with a build for microblaze, nios2, and tilepro.
* math/s_iseqsig_template.c: Include math-private.h.
This patch consolidates mostly of the Linux posix_fadvise{64} implementations
on sysdeps/unix/sysv/linux/posix_fadvise{64}.c. It still keeps arch-specific
files for:
* S390-32: it uses a packed structure to pass all the arguments on syscall.
It is the only supported port that implements __NR_fadvise64_64 in this
way.
* ARM: it does not implement __NR_fadvise64 (as other 32-bits ports), so
posix_fadvise calls internal posix_fadvise64 symbol.
* MIPS64 n64: it requires a different version number that other ports.
The new macro SYSCALL_LL{64} is used to handle the offset argument and
INTERNAL_SYSCALL_CALL to handle passing the correct number of expect
arguments.
The default Linux adds two new defines a port can use to control how
__NR_fadvise64_64 passes the kernel arguments:
* __ASSUME_FADVISE64_64_6ARG: the 'advise' argument is moved on second
position. This is the case of powerpc32 and arm to avoid implement
7 argument syscall.
* __ASSUME_FADVISE64_64_NO_ALIGN: for ABIs that defines
__ASSUME_ALIGNED_REGISTER_PAIRS packs the offset without the leading
'0'. This is the case of tile 32 bits.
ARM also defines __NR_fadvise64_64 as __NR_arm_fadvise64_64 (which is also
handled on arch kernel-feature.h).
Tested on x86_64, x32, i686, armhf, and aarch64.
* posix/Makefile (tests): Add tst-posix_fadvise and tst-posix_fadvise64.
* posix/tst-posix_fadvise.c: New file.
* posix/tst-posix_fadvise64.c: Likewise.
* posix/tst-posix_fadvise-common.c: Likewise.
* sysdeps/unix/sysv/linux/arm/kernel-features.h
(__ASSUME_FADVISE64_64_6ARG): Define.
* sysdeps/unix/sysv/linux/powerpc/kernel-features.h
[!__powerpc64__] (__ASSUME_FADVISE64_64_6ARG): Add define.
* sysdeps/unix/sysv/linux/arm/posix_fadvise64.c: Remove file.
* sysdeps/unix/sysv/linux/generic/wordsize-32/posix_fadvise.c: Likewise.
* sysdeps/unix/sysv/linux/i386/posix_fadvise64.S: Likewise.
* sysdeps/unix/sysv/linux/mips/mips32/posix_fadvise.c: Likewise.
* sysdeps/unix/sysv/linux/mips/mips32/posix_fadvise64.c: Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/n32/posix_fadvise.c: Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/n32/posix_fadvise64.c: Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/n64/posix_fadvise.c: Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/posix_fadvise.c: Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/posix_fadvise64.c:
Likewise.
* sysdeps/unix/sysv/linux/wordsize-64/posix_fadvise.c: Likewise.
* sysdeps/unix/sysv/linux/wordsize-64/posix_fadvise64.c: Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/n64/posix_fadvise64.c
(SHLIB_COMPAT(libc, GLIBC_2_2, GLIBC_2_3_3) [__posix_fadvise64_l64]:
Alias to __posix_fadvise64_l32.
(SHLIB_COMPAT(libc, GLIBC_2_2, GLIBC_2_3_3) [__posix_fadvise64_l32]:
Add compat definition to posix_fadvise64.
(SHLIB_COMPAT(libc, GLIBC_2_2, GLIBC_2_3_3) [__posix_fadvise64_l64]:
Add versioned definition to posix_fadvise64.
* sysdeps/unix/sysv/linux/posix_fadvise.c (posix_fadvise): Build iff
__OFF_T_MATCHES_OFF64_T is defined, use INTERNAL_SYSCALL_CALL, add
__ASSUME_FADVISE64_64_6ARG/__ASSUME_FADVISE64_64_NO_ALIGN support.
* sysdeps/unix/sysv/linux/posix_fadvise64.c (posix_fadvise64): Add
__ASSUME_FADVISE64_64_NO_ALIGN support and use INTERNAL_SYSCALL_CALL.
This patch consolidates all the posix_fallocate{64} implementation for Linux
in only one (sysdeps/unix/sysv/linux/posix_fallocate{64}.c). It also removes
the syscall from the auto-generation using assembly macros.
The macro SYSCALL_LL{64} is used to handle the offset argument along with
the new INTERNAL_SYSCALL_CALL macro to define correct argument count for
internal INTERNAL_SYSCALL call.
Tested on x86_64, i686, x32, aarch64, ppc64le, and armhf.
* io/Makefile (tests): Add tst-posix_fallocate and
tst-posix_fallocate64.
* io/tst-posix_fallocate-common.c: New file.
* io/tst-posix_fallocate.c: Likewise.
* io/tst-posix_fallocate64.c: Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/n32/posix_fallocate.c: Remove
file.
* sysdeps/unix/sysv/linux/mips/mips64/n32/posix_fallocate64.c:
Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/n64/posix_fallocate.c: Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/n64/posix_fallocate64.c:
Likewise.
* sysdeps/unix/sysv/linux/wordsize-64/posix_fallocate.c: Likewise.
* sysdeps/unix/sysv/linux/wordsize-64/posix_fallocate64.c: Likewise.
* sysdeps/unix/sysv/linux/posix_fallocate.c (posix_fallocate): Use
SYSCALL_LL to pass both offset and len arguments.
* sysdeps/unix/sysv/linux/posix_fallocate64.c (posix_fallocate64):
Likewise.
* sysdeps/unix/sysv/linux/x86_64/syscalls.list (pwrite64): Add
__libc_pwrite64 alias used by posix_fallocate64.
This patch consolidates all the fallocate{64} implementation for Linux
in only one (sysdeps/unix/sysv/linux/fallocate{64}.c). It also removes the
syscall from the auto-generation using assembly macros.
The new macro SYSCALL_LL{64} is used to handle the offset argument.
Checked on x86_64, x32, i386, aarch64, and ppc64le.
* sysdeps/unix/sysv/linux/Makefile (test): Add tst-fallocate and
tst-fallocate64.
* sysdeps/unix/sysv/linux/tst-fallocate.c: New file.
* sysdeps/unix/sysv/linux/tst-fallocate64.c: Likewise.
* sysdeps/unix/sysv/linux/tst-fallocate-common.c: Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/n32/fallocate.c: Remove file.
* sysdeps/unix/sysv/linux/mips/mips64/n32/fallocate64.c: Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/n64/fallocate.c: Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/n64/fallocate64.c: Likewise.
* sysdeps/unix/sysv/linux/wordsize-64/fallocate.c: Likewise.
* sysdeps/unix/sysv/linux/wordsize-64/fallocate64.c: Likewise.
* sysdeps/unix/sysv/linux/fallocate.c (fallocate): Use SYSCALL_LL
macro on offset argument.
* sysdeps/unix/sysv/linux/fallocate64.c (fallocate64): Use
SYSCALL_LL64 on offset argument.
* test-skeleton.c (FAIL_RET): Add macro.
(FAIL_EXIT): Likewise.
(FAIL_EXIT1): Likewise.
(_FAIL): Likewise.
In ns_name_ntop, the NS_CMPRSFLGS check is no longer needed because
labellen (called earlier) already rejects everything which is not
a plain label (compression references and extended label types).
This patch uses the libc_ifunc macro to create already existing ifunc functions
longjmp_ifunc, siglongjmp_ifunc if HAVE_IFUNC is defined.
The s390 pt-longjmp.c includes the common pt-longjmp.c and uses strong_alias
to create the longjmp, siglongjmp symbols for glibc version 2.19.
ChangeLog:
* nptl/pt-longjmp.c (DEFINE_LONGJMP): Use libc_ifunc macro.
* sysdeps/unix/sysv/linux/s390/pt-longjmp.c (longjmp, siglongjmp):
Use strong_alias to create symbols for glibc verison 2.19.
This patch uses the libc_ifunc macro to create already existing ifunc functions
vfork_ifunc and __vfork_ifunc if HAVE_IFUNC is defined.
ChangeLog:
* nptl/pt-vfork.c (DEFINE_VFORK): Use libc_ifunc macro.
This patch uses the libc_ifunc macro to create already existing ifunc function
system_ifunc if HAVE_IFUNC is defined.
ChangeLog:
* nptl/pt-system.c (system_ifunc): Use libc_ifunc macro.
This patch uses the libc_ifunc macro to create already existing ifunc functions
clock_getres, clock_gettime, clock_settime, clock_getcpuclockid and
clock_nanosleep. If HAVE_IFUNC is defined, the macro COMPAT_REDIRECT uses
the libc_ifunc macro.
Furthermore some whitespace damage is cleaned.
ChangeLog:
* rt/clock-compat.c (COMPAT_REDIRECT): Use libc_ifunc macro.
This patch uses the libc_ifunc_hidden macro to create already existing ifunc functions
time and gettimeofday on power. This way, the libc_hidden_def macro can be used
instead of inline assemblies.
On ppc32, the __GI_* symbols do not target the ifunc symbol and thus the
redirection construct has to be applied here.
ChangeLog:
* sysdeps/unix/sysv/linux/powerpc/gettimeofday.c (__gettimeofday):
Use libc_ifunc_hidden and libc_hidden_def macro. Redirect ifunced function
in header for using it as type for ifunc function because __GI_* symbols
for ppc32 do not target the ifunc symbols.
* sysdeps/unix/sysv/linux/powerpc/time.c (time): Likewise.
This patch uses the libc_ifunc_hidden macro to create already existing ifunc functions
time and gettimeofday on intel. This way, the libc_hidden_def macro can be used
instead of the libc_ifunc_hidden_def one which was only used here. Thus the
macro is removed from libc-symbols.h.
On i386, the __GI_* symbols do not target the ifunc symbol and thus the
redirection construct has to be applied here.
ChangeLog:
* sysdeps/unix/sysv/linux/x86/gettimeofday.c (__gettimeofday):
Use libc_ifunc_hidden macro. Use libc_hidden_def instead of
libc_ifunc_hidden_def.
* sysdeps/unix/sysv/linux/x86/time.c (time): Likewise.
* sysdeps/unix/sysv/linux/i386/gettimeofday.c (__gettimeofday):
Redirect ifunced function in header for using it as type of ifunc'ed
function. Redefine libc_hidden_def to use fallback non ifunc'ed
function for __GI_* symbol.
* sysdeps/unix/sysv/linux/i386/time.c (time): Likewise.
* include/libc-symbols.h
(libc_ifunc_hidden_def, libc_ifunc_hidden_def1): Delete macro.
This patch adjusts the s390 specific ifunc helper macros in ifunc-resolve.h to
use the common __ifunc macro, which uses gcc attribute ifunc to get rid of the
false debuginfo. Therefore the redirection construct is applied where needed.
Perhaps in future we can switch some of the internal symbols __GI_* from the
fallback variant to the ifunc function. But this change is not
straightforward due to a segmentation fault while linking libc.so with older
binutils on s390.
ChangeLog:
[BZ #20478]
* sysdeps/s390/multiarch/ifunc-resolve.h
(s390_vx_libc_ifunc2, s390_libc_ifunc): Use __ifunc from libc-symbols.h
to create ifunc symbols.
(s390_vx_libc_ifunc_init, s390_vx_libc_ifunc_redirected
, s390_vx_libc_ifunc2_redirected, s390_libc_ifunc_init): New define.
* sysdeps/s390/multiarch/memchr.c: Redirect ifunced function in header
for using it as type for ifunc function.
* sysdeps/s390/multiarch/mempcpy.c: Likewise.
* sysdeps/s390/multiarch/rawmemchr.c: Likewise.
* sysdeps/s390/multiarch/stpcpy.c: Likewise.
* sysdeps/s390/multiarch/stpncpy.c: Likewise.
* sysdeps/s390/multiarch/strcat.c: Likewise.
* sysdeps/s390/multiarch/strchr.c: Likewise.
* sysdeps/s390/multiarch/strcmp.c: Likewise.
* sysdeps/s390/multiarch/strcpy.c: Likewise.
* sysdeps/s390/multiarch/strcspn.c: Likewise.
* sysdeps/s390/multiarch/strlen.c: Likewise.
* sysdeps/s390/multiarch/strncmp.c: Likewise.
* sysdeps/s390/multiarch/strncpy.c: Likewise.
* sysdeps/s390/multiarch/strnlen.c: Likewise.
* sysdeps/s390/multiarch/strpbrk.c: Likewise.
* sysdeps/s390/multiarch/strrchr.c: Likewise.
* sysdeps/s390/multiarch/strspn.c: Likewise.
* sysdeps/s390/multiarch/wcschr.c: Likewise.
* sysdeps/s390/multiarch/wcscmp.c: Likewise.
* sysdeps/s390/multiarch/wcspbrk.c: Likewise.
* sysdeps/s390/multiarch/wcsspn.c: Likewise.
* sysdeps/s390/multiarch/wmemchr.c: Likewise.
* sysdeps/s390/multiarch/wmemset.c: Likewise.
* sysdeps/s390/s390-32/multiarch/memcmp.c: Likewise.
* sysdeps/s390/s390-32/multiarch/memcpy.c: Likewise.
* sysdeps/s390/s390-32/multiarch/memset.c: Likewise.
* sysdeps/s390/s390-64/multiarch/memcmp.c: Likewise.
* sysdeps/s390/s390-64/multiarch/memcpy.c: Likewise.
* sysdeps/s390/s390-64/multiarch/memset.c: Likewise.
The current s390 ifunc resolver for vector optimized functions and the common
libc_ifunc macro in include/libc-symbols.h uses something like that to generate ifunc'ed functions:
extern void *__resolve___strlen(unsigned long int dl_hwcap) asm (strlen);
asm (".type strlen, %gnu_indirect_function");
This leads to false debug information:
objdump --dwarf=info libc.so:
...
<1><1e6424>: Abbrev Number: 43 (DW_TAG_subprogram)
<1e6425> DW_AT_external : 1
<1e6425> DW_AT_name : (indirect string, offset: 0x1146e): __resolve___strlen
<1e6429> DW_AT_decl_file : 1
<1e642a> DW_AT_decl_line : 23
<1e642b> DW_AT_linkage_name: (indirect string, offset: 0x1147a): strlen
<1e642f> DW_AT_prototyped : 1
<1e642f> DW_AT_type : <0x1e4ccd>
<1e6433> DW_AT_low_pc : 0x998e0
<1e643b> DW_AT_high_pc : 0x16
<1e6443> DW_AT_frame_base : 1 byte block: 9c (DW_OP_call_frame_cfa)
<1e6445> DW_AT_GNU_all_call_sites: 1
<1e6445> DW_AT_sibling : <0x1e6459>
<2><1e6449>: Abbrev Number: 44 (DW_TAG_formal_parameter)
<1e644a> DW_AT_name : (indirect string, offset: 0x1845): dl_hwcap
<1e644e> DW_AT_decl_file : 1
<1e644f> DW_AT_decl_line : 23
<1e6450> DW_AT_type : <0x1e4c8d>
<1e6454> DW_AT_location : 0x122115 (location list)
...
The debuginfo for the ifunc-resolver function contains the DW_AT_linkage_name
field, which names the real function name "strlen". If you perform an inferior
function call to strlen in lldb, then it fails due to something like that:
"error: no matching function for call to 'strlen'
candidate function not viable: no known conversion from 'const char [6]'
to 'unsigned long' for 1st argument"
The unsigned long is the dl_hwcap argument of the resolver function.
The strlen function itself has no debufinfo.
The s390 ifunc resolver for memset & co uses something like that:
asm (".globl FUNC"
".type FUNC, @gnu_indirect_function"
".set FUNC, __resolve_FUNC");
This way the debuginfo for the ifunc-resolver function does not conain the
DW_AT_linkage_name field and the real function has no debuginfo, too.
Using this strategy for the vector optimized functions leads to some troubles
for functions like strnlen. Here we have __strnlen and a weak alias strnlen.
The __strnlen function is the ifunc function, which is realized with the asm-
statement above. The weak_alias-macro can't be used here due to undefined symbol:
gcc ../sysdeps/s390/multiarch/strnlen.c -c ...
In file included from <command-line>:0:0:
../sysdeps/s390/multiarch/strnlen.c:28:24: error: ‘strnlen’ aliased to undefined symbol ‘__strnlen’
weak_alias (__strnlen, strnlen)
^
./../include/libc-symbols.h:111:26: note: in definition of macro ‘_weak_alias’
extern __typeof (name) aliasname __attribute__ ((weak, alias (#name)));
^
../sysdeps/s390/multiarch/strnlen.c:28:1: note: in expansion of macro ‘weak_alias’
weak_alias (__strnlen, strnlen)
^
make[2]: *** [build/string/strnlen.o] Error 1
As the __strnlen function is defined with asm-statements the function name
__strnlen isn't known by gcc. But the weak alias can also be done with an
asm statement to resolve this issue:
__asm__ (".weak strnlen\n\t"
".set strnlen,__strnlen\n");
In order to use the weak_alias macro, gcc needs to know the ifunc function. The
minimum gcc to build glibc is currently 4.7, which supports attribute((ifunc)).
See https://gcc.gnu.org/onlinedocs/gcc-4.7.0/gcc/Function-Attributes.html.
It is only supported if gcc is configured with --enable-gnu-indirect-function
or gcc supports it by default for at least intel and s390x architecture.
This patch uses the old behaviour if gcc support is not available.
Usage of attribute ifunc is something like that:
__typeof (FUNC) FUNC __attribute__ ((ifunc ("__resolve_FUNC")));
Then gcc produces the same .globl, .type, .set assembler instructions like above.
And the debuginfo does not contain the DW_AT_linkage_name field and there is no
debuginfo for the real function, too.
But in order to get it work, there is also some extra work to do.
Currently, the glibc internal symbol on s390x e.g. __GI___strnlen is not the
ifunc symbol, but the fallback __strnlen_c symbol. Thus I have to omit the
libc_hidden_def macro in strnlen.c (here is the ifunc function __strnlen)
because it is already handled in strnlen-c.c (here is __strnlen_c).
Due to libc_hidden_proto (__strnlen) in string.h, compiling fails:
gcc ../sysdeps/s390/multiarch/strnlen.c -c ...
In file included from <command-line>:0:0:
../sysdeps/s390/multiarch/strnlen.c:53:24: error: ‘strnlen’ aliased to undefined symbol ‘__strnlen’
weak_alias (__strnlen, strnlen)
^
./../include/libc-symbols.h:111:26: note: in definition of macro ‘_weak_alias’
extern __typeof (name) aliasname __attribute__ ((weak, alias (#name)));
^
../sysdeps/s390/multiarch/strnlen.c:53:1: note: in expansion of macro ‘weak_alias’
weak_alias (__strnlen, strnlen)
^
make[2]: *** [build/string/strnlen.os] Error 1
I have to redirect the prototypes for __strnlen in string.h and create a copy
of the prototype for using as ifunc function:
__typeof (__redirect___strnlen) __strnlen __attribute__ ((ifunc ("__resolve_strnlen")));
weak_alias (__strnlen, strnlen)
This way there is no trouble with the internal __GI_* symbols.
Glibc builds fine with this construct and the debuginfo is "correct".
For functions without a __GI_* symbol like memccpy this redirection is not needed.
This patch adjusts the common libc_ifunc and libm_ifunc macro to use gcc
attribute ifunc. Due to this change, the macro users where the __GI_* symbol
does not target the ifunc symbol have to be prepared with the redirection
construct.
Furthermore a configure check to test gcc support is added. If it is not supported,
the old behaviour is used.
This patch also prepares the libc_ifunc macro to be useable in s390-ifunc-macro.
The s390 ifunc-resolver-functions do have an hwcaps parameter and not all
resolvers need the same initialization code. The next patch in this series
changes the s390 ifunc macros to use this common one.
ChangeLog:
* include/libc-symbols.h (__ifunc_resolver):
New macro is used by __ifunc* macros.
(__ifunc): New macro uses gcc attribute ifunc or inline assembly
depending on HAVE_GCC_IFUNC.
(libc_ifunc, libm_ifunc): Use __ifunc as base macro.
(libc_ifunc_redirected, libc_ifunc_hidden, libm_ifunc_init): New macro.
* sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_finite.c:
Redirect ifunced function in header for using as type for ifunc function.
* sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_finitef.c: Likewise.
* sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_isinf.c: Likewise.
* sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_isinff.c: Likewise.
* sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_isnan.c: Likewise.
* sysdeps/powerpc/powerpc32/power4/multiarch/memcmp.c: Likewise.
* sysdeps/powerpc/powerpc32/power4/multiarch/memcpy.c: Likewise.
* sysdeps/powerpc/powerpc32/power4/multiarch/memmove.c: Likewise.
* sysdeps/powerpc/powerpc32/power4/multiarch/mempcpy.c: Likewise.
* sysdeps/powerpc/powerpc32/power4/multiarch/memset.c: Likewise.
* sysdeps/powerpc/powerpc32/power4/multiarch/rawmemchr.c: Likewise.
* sysdeps/powerpc/powerpc32/power4/multiarch/strchr.c: Likewise.
* sysdeps/powerpc/powerpc32/power4/multiarch/strlen.c: Likewise.
* sysdeps/powerpc/powerpc32/power4/multiarch/strncmp.c: Likewise.
* sysdeps/powerpc/powerpc32/power4/multiarch/strnlen.c: Likewise.
* sysdeps/powerpc/powerpc64/fpu/multiarch/s_finite.c: Likewise.
* sysdeps/powerpc/powerpc64/fpu/multiarch/s_finitef.c: Likewise.
* sysdeps/powerpc/powerpc64/fpu/multiarch/s_isinf.c: Likewise.
* sysdeps/powerpc/powerpc64/fpu/multiarch/s_isinff.c: Likewise.
* sysdeps/powerpc/powerpc64/fpu/multiarch/s_isnan.c: Likewise.
* sysdeps/powerpc/powerpc64/multiarch/memcmp.c: Likewise.
* sysdeps/powerpc/powerpc64/multiarch/mempcpy.c: Likewise.
* sysdeps/powerpc/powerpc64/multiarch/rawmemchr.c: Likewise.
* sysdeps/powerpc/powerpc64/multiarch/stpncpy.c: Likewise.
* sysdeps/powerpc/powerpc64/multiarch/strcat.c: Likewise.
* sysdeps/powerpc/powerpc64/multiarch/strchr.c: Likewise.
* sysdeps/powerpc/powerpc64/multiarch/strcmp.c: Likewise.
* sysdeps/powerpc/powerpc64/multiarch/strcpy.c: Likewise.
* sysdeps/powerpc/powerpc64/multiarch/strncmp.c: Likewise.
* sysdeps/powerpc/powerpc64/multiarch/strncpy.c: Likewise.
* sysdeps/powerpc/powerpc64/multiarch/strnlen.c: Likewise.
* sysdeps/powerpc/powerpc64/multiarch/strrchr.c: Likewise.
* sysdeps/powerpc/powerpc64/multiarch/strstr.c: Likewise.
* sysdeps/powerpc/powerpc64/multiarch/wcschr.c: Likewise.
* sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_isnanf.c:
Add libc_hidden_def() and use libc_ifunc_hidden() macro
instead of libc_ifunc() macro.
* sysdeps/powerpc/powerpc64/fpu/multiarch/s_isnanf.c: Likewise.
* sysdeps/powerpc/powerpc64/multiarch/stpcpy.c: Likewise.
This patch adds a configure check to test if gcc supports attribute ifunc.
The support can either be enabled in <gcc-src>/gcc/config.gcc for one
architecture in general by setting default_gnu_indirect_function variable to yes
or by configuring gcc with --enable-gnu-indirect-function.
The next patch rewrites libc_ifunc macro to use gcc attribute ifunc instead
of inline assembly to generate the IFUNC symbols due to false debuginfo.
If gcc does not support attribute ifunc, the old approach for generating
ifunc'ed symbols is used. Then the debug-information is false. Thus it is
recommended to use a gcc with indirect function support (See notes in INSTALL).
After this patch-series these inline assemblies for ifunc-handling are not
scattered in multiple files but are used only indirect via ifunc-macros
and can simply removed in libc-symbols.h in future.
If glibc is configured with --enable-multi-arch and gcc does not support
attribute ifunc, a configure warning is dumped!
ChangeLog:
* config.h.in (HAVE_GCC_IFUNC): New undef.
* configure.ac: Add check if gcc supports attribute ifunc feature.
* configure: Regenerated.
* manual/install.texi: Add recommendation for gcc with
indirect-function support.
* INSTALL: Regenerated.
TS 18661-1 adds an iseqsig type-generic comparison macro to <math.h>.
This macro is like the == operator except that unordered operands
result in the "invalid" exception and errno being set to EDOM.
This patch implements this macro for glibc. Given the need to set
errno, this is implemented with out-of-line functions __iseqsigf,
__iseqsig and __iseqsigl (of which the last only exists at all if long
double is ABI-distinct from double, so no function aliases or compat
support are needed). The present patch ignores excess precision
issues; I intend to deal with those in a followup patch. (Like
comparison operators, type-generic comparison macros should *not*
convert operands to their semantic types but should preserve excess
range and precision, meaning that for some argument types and values
of FLT_EVAL_METHOD, an underlying function should be called for a
wider type than that of the arguments.)
The underlying functions are implemented with the type-generic
template machinery. Comparing x <= y && x >= y is sufficient in ISO C
to achieve an equality comparison with "invalid" raised for unordered
operands (and the results of those two comparisons can also be used to
tell whether errno needs to be set). However, some architectures have
GCC bugs meaning that unordered comparison instructions are used
instead of ordered ones. Thus, a mechanism is provided for
architectures to use an explicit call to feraiseexcept to raise
exceptions if required. If your architecture has such a bug you
should add a fix-fp-int-compare-invalid.h header for it, with a
comment pointing to the relevant GCC bug report; if such a GCC bug is
fixed, that header's contents should have a __GNUC_PREREQ conditional
added so that the workaround can eventually be removed for that
architecture.
Tested for x86_64, x86, mips64, arm and powerpc.
* math/math.h [__GLIBC_USE (IEC_60559_BFP_EXT)] (iseqsig): New
macro.
* math/bits/mathcalls.h [__GLIBC_USE (IEC_60559_BFP_EXT)]
(__iseqsig): New declaration.
* math/s_iseqsig_template.c: New file.
* math/Versions (__iseqsigf): New libm symbol at version
GLIBC_2.25.
(__iseqsig): Likewise.
(__iseqsigl): Likewise.
* math/libm-test.inc (iseqsig_test_data): New array.
(iseqsig_test): New function.
(main): Call iseqsig_test.
* math/Makefile (gen-libm-calls): Add s_iseqsigF.
* manual/arith.texi (FP Comparison Functions): Document iseqsig.
* manual/libm-err-tab.pl: Update comment on interfaces without
ulps tabulated.
* sysdeps/generic/fix-fp-int-compare-invalid.h: New file.
* sysdeps/powerpc/fpu/fix-fp-int-compare-invalid.h: Likewise.
* sysdeps/x86/fpu/fix-fp-int-compare-invalid.h: Likewise.
* sysdeps/nacl/libm.abilist: Update.
* sysdeps/unix/sysv/linux/aarch64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/alpha/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/arm/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/hppa/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/i386/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/ia64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/m68k/coldfire/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/m68k/m680x0/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/microblaze/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips32/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/nios2/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libm-le.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/s390/s390-32/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/sh/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc32/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/tile/tilepro/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/x86_64/64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/x86_64/x32/libm.abilist: Likewise.
Like the previous change, make the quadrant shift a boolean to make it
clearer that we will do at most a single rotation of the quadrants to
compute the cosine from the sine function.
This does not affect codegen.
