- - - -
New in version 6: Due to an oversight (i.e. coding error), version 5
changed the use of __LIBGCC_TF_EPSILON__ to __LIBGCC_DF_EPSILON__ but
not the other LIBGCC_TF values. For correct execution of the long
double test case it is necessary to also switch to using
__LIBGCC_DF_MIN__. For consistency we also switch to using
__LIBGCC_DF_MAX__. LDBL_MIN is 2**53 times as larger than DBL_MIN.
The larger value causes the code to switch the order of computation
when it is not optimal, resulting in failure for one of the values
in the cdivchk_ld.c test. Using DBL_MIN does not cause that failure..
There may be opportunity for further refinement of IBM128 format
Long Double complex divide, but that's beyond the scope of this
patch.
- - - -
This revision adds a test in libgcc/libgcc2.c for when
"__LIBGCC_TF_MANT_DIG__ == 106" to use __LIBGCC_DF_EPSILON__ instead
of __LIBGCC_TF_EPSILON__. That is specific to IBM 128-bit format long
doubles where EPSILON is very, very small and 1/EPSILON oveflows to
infinity. This change avoids the overflow without affecting any other
platform. Discussion in the patch is adjusted to reflect this
limitation.
It does not make any changes to .../rs6000/_divkc3.c, leaving it to
use __LIBGCC_KF__*. That means the upstream gcc will not build in
older IBM environments that do not recognize the KF floating point
mode properly. Environments that do not need IBM longdouble support
do build cleanly.
- - - -
This patch addresses the failure of powerpc64 long double complex divide
in native ibm long double format after the patch "Practical improvement
to libgcc complex divide".
The new code uses the following macros which are intended to be mapped
to appropriate values according to the underlying hardware representation.
See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101104
RBIG a value near the maximum representation
RMIN a value near the minimum representation
(but not in the subnormal range)
RMIN2 a value moderately less than 1
RMINSCAL the inverse of RMIN2
RMAX2 RBIG * RMIN2 - a value to limit scaling to not overflow
When "long double" values were not using the IEEE 128-bit format but
the traditional IBM 128-bit, the previous code used the LDBL values
which caused overflow for RMINSCAL. The new code uses the DBL values.
RBIG LDBL_MAX = 0x1.fffffffffffff800p+1022
DBL_MAX = 0x1.fffffffffffff000p+1022
RMIN LDBL_MIN = 0x1.0000000000000000p-969
RMIN DBL_MIN = 0x1.0000000000000000p-1022
RMIN2 LDBL_EPSILON = 0x0.0000000000001000p-1022 = 0x1.0p-1074
RMIN2 DBL_EPSILON = 0x1.0000000000000000p-52
[ORMINSCAL 1/LDBL_EPSILON = inf (1.0p+1074 does not fit in IBM 128-bit).
1/DBL_EPSILON = 0x1.0000000000000000p+52
RMAX2 = RBIG * RMIN2 = 0x1.fffffffffffff800p-52
RBIG * RMIN2 = 0x1.fffffffffffff000p+970
The MAX and MIN values have only modest changes since the maximum and
minimum values are about the same as for double precision. The
EPSILON field is considerably different. Due to how very small values
can be represented in the lower 64 bits of the IBM 128-bit floating
point, EPSILON is extremely small, so far beyond the desired value
that inversion of the value overflows and even without the overflow,
the RMAX2 is so small as to eliminate most usage of the test.
The change has been tested on gcc135.fsffrance.org and gains the
expected improvements in accuracy for long double complex divide.
libgcc/
PR target/101104
* libgcc2.c (RMIN2, RMINSCAL, RMAX2):
Use more correct values for native IBM 128-bit.
These two symbols have been emitted since 4.8, but were not added
to the Darwin exports, so we have been using the ones from libgcc.a.
Added to libgcc_s now.
Signed-off-by: Iain Sandoe <iain@sandoe.co.uk>
libgcc/ChangeLog:
* config/i386/libgcc-darwin.ver: Add Symbols for
__cpu_model, __cpu_indicator_init.
Existing code in the sfp-machine header has been using __MACH__
as a guard for Mach-O, where currently symbols aliases are not
supported.
__MACH__ is not a sufficient guard for this, since the define
is also emitted for HURD, at least.
Fixed by amending the guard to use __APPLE__ instead.
Signed-off-by: Iain Sandoe <iain@sandoe.co.uk>
libgcc/ChangeLog:
* config/i386/sfp-machine.h: Guard Mach-O-specific code
using __APPLE__.
These were used on older systems to equate the FAT libgcc_s
library to single-slice equivalents. Unused for any current
system and never emitted by GCC.
Signed-off-by: Iain Sandoe <iain@sandoe.co.uk>
libgcc/ChangeLog:
* config/t-slibgcc-darwin: Delete unused code.
This reorganises the Darwin symbol vers files to include
the generic ones at the top level; allowing for arch ports
to override (via either exclusion or inclusion as needed).
We add an X86-specific vers file containing the new HF
symbols. Note that although Darwin does not use ELF-style
symbol versioning - the parser that produces the map can
consume it. Using the ELF-style description will help us
know at which rev the symbols were introduced.
Signed-off-by: Iain Sandoe <iain@sandoe.co.uk>
libgcc/ChangeLog:
* config/i386/t-darwin: Add in a vers file for X86-specific
symbols.
* config/t-darwin: Add the generic symbol maps here...
* config/t-slibgcc-darwin: ... removing from here.
* config/i386/libgcc-darwin.ver: New file.
We want to override the libgcc2 generic version of these functions
for X86. First exclude the original and the add in the replacements.
Signed-off-by: Iain Sandoe <iain@sandoe.co.uk>
libgcc/ChangeLog:
* config/i386/t-softfp: Exclude libgcc2 versions of __divhc3
and __mulhc3.
We have a small unwinder shim that is only used for Darwin10
(and only then in quite specific cases). To avoid linking
this code for every executable or DSO, we can present the crt
as a convenience library (rather than a .o file).
Signed-off-by: Iain Sandoe <iain@sandoe.co.uk>
gcc/ChangeLog:
* config/darwin.h (LINK_COMMAND_SPEC_A): Use Darwin10
unwinder shim as a convenience library.
libgcc/ChangeLog:
* config.host: Use convenience library for Darwin10
unwinder shim.
* config/t-darwin: Build Darwin10 unwinder shim as a
convenience library.
m32r support never made it to glibc and the support for the Linux kernel
was removed with 4.18. It does not remove much but no reason to keep
around a port which never worked or one which the support in other
projects is gone.
OK? Checked to make sure m32r-linux and m32rle-linux were rejected
when building.
contrib/ChangeLog:
* config-list.mk: Remove m32r-linux and m32rle-linux
from the list.
gcc/ChangeLog:
* config.gcc: Add m32r-*-linux* and m32rle-*-linux*
to the Unsupported targets list.
Remove support for m32r-*-linux* and m32rle-*-linux*.
* config/m32r/linux.h: Removed.
* config/m32r/t-linux: Removed.
libgcc/ChangeLog:
* config.host: Remove m32r-*-linux* and m32rle-*-linux*.
* config/m32r/libgcc-glibc.ver: Removed.
* config/m32r/t-linux: Removed.
The following patch exports it for Linux from config/i386/*.ver where it
IMNSHO belongs, aarch64 already exports some of those at GCC_11* and other
targets might add them at completely different gcc versions.
2021-09-08 Jakub Jelinek <jakub@redhat.com>
Iain Sandoe <iain@sandoe.co.uk>
* config/i386/libgcc-glibc.ver: Add %inherit GCC_12.0.0 GCC_7.0.0
and export *hf* and *hc* functions at GCC_12.0.0.
For 32-bit libgcc configure w/o sse2, there's would be an error since
GCC only support _Float16 under sse2. Explicitly add -msse2 for those
HF related libgcc functions, so users can still link them w/ the
upper configuration.
libgcc/ChangeLog:
* Makefile.in: Adjust to support specific CFLAGS for each
libgcc source file.
* config/i386/64/t-softfp: Explicitly add -msse2 for HF
related libgcc source files.
* config/i386/t-softfp: Ditto.
* config/i386/_divhc3.c: New file.
* config/i386/_mulhc3.c: New file.
Darwin does not support strong symbol aliases and a work-
around is provided in sfp-machine.h where a second function
is created that simply calls the original. However this
needs the arguments to the synthesized function to track
the mode of the original function.
So the fix here is to match known floating point modes from
the incoming function and apply the one found to the new
function args.
The matching is highly specific to the current set of modes
and will need adjusting should more cases be added.
Signed-off-by: Iain Sandoe <iain@sandoe.co.uk>
libgcc/ChangeLog:
* config/i386/sfp-machine.h (alias_HFtype, alias_SFtype
alias_DFtype, alias_TFtype): New.
(ALIAS_SELECTOR): New.
(strong_alias): Use __typeof and a _Generic selector to
provide the type to the synthesized function.
libgcc/ChangeLog
* soft-fp/eqhf2.c: New file.
* soft-fp/extendhfdf2.c: New file.
* soft-fp/extendhfsf2.c: New file.
* soft-fp/half.h (FP_CMP_EQ_H): New marco.
* soft-fp/truncdfhf2.c: New file
* soft-fp/truncsfhf2.c: New file
Do not declare abort in "libgcc/unwind-arm-common.inc" since it is already
provided by "tsystem.h". It fixes the following build error:
In file included from libgcc/config/arm/unwind-arm.c:144:
libgcc/unwind-arm-common.inc:55:24: error: macro "abort" passed 1 arguments, but takes just 0
55 | extern void abort (void);
libgcc/
* unwind-arm-common.inc (abort): Remove.
Quoting from https://gcc.gnu.org/pipermail/gcc/2021-July/236716.html:
--------------------------------------------------------------------
It was pointed out to me off-list that config/aarch64/value-unwind.h
is missing the runtime exception. It looks like a few other files
are too; a fuller list is:
libgcc/config/aarch64/value-unwind.h
libgcc/config/frv/frv-abi.h
libgcc/config/i386/value-unwind.h
libgcc/config/pa/pa64-hpux-lib.h
Certainly for the aarch64 file this was simply a mistake;
it seems to have been copied from the i386 version, both of which
reference the runtime exception but don't actually include it.
--------------------------------------------------------------------
Similarly, frv-abi.h referenced the exception but didn't include it.
pa64-hpux-lib.h was missing any reference to the exception.
The decision was that this was simply a mistake
[https://gcc.gnu.org/pipermail/gcc/2021-July/236717.html]:
--------------------------------------------------------------------
[…] It generally is
considered a textual omission. The runtime library components of GCC
are intended to be licensed under the runtime exception, which was
granted and approved at the time of introduction.
--------------------------------------------------------------------
and that we should simply change all of the files above
[https://gcc.gnu.org/pipermail/gcc/2021-July/236719.html]:
--------------------------------------------------------------------
Please correct the text in the files. The files in libgcc used in the
GCC runtime are intended to be licensed with the runtime exception and
GCC previously was granted approval for that licensing and purpose.
[…]
The runtime exception explicitly was intended for this purpose and
usage at the time that GCC received approval to apply the exception.
--------------------------------------------------------------------
libgcc/
* config/aarch64/value-unwind.h: Add missing runtime exception
paragraph.
* config/frv/frv-abi.h: Likewise.
* config/i386/value-unwind.h: Likewise.
* config/pa/pa64-hpux-lib.h: Likewise.
While performing some tests of IEEE 128 float for PPC64LE, Michael
Meissner noticed that __gcc_qsub is substantially slower than
__gcc_qadd. __gcc_qsub calls __gcc_add with the second operand
negated. Because the functions normally are invoked through
libgcc shared object, the extra PLT overhead has a large impact
on the overall time of the function. This patch converts
__gcc_qadd to a static inline function invoked by __gcc_qadd
and __gcc_qsub.
libgcc/ChangeLog:
* config/rs6000/ibm-ldouble.c (ldouble_qadd_internal): Rename from
__gcc_qadd.
(__gcc_qadd): Call ldouble_qadd_internal.
(__gcc_qsub): Call ldouble_qadd_internal with second long double
argument negated.
Add the recommended erratum mitigation sequence to
__gnu_cmse_nonsecure_call for use on Armv8-m.main devices. Since this
is in the library code we cannot know in advance whether the core we
are running on will be affected by this, so always enable it.
libgcc:
PR target/102035
* config/arm/cmse_nonsecure_call.S (__gnu_cmse_nonsecure_call):
Add vlldm erratum work-around.
If -fprofile-update=atomic is used, then the target must provide atomic
operations for the counters of the type returned by get_gcov_type().
This is a 64-bit type for targets which have a 64-bit long long type.
On 32-bit targets this could be an issue since they may not provide
64-bit atomic operations. Allow targets to override the default type
size with the new TARGET_GCOV_TYPE_SIZE target hook.
If a 32-bit gcov type size is used, then there is currently a warning in
libgcov-driver.c in a dead code block due to
sizeof (counter) == sizeof (gcov_unsigned_t):
libgcc/libgcov-driver.c: In function 'dump_counter':
libgcc/libgcov-driver.c:401:46: warning: right shift count >= width of type [-Wshift-count-overflow]
401 | dump_unsigned ((gcov_unsigned_t)(counter >> 32), dump_fn, arg);
| ^~
gcc/c-family/
* c-cppbuiltin.c (c_cpp_builtins): Define
__LIBGCC_GCOV_TYPE_SIZE if flag_building_libgcc is true.
gcc/
* config/sparc/rtemself.h (SPARC_GCOV_TYPE_SIZE): Define.
* config/sparc/sparc.c (sparc_gcov_type_size): New.
(TARGET_GCOV_TYPE_SIZE): Redefine if SPARC_GCOV_TYPE_SIZE is defined.
* coverage.c (get_gcov_type): Use targetm.gcov_type_size().
* doc/tm.texi (TARGET_GCOV_TYPE_SIZE): Add hook under "Misc".
* doc/tm.texi.in: Regenerate.
* target.def (gcov_type_size): New target hook.
* targhooks.c (default_gcov_type_size): New.
* targhooks.h (default_gcov_type_size): Declare.
* tree-profile.c (gimple_gen_edge_profiler): Use precision of
gcov_type_node.
(gimple_gen_time_profiler): Likewise.
libgcc/
* libgcov.h (gcov_type): Define using __LIBGCC_GCOV_TYPE_SIZE.
(gcov_type_unsigned): Likewise.
When linking gcc runtime objects into large binaries the link may fail
with the below errors. This will happen even if we are building with
-mcmodel=large.
/home/shorne/work/openrisc/output/host/lib/gcc/or1k-buildroot-linux-uclibc/10.3.0/crtbeginS.o: in function `deregister_tm_clones':
crtstuff.c:(.text+0x3c): relocation truncated to fit: R_OR1K_GOT16 against undefined symbol `_ITM_deregisterTMCloneTable'
/home/shorne/work/openrisc/output/host/lib/gcc/or1k-buildroot-linux-uclibc/10.3.0/crtbeginS.o: in function `register_tm_clones':
crtstuff.c:(.text+0xc0): relocation truncated to fit: R_OR1K_GOT16 against undefined symbol `_ITM_registerTMCloneTable'
This patch builds the gcc crtstuff binaries always with the
-mcmodel=large option to ensure they can be linked into large binaries.
libgcc/ChangeLog:
PR target/99783
* config.host (or1k-*, tmake_file): Add or1k/t-crtstuff.
* config/or1k/t-crtstuff: New file.
In the patch to add __gcov_info_to_gcda(), the include of <stdint.h> was added
to libgcov-driver.c even if inhibit_libc is defined. It turned out that this
header file is not always available. Remove the include of <stdint.h> and
replace the intptr_t with the compiler provided __INTPTR_TYPE__.
libgcc/
* libgcov-driver.c (#include <stdint.h>): Remove.
(write_topn_counters): Use __INTPTR_TYPE__ instead of intptr_t.
Add __gcov_info_to_gcda() to libgcov to get the gcda data for a gcda info in a
freestanding environment. It is intended to be used with the
-fprofile-info-section option. A crude test program which doesn't use a linker
script is (use "gcc -coverage -fprofile-info-section -lgcov test.c" to compile
it):
#include <gcov.h>
#include <stdio.h>
#include <stdlib.h>
extern const struct gcov_info *my_info;
static void
filename (const char *f, void *arg)
{
printf("filename: %s\n", f);
}
static void
dump (const void *d, unsigned n, void *arg)
{
const unsigned char *c = d;
for (unsigned i = 0; i < n; ++i)
printf ("%02x", c[i]);
}
static void *
allocate (unsigned length, void *arg)
{
return malloc (length);
}
int main()
{
__asm__ volatile (".set my_info, .LPBX2");
__gcov_info_to_gcda (my_info, filename, dump, allocate, NULL);
return 0;
}
With this patch, <stdint.h> is included in libgcov-driver.c even if
inhibit_libc is defined. This header file should be also available for
freestanding environments. If this is not the case, then we have to define
intptr_t somehow.
The patch removes one use of memset() which makes the <string.h> include
superfluous.
gcc/
* gcov-io.h (gcov_write): Declare.
* gcov-io.c (gcov_write): New.
(gcov_write_counter): Remove.
(gcov_write_tag_length): Likewise.
(gcov_write_summary): Replace gcov_write_tag_length() with calls to
gcov_write_unsigned().
* doc/invoke.texi (fprofile-info-section): Mention
__gcov_info_to_gdca().
gcc/testsuite/
* gcc.dg/gcov-info-to-gcda.c: New test.
libgcc/
* Makefile.in (LIBGCOV_DRIVER): Add _gcov_info_to_gcda.
* gcov.h (gcov_info): Declare.
(__gcov_info_to_gdca): Likewise.
* libgcov.h (gcov_write_counter): Remove.
(gcov_write_tag_length): Likewise.
* libgcov-driver.c (#include <stdint.h>): New.
(#include <string.h>): Remove.
(NEED_L_GCOV): Conditionally define.
(NEED_L_GCOV_INFO_TO_GCDA): Likewise.
(are_all_counters_zero): New.
(gcov_dump_handler): Likewise.
(gcov_allocate_handler): Likewise.
(dump_unsigned): Likewise.
(dump_counter): Likewise.
(write_topn_counters): Add dump_fn, allocate_fn, and arg parameters.
Use dump_unsigned() and dump_counter().
(write_one_data): Add dump_fn, allocate_fn, and arg parameters. Use
dump_unsigned(), dump_counter(), and are_all_counters_zero().
(__gcov_info_to_gcda): New.
When building gcc with some specific LDFLAGS_FOR_TARGET, e.g.
LDFLAGS_FOR_TARGET=-Wl,-z,relro,-z,now
those flags propagate info linking of target shared libraries,
e.g. lib{ubsan,tsan,stdc++,quadmath,objc,lsan,itm,gphobos,gdruntime,gomp,go,gfortran,atomic,asan}.so.*
but there is one important exception, libgcc_s.so.* linking ignores it.
The following patch fixes that.
Bootstrapped/regtested on x86_64-linux with LDFLAGS_FOR_TARGET=-Wl,-z,relro,-z,now
and verified that libgcc_s.so.* is BIND_NOW when it previously wasn't, and
without any LDFLAGS_FOR_TARGET on x86_64-linux and i686-linux.
There on x86_64-linux I've verified that the libgcc_s.so.1 linking command
line for -m64 is identical except for whitespace to one without the patch,
and for -m32 multilib $(LDFLAGS) actually do supply there an extra -m32
that also repeats later in the @multilib_flags@, which should be harmless.
2021-08-04 Jakub Jelinek <jakub@redhat.com>
* config/t-slibgcc (SHLIB_LINK): Add $(LDFLAGS).
* config/t-slibgcc-darwin (SHLIB_LINK): Likewise.
* config/t-slibgcc-vms (SHLIB_LINK): Likewise.
* config/t-slibgcc-fuchsia (SHLIB_LDFLAGS): Remove $(LDFLAGS).
The file has two identical halves, seems like twice applied patch.
2021-08-04 Jakub Jelinek <jakub@redhat.com>
* config/t-slibgcc-fuchsia: Undo doubly applied patch.
Compiling gcc/testsuite/gcc.dg/split-*.c and others with -mcpu=power10
and linking with a non-pcrel libgcc results in crashes due to the
power10 pcrel code not having r2 set for the generic-morestack.c
functions called from __morestack. There is also a problem when
non-pcrel code calls a pcrel libgcc. See the patch comments.
A similar situation theoretically occurs with ELFv1 multi-toc
executables, when __morestack might be located in a different toc
group to its caller. This patch makes no attempt to fix that, since
the gold linker does not support multi-toc (gold is needed for proper
support of -fsplit-stack code) nor does gcc emit __morestack calls
that support multi-toc.
* config/rs6000/morestack.S (R2_SAVE): Define.
(__morestack): Save and restore r2. Set up r2 for called
functions.
