Investigating the reasons for libgcc build failures in a canadian
context, orthogonally to the recent update of vxcrtstuff, exposed
interesting differences in the way include search paths are managed
between a regular Linux->VxWorks cross build and a canadian setup
building a Windows->VxWorks toolchain in a Linux environment.
This change augments the comment attached to LIBGCC2_INCLUDE in
libgcc/config/t-vxworks to better describe the parameters at play.
It also adjusts the addition of options for gcc/include and
gcc/include-fixed to minimize the actual differences for libgcc
in the two kinds of configurations.
2022-03-06 Olivier Hainque <hainque@adacore.com>
libgcc/
* config/t-vxworks (LIBGCC2_INCLUDE): Augment comment. Move
-I options for gcc/include and gcc/include-fixed at the end
and make them -isystem.
Within gthr-vxworks.h, we prevent C++ errors from missing
declarations in some system headers by prepending their inclusion
with a
#pragma GCC diagnostic ignored "-Wstrict-prototypes"
But Wstrict-prototypes is internally registered as valid for
C/ObjC only, not C++, and this trick in turn triggers a Wpragma
warning with -Wsystem-headers.
This change just arranges to ignore the secondary warning locally.
2021-02-03 Olivier Hainque <hainque@adacore.com>
* config/gthr-vxworks.h: Prevent Wpragma warning for the
pragma diagnostics on Wstrict-prototypes.
This change augments the comment attached to the use of auto-host.h
in vxcrtstuff.c to better describe the reason for including it and
for the associated series of #undef directives.
It also augments the comment on dso_handle and removes a redundant
guard on HAVE_INITFINI_ARRAY_SUPPORT for the shared version of the
objects, nested within a section guarded on USE_INITFINI_ARRAY.
2022-09-29 Olivier Hainque <hainque@adacore.com>
libgcc/
* config/vxcrtstuff.c: Improve the comment attached to the use
of auto-host.h and of __dso_handle. Remove redundant guard on
HAVE_INITFINI_ARRAY_SUPPORT within a USE_INITFINI_ARRAY section.
When using the atomic fast path deregistering can fail during
program shutdown if the lookup structures are already destroyed.
The assert in __deregister_frame_info_bases takes that into
account. In the non-fast-path case however is not aware of
program shutdown, which caused a compiler error on such platforms.
We fix that by introducing a constant for in_shutdown in
non-fast-path builds.
We also drop the destructor priority, as it is not supported on
all platforms and we no longer rely upon the priority anyway.
libgcc/ChangeLog:
* unwind-dw2-fde.c: Introduce a constant for in_shutdown
for the non-fast-path case. Drop destructor priority.
In some scenarios (e.g., when mixing gcc and clang code), it can
happen that frames are deregistered after the lookup structure
has already been destroyed. That in itself would be fine, but
it triggers an assert in __deregister_frame_info_bases that
expects to find the frame.
To avoid that, we now remember that the btree as already been
destroyed and disable the assert in that case.
libgcc/ChangeLog:
* unwind-dw2-fde.c: (release_register_frames) Remember
when the btree has been destroyed.
(__deregister_frame_info_bases) Disable the assert when
shutting down.
this patch fixed PR target/99184 which incorrectly rounded during 64-bit
(long) double to 16-bit and 32-bit integers.
The patch just removes the respective roundings from
libf7-asm.sx::to_integer and ::to_unsigned. Luckily, LibF7 does nowhere
use respective functions internally, the only user is in libf7.c::f7_exp
which reads
f7_round (qq, qq);
int16_t q = f7_get_s16 (qq);
so that f7_get_s16() operates on an already rounded value, and therefore
this code works unaltered with or without rounding in to_integer.
PR target/99184
libgcc/config/avr/libf7/
* libf7-asm.sx (to_integer, to_unsigned): Don't round 16-bit
and 32-bit integers.
uintptr_t is no available for all targets, use __UINTPTR_TYPE__
instead.
libgcc/ChangeLog:
* unwind-dw2-fde.c: Replace uintptr_t with typedef
for __UINTPTR_TYPE__.
* unwind-dw2-btree.h: Likewise.
The __register_frame/__deregister_frame functions are used to register
unwinding frames from JITed code in a sorted list. That list itself
is protected by object_mutex, which leads to terrible performance
in multi-threaded code and is somewhat expensive even if single-threaded.
There was already a fast-path that avoided taking the mutex if no
frame was registered at all.
This commit eliminates both the mutex and the sorted list from
the atomic fast path, and replaces it with a btree that uses
optimistic lock coupling during lookup. This allows for fully parallel
unwinding and is essential to scale exception handling to large
core counts.
libgcc/ChangeLog:
* unwind-dw2-fde.c (release_registered_frames): Cleanup at shutdown.
(__register_frame_info_table_bases): Use btree in atomic fast path.
(__deregister_frame_info_bases): Likewise.
(_Unwind_Find_FDE): Likewise.
(base_from_object): Make parameter const.
(classify_object_over_fdes): Add query-only mode.
(get_pc_range): Compute PC range for lookup.
* unwind-dw2-fde.h (last_fde): Make parameter const.
* unwind-dw2-btree.h: New file.
The ARC soft udivmodsi4 algorithm and as well as using umodsi3
for reduced register set configurations are wrong.
libgcc/
* config/arc/lib2funcs.c (udivmodsi4): Update AND mask.
* config/arc/lib1funcs.S (umodsi3): Don't use it for RF16
configurations.
> (clrsb:m x)
> Represents the number of redundant leading sign bits in x, represented
> as an integer of mode m, starting at the most significant bit position.
This explanation is just what the NSA instruction (not ever emitted before)
calculates in Xtensa ISA.
gcc/ChangeLog:
* config/xtensa/xtensa.md (clrsbsi2): New insn pattern.
libgcc/ChangeLog:
* config/xtensa/lib1funcs.S (__clrsbsi2): New function.
* config/xtensa/t-xtensa (LIB1ASMFUNCS): Add _clrsbsi2.
Aligne __EH_FRAME_BEGIN__ to pointer size since gcc/unwind-dw2-fde.h has
/* The first few fields of a CIE. The CIE_id field is 0 for a CIE,
to distinguish it from a valid FDE. FDEs are aligned to an addressing
unit boundary, but the fields within are unaligned. */
struct dwarf_cie
{
uword length;
sword CIE_id;
ubyte version;
unsigned char augmentation[];
} __attribute__ ((packed, aligned (__alignof__ (void *))));
/* The first few fields of an FDE. */
struct dwarf_fde
{
uword length;
sword CIE_delta;
unsigned char pc_begin[];
} __attribute__ ((packed, aligned (__alignof__ (void *))));
which indicates that CIE/FDE should be aligned at the pointer size.
PR libgcc/27576
* crtstuff.c (__EH_FRAME_BEGIN__): Aligned to pointer size.
Increase the priority of the init_have_lse_atomics constructor so it runs
before other constructors. This improves chances that rr works when LSE
atomics are supported.
libgcc/
PR libgcc/105708
* config/aarch64/lse-init.c: Increase constructor priority.
The RA_SIGN_STATE dwarf pseudo-register is normally only set using the
DW_CFA_AARCH64_negate_ra_state (== DW_CFA_window_save) operation which
toggles the return address signedness state (the default state is 0).
(It may be set by remember/restore_state CFI too, those save/restore
the state of all registers.)
However RA_SIGN_STATE can be set directly via DW_CFA_val_expression too.
GCC does not generate such CFI but some other compilers reportedly do.
Note: the toggle operation must not be mixed with other dwarf register
rule CFI within the same CIE and FDE.
In libgcc we assume REG_UNSAVED means the RA_STATE is set using toggle
operations, otherwise we assume its value is set by other CFI.
libgcc/ChangeLog:
PR target/104689
* config/aarch64/aarch64-unwind.h (aarch64_frob_update_context):
Handle the !REG_UNSAVED case.
* unwind-dw2.c (execute_cfa_program): Fail toggle if !REG_UNSAVED.
gcc/testsuite/ChangeLog:
PR target/104689
* gcc.target/aarch64/pr104689.c: New test.
This patch replaces libbid's implementations of clz and ctz for 32 and
64 bits inputs which used several masks, and switches to the
corresponding builtins. This will provide a better implementation,
especially on targets with clz/ctz instructions.
2022-05-06 Christophe Lyon <christophe.lyon@arm.com>
libgcc/config/libbid/ChangeLog:
* bid_binarydecimal.c (CLZ32_MASK16): Delete.
(CLZ32_MASK8): Delete.
(CLZ32_MASK4): Delete.
(CLZ32_MASK2): Delete.
(CLZ32_MASK1): Delete.
(clz32_nz): Use __builtin_clz.
(ctz32_1bit): Delete.
(ctz32): Use __builtin_ctz.
(CLZ64_MASK32): Delete.
(CLZ64_MASK16): Delete.
(CLZ64_MASK8): Delete.
(CLZ64_MASK4): Delete.
(CLZ64_MASK2): Delete.
(CLZ64_MASK1): Delete.
(clz64_nz): Use __builtin_clzl.
(ctz64_1bit): Delete.
(ctz64): Use __builtin_ctzl.
This patch adds support for trunc and extend operations between HF
mode (_Float16) and Decimal Floating Point formats (_Decimal32,
_Decimal64 and _Decimal128).
For simplicity we rely on the implicit conversions inserted by the
compiler between HF and SD/DF/TF modes. The existing bid*_to_binary*
and binary*_to_bid* functions are non-trivial and at this stage it is
not clear if there is a performance-critical use case involving _Float16
and _Decimal* formats.
The patch also adds two executable tests, to make sure the right
functions are called, available (link phase) and functional.
Tested on aarch64 and x86_64. The number of symbol matches in the
testcases includes the .global XXX to avoid having to match different
call instructions for different targets.
2022-05-04 Christophe Lyon <christophe.lyon@arm.com>
libgcc/ChangeLog:
* Makefile.in (D32PBIT_FUNCS): Add _hf_to_sd and _sd_to_hf.
(D64PBIT_FUNCS): Add _hf_to_dd and _dd_to_hf.
(D128PBIT_FUNCS): Add _hf_to_td _td_to_hf.
libgcc/config/libbid/ChangeLog:
* bid_gcc_intrinsics.h (LIBGCC2_HAS_HF_MODE): Define according to
__LIBGCC_HAS_HF_MODE__.
(BID_HAS_HF_MODE): Define.
(HFtype): Define.
(__bid_extendhfsd): New prototype.
(__bid_extendhfdd): Likewise.
(__bid_extendhftd): Likewise.
(__bid_truncsdhf): Likewise.
(__bid_truncddhf): Likewise.
(__bid_trunctdhf): Likewise.
* _dd_to_hf.c: New file.
* _hf_to_dd.c: New file.
* _hf_to_sd.c: New file.
* _hf_to_td.c: New file.
* _sd_to_hf.c: New file.
* _td_to_hf.c: New file.
gcc/testsuite/ChangeLog:
* gcc.dg/torture/convert-dfp-2.c: New test.
* gcc.dg/torture/convert-dfp.c: New test.
DFP support on AArch64 relies on libgcc, so enable its DFP routines
for all AArch64 targets.
2022-03-31 Christophe Lyon <christophe.lyon@arm.com>
libgcc/
* config.host: Add t-dfprules to AArch64 targets.
gcov_info::n_functions type is initialized by generated
code in build_info_type:
/* n_functions */
field = build_decl (BUILTINS_LOCATION, FIELD_DECL, NULL_TREE,
get_gcov_unsigned_t ());
It uses gcov_unsigned_t, but the struct definition in libgcov.h uses
unsigned type. That brings troubled on 16-bit targets.
PR gcov-profile/105535
libgcc/ChangeLog:
* libgcov.h (struct gcov_info): Use gcov_unsigned_t for
n_functions.
Co-Authored-By: Hans-Peter Helfert <peter-helfert@t-online.de>
