As mentioned in the PR, since 2005 we reject if array elements are smaller
than their alignment (i.e. overaligned elements), because such arrays don't
make much sense, only their first element is guaranteed to be aligned as
user requested, but the next element can't be.
The following testcases show something we've been silent about but is
equally bad, the 2005 case is just the most common special case of that
the array element size is not divisible by the alignment. In those arrays
too only the first element is guaranteed to be properly aligned and the
second one can't be.
This patch rejects those cases too, but keeps the existing wording for the
old common case.
Unfortunately, the patch breaks bootstrap, because libbid uses this mess
(forms arrays with 24 byte long elements with 16 byte element alignment).
I don't really see justification for that, so I've decreased the alignment
to 8 bytes instead.
2020-10-23 Jakub Jelinek <jakub@redhat.com>
PR tree-optimization/97164
gcc/
* stor-layout.c (layout_type): Also reject arrays where element size
is constant, but not a multiple of element alignment.
gcc/testsuite/
* c-c++-common/pr97164.c: New test.
* gcc.c-torture/execute/pr36093.c: Move ...
* gcc.dg/pr36093.c: ... here. Add dg-do compile and dg-error
directives.
* gcc.c-torture/execute/pr43783.c: Move ...
* gcc.dg/pr43783.c: ... here. Add dg-do compile, dg-options and
dg-error directives.
libgcc/config/libbid/
* bid_functions.h (UINT192): Decrease alignment to 8 bytes.
This patch removes the LIBGCC2_HAS_{SF,DF,XF,TF}_MODE target macros,
replacing them by predefines with -fbuilding-libgcc, together with a
target hook that can influence those predefines when needed.
The new default is that a floating-point mode is supported in libgcc
if (a) it passes the scalar_mode_supported_p hook (otherwise it's not
plausible for it to be supported in libgcc) and (b) it's one of those
four modes (since those are the modes for which libgcc hardcodes the
possibility of support). The target hook can override the default
choice (in either direction) for modes that pass
scalar_mode_supported_p (although overriding in the direction of
returning true when the default would return false only makes sense if
all relevant functions are specially defined in libgcc for that
particular target).
The previous default settings depended on various settings such as
LIBGCC2_LONG_DOUBLE_TYPE_SIZE, as well as targets defining the above
target macros if the default wasn't correct.
The default scalar_mode_supported_p only declares a floating-point
mode to be supported if it matches one of float / double / long
double. This means that in most cases where a mode is only supported
conditionally in libgcc (TFmode only supported if it's the mode of
long double, most commonly), the default gets things right. Overrides
were needed in the following cases:
* SFmode would always have been supported in libgcc (the condition was
BITS_PER_UNIT == 8, true for all current targets), but pdp11
defaults to 64-bit float, and in that case SFmode would fail
scalar_mode_supported_p. I don't know if libgcc actually built for
pdp11 (and the port may well no longer be being used), but this
patch adds a scalar_mode_supported_p hook to it to ensure SFmode is
treated as supported.
* Certain i386 and ia64 targets need the new hook to match the
existing cases for when XFmode or TFmode support is present in
libgcc. For i386, the hook can always declare XFmode to be
supported - the cases where it's not are the cases where long double
is TFmode, in which case XFmode fails scalar_mode_supported_p[*] -
but TFmode support needs to be conditional. (And of the targets not
defining LIBGCC2_HAS_TF_MODE before this patch, some defined
LONG_DOUBLE_TYPE_SIZE to 64, so ensuring LIBGCC2_HAS_TF_MODE would
always be false, while others did not define it, so allowing it to
be true in the -mlong-double-128 case. This patch matches that
logic, although I suspect all the latter targets would have been
broken if you tried to enable -mlong-double-128 by default, for lack
of the soft-fp TFmode support in libgcc, which is separately
configured.)
[*] I don't know if it's deliberate not to support __float80 at all
with -mlong-double-128.
In order to implement the default version of the new hook,
insn-modes.h was made to contain macros such as HAVE_TFmode for each
machine mode, so the default hook can contain conditionals on whether
XFmode and TFmode exist (to match the hardcoding of a list of modes in
libgcc). This is also used in fortran/trans-types.c; previously it
had a conditional on defined(LIBGCC2_HAS_TF_MODE) (a bit dubious,
since it ignored the value of the macro), which is replaced by testing
defined(HAVE_TFmode), in conjunction with requiring
targetm.libgcc_floating_mode_supported_p.
(Fortran is testing something stronger than that hook: not only is
libgcc support required, but also libm or equivalent. Thus, it has a
test for ENABLE_LIBQUADMATH_SUPPORT in the case that the mode is
TFmode and that's not the same as any of the three standard types.
The old and new tests are intended to accept exactly the same set of
modes for all targets.)
Apart from the four target macros eliminated by this patch, it gets us
closer to eliminating LIBGCC2_LONG_DOUBLE_TYPE_SIZE as well, though a
few more places using that macro need changing first.
Bootstrapped with no regressions on x86_64-unknown-linux-gnu; also
built cc1 for crosses to ia64-elf and pdp11-none as a minimal test of
changes for those targets.
gcc:
* target.def (libgcc_floating_mode_supported_p): New hook.
* targhooks.c (default_libgcc_floating_mode_supported_p): New
function.
* targhooks.h (default_libgcc_floating_mode_supported_p): Declare.
* doc/tm.texi.in (LIBGCC2_HAS_DF_MODE, LIBGCC2_HAS_XF_MODE)
(LIBGCC2_HAS_TF_MODE): Remove.
(TARGET_LIBGCC_FLOATING_MODE_SUPPORTED_P): New @hook.
* doc/tm.texi: Regenerate.
* genmodes.c (emit_insn_modes_h): Define HAVE_%smode for each
machine mode.
* system.h (LIBGCC2_HAS_SF_MODE, LIBGCC2_HAS_DF_MODE)
(LIBGCC2_HAS_XF_MODE, LIBGCC2_HAS_TF_MODE): Poison.
* config/i386/cygming.h (LIBGCC2_HAS_TF_MODE): Remove.
* config/i386/darwin.h (LIBGCC2_HAS_TF_MODE): Remove.
* config/i386/djgpp.h (IX86_MAYBE_NO_LIBGCC_TFMODE): Define.
* config/i386/dragonfly.h (LIBGCC2_HAS_TF_MODE): Remove.
* config/i386/freebsd.h (LIBGCC2_HAS_TF_MODE): Remove.
* config/i386/gnu-user-common.h (LIBGCC2_HAS_TF_MODE): Remove.
* config/i386/i386-interix.h (IX86_NO_LIBGCC_TFMODE): Define.
* config/i386/i386.c (ix86_libgcc_floating_mode_supported_p): New
function.
(TARGET_LIBGCC_FLOATING_MODE_SUPPORTED_P): Define.
* config/i386/i386elf.h (IX86_MAYBE_NO_LIBGCC_TFMODE): Define.
* config/i386/lynx.h (IX86_MAYBE_NO_LIBGCC_TFMODE): Define.
* config/i386/netbsd-elf.h (IX86_MAYBE_NO_LIBGCC_TFMODE): Define.
* config/i386/netbsd64.h (IX86_MAYBE_NO_LIBGCC_TFMODE): Define.
* config/i386/nto.h (IX86_MAYBE_NO_LIBGCC_TFMODE): Define.
* config/i386/openbsd.h (IX86_MAYBE_NO_LIBGCC_TFMODE): Define.
* config/i386/openbsdelf.h (LIBGCC2_HAS_TF_MODE): Remove.
* config/i386/rtemself.h (IX86_NO_LIBGCC_TFMODE): Define.
* config/i386/sol2.h (LIBGCC2_HAS_TF_MODE): Remove.
* config/i386/vx-common.h (IX86_MAYBE_NO_LIBGCC_TFMODE): Define.
* config/ia64/elf.h (IA64_NO_LIBGCC_TFMODE): Define.
* config/ia64/freebsd.h (IA64_NO_LIBGCC_TFMODE): Define.
* config/ia64/hpux.h (LIBGCC2_HAS_XF_MODE, LIBGCC2_HAS_TF_MODE):
Remove.
* config/ia64/ia64.c (TARGET_LIBGCC_FLOATING_MODE_SUPPORTED_P):
New macro.
(ia64_libgcc_floating_mode_supported_p): New function.
* config/ia64/linux.h (LIBGCC2_HAS_TF_MODE): Remove.
* config/ia64/vms.h (IA64_NO_LIBGCC_XFMODE)
(IA64_NO_LIBGCC_TFMODE): Define.
* config/msp430/msp430.h (LIBGCC2_HAS_DF_MODE): Remove.
* config/pdp11/pdp11.c (TARGET_SCALAR_MODE_SUPPORTED_P): New
macro.
(pdp11_scalar_mode_supported_p): New function.
* config/rl78/rl78.h (LIBGCC2_HAS_DF_MODE): Remove.
* config/rx/rx.h (LIBGCC2_HAS_DF_MODE): Remove.
gcc/c-family:
* c-cppbuiltin.c (c_cpp_builtins): Define __LIBGCC_HAS_%s_MODE__
macros for floating-point modes.
gcc/fortran:
* trans-types.c (gfc_init_kinds): Check
targetm.libgcc_floating_mode_supported_p for floating-point
modes. Check HAVE_TFmode instead of LIBGCC2_HAS_TF_MODE.
libgcc:
* libgcc2.h (LIBGCC2_HAS_SF_MODE): Define using
__LIBGCC_HAS_SF_MODE__.
(LIBGCC2_HAS_DF_MODE): Define using __LIBGCC_HAS_DF_MODE__.
(LIBGCC2_HAS_XF_MODE): Define using __LIBGCC_HAS_XF_MODE__.
(LIBGCC2_HAS_TF_MODE): Define using __LIBGCC_HAS_TF_MODE__.
* config/libbid/bid_gcc_intrinsics.h
(LIBGCC2_LONG_DOUBLE_TYPE_SIZE): Do not define.
(LIBGCC2_HAS_XF_MODE): Define using __LIBGCC_HAS_XF_MODE__.
(LIBGCC2_HAS_TF_MODE): Define using __LIBGCC_HAS_TF_MODE__.
* fixed-bit.h (LIBGCC2_LONG_DOUBLE_TYPE_SIZE): Do not define.
(LIBGCC2_HAS_SF_MODE): Define using __LIBGCC_HAS_SF_MODE__.
(LIBGCC2_HAS_DF_MODE): Define using __LIBGCC_HAS_DF_MODE__.
From-SVN: r215215
config/
2007-07-06 H.J. Lu <hongjiu.lu@intel.com>
* tls.m4 (GCC_CHECK_CC_TLS): New.
libgcc/
2007-07-06 H.J. Lu <hongjiu.lu@intel.com>
* config.host (tmake_file): Add t-tls for i[34567]86-*-linux*
and x86_64-*-linux*.
* config/t-tls: New file.
* Makefile.in (INTERNAL_CFLAGS): Add @set_have_cc_tls@.
* configure.ac: Include ../config/enable.m4 and
../config/tls.m4. Use GCC_CHECK_CC_TLS to check if assembler
supports TLS and substitute set_have_cc_tls.
* configure: Regenerated.
libbid/
2007-07-06 H.J. Lu <hongjiu.lu@intel.com>
Updated from Intel BID library:
* bid_conf.h (BID_THREAD): Defined only if both HAVE_CC_TLS
and USE_TLS are defined.
From-SVN: r126416
