When libm-test.inc prints the results of failing tests, the output can
be unhelpful for ldbl-128 and ldbl-128ibm because the precision used
is insufficient to distinguish values of those types, resulting in
reported values that look identical but differ by a large number of
ulps.
This patch changes it to use a precision appropriate for the type, for
both decimal and hex output (so output for float is more compact,
output for ldbl-128 and ldbl-128ibm is substantially wider). The
natural precision to use for decimal is given by the C11 <float.h>
macros such as FLT_DECIMAL_DIG. GCC's <float.h> only defines those in
C11 mode, so this patch uses the predefines such as
__FLT_DECIMAL_DIG__ (added in GCC 4.6) instead; if we move to building
with -std=gnu11 (or -std=gnu1x if we can't get rid of 4.6 support).
Tested for powerpc and mips64.
* math/libm-test.inc (TYPE_DECIMAL_DIG): New macro.
(TYPE_HEX_DIG): Likewise.
(print_float): Use TYPE_DECIMAL_DIG - 1 and TYPE_HEX_DIG - 1 as
precisions when printing floating-point numbers.
(check_float_internal): Likewise.
The ldbl-128ibm implementation of exp10l uses a version of log(10)
split into high and low parts - but the low part is negative, so
causing spurious overflows from __ieee754_expl (exp_high) in cases
close to the overflow threshold (I added relevant tests close to the
overflow threshold to the testsuite earlier today). The same issue
applies close to the underflow threshold as well (except that spurious
underflows in IBM long double arithmetic are harder to fix than the
other deficiencies, so we might end up permitting those for IBM long
double in the libm testsuite, as permitted by ISO C).
This patch fixes it to use a low part rounded downward to 48 bits
instead. (The choice of 48 instead of 53 bits is to make it more
obviously safe even when the low part of the argument is negative.)
Tested for powerpc. (Note that because of libgcc bugs with
multiplication very close to LDBL_MAX, libgcc also needs patching for
all the problem cases to be fixed, but this patch is still safe and
correct in the absence of such libgcc fixes.)
[BZ #16620]
* sysdeps/ieee754/ldbl-128ibm/e_exp10l.c (log10_high): Use value
of log (10) rounded downward to 48 bits.
(log10_low): Use corresponding low part of log (10).
The i386 versions of acoshf and acosh raise a spurious "invalid"
exception for an argument that is a quiet NaN with the sign bit set.
The integer arithmetic to detect arguments < 1 also detects -NaN, and
then the computation 0 / 0 in that case raises the exception. This
patch fixes this by using (x - x) / (x - x) as the computation in that
case instead, which will always raise the exception for non-NaN
arguments reaching that code, but not for quiet NaN arguments.
Tested for x86_64 and x86.
[BZ #19032]
* sysdeps/i386/fpu/e_acosh.S (__ieee754_acosh): For arguments < 1,
compute result as (x - x) / (x - x) not as 0 / 0.
* sysdeps/i386/fpu/e_acoshf.S (__ieee754_acoshf): Likewise.
* math/libm-test.inc (acosh_test_data): Add another test of acosh.
This patch improves test coverage of the real libm functions [a-e]*,
ensuring that special cases and ranges of input values of potential
significance (such as close to overflow and underflow thresholds) are
more systematically covered.
This is a followup to
<https://sourceware.org/ml/libc-alpha/2013-12/msg00757.html> which
covered [a-c]* (however, I found more weaknesses in the coverage of
those functions when preparing this patch, hence the additional tests
being added for them here).
Addition of a test for acosh (-qNaN) is temporarily deferred, to be
included as part of a fix for bug 19032 which was discovered in the
course of adding these tests (and which illustrates the use of testing
-qNaN as well as +qNaN as input even to functions for which the sign
of a NaN isn't meant to be significant).
Tested for x86_64 and x86.
* math/auto-libm-test-in: Add more tests of acos, acosh, asin,
atan, atan2, atanh, cbrt, cos, cosh, erf, erfc, exp, exp10, exp2
and expm1.
* math/auto-libm-test-out: Regenerated.
* math/libm-test.inc (acos_test_data): Add more tests.
(asin_test_data): Likewise.
(asinh_test_data): Likewise.
(atan_test_data): Likewise.
(atanh_test_data): Likewise.
(atan2_test_data): Likewise.
(cbrt_test_data): Likewise.
(ceil_test_data): Likewise.
(copysign_test_data): Likewise.
(cos_test_data): Likewise.
(cosh_test_data): Likewise.
(erf_test_data): Likewise.
(erfc_test_data): Likewise.
(exp_test_data): Likewise.
(exp10_test_data): Likewise.
(exp2_test_data): Likewise.
(expm1_test_data): Likewise.
* sysdeps/x86_64/fpu/libm-test-ulps: Update.
This patch makes math/libm-test.inc more consistent regarding
including expectations for errno setting and "inexact" exceptions
where expected test results are given manually. Mostly this is a
matter of including ERRNO_UNCHANGED in expectations, but there are
also some cases where expectations regarding "inexact" were missing
for exactly determined functions (especially in cases where some other
exception was expected and it should also have been expected that
"inexact" was not set with that other exception), and one case for pow
where the NO_INEXACT_EXCEPTION expectation should not have been there
(the rule about not having "inexact" exceptions for NaN arguments is
only when those NaN arguments produce NaN results).
I deferred making such changes for complex functions and scalb.
Tested for x86_64 and x86.
* math/libm-test.inc (acos_test_data): Refine expectations for
errno and "inexact" exceptions.
(acosh_test_data): Likewise.
(asin_test_data): Likewise.
(asinh_test_data): Likewise.
(atan_test_data): Likewise.
(atanh_test_data): Likewise.
(atan2_test_data): Likewise.
(cbrt_test_data): Likewise.
(ceil_test_data): Likewise.
(copysign_test_data): Likewise.
(cosh_test_data): Likewise.
(erf_test_data): Likewise.
(erfc_test_data): Likewise.
(exp_test_data): Likewise.
(exp10_test_data): Likewise.
(exp2_test_data): Likewise.
(expm1_test_data): Likewise.
(fabs_test_data): Likewise.
(floor_test_data): Likewise.
(fma_test_data): Likewise.
(fmax_test_data): Likewise.
(fmin_test_data): Likewise.
(fmod_test_data): Likewise.
(fpclassify_test_data): Likewise.
(frexp_test_data): Likewise.
(hypot_test_data): Likewise.
(ilogb_test_data): Likewise.
(isgreater_test_data): Likewise.
(isgreaterequal_test_data): Likewise.
(isinf_test_data): Likewise.
(isless_test_data): Likewise.
(islessequal_test_data): Likewise.
(islessgreater_test_data): Likewise.
(isnan_test_data): Likewise.
(isnormal_test_data): Likewise.
(issignaling_test_data): Likewise.
(isunordered_test_data): Likewise.
(j0_test_data): Likewise.
(j1_test_data): Likewise.
(jn_test_data): Likewise.
(lgamma_test_data): Likewise.
(lrint_test_data): Likewise.
(llrint_test_data): Likewise.
(log_test_data): Likewise.
(log10_test_data): Likewise.
(log1p_test_data): Likewise.
(log2_test_data): Likewise.
(logb_test_data): Likewise.
(lround_test_data): Likewise.
(llround_test_data): Likewise.
(modf_test_data): Likewise.
(nearbyint_test_data): Likewise.
(nextafter_test_data): Likewise.
(nexttoward_test_data): Likewise.
(pow_test_data): Likewise.
(remainder_test_data): Likewise.
(remquo_test_data): Likewise.
(rint_test_data): Likewise.
(round_test_data): Likewise.
(signbit_test_data): Likewise.
(sinh_test_data): Likewise.
(sqrt_test_data): Likewise.
(tanh_test_data): Likewise.
(tgamma_test_data): Likewise.
(trunc_test_data): Likewise.
(y0_test_data): Likewise.
(y1_test_data): Likewise.
(yn_test_data): Likewise.
(significand_test_data): Likewise.
In the posix_fallocate description in the manual we list various
drawbacks with the emulation, including the fact that a file opened
with O_APPEND fails with EBADF. Similarly a file opened with O_WRONLY
fails with EBADF. We must be able to emulate a compare-and-swap via
pread/compare/pwrite in order to make the emulation as safe as possible.
It is not acceptable to ignore the read failure because it could result
in significant data loss across all of the blocks. There is no other way
to make this work without a true atomic CAS and SIGBUS handler (which
is looking more attractive as a way to remove the race condition).
This patch adds O_WRONLY to the manual as another bullet to clarify the
limits of the emulation.
Manual looks good in PDF.
For arguments with X^2 + Y^2 close to 1, clog and clog10 avoid large
errors from log(hypot) by computing X^2 + Y^2 - 1 in a way that avoids
cancellation error and then using log1p.
However, the thresholds for using that approach still result in log
being used on argument as large as sqrt(13/16) > 0.9, leading to
significant errors, in some cases above the 9ulp maximum allowed in
glibc libm. This patch arranges for the approach using log1p to be
used in any cases where |X|, |Y| < 1 and X^2 + Y^2 >= 0.5 (with the
existing allowance for cases where one of X and Y is very small),
adjusting the __x2y2m1 functions to work with the wider range of
inputs. This way, log only gets used on arguments below sqrt(1/2) (or
substantially above 1), where the error involved is much less.
Tested for x86_64, x86, mips64 and powerpc. For the ulps regeneration
I removed the existing clog and clog10 ulps before regenerating to
allow any reduced ulps to appear. Tests added include those found by
random test generation to produce large ulps either before or after
the patch, and some found by trying inputs close to the (0.75, 0.5)
threshold where the potential errors from using log are largest.
[BZ #19016]
* sysdeps/generic/math_private.h (__x2y2m1f): Update comment to
allow more cases with X^2 + Y^2 >= 0.5.
* sysdeps/ieee754/dbl-64/x2y2m1.c (__x2y2m1): Likewise. Add -1 as
normal element in sum instead of special-casing based on values of
arguments.
* sysdeps/ieee754/dbl-64/x2y2m1f.c (__x2y2m1f): Update comment.
* sysdeps/ieee754/ldbl-128/x2y2m1l.c (__x2y2m1l): Likewise. Add
-1 as normal element in sum instead of special-casing based on
values of arguments.
* sysdeps/ieee754/ldbl-128ibm/x2y2m1l.c (__x2y2m1l): Likewise.
* sysdeps/ieee754/ldbl-96/x2y2m1.c [FLT_EVAL_METHOD != 0]
(__x2y2m1): Update comment.
* sysdeps/ieee754/ldbl-96/x2y2m1l.c (__x2y2m1l): Likewise. Add -1
as normal element in sum instead of special-casing based on values
of arguments.
* math/s_clog.c (__clog): Handle more cases using log1p without
hypot.
* math/s_clog10.c (__clog10): Likewise.
* math/s_clog10f.c (__clog10f): Likewise.
* math/s_clog10l.c (__clog10l): Likewise.
* math/s_clogf.c (__clogf): Likewise.
* math/s_clogl.c (__clogl): Likewise.
* math/auto-libm-test-in: Add more tests of clog and clog10.
* math/auto-libm-test-out: Regenerated.
* sysdeps/i386/fpu/libm-test-ulps: Update.
* sysdeps/x86_64/fpu/libm-test-ulps: Likewise.
The flt-32 version of powf can be inaccurate because of bugs in the
extra-precision calculation of (x-1)/(x+1) or (x-1.5)/(x+1.5) as part
of calculating log(x) with extra precision: a constant used (as part
of adding 1 or 1.5 through integer arithmetic) is incorrect, and then
the code fails to mask a computed high part before using it in
arithmetic that relies on s_h*t_h being exactly representable. This
patch fixes these bugs.
Tested for x86_64 and x86. x86_64 ulps for powf removed and
regenerated to reflect reduced ulps from the increased accuracy for
existing tests.
[BZ #18956]
* sysdeps/ieee754/flt-32/e_powf.c (__ieee754_powf): Add 0x00400000
not 0x0040000 for high bit of mantissa. Mask with 0xfffff000 when
extracting high part.
* math/auto-libm-test-in: Add another test of pow.
* math/auto-libm-test-out: Regenerated.
* sysdeps/x86_64/fpu/libm-test-ulps: Update.
Similar to various other bugs in this area, pow functions can fail to
raise the underflow exception when the result is tiny and inexact but
one or more low bits of the intermediate result that is scaled down
(or, in the i386 case, converted from a wider evaluation format) are
zero. This patch forces the exception in a similar way to previous
fixes, thereby concluding the fixes for known bugs with missing
underflow exceptions currently filed in Bugzilla.
Tested for x86_64, x86, mips64 and powerpc.
[BZ #18825]
* sysdeps/i386/fpu/i386-math-asm.h (FLT_NARROW_EVAL_UFLOW_NONNAN):
New macro.
(DBL_NARROW_EVAL_UFLOW_NONNAN): Likewise.
(LDBL_CHECK_FORCE_UFLOW_NONNAN): Likewise.
* sysdeps/i386/fpu/e_pow.S: Use DEFINE_DBL_MIN.
(__ieee754_pow): Use DBL_NARROW_EVAL_UFLOW_NONNAN instead of
DBL_NARROW_EVAL, reloading the PIC register as needed.
* sysdeps/i386/fpu/e_powf.S: Use DEFINE_FLT_MIN.
(__ieee754_powf): Use FLT_NARROW_EVAL_UFLOW_NONNAN instead of
FLT_NARROW_EVAL. Use separate return path for case when first
argument is NaN.
* sysdeps/i386/fpu/e_powl.S: Include <i386-math-asm.h>. Use
DEFINE_LDBL_MIN.
(__ieee754_powl): Use LDBL_CHECK_FORCE_UFLOW_NONNAN, reloading the
PIC register.
* sysdeps/ieee754/dbl-64/e_pow.c (__ieee754_pow): Use
math_check_force_underflow_nonneg.
* sysdeps/ieee754/flt-32/e_powf.c (__ieee754_powf): Force
underflow for subnormal result.
* sysdeps/ieee754/ldbl-128/e_powl.c (__ieee754_powl): Likewise.
* sysdeps/ieee754/ldbl-128ibm/e_powl.c (__ieee754_powl): Use
math_check_force_underflow_nonneg.
* sysdeps/x86/fpu/powl_helper.c (__powl_helper): Use
math_check_force_underflow.
* sysdeps/x86_64/fpu/x86_64-math-asm.h
(LDBL_CHECK_FORCE_UFLOW_NONNAN): New macro.
* sysdeps/x86_64/fpu/e_powl.S: Include <x86_64-math-asm.h>. Use
DEFINE_LDBL_MIN.
(__ieee754_powl): Use LDBL_CHECK_FORCE_UFLOW_NONNAN.
* math/auto-libm-test-in: Add more tests of pow.
* math/auto-libm-test-out: Regenerated.
It used to be common practice to have a statically linked shell for an
alternative root account, as in:
root❌0:0:root:/root:/bin/bash
toor❌0:0:root recovery account:/root:/sbin/sash
This causes problems with passwd NSS tests because a UID-based lookup
will only retrieve one of those entries. The original version of
nss/bug17079.c detected this, but failed to use this information later
on.
Systems without floating-point exceptions and rounding modes should
use the soft-fp versions of fmaf and fma, not the sysdeps/ieee754
versions that rely on setting rounding to zero and testing for the
"inexact" exception; this has been noted on
<https://sourceware.org/glibc/wiki/PortStatus> for some time. This
patch makes no-FPU ColdFire use the soft-fp files; sfp-machine.h is
made to include the nios2 version of sfp-machine.h which seems
sufficiently generic for 32-bit systems.
[BZ #13304]
* sysdeps/m68k/coldfire/nofpu/s_fma.c: New file.
* sysdeps/m68k/coldfire/nofpu/s_fmaf.c: Likewise.
* sysdeps/m68k/coldfire/nofpu/sfp-machine.h: Likewise.
Systems without floating-point exceptions and rounding modes should
use the soft-fp versions of fmaf and fma, not the sysdeps/ieee754
versions that rely on setting rounding to zero and testing for the
"inexact" exception; this has been noted on
<https://sourceware.org/glibc/wiki/PortStatus> for some time. This
patch makes MicroBlaze use the soft-fp files; sfp-machine.h is made to
include the nios2 version of sfp-machine.h which seems sufficiently
generic for 32-bit systems.
[BZ #13304]
* sysdeps/microblaze/s_fma.c: New file.
* sysdeps/microblaze/s_fmaf.c: Likewise.
* sysdeps/microblaze/sfp-machine.h: Likewise.
Fix a regression introduced with commit 0d23a5c1 [Static dlopen
correction fallout fixes] that caused the default library search path to
be ignored for modules loaded with dlopen from static executables.
[BZ #17250]
* elf/dl-support.c (_dl_main_map): Don't initialize l_flags_1
member.
Similar to various other bugs in this area, hypot functions can fail
to raise the underflow exception when the result is tiny and inexact
but one or more low bits of the intermediate result that is scaled
down (or, in the i386 case, converted from a wider evaluation format)
are zero. This patch forces the exception in a similar way to
previous fixes.
Note that this issue cannot arise for implementations of hypotf using
double (or wider) for intermediate evaluation (if hypotf should
underflow, that means the double square root is being computed of some
number of the form N*2^-298, for 0 < N < 2^46, which is exactly
represented as a double, and whatever the rounding mode such a square
root cannot have a mantissa with all zeroes after the initial 23
bits). Thus no changes are made to hypotf implementations in this
patch, only to hypot and hypotl.
Tested for x86_64, x86, mips64 and powerpc.
[BZ #18803]
* sysdeps/i386/fpu/e_hypot.S: Use DEFINE_DBL_MIN.
(MO): New macro.
(__ieee754_hypot) [PIC]: Load PIC register.
(__ieee754_hypot): Use DBL_NARROW_EVAL_UFLOW_NONNEG instead of
DBL_NARROW_EVAL.
* sysdeps/ieee754/dbl-64/e_hypot.c (__ieee754_hypot): Use
math_check_force_underflow_nonneg in case where result might be
tiny.
* sysdeps/ieee754/ldbl-128/e_hypotl.c (__ieee754_hypotl):
Likewise.
* sysdeps/ieee754/ldbl-128ibm/e_hypotl.c (__ieee754_hypotl):
Likewise.
* sysdeps/ieee754/ldbl-96/e_hypotl.c (__ieee754_hypotl): Likewise.
* sysdeps/powerpc/fpu/e_hypot.c (__ieee754_hypot): Likewise.
* math/auto-libm-test-in: Add more tests of hypot.
* math/auto-libm-test-out: Regenerated.
This patch refactors code in sysdeps/x86_64/fpu that forces underflow
exceptions and closely follows corresponding i386 code to use common
macros in x86_64-math-asm.h for that purpose. This is mainly about
keeping the code similar to the i386 code as far as possible, since
each macro apart from DEFINE_LDBL_MIN ends up used only once. It
would be possible to do a further refactoring to share these macros
between i386 and x86_64 (with i386 using the fcomip / fucomip versions
when building for i686 and above), but I have no immediate plans to do
so.
Tested for x86_64.
* sysdeps/x86_64/fpu/x86_64-math-asm.h: New file.
* sysdeps/x86_64/fpu/e_exp2l.S: Include <x86_64-math-asm.h>.
(ldbl_min): Replace with use of DEFINE_LDBL_MIN.
(__ieee754_exp2l): Use LDBL_CHECK_FORCE_UFLOW_NONNEG_NAN.
* sysdeps/x86_64/fpu/e_expl.S: Include <x86_64-math-asm.h>.
[!USE_AS_EXPM1L] (cmin): Replace with use of DEFINE_LDBL_MIN.
(IEEE754_EXPL): Use LDBL_CHECK_FORCE_UFLOW_NONNEG.
sysdeps/i386/fpu/e_atanh.S, unlike all other functions in that
directory, loads the PIC register with its own code using
_GLOBAL_OFFSET_TABLE_, rather than with the LOAD_PIC_REG macro. I see
no good reason for the difference; this patch makes it use the common
macro.
Tested for x86.
* sysdeps/i386/fpu/e_atanh.S (__ieee754_atanh) [PIC]: Use
LOAD_PIC_REG.
This patch refactors code in sysdeps/i386/fpu that forces underflow
exceptions to use common macros for that purpose as far as possible.
(Although some of the macros end up used in only one place, I think
it's cleanest to define all these macros together so that all the code
forcing underflow uses such macros. Some more uses of such macros
will also be introduced when fixing remaining bugs about missing
underflow exceptions, and it would be possible to do further
refactoring of the macros in i386-math-asm.h to share more code by
using other macros internally. Places that test for underflow by
examining the representation of the argument with integer operations,
rather that using floating-point comparisons on the argument or
result, are unchanged by this patch.)
Most of this code uses a macro MO to abstract away the differences
between PIC and non-PIC memory references to constants. log1p
functions, however, hardcoded PIC conditionals for this. Because the
common macros rely on the use of MO, I changed the log1p functions to
use the normal style here, and, for consistency, also made that change
to log1pl which is otherwise unaffected by this patch.
Tested for x86.
* sysdeps/i386/fpu/i386-math-asm.h (DEFINE_LDBL_MIN): New macro.
(FLT_CHECK_FORCE_UFLOW): Likewise.
(DBL_CHECK_FORCE_UFLOW): Likewise.
(FLT_CHECK_FORCE_UFLOW_NARROW): Likewise.
(DBL_CHECK_FORCE_UFLOW_NARROW): Likewise.
(LDBL_CHECK_FORCE_UFLOW_NONNEG_NAN): Likewise.
(FLT_CHECK_FORCE_UFLOW_NONNAN): Likewise.
(DBL_CHECK_FORCE_UFLOW_NONNAN): Likewise.
(FLT_CHECK_FORCE_UFLOW_NONNEG): Likewise.
(DBL_CHECK_FORCE_UFLOW_NONNEG): Likewise.
(LDBL_CHECK_FORCE_UFLOW_NONNEG): Likewise.
* sysdeps/i386/fpu/e_asin.S: Include <i386-math-asm.h>.
(dbl_min): Replace with use of DEFINE_DBL_MIN.
(__ieee754_asin): Use DBL_CHECK_FORCE_UFLOW.
* sysdeps/i386/fpu/e_asinf.S: Include <i386-math-asm.h>.
(flt_min): Replace with use of DEFINE_FLT_MIN.
(__ieee754_asinf): Use FLT_CHECK_FORCE_UFLOW.
* sysdeps/i386/fpu/e_atan2.S: Include <i386-math-asm.h>.
(dbl_min): Replace with use of DEFINE_DBL_MIN.
(__ieee754_atan2): Use DBL_CHECK_FORCE_UFLOW_NARROW.
* sysdeps/i386/fpu/e_atan2f.S: Include <i386-math-asm.h>.
(flt_min): Replace with use of DEFINE_FLT_MIN.
(__ieee754_atan2f): Use FLT_CHECK_FORCE_UFLOW_NARROW.
* sysdeps/i386/fpu/e_atanh.S: Include <i386-math-asm.h>.
(dbl_min): Replace with use of DEFINE_DBL_MIN.
(__ieee754_atanh): Use DBL_CHECK_FORCE_UFLOW_NONNEG.
* sysdeps/i386/fpu/e_atanhf.S: Include <i386-math-asm.h>.
(flt_min): Replace with use of DEFINE_FLT_MIN.
(__ieee754_atanhf): Use FLT_CHECK_FORCE_UFLOW_NONNEG.
* sysdeps/i386/fpu/e_exp2l.S: Include <i386-math-asm.h>.
(ldbl_min): Replace with use of DEFINE_LDBL_MIN.
(__ieee754_exp2l): Use LDBL_CHECK_FORCE_UFLOW_NONNEG_NAN.
* sysdeps/i386/fpu/e_expl.S: Include <i386-math-asm.h>.
[!USE_AS_EXPM1L] (cmin): Replace with use of DEFINE_LDBL_MIN.
(IEEE754_EXPL): Use LDBL_CHECK_FORCE_UFLOW_NONNEG.
* sysdeps/i386/fpu/s_atan.S: Include <i386-math-asm.h>.
(dbl_min): Replace with use of DEFINE_DBL_MIN.
(__atan): Use DBL_CHECK_FORCE_UFLOW.
* sysdeps/i386/fpu/s_atanf.S: Include <i386-math-asm.h>.
(flt_min): Replace with use of DEFINE_FLT_MIN.
(__atanf): Use FLT_CHECK_FORCE_UFLOW.
* sysdeps/i386/fpu/s_expm1.S: Include <i386-math-asm.h>.
(dbl_min): Replace with use of DEFINE_DBL_MIN.
(__expm1): Use DBL_CHECK_FORCE_UFLOW. Move underflow check after
main computation.
* sysdeps/i386/fpu/s_expm1f.S: Include <i386-math-asm.h>.
(flt_min): Replace with use of DEFINE_FLT_MIN.
(__expm1f): Use FLT_CHECK_FORCE_UFLOW. Move underflow check after
main computation.
* sysdeps/i386/fpu/s_log1p.S: Include <i386-math-asm.h>.
(dbl_min): Replace with use of DEFINE_DBL_MIN.
(MO): New macro.
(__log1p): Use MO. Use DBL_CHECK_FORCE_UFLOW_NONNAN.
* sysdeps/i386/fpu/s_log1pf.S: Include <i386-math-asm.h>.
(flt_min): Replace with use of DEFINE_FLT_MIN.
(MO): New macro.
(__log1pf): Use MO. Use FLT_CHECK_FORCE_UFLOW_NONNAN.
* sysdeps/i386/fpu/s_log1pl.S (MO): New macro.
(__log1pl): Use MO.
The x86_64 fma4 version of pow fails to disable contraction of
operations other than those explicitly intended to use fma
instructions, so resulting in large ulps errors on processors with
fma4 instructions, as in bug 18104 (165ulp for the test added for that
bug; error originally reported by "blaaa" on #glibc). This patch adds
$(config-cflags-nofma) for e_pow-fma4.c, corresponding to the use for
e_pow.c in sysdeps/ieee754/dbl-64/Makefile.
Tested for x86_64 on a processor with fma4.
[BZ #19003]
* sysdeps/x86_64/fpu/multiarch/Makefile (CFLAGS-e_pow-fma4.c): Add
$(config-cflags-nofma).
sysdeps/ieee754/flt-32/e_exp2f.c declares two variable as "static
const volatile float". Maybe this use of "volatile" was originally
intended to inhibit optimization of underflowing / overflowing
operations such as TWOM100 * TWOM100; in any case, it's not currently
needed, as given -frounding-math constant folding of such expressions
is properly disabled when it would be unsafe. This patch removes the
unnecessary use of "volatile".
Tested for x86_64.
* sysdeps/ieee754/flt-32/e_exp2f.c (TWOM100): Remove volatile.
(TWO127): Likewise.
Where glibc code needs to avoid excess range and precision in
floating-point arithmetic, code variously uses either asms or volatile
to force the results of that arithmetic to memory; mostly this is
conditional on FLT_EVAL_METHOD, but in the case of lrint / llrint
functions some use of volatile is unconditional (and is present
unnecessarily in versions for long double). This patch make such code
use the recently-added math_narrow_eval macro consistently, removing
the unnecessary uses of volatile in long double lrint / llrint
implementations completely.
Tested for x86_64, x86, mips64 and powerpc.
* math/s_nexttowardf.c (__nexttowardf): Use math_narrow_eval.
* stdlib/strtod_l.c: Include <math_private.h>.
(overflow_value): Use math_narrow_eval.
(underflow_value): Likewise.
* sysdeps/i386/fpu/s_nexttoward.c (__nexttoward): Likewise.
* sysdeps/i386/fpu/s_nexttowardf.c (__nexttowardf): Likewise.
* sysdeps/ieee754/dbl-64/e_gamma_r.c (gamma_positive): Likewise.
(__ieee754_gamma_r): Likewise.
* sysdeps/ieee754/dbl-64/gamma_productf.c (__gamma_productf):
Likewise.
* sysdeps/ieee754/dbl-64/k_rem_pio2.c (__kernel_rem_pio2):
Likewise.
* sysdeps/ieee754/dbl-64/lgamma_neg.c (__lgamma_neg): Likewise.
* sysdeps/ieee754/dbl-64/s_erf.c (__erfc): Likewise.
* sysdeps/ieee754/dbl-64/s_llrint.c (__llrint): Likewise.
* sysdeps/ieee754/dbl-64/s_lrint.c (__lrint): Likewise.
* sysdeps/ieee754/flt-32/e_gammaf_r.c (gammaf_positive): Likewise.
(__ieee754_gammaf_r): Likewise.
* sysdeps/ieee754/flt-32/k_rem_pio2f.c (__kernel_rem_pio2f):
Likewise.
* sysdeps/ieee754/flt-32/lgamma_negf.c (__lgamma_negf): Likewise.
* sysdeps/ieee754/flt-32/s_erff.c (__erfcf): Likewise.
* sysdeps/ieee754/flt-32/s_llrintf.c (__llrintf): Likewise.
* sysdeps/ieee754/flt-32/s_lrintf.c (__lrintf): Likewise.
* sysdeps/ieee754/ldbl-128/s_llrintl.c (__llrintl): Do not use
volatile.
* sysdeps/ieee754/ldbl-128/s_lrintl.c (__lrintl): Likewise.
* sysdeps/ieee754/ldbl-128/s_nexttoward.c (__nexttoward): Use
math_narrow_eval.
* sysdeps/ieee754/ldbl-128ibm/s_nexttoward.c (__nexttoward):
Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_nexttowardf.c (__nexttowardf):
Likewise.
* sysdeps/ieee754/ldbl-96/gamma_product.c (__gamma_product):
Likewise.
* sysdeps/ieee754/ldbl-96/s_llrintl.c (__llrintl): Do not use
volatile.
* sysdeps/ieee754/ldbl-96/s_lrintl.c (__lrintl): Likewise.
* sysdeps/ieee754/ldbl-96/s_nexttoward.c (__nexttoward): Use
math_narrow_eval.
* sysdeps/ieee754/ldbl-96/s_nexttowardf.c (__nexttowardf):
Likewise.
* sysdeps/ieee754/ldbl-opt/s_nexttowardfd.c (__nldbl_nexttowardf):
Likewise.
Some distros build+install the timezone tools (zic/zdump/tzselect) outside
of glibc and use the upstream package directly. Add a configure flag to
glibc so they can disable install of those tools.
This allows tests to run & pass regardless of the configure flag. Only
the install of them is impacted.
i386 exp, hypot and pow functions can return overflowing and
underflowing values with excess range and precision; ; Wilco
Dijkstra's patches to make isfinite etc. expand inline cause this
pre-existing issue to result in test failures.
This patch fixes those functions to avoid excess range and precision
in their return values. Appropriate macros are added for the repeated
code sequences; in future I'll add more such macros and refactor
existing code forcing underflow (with or without also eliminating
excess range and precision from the return value) to use such macros.
Tested for x86. If, after this patch, you still see x86 libm test
failures with excess range or precision, please file bugs in Bugzilla.
[BZ #18980]
* sysdeps/i386/fpu/i386-math-asm.h (DEFINE_FLT_MIN): New macro.
(DEFINE_DBL_MIN): Likewise.
(FLT_NARROW_EVAL_UFLOW_NONNEG_NAN): Likewise.
(DBL_NARROW_EVAL_UFLOW_NONNEG_NAN): Likewise.
(FLT_NARROW_EVAL_UFLOW_NONNEG): Likewise.
(DBL_NARROW_EVAL_UFLOW_NONNEG): Likewise.
* sysdeps/i386/fpu/e_exp.S: Include <i386-math-asm.h>.
(dbl_min): Replace with use of DEFINE_DBL_MIN.
(__ieee754_exp): Use DBL_NARROW_EVAL_UFLOW_NONNEG_NAN.
(__exp_finite): Use DBL_NARROW_EVAL_UFLOW_NONNEG.
* sysdeps/i386/fpu/e_exp10.S: Include <i386-math-asm.h>.
(dbl_min): Replace with use of DEFINE_DBL_MIN.
(__ieee754_exp10): Use DBL_NARROW_EVAL_UFLOW_NONNEG_NAN.
* sysdeps/i386/fpu/e_exp10f.S: Include <i386-math-asm.h>.
(flt_min): Replace with use of DEFINE_FLT_MIN.
(__ieee754_exp10f): Use FLT_NARROW_EVAL_UFLOW_NONNEG_NAN.
* sysdeps/i386/fpu/e_exp2.S: Include <i386-math-asm.h>.
(dbl_min): Replace with use of DEFINE_DBL_MIN.
(__ieee754_exp2): Use DBL_NARROW_EVAL_UFLOW_NONNEG_NAN.
* sysdeps/i386/fpu/e_exp2f.S: Include <i386-math-asm.h>.
(flt_min): Replace with use of DEFINE_FLT_MIN.
(__ieee754_exp2f): Use FLT_NARROW_EVAL_UFLOW_NONNEG_NAN.
* sysdeps/i386/fpu/e_expf.S: Include <i386-math-asm.h>.
(flt_min): Replace with use of DEFINE_FLT_MIN.
(__ieee754_expf): Use FLT_NARROW_EVAL_UFLOW_NONNEG_NAN.
(__expf_finite): Use FLT_NARROW_EVAL_UFLOW_NONNEG.
* sysdeps/i386/fpu/e_hypot.S: Include <i386-math-asm.h>.
(__ieee754_hypot): Use DBL_NARROW_EVAL.
* sysdeps/i386/fpu/e_hypotf.S: Include <i386-math-asm.h>.
(__ieee754_hypotf): Use FLT_NARROW_EVAL.
* sysdeps/i386/fpu/e_pow.S: Include <i386-math-asm.h>.
(__ieee754_pow): Use DBL_NARROW_EVAL.
* sysdeps/i386/fpu/e_powf.S: Include <i386-math-asm.h>.
(__ieee754_powf): Use FLT_NARROW_EVAL.
* sysdeps/i386/i686/fpu/multiarch/e_expf-sse2.S
(__ieee754_expf_sse2): Convert double-precision result to single
precision.
* sysdeps/i386/fpu/libm-test-ulps: Update.
i386 scalb / scalbn / scalbln (and thus ldexp) functions for float and
double can return results with excess range (and consequently excess
precision for subnormal results). As the results of these functions
are fully determined by reference to IEEE 754 operations, this is
unambiguously a bug, apart from the testsuite failures it causes.
This patch makes those functions store their results on the stack and
load them back to eliminate the excess range. Double rounding is not
a problem, as the only cases where it could occur are when the result
overflows or underflows for extended precision, and then the
double-rounded results are the same as the single-rounded results.
The new macros will be used for more functions, more such macros
added, and existing code refactored to use such macros, in subsequent
patches.
Tested for x86. Committed.
[BZ #18981]
* sysdeps/i386/fpu/i386-math-asm.h: New file.
* sysdeps/i386/fpu/e_scalb.S: Include <i386-math-asm.h>.
(__ieee754_scalb): Use DBL_NARROW_EVAL.
* sysdeps/i386/fpu/e_scalbf.S: Include <i386-math-asm.h>.
(__ieee754_scalbf): Use FLT_NARROW_EVAL.
* sysdeps/i386/fpu/s_scalbn.S: Include <i386-math-asm.h>.
(__scalbn): Use DBL_NARROW_EVAL.
* sysdeps/i386/fpu/s_scalbnf.S: Include <i386-math-asm.h>.
(__scalbnf): Use FLT_NARROW_EVAL.
The XT testdata install rules expect the testdata dir to already exist in
the build tree, but it doesn't actually create it. Instead, it relies on
the build-testdata define happening to be executed before it (which runs
zic which creates the dir). When we run in parallel though, it's easy to
hit a failure:
$ cd timezone
$ rm -rf $objdir/timezone/testdata
$ make check -j
...
cp testdata/XT1 .../timezone/testdata/XT1
cp: cannot create regular file '.../timezone/testdata/XT1': No such file or directory
Makefile:116: recipe for target '.../timezone/testdata/XT1' failed
make: *** [.../timezone/testdata/XT1] Error 1
make: *** Waiting for unfinished jobs....
Various i386 libm functions return values with excess range and
precision; Wilco Dijkstra's patches to make isfinite etc. expand
inline cause this pre-existing issue to result in test failures (when
e.g. a result that overflows float but not long double gets counted as
overflowing for some purposes but not others).
This patch addresses those cases arising from functions defined in C,
adding a math_narrow_eval macro that forces values to memory to
eliminate excess precision if FLT_EVAL_METHOD indicates this is
needed, and is a no-op otherwise. I'll convert existing uses of
volatile and asm for this purpose to use the new macro later, once
i386 has clean test results again (which requires fixes for .S files
as well).
Tested for x86_64 and x86. Committed.
[BZ #18980]
* sysdeps/generic/math_private.h: Include <float.h>.
(math_narrow_eval): New macro.
[FLT_EVAL_METHOD != 0] (excess_precision): Likewise.
* sysdeps/ieee754/dbl-64/e_cosh.c (__ieee754_cosh): Use
math_narrow_eval on overflowing return value.
* sysdeps/ieee754/dbl-64/e_lgamma_r.c (__ieee754_lgamma_r):
Likewise.
* sysdeps/ieee754/dbl-64/e_sinh.c (__ieee754_sinh): Likewise.
* sysdeps/ieee754/flt-32/e_coshf.c (__ieee754_coshf): Likewise.
* sysdeps/ieee754/flt-32/e_lgammaf_r.c (__ieee754_lgammaf_r):
Likewise.
* sysdeps/ieee754/flt-32/e_sinhf.c (__ieee754_sinhf): Likewise.
The logic in setjmp/__longjmp incorrectly uses "PIC" to figure out
whether the code is going into a shared library when it should be
using "SHARED". If you build glibc with a gcc version that has PIE
enabled by default, then the code will try to use symbols that are
only in the shared library.
URL: https://bugs.gentoo.org/336914
built-ins when available. Since going through the PLT is expensive for these small functions,
inlining results in major speedups (about 7x on Cortex-A57 for isinf). The GCC built-ins are not
correct if signalling NaN support is required, and thus are turned off in that case (see GCC bug
66462). The test-snan.c tests sNaNs and so must be explicitly built with -fsignaling-nans.
2015-09-18 Wilco Dijkstra <wdijkstr@arm.com>
[BZ #15367]
[BZ #17441]
* math/Makefile: Build test-snan.c with -fsignaling-nans.
* math/math.h (fpclassify): Use __builtin_fpclassify when
available. (signbit): Use __builtin_signbit(f/l).
(isfinite): Use__builtin_isfinite. (isnormal): Use
__builtin_isnormal. (isnan): Use __builtin_isnan.
(isinf): Use __builtin_isinf_sign.
ChangeLog:
2015-09-18 Wilco Dijkstra <wdijkstr@arm.com>
* benchtests/Makefile: Add bench-math-inlines, link with libm.
* benchtests/bench-math-inlines.c: New benchmark.
* benchtests/bench-util.h: New file.
* benchtests/bench-util.c: New file.
* benchtests/bench-skeleton.c: Add include of bench-util.c/h.
The test error messages incorrectly reference LIBC_SO
when they should reference the dlmopen'd library
tst-dlmopen1mod.so. Define TEST_SO and use it in
all the error messages.
Cleanup _dl_map_object_from_fd to make it clear exactly
what we're doing with the mappings i.e. extending the the
start of the map down to a page boundary, extending the
end of the map up to a page boundary, and offset itself
also to page boundary. The result is much easier to read
as expected from the ALIGN_* cleanups.
