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.
Similar to various other bugs in this area, some expm1 implementations
do not raise the underflow exception for subnormal arguments, when the
result is tiny and inexact. This patch forces the exception in a
similar way to previous fixes.
(The issue does not apply to the ldbl-* implementations or to those
for x86 / x86_64 long double. The change to
sysdeps/ieee754/dbl-64/wordsize-64/e_cosh.c is one I missed when
previously fixing bug 16354; the bug in that implementation was
previously latent, but the expm1 fixes stopped it being latent and so
required it to be fixed to avoid spurious underflows from cosh.)
Tested for x86_64 and x86.
[BZ #16353]
* sysdeps/i386/fpu/s_expm1.S (dbl_min): New object.
(__expm1): Force underflow exception for arguments with small
absolute value.
* sysdeps/i386/fpu/s_expm1f.S (flt_min): New object.
(__expm1f): Force underflow exception for arguments with small
absolute value.
* sysdeps/ieee754/dbl-64/s_expm1.c: Include <float.h>.
(__expm1): Force underflow exception for arguments with small
absolute value.
* sysdeps/ieee754/flt-32/s_expm1f.c: Include <float.h>.
(__expm1f): Force underflow exception for arguments with small
absolute value.
* sysdeps/ieee754/dbl-64/wordsize-64/e_cosh.c (__ieee754_cosh):
Check for small arguments before calling __expm1.
* math/auto-libm-test-in: Do not mark underflow exceptions as
possibly missing for bug 16353.
* math/auto-libm-test-out: Regenerated.
Bug 16293 is inaccuracy of x86/x86_64 versions of expm1, near 0 in
directed rounding modes, that arises from frndint rounding the
exponent to 1 or -1 instead of 0, resulting in large cancellation
error. This inaccuracy in turn affects other functions such as sinh
that use expm1. This patch fixes the problem by setting
round-to-nearest mode temporarily around the affected calls to
frndint. I don't think this is needed for other uses of frndint, such
as in exp itself, as only for expm1 is the cancellation error
significant.
Tested x86_64 and x86 and ulps updated accordingly.
* sysdeps/i386/fpu/e_expl.S (IEEE754_EXPL) [USE_AS_EXPM1L]: Set
round-to-nearest mode when using frndint.
* sysdeps/i386/fpu/s_expm1.S (__expm1): Likewise.
* sysdeps/i386/fpu/s_expm1f.S (__expm1f): Likewise.
* sysdeps/x86_64/fpu/e_expl.S (IEEE754_EXPL) [USE_AS_EXPM1L]:
Likewise.
* math/auto-libm-test-in: Add more tests of expm1. Do not expect
sinh test to fail.
* math/auto-libm-test-out: Regenerated.
* math/libm-test.inc (TEST_COND_x86_64): Remove macro.
(TEST_COND_x86): Likewise.
(expm1_tonearest_test_data): New array.
(expm1_test_tonearest): New function.
(expm1_towardzero_test_data): New array.
(expm1_test_towardzero): New function.
(expm1_downward_test_data): New array.
(expm1_test_downward): New function.
(expm1_upward_test_data): New array.
(expm1_test_upward): New function.
(main): Run the new test functions.
* sysdeps/i386/fpu/libm-test-ulps: Update.
* sysdeps/x86_64/fpu/libm-test-ulps: Likewise.
2001-07-06 Paul Eggert <eggert@twinsun.com>
* manual/argp.texi: Remove ignored LGPL copyright notice; it's
not appropriate for documentation anyway.
* manual/libc-texinfo.sh: "Library General Public License" ->
"Lesser General Public License".
2001-07-06 Andreas Jaeger <aj@suse.de>
* All files under GPL/LGPL version 2: Place under LGPL version
2.1.
