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| author | Wilco Dijkstra <wilco.dijkstra@arm.com> | 2024-12-13 15:43:07 +0000 |
|---|---|---|
| committer | Wilco Dijkstra <wilco.dijkstra@arm.com> | 2025-02-28 14:23:10 +0000 |
| commit | d8e8342369831808b00324790c8809ba33408ee7 (patch) | |
| tree | 074eda264ddf2c0c3bf92c472f894aff2984bf32 | |
| parent | d6175a44e95fe443d0fbfed37a9ff7424f1e2661 (diff) | |
| download | glibc-d8e8342369831808b00324790c8809ba33408ee7.tar.xz glibc-d8e8342369831808b00324790c8809ba33408ee7.zip | |
math: Improve layout of exp/exp10 data
GCC aligns global data to 16 bytes if their size is >= 16 bytes. This patch
changes the exp_data struct slightly so that the fields are better aligned
and without gaps. As a result on targets that support them, more load-pair
instructions are used in exp. Exp10 is improved by moving invlog10_2N later
so that neglog10_2hiN and neglog10_2loN can be loaded using load-pair.
The exp benchmark improves 2.5%, "144bits" by 7.2%, "768bits" by 12.7% on
Neoverse V2. Exp10 improves by 1.5%.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
(cherry picked from commit 5afaf99edb326fd9f36eb306a828d129a3a1d7f7)
| -rw-r--r-- | sysdeps/ieee754/dbl-64/math_config.h | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/sysdeps/ieee754/dbl-64/math_config.h b/sysdeps/ieee754/dbl-64/math_config.h index ef87cfa6be..05515fd95a 100644 --- a/sysdeps/ieee754/dbl-64/math_config.h +++ b/sysdeps/ieee754/dbl-64/math_config.h @@ -195,16 +195,18 @@ check_uflow (double x) extern const struct exp_data { double invln2N; - double shift; double negln2hiN; double negln2loN; double poly[4]; /* Last four coefficients. */ + double shift; + double exp2_shift; double exp2_poly[EXP2_POLY_ORDER]; - double invlog10_2N; + double neglog10_2hiN; double neglog10_2loN; double exp10_poly[5]; + double invlog10_2N; uint64_t tab[2*(1 << EXP_TABLE_BITS)]; } __exp_data attribute_hidden; |