3f78683353
[libc++] Implements 128-bit support in to_chars.
...
This is required by the Standard and makes it possible to add full
128-bit support to format.
The patch also fixes 128-bit from_chars "support". One unit test
required a too large value, this failed on 128-bit; the fix was to add
more characters to the input.
Note only base 10 has been optimized. Other bases can be optimized.
Note the 128-bit lookup table could be made smaller. This will be done later. I
really want to get 128-bit working in to_chars and format in the upcomming
LLVM 15 release, these optimizations aren't critical.
Reviewed By: #libc, ldionne
Differential Revision: https://reviews.llvm.org/D128929
2022-07-07 17:32:27 +02:00
3561ee586e
[libc++] Improve charconv base10 algorithm.
...
This change is a preparation to add the 128-bit integral output.
Before
```
--------------------------------------------------------------
Benchmark Time CPU Iterations
--------------------------------------------------------------
BM_to_chars_good/2 20.1 ns 20.1 ns 35045000
BM_to_chars_good/3 117 ns 117 ns 5916000
BM_to_chars_good/4 83.7 ns 83.7 ns 8401000
BM_to_chars_good/5 70.6 ns 70.6 ns 9915000
BM_to_chars_good/6 59.9 ns 59.9 ns 11678000
BM_to_chars_good/7 53.9 ns 53.8 ns 12995000
BM_to_chars_good/8 19.0 ns 19.0 ns 37110000
BM_to_chars_good/9 45.9 ns 45.8 ns 15278000
BM_to_chars_good/10 9.24 ns 9.24 ns 75343000
BM_to_chars_good/11 42.6 ns 42.6 ns 16449000
BM_to_chars_good/12 38.8 ns 38.8 ns 18101000
BM_to_chars_good/13 38.8 ns 38.8 ns 17999000
BM_to_chars_good/14 37.7 ns 37.6 ns 18571000
BM_to_chars_good/15 35.8 ns 35.8 ns 19660000
BM_to_chars_good/16 15.4 ns 15.4 ns 46129000
BM_to_chars_good/17 32.3 ns 32.3 ns 21763000
BM_to_chars_good/18 32.8 ns 32.8 ns 21396000
BM_to_chars_good/19 33.4 ns 33.4 ns 21078000
BM_to_chars_good/20 33.3 ns 33.3 ns 21020000
BM_to_chars_good/21 32.3 ns 32.3 ns 21807000
BM_to_chars_good/22 31.6 ns 31.6 ns 22057000
BM_to_chars_good/23 30.7 ns 30.7 ns 22938000
BM_to_chars_good/24 28.3 ns 28.3 ns 24659000
BM_to_chars_good/25 28.2 ns 28.2 ns 24790000
BM_to_chars_good/26 28.4 ns 28.4 ns 24410000
BM_to_chars_good/27 28.7 ns 28.7 ns 24423000
BM_to_chars_good/28 28.9 ns 28.9 ns 24139000
BM_to_chars_good/29 28.9 ns 28.9 ns 24347000
BM_to_chars_good/30 29.2 ns 29.2 ns 24141000
BM_to_chars_good/31 29.6 ns 29.6 ns 23699000
BM_to_chars_good/32 29.5 ns 29.5 ns 23933000
BM_to_chars_good/33 28.9 ns 28.9 ns 24042000
BM_to_chars_good/34 28.7 ns 28.7 ns 24361000
BM_to_chars_good/35 28.3 ns 28.3 ns 24703000
BM_to_chars_good/36 28.1 ns 28.1 ns 24924000
BM_to_chars_bad/2 6.16 ns 6.15 ns 114101000
BM_to_chars_bad/3 14.5 ns 14.5 ns 48244000
BM_to_chars_bad/4 16.9 ns 16.9 ns 41974000
BM_to_chars_bad/5 12.5 ns 12.5 ns 56080000
BM_to_chars_bad/6 10.9 ns 10.9 ns 64036000
BM_to_chars_bad/7 14.5 ns 14.5 ns 47294000
BM_to_chars_bad/8 6.36 ns 6.35 ns 110430000
BM_to_chars_bad/9 12.4 ns 12.4 ns 56448000
BM_to_chars_bad/10 5.13 ns 5.13 ns 137596000
BM_to_chars_bad/11 9.88 ns 9.88 ns 69015000
BM_to_chars_bad/12 10.8 ns 10.8 ns 63990000
BM_to_chars_bad/13 10.7 ns 10.7 ns 65066000
BM_to_chars_bad/14 9.71 ns 9.71 ns 71775000
BM_to_chars_bad/15 9.18 ns 9.18 ns 75267000
BM_to_chars_bad/16 6.12 ns 6.12 ns 115000000
BM_to_chars_bad/17 10.7 ns 10.7 ns 65504000
BM_to_chars_bad/18 10.6 ns 10.6 ns 65685000
BM_to_chars_bad/19 9.98 ns 9.98 ns 69894000
BM_to_chars_bad/20 9.74 ns 9.74 ns 72098000
BM_to_chars_bad/21 9.25 ns 9.25 ns 75184000
BM_to_chars_bad/22 9.10 ns 9.10 ns 75602000
BM_to_chars_bad/23 9.48 ns 9.48 ns 72824000
BM_to_chars_bad/24 9.27 ns 9.27 ns 75112000
BM_to_chars_bad/25 9.61 ns 9.61 ns 72080000
BM_to_chars_bad/26 9.72 ns 9.72 ns 72178000
BM_to_chars_bad/27 10.0 ns 10.0 ns 69733000
BM_to_chars_bad/28 10.3 ns 10.3 ns 67409000
BM_to_chars_bad/29 9.97 ns 9.97 ns 69193000
BM_to_chars_bad/30 10.1 ns 10.1 ns 69007000
BM_to_chars_bad/31 9.68 ns 9.68 ns 72232000
BM_to_chars_bad/32 8.99 ns 8.99 ns 76825000
BM_to_chars_bad/33 8.82 ns 8.82 ns 79293000
BM_to_chars_bad/34 8.64 ns 8.64 ns 80441000
BM_to_chars_bad/35 8.96 ns 8.96 ns 75320000
BM_to_chars_bad/36 8.87 ns 8.87 ns 77293000
```
After
```
--------------------------------------------------------------
Benchmark Time CPU Iterations
--------------------------------------------------------------
BM_to_chars_good/2 14.7 ns 14.7 ns 47583000
BM_to_chars_good/3 101 ns 101 ns 6901000
BM_to_chars_good/4 68.4 ns 68.4 ns 10088000
BM_to_chars_good/5 58.2 ns 58.2 ns 12007000
BM_to_chars_good/6 51.1 ns 51.1 ns 13687000
BM_to_chars_good/7 45.6 ns 45.6 ns 15323000
BM_to_chars_good/8 14.6 ns 14.6 ns 47795000
BM_to_chars_good/9 40.7 ns 40.7 ns 17371000
BM_to_chars_good/10 7.48 ns 7.48 ns 90931000
BM_to_chars_good/11 37.6 ns 37.6 ns 18542000
BM_to_chars_good/12 35.2 ns 35.2 ns 19922000
BM_to_chars_good/13 34.9 ns 34.9 ns 20105000
BM_to_chars_good/14 33.5 ns 33.5 ns 20863000
BM_to_chars_good/15 31.9 ns 31.9 ns 22014000
BM_to_chars_good/16 11.7 ns 11.7 ns 60012000
BM_to_chars_good/17 28.9 ns 28.9 ns 24148000
BM_to_chars_good/18 29.0 ns 29.0 ns 24317000
BM_to_chars_good/19 28.7 ns 28.7 ns 24363000
BM_to_chars_good/20 28.1 ns 28.1 ns 24899000
BM_to_chars_good/21 27.5 ns 27.5 ns 25499000
BM_to_chars_good/22 26.9 ns 26.9 ns 25929000
BM_to_chars_good/23 26.2 ns 26.2 ns 26828000
BM_to_chars_good/24 25.1 ns 25.1 ns 27742000
BM_to_chars_good/25 25.3 ns 25.3 ns 27720000
BM_to_chars_good/26 25.2 ns 25.2 ns 27789000
BM_to_chars_good/27 25.3 ns 25.3 ns 27777000
BM_to_chars_good/28 25.3 ns 25.3 ns 27643000
BM_to_chars_good/29 25.3 ns 25.3 ns 27750000
BM_to_chars_good/30 25.4 ns 25.4 ns 27566000
BM_to_chars_good/31 25.4 ns 25.4 ns 27611000
BM_to_chars_good/32 25.8 ns 25.8 ns 27218000
BM_to_chars_good/33 25.7 ns 25.7 ns 27070000
BM_to_chars_good/34 26.1 ns 26.1 ns 26693000
BM_to_chars_good/35 26.4 ns 26.4 ns 26486000
BM_to_chars_good/36 26.3 ns 26.3 ns 26619000
BM_to_chars_bad/2 5.99 ns 5.99 ns 118787000
BM_to_chars_bad/3 14.3 ns 14.3 ns 48567000
BM_to_chars_bad/4 16.0 ns 16.0 ns 43239000
BM_to_chars_bad/5 12.6 ns 12.6 ns 55354000
BM_to_chars_bad/6 10.7 ns 10.7 ns 65491000
BM_to_chars_bad/7 14.4 ns 14.4 ns 48723000
BM_to_chars_bad/8 6.50 ns 6.50 ns 104967000
BM_to_chars_bad/9 12.0 ns 12.0 ns 56552000
BM_to_chars_bad/10 5.16 ns 5.16 ns 136380000
BM_to_chars_bad/11 10.5 ns 10.5 ns 66764000
BM_to_chars_bad/12 10.7 ns 10.7 ns 65534000
BM_to_chars_bad/13 11.0 ns 11.0 ns 63426000
BM_to_chars_bad/14 9.90 ns 9.90 ns 68575000
BM_to_chars_bad/15 9.52 ns 9.52 ns 70932000
BM_to_chars_bad/16 6.14 ns 6.14 ns 111762000
BM_to_chars_bad/17 10.6 ns 10.6 ns 65883000
BM_to_chars_bad/18 10.5 ns 10.5 ns 67606000
BM_to_chars_bad/19 9.96 ns 9.96 ns 68898000
BM_to_chars_bad/20 9.40 ns 9.41 ns 73116000
BM_to_chars_bad/21 9.12 ns 9.12 ns 78647000
BM_to_chars_bad/22 8.95 ns 8.95 ns 80211000
BM_to_chars_bad/23 9.50 ns 9.49 ns 73571000
BM_to_chars_bad/24 9.29 ns 9.29 ns 74690000
BM_to_chars_bad/25 9.65 ns 9.65 ns 72877000
BM_to_chars_bad/26 9.78 ns 9.78 ns 70171000
BM_to_chars_bad/27 10.1 ns 10.1 ns 69543000
BM_to_chars_bad/28 10.4 ns 10.4 ns 67582000
BM_to_chars_bad/29 10.00 ns 10.00 ns 70806000
BM_to_chars_bad/30 9.99 ns 9.99 ns 70340000
BM_to_chars_bad/31 9.56 ns 9.56 ns 74159000
BM_to_chars_bad/32 8.97 ns 8.97 ns 78052000
BM_to_chars_bad/33 8.86 ns 8.86 ns 78586000
BM_to_chars_bad/34 8.81 ns 8.81 ns 78562000
BM_to_chars_bad/35 8.90 ns 8.90 ns 77384000
BM_to_chars_bad/36 9.04 ns 9.04 ns 77263000
```
Reviewed By: #libc, ldionne
Differential Revision: https://reviews.llvm.org/D127764
2022-06-21 17:45:40 +02:00
dea7a8e616
[libc++] Don't use static constexpr in headers.
...
This was noticed in the review of D125704. In that commit only the new
table has been adapted. This adapts the existing tables.
Note since libc++'s charconv is backported to C++11 it's not possible to
use inline constexpr variables. The were introduced in C++17.
Reviewed By: #libc, ldionne
Differential Revision: https://reviews.llvm.org/D126887
2022-06-07 18:47:44 +02:00
a15ae4139c
[libc++] Make to_chars base 10 header only.
...
The functions to_chars and from_chars should offer 128-bit support. This
is the first step to implement 128-bit version of to_chars. Before
implementing 128-bit support the current code will be polished.
This moves the code from the dylib to the header in prepartion of
P2291 "Add Constexpr Modifiers to Functions to_chars and from_chars for
Integral Types in <charconv> Header"
Note some more cleanups will be done in follow-up commits
- Remove the _LIBCPP_AVAILABILITY_TO_CHARS from to_chars. With all code
in the header the availablilty macro is no longer needed. This
requires enabling the unit tests for additional platforms.
- The code in the dylib can switch to using the header implementation.
This allows removing the code duplicated in the header and the dylib.
Reviewed By: #libc, ldionne
Differential Revision: https://reviews.llvm.org/D125704
2022-06-02 08:00:31 +02:00
Mark de Wever