422 Commits

Author SHA1 Message Date
Nikolas Klauser
fc5e0c071b
[libc++] Simplify most of the segmented iterator optimizations (#164797)
This patch does two things.
(1) It replaces SFINAE with `if constexpr`, avoiding some overload
resolution and unnecessary boilerplate.
(2) It removes an overload from `__for_each_n` to forward to
`__for_each`, since `__for_each` doesn't provide any further
optimizations.
2025-11-07 08:27:55 +01:00
Connector Switch
0621fd0b88
[libcxx] Optimize rng::generate_n for segmented iterators (#165280)
Part of #102817.

This patch optimizes `rng::generate_n` for segmented iterators by
forwarding the implementation directly to `std::generate_n`.

- before

```
rng::generate_n(deque<int>)/32          21.7 ns         22.0 ns     32000000
rng::generate_n(deque<int>)/50          30.8 ns         30.7 ns     22400000
rng::generate_n(deque<int>)/1024         492 ns          488 ns      1120000
rng::generate_n(deque<int>)/8192        3938 ns         3924 ns       179200
```

- after

```
rng::generate_n(deque<int>)/32          11.0 ns         11.0 ns     64000000
rng::generate_n(deque<int>)/50          16.2 ns         16.1 ns     40727273
rng::generate_n(deque<int>)/1024         292 ns          286 ns      2240000
rng::generate_n(deque<int>)/8192        2291 ns         2302 ns       298667
```
2025-10-28 22:22:26 +08:00
Connector Switch
abf80b54bc
[libc++][IWYU] Remove std::move header in std::for_each (#164272)
It seems this was accidentally included; there's no use of std::move in
this header.
2025-10-21 15:03:09 +00:00
Connector Switch
c06ae43e26
[libcxx] Optimize std::generate_n for segmented iterators (#164266)
Part of #102817.

This is a natural follow-up to #163006. We are forwarding
`std::generate_n` to `std::__for_each_n` (`std::for_each_n` needs
c++17), resulting in improved performance for segmented iterators.

before:

```
std::generate_n(deque<int>)/32          17.5 ns         17.3 ns     40727273
std::generate_n(deque<int>)/50          25.7 ns         25.5 ns     26352941
std::generate_n(deque<int>)/1024         490 ns          487 ns      1445161
std::generate_n(deque<int>)/8192        3908 ns         3924 ns       179200
```

after:

```
std::generate_n(deque<int>)/32          11.1 ns         11.0 ns     64000000
std::generate_n(deque<int>)/50          16.1 ns         16.0 ns     44800000
std::generate_n(deque<int>)/1024         291 ns          292 ns      2357895
std::generate_n(deque<int>)/8192        2269 ns         2250 ns       298667
```
2025-10-21 12:01:36 +02:00
Connector Switch
46e8816928
[libcxx] Optimize std::generate for segmented iterators (#163006)
Part of #102817.

This patch attempts to optimize the performance of `std::generate` for
segmented iterators. Below are the benchmark numbers from
`libcxx\test\benchmarks\algorithms\modifying\generate.bench.cpp`. Test
cases that use segmented iterators have also been added.

- before

```
std::generate(deque<int>)/32           194 ns          193 ns      3733333
std::generate(deque<int>)/50           276 ns          276 ns      2488889
std::generate(deque<int>)/1024        5096 ns         5022 ns       112000
std::generate(deque<int>)/8192       40806 ns        40806 ns        17231
```

- after

```
std::generate(deque<int>)/32           106 ns          105 ns      6400000
std::generate(deque<int>)/50           139 ns          138 ns      4977778
std::generate(deque<int>)/1024        2713 ns         2699 ns       248889
std::generate(deque<int>)/8192       18983 ns        19252 ns        37333
```

---------

Co-authored-by: A. Jiang <de34@live.cn>
2025-10-20 19:37:33 +08:00
Peng Liu
d0cee6939a
[libc++] Optimize std::{,ranges}::{fill,fill_n} for segmented iterators (#132665)
This patch optimizes `std::fill`, `std::fill_n`, `std::ranges::fill`,
and `std::ranges::fill_n` for segmented iterators, achieving substantial
performance improvements. Specifically, for `deque<int>` iterators, the
performance improvements are above 10x for all these algorithms. The
optimization also enables filling segmented memory of `deque<int>` to
approach the performance of filling contiguous memory of `vector<int>`.


Benchmark results comparing the before and after implementations are
provided below. For additional context, we’ve included `vector<int>`
results, which remain unchanged, as this patch specifically targets
segmented iterators and leaves non-segmented iterator behavior
untouched.



Fixes two subtasks outlined in #102817.

#### `fill_n`

```
-----------------------------------------------------------------------------
Benchmark                                Before            After      Speedup
-----------------------------------------------------------------------------
std::fill_n(deque<int>)/32              11.4 ns          2.28 ns        5.0x
std::fill_n(deque<int>)/50              19.7 ns          3.40 ns        5.8x
std::fill_n(deque<int>)/1024             391 ns          37.3 ns       10.5x
std::fill_n(deque<int>)/8192            3174 ns           301 ns       10.5x
std::fill_n(deque<int>)/65536          26504 ns          2951 ns        9.0x
std::fill_n(deque<int>)/1048576       407960 ns         80658 ns        5.1x
rng::fill_n(deque<int>)/32              14.3 ns          2.15 ns        6.6x
rng::fill_n(deque<int>)/50              20.2 ns          3.22 ns        6.3x
rng::fill_n(deque<int>)/1024             381 ns          37.8 ns       10.1x
rng::fill_n(deque<int>)/8192            3101 ns           294 ns       10.5x
rng::fill_n(deque<int>)/65536          25098 ns          2926 ns        8.6x
rng::fill_n(deque<int>)/1048576       394342 ns         78874 ns        5.0x
std::fill_n(vector<int>)/32             1.76 ns          1.72 ns        1.0x
std::fill_n(vector<int>)/50             3.00 ns          2.73 ns        1.1x
std::fill_n(vector<int>)/1024           38.4 ns          37.9 ns        1.0x
std::fill_n(vector<int>)/8192            258 ns           252 ns        1.0x
std::fill_n(vector<int>)/65536          2993 ns          2889 ns        1.0x
std::fill_n(vector<int>)/1048576       80328 ns         80468 ns        1.0x
rng::fill_n(vector<int>)/32             1.99 ns          1.35 ns        1.5x
rng::fill_n(vector<int>)/50             2.66 ns          2.12 ns        1.3x
rng::fill_n(vector<int>)/1024           37.7 ns          35.8 ns        1.1x
rng::fill_n(vector<int>)/8192            253 ns           250 ns        1.0x
rng::fill_n(vector<int>)/65536          2922 ns          2930 ns        1.0x
rng::fill_n(vector<int>)/1048576       79739 ns         79742 ns        1.0x
```

#### `fill`

```
--------------------------------------------------------------------------
Benchmark                              Before            After     Speedup
--------------------------------------------------------------------------
std::fill(deque<int>)/32              13.7 ns          2.45 ns        5.6x
std::fill(deque<int>)/50              21.7 ns          4.57 ns        4.7x
std::fill(deque<int>)/1024             367 ns          38.5 ns        9.5x
std::fill(deque<int>)/8192            2896 ns           247 ns       11.7x
std::fill(deque<int>)/65536          23723 ns          2907 ns        8.2x
std::fill(deque<int>)/1048576       379043 ns         79885 ns        4.7x
rng::fill(deque<int>)/32              13.6 ns          2.70 ns        5.0x
rng::fill(deque<int>)/50              23.4 ns          3.94 ns        5.9x
rng::fill(deque<int>)/1024             377 ns          37.9 ns        9.9x
rng::fill(deque<int>)/8192            2914 ns           286 ns       10.2x
rng::fill(deque<int>)/65536          23612 ns          2939 ns        8.0x
rng::fill(deque<int>)/1048576       379841 ns         80079 ns        4.7x
std::fill(vector<int>)/32             1.99 ns          1.79 ns        1.1x
std::fill(vector<int>)/50             3.05 ns          3.06 ns        1.0x
std::fill(vector<int>)/1024           37.6 ns          38.0 ns        1.0x
std::fill(vector<int>)/8192            255 ns           257 ns        1.0x
std::fill(vector<int>)/65536          2966 ns          2981 ns        1.0x
std::fill(vector<int>)/1048576       78300 ns         80348 ns        1.0x
rng::fill(vector<int>)/32             1.77 ns          1.75 ns        1.0x
rng::fill(vector<int>)/50             4.85 ns          2.31 ns        2.1x
rng::fill(vector<int>)/1024           39.6 ns          36.1 ns        1.1x
rng::fill(vector<int>)/8192            238 ns           251 ns        0.9x
rng::fill(vector<int>)/65536          2941 ns          2918 ns        1.0x
rng::fill(vector<int>)/1048576       80497 ns         80442 ns        1.0x
```

---------

Co-authored-by: Louis Dionne <ldionne.2@gmail.com>
Co-authored-by: A. Jiang <de34@live.cn>
2025-10-17 07:41:24 +08:00
A. Jiang
d6d5026b51
[libc++] Avoid transitive inclusion for <__algorithm/find.h> (#162508)
Currently, `size_t` and `__libcpp_is_constant_evaluated` are obtained by
transitive inclusion in `<__algorithm/find.h>` when `<cwchar>` is not
included. This broke module build when `_LIBCPP_HAS_WIDE_CHARACTERS` is
`1` and caused CI failure. We should explicitly include the
corresponding internal headers.
2025-10-09 17:57:59 +08:00
Nikolas Klauser
70b7874ab2
[libc++] Make the naming of the iterator_traits aliases consistent (#161661)
This renames all the `iterator_traits` alises to be
`__iterator_<type-name>`. e.g `iterator_traits<T>::value_type` will be
`__iterator_value_type<T>`.
2025-10-07 14:42:11 +02:00
Nikolas Klauser
55803b8af1
Reapply "[libc++] Avoid constructing additional objects when using map::at" (#160738) (#161485)
This reverts commit b86aaacf28b358b187071bc87075f1faa2d65c4e.

The issue in LLVM has been fixed now.
2025-10-02 11:15:33 +02:00
Nikolas Klauser
66558d70dc
[libc++] Fix <__algorithm/find.h> when using -flax-vector-conversions=none (#161362) 2025-10-02 10:05:26 +02:00
Nikolas Klauser
97367d1046
[libc++] Vectorize std::find (#156431)
```
Apple M4:
-----------------------------------------------------------------------------
Benchmark                                                 old             new
-----------------------------------------------------------------------------
std::find(vector<char>) (bail 25%)/8                  1.43 ns         1.44 ns
std::find(vector<char>) (bail 25%)/1024               5.54 ns         5.59 ns
std::find(vector<char>) (bail 25%)/8192               38.4 ns         39.1 ns
std::find(vector<char>) (bail 25%)/32768               134 ns          136 ns
std::find(vector<int>) (bail 25%)/8                   1.56 ns         1.57 ns
std::find(vector<int>) (bail 25%)/1024                65.3 ns         65.4 ns
std::find(vector<int>) (bail 25%)/8192                 465 ns          464 ns
std::find(vector<int>) (bail 25%)/32768               1832 ns         1832 ns
std::find(vector<long long>) (bail 25%)/8            0.920 ns         1.20 ns
std::find(vector<long long>) (bail 25%)/1024          65.2 ns         31.2 ns
std::find(vector<long long>) (bail 25%)/8192           464 ns          255 ns
std::find(vector<long long>) (bail 25%)/32768         1833 ns          992 ns
std::find(vector<char>) (process all)/8               1.21 ns         1.22 ns
std::find(vector<char>) (process all)/50              1.92 ns         1.93 ns
std::find(vector<char>) (process all)/1024            16.6 ns         16.9 ns
std::find(vector<char>) (process all)/8192             134 ns          136 ns
std::find(vector<char>) (process all)/32768            488 ns          503 ns
std::find(vector<int>) (process all)/8                2.45 ns         2.48 ns
std::find(vector<int>) (process all)/50               12.7 ns         12.7 ns
std::find(vector<int>) (process all)/1024              236 ns          236 ns
std::find(vector<int>) (process all)/8192             1830 ns         1834 ns
std::find(vector<int>) (process all)/32768            7351 ns         7346 ns
std::find(vector<long long>) (process all)/8          2.02 ns         1.45 ns
std::find(vector<long long>) (process all)/50         12.0 ns         6.12 ns
std::find(vector<long long>) (process all)/1024        235 ns          123 ns
std::find(vector<long long>) (process all)/8192       1830 ns          983 ns
std::find(vector<long long>) (process all)/32768      7306 ns         3969 ns
std::find(vector<bool>) (process all)/8               1.14 ns         1.15 ns
std::find(vector<bool>) (process all)/50              1.16 ns         1.17 ns
std::find(vector<bool>) (process all)/1024            4.51 ns         4.53 ns
std::find(vector<bool>) (process all)/8192            33.6 ns         33.5 ns
std::find(vector<bool>) (process all)/1048576         3660 ns         3660 ns
```
2025-09-29 11:10:19 +02:00
Andrew Lazarev
b86aaacf28
Revert "[libc++] Avoid constructing additional objects when using map::at" (#160738)
Reverts llvm/llvm-project#157866

It breaks a lot of sanitizer buildbots
2025-09-25 15:10:37 -07:00
Nikolas Klauser
833d5f0cd8
[libc++] Avoid constructing additional objects when using map::at (#157866)
This patch adds additional overloads to `map::at` in case its known that
the argument is transparently comparable to the key type. This avoids
actually constructing the key type in some cases, potentially removing
allocations.

```
--------------------------------------------------------
Benchmark                            old             new
--------------------------------------------------------
BM_map_find_string_literal       12.8 ns         2.68 ns
```
2025-09-25 11:35:41 +02:00
Prabhu Rajasekaran
59b4621b6a
[libc++] Fix use of static in constexpr (#160180)
`static` is not allowed inside constexpr functions in C++ versions below
23. This is causing a build error when compiled with GCC and warning
when compiled with Clang. This patch fixes this.

---------

Co-authored-by: A. Jiang <de34@live.cn>
2025-09-24 07:26:14 +08:00
Nikolas Klauser
04518e7357
[libc++] Improve the performance of std::make_heap a bit (#154092)
```
Apple M4:
-----------------------------------------------------------------------------------------------------
Benchmark                                                                         old             new
-----------------------------------------------------------------------------------------------------
BM_MakeHeap_uint32_Random_1                                                  0.285 ns        0.271 ns
BM_MakeHeap_uint32_Random_4                                                   2.09 ns         1.80 ns
BM_MakeHeap_uint32_Random_16                                                  1.85 ns         1.83 ns
BM_MakeHeap_uint32_Random_64                                                  1.92 ns         1.50 ns
BM_MakeHeap_uint32_Random_256                                                 2.10 ns         1.87 ns
BM_MakeHeap_uint32_Random_1024                                                1.73 ns         1.86 ns
BM_MakeHeap_uint32_Random_16384                                               2.17 ns         2.05 ns
BM_MakeHeap_uint32_Random_262144                                              1.77 ns         1.77 ns
BM_MakeHeap_uint32_Ascending_1                                               0.288 ns        0.277 ns
BM_MakeHeap_uint32_Ascending_4                                               0.658 ns        0.481 ns
BM_MakeHeap_uint32_Ascending_16                                              0.636 ns        0.637 ns
BM_MakeHeap_uint32_Ascending_64                                              0.643 ns        0.601 ns
BM_MakeHeap_uint32_Ascending_256                                             0.710 ns        0.636 ns
BM_MakeHeap_uint32_Ascending_1024                                            0.747 ns        0.660 ns
BM_MakeHeap_uint32_Ascending_16384                                           0.713 ns        0.633 ns
BM_MakeHeap_uint32_Ascending_262144                                          0.769 ns        0.731 ns
BM_MakeHeap_uint32_Descending_1                                              0.294 ns        0.280 ns
BM_MakeHeap_uint32_Descending_4                                              0.379 ns        0.305 ns
BM_MakeHeap_uint32_Descending_16                                             0.376 ns        0.268 ns
BM_MakeHeap_uint32_Descending_64                                             0.358 ns        0.271 ns
BM_MakeHeap_uint32_Descending_256                                            0.377 ns        0.284 ns
BM_MakeHeap_uint32_Descending_1024                                           0.355 ns        0.267 ns
BM_MakeHeap_uint32_Descending_16384                                          0.348 ns        0.248 ns
BM_MakeHeap_uint32_Descending_262144                                         0.349 ns        0.247 ns
BM_MakeHeap_uint32_SingleElement_1                                           0.292 ns        0.280 ns
BM_MakeHeap_uint32_SingleElement_4                                           0.570 ns        0.332 ns
BM_MakeHeap_uint32_SingleElement_16                                          0.635 ns        0.604 ns
BM_MakeHeap_uint32_SingleElement_64                                          0.653 ns        0.567 ns
BM_MakeHeap_uint32_SingleElement_256                                         0.703 ns        0.609 ns
BM_MakeHeap_uint32_SingleElement_1024                                        0.737 ns        0.604 ns
BM_MakeHeap_uint32_SingleElement_16384                                       0.699 ns        0.574 ns
BM_MakeHeap_uint32_SingleElement_262144                                      0.803 ns        0.684 ns
BM_MakeHeap_uint32_PipeOrgan_1                                               0.291 ns        0.284 ns
BM_MakeHeap_uint32_PipeOrgan_4                                               0.588 ns        0.399 ns
BM_MakeHeap_uint32_PipeOrgan_16                                              0.648 ns         1.12 ns
BM_MakeHeap_uint32_PipeOrgan_64                                              0.662 ns        0.771 ns
BM_MakeHeap_uint32_PipeOrgan_256                                             0.723 ns        0.672 ns
BM_MakeHeap_uint32_PipeOrgan_1024                                            0.749 ns        0.674 ns
BM_MakeHeap_uint32_PipeOrgan_16384                                           0.708 ns        0.638 ns
BM_MakeHeap_uint32_PipeOrgan_262144                                          0.786 ns        0.743 ns
BM_MakeHeap_uint32_Heap_1                                                    0.298 ns        0.282 ns
BM_MakeHeap_uint32_Heap_4                                                    0.396 ns        0.308 ns
BM_MakeHeap_uint32_Heap_16                                                   0.377 ns        0.268 ns
BM_MakeHeap_uint32_Heap_64                                                   0.356 ns        0.271 ns
BM_MakeHeap_uint32_Heap_256                                                  0.378 ns        0.290 ns
BM_MakeHeap_uint32_Heap_1024                                                 0.356 ns        0.275 ns
BM_MakeHeap_uint32_Heap_16384                                                0.348 ns        0.252 ns
BM_MakeHeap_uint32_Heap_262144                                               0.347 ns        0.250 ns
BM_MakeHeap_uint32_QuickSortAdversary_1                                      0.290 ns        0.284 ns
BM_MakeHeap_uint32_QuickSortAdversary_4                                      0.627 ns        0.409 ns
BM_MakeHeap_uint32_QuickSortAdversary_16                                     0.640 ns        0.653 ns
BM_MakeHeap_uint32_QuickSortAdversary_64                                     0.577 ns        0.484 ns
BM_MakeHeap_uint32_QuickSortAdversary_256                                    0.613 ns        0.521 ns
BM_MakeHeap_uint32_QuickSortAdversary_1024                                   0.652 ns        0.514 ns
BM_MakeHeap_uint32_QuickSortAdversary_16384                                  0.428 ns        0.308 ns
BM_MakeHeap_uint32_QuickSortAdversary_262144                                 0.373 ns        0.261 ns
BM_MakeHeap_uint64_Random_1                                                  0.291 ns        0.281 ns
BM_MakeHeap_uint64_Random_4                                                   2.20 ns         1.97 ns
BM_MakeHeap_uint64_Random_16                                                  1.93 ns         1.70 ns
BM_MakeHeap_uint64_Random_64                                                  1.89 ns         1.48 ns
BM_MakeHeap_uint64_Random_256                                                 2.10 ns         1.99 ns
BM_MakeHeap_uint64_Random_1024                                                1.41 ns         2.04 ns
BM_MakeHeap_uint64_Random_16384                                               2.12 ns         1.83 ns
BM_MakeHeap_uint64_Random_262144                                              1.83 ns         1.63 ns
BM_MakeHeap_uint64_Ascending_1                                               0.288 ns        0.283 ns
BM_MakeHeap_uint64_Ascending_4                                               0.624 ns        0.493 ns
BM_MakeHeap_uint64_Ascending_16                                              0.648 ns        0.688 ns
BM_MakeHeap_uint64_Ascending_64                                              0.671 ns        0.634 ns
BM_MakeHeap_uint64_Ascending_256                                             0.739 ns        0.680 ns
BM_MakeHeap_uint64_Ascending_1024                                            0.761 ns        0.698 ns
BM_MakeHeap_uint64_Ascending_16384                                           0.740 ns        0.685 ns
BM_MakeHeap_uint64_Ascending_262144                                          0.849 ns        0.837 ns
BM_MakeHeap_uint64_Descending_1                                              0.304 ns        0.287 ns
BM_MakeHeap_uint64_Descending_4                                              0.395 ns        0.312 ns
BM_MakeHeap_uint64_Descending_16                                             0.374 ns        0.276 ns
BM_MakeHeap_uint64_Descending_64                                             0.358 ns        0.272 ns
BM_MakeHeap_uint64_Descending_256                                            0.389 ns        0.303 ns
BM_MakeHeap_uint64_Descending_1024                                           0.361 ns        0.278 ns
BM_MakeHeap_uint64_Descending_16384                                          0.352 ns        0.253 ns
BM_MakeHeap_uint64_Descending_262144                                         0.350 ns        0.251 ns
BM_MakeHeap_uint64_SingleElement_1                                           0.295 ns        0.285 ns
BM_MakeHeap_uint64_SingleElement_4                                           0.569 ns        0.358 ns
BM_MakeHeap_uint64_SingleElement_16                                          0.649 ns        0.652 ns
BM_MakeHeap_uint64_SingleElement_64                                          0.673 ns        0.565 ns
BM_MakeHeap_uint64_SingleElement_256                                         0.732 ns        0.651 ns
BM_MakeHeap_uint64_SingleElement_1024                                        0.759 ns        0.632 ns
BM_MakeHeap_uint64_SingleElement_16384                                       0.748 ns        0.614 ns
BM_MakeHeap_uint64_SingleElement_262144                                      0.947 ns        0.797 ns
BM_MakeHeap_uint64_PipeOrgan_1                                               0.295 ns        0.284 ns
BM_MakeHeap_uint64_PipeOrgan_4                                               0.601 ns        0.496 ns
BM_MakeHeap_uint64_PipeOrgan_16                                              0.655 ns         1.18 ns
BM_MakeHeap_uint64_PipeOrgan_64                                              0.682 ns        0.803 ns
BM_MakeHeap_uint64_PipeOrgan_256                                             0.759 ns        0.710 ns
BM_MakeHeap_uint64_PipeOrgan_1024                                            0.759 ns        0.713 ns
BM_MakeHeap_uint64_PipeOrgan_16384                                           0.739 ns        0.696 ns
BM_MakeHeap_uint64_PipeOrgan_262144                                          0.870 ns        0.849 ns
BM_MakeHeap_uint64_Heap_1                                                    0.290 ns        0.284 ns
BM_MakeHeap_uint64_Heap_4                                                    0.413 ns        0.314 ns
BM_MakeHeap_uint64_Heap_16                                                   0.378 ns        0.277 ns
BM_MakeHeap_uint64_Heap_64                                                   0.362 ns        0.272 ns
BM_MakeHeap_uint64_Heap_256                                                  0.389 ns        0.303 ns
BM_MakeHeap_uint64_Heap_1024                                                 0.362 ns        0.283 ns
BM_MakeHeap_uint64_Heap_16384                                                0.352 ns        0.253 ns
BM_MakeHeap_uint64_Heap_262144                                               0.350 ns        0.251 ns
BM_MakeHeap_uint64_QuickSortAdversary_1                                      0.293 ns        0.284 ns
BM_MakeHeap_uint64_QuickSortAdversary_4                                      0.606 ns        0.494 ns
BM_MakeHeap_uint64_QuickSortAdversary_16                                     0.645 ns        0.691 ns
BM_MakeHeap_uint64_QuickSortAdversary_64                                     0.607 ns        0.511 ns
BM_MakeHeap_uint64_QuickSortAdversary_256                                    0.641 ns        0.537 ns
BM_MakeHeap_uint64_QuickSortAdversary_1024                                   0.657 ns        0.529 ns
BM_MakeHeap_uint64_QuickSortAdversary_16384                                  0.435 ns        0.316 ns
BM_MakeHeap_uint64_QuickSortAdversary_262144                                 0.382 ns        0.266 ns
BM_MakeHeap_pair<uint32, uint32>_Random_1                                    0.297 ns        0.378 ns
BM_MakeHeap_pair<uint32, uint32>_Random_4                                     2.80 ns        0.765 ns
BM_MakeHeap_pair<uint32, uint32>_Random_16                                    2.92 ns         2.20 ns
BM_MakeHeap_pair<uint32, uint32>_Random_64                                    3.17 ns         3.64 ns
BM_MakeHeap_pair<uint32, uint32>_Random_256                                   3.44 ns         3.20 ns
BM_MakeHeap_pair<uint32, uint32>_Random_1024                                  3.35 ns         3.64 ns
BM_MakeHeap_pair<uint32, uint32>_Random_16384                                 3.22 ns         3.50 ns
BM_MakeHeap_pair<uint32, uint32>_Random_262144                                3.61 ns         3.46 ns
BM_MakeHeap_pair<uint32, uint32>_Ascending_1                                 0.291 ns        0.379 ns
BM_MakeHeap_pair<uint32, uint32>_Ascending_4                                 0.779 ns        0.436 ns
BM_MakeHeap_pair<uint32, uint32>_Ascending_16                                0.943 ns         1.01 ns
BM_MakeHeap_pair<uint32, uint32>_Ascending_64                                 1.17 ns         1.26 ns
BM_MakeHeap_pair<uint32, uint32>_Ascending_256                                1.38 ns         1.44 ns
BM_MakeHeap_pair<uint32, uint32>_Ascending_1024                               1.37 ns         1.43 ns
BM_MakeHeap_pair<uint32, uint32>_Ascending_16384                              1.29 ns         1.31 ns
BM_MakeHeap_pair<uint32, uint32>_Ascending_262144                             1.37 ns         1.40 ns
BM_MakeHeap_pair<uint32, uint32>_Descending_1                                0.292 ns        0.382 ns
BM_MakeHeap_pair<uint32, uint32>_Descending_4                                0.440 ns        0.347 ns
BM_MakeHeap_pair<uint32, uint32>_Descending_16                               0.529 ns        0.520 ns
BM_MakeHeap_pair<uint32, uint32>_Descending_64                               0.540 ns        0.527 ns
BM_MakeHeap_pair<uint32, uint32>_Descending_256                              0.637 ns        0.583 ns
BM_MakeHeap_pair<uint32, uint32>_Descending_1024                             0.552 ns        0.513 ns
BM_MakeHeap_pair<uint32, uint32>_Descending_16384                            0.522 ns        0.488 ns
BM_MakeHeap_pair<uint32, uint32>_Descending_262144                           0.515 ns        0.492 ns
BM_MakeHeap_pair<uint32, uint32>_SingleElement_1                             0.299 ns        0.377 ns
BM_MakeHeap_pair<uint32, uint32>_SingleElement_4                             0.787 ns        0.474 ns
BM_MakeHeap_pair<uint32, uint32>_SingleElement_16                             1.07 ns        0.921 ns
BM_MakeHeap_pair<uint32, uint32>_SingleElement_64                             1.20 ns         1.15 ns
BM_MakeHeap_pair<uint32, uint32>_SingleElement_256                            1.30 ns         1.27 ns
BM_MakeHeap_pair<uint32, uint32>_SingleElement_1024                           1.30 ns         1.31 ns
BM_MakeHeap_pair<uint32, uint32>_SingleElement_16384                          1.29 ns         1.28 ns
BM_MakeHeap_pair<uint32, uint32>_SingleElement_262144                         1.37 ns         1.38 ns
BM_MakeHeap_pair<uint32, uint32>_PipeOrgan_1                                 0.293 ns        0.385 ns
BM_MakeHeap_pair<uint32, uint32>_PipeOrgan_4                                 0.677 ns        0.438 ns
BM_MakeHeap_pair<uint32, uint32>_PipeOrgan_16                                 1.04 ns         1.00 ns
BM_MakeHeap_pair<uint32, uint32>_PipeOrgan_64                                 1.20 ns         1.27 ns
BM_MakeHeap_pair<uint32, uint32>_PipeOrgan_256                                1.40 ns         1.43 ns
BM_MakeHeap_pair<uint32, uint32>_PipeOrgan_1024                               1.36 ns         1.43 ns
BM_MakeHeap_pair<uint32, uint32>_PipeOrgan_16384                              1.27 ns         1.31 ns
BM_MakeHeap_pair<uint32, uint32>_PipeOrgan_262144                             1.37 ns         1.41 ns
BM_MakeHeap_pair<uint32, uint32>_Heap_1                                      0.292 ns        0.378 ns
BM_MakeHeap_pair<uint32, uint32>_Heap_4                                      0.440 ns        0.380 ns
BM_MakeHeap_pair<uint32, uint32>_Heap_16                                     0.560 ns        0.606 ns
BM_MakeHeap_pair<uint32, uint32>_Heap_64                                     0.588 ns        0.573 ns
BM_MakeHeap_pair<uint32, uint32>_Heap_256                                    0.632 ns        0.607 ns
BM_MakeHeap_pair<uint32, uint32>_Heap_1024                                   0.598 ns        0.580 ns
BM_MakeHeap_pair<uint32, uint32>_Heap_16384                                  0.576 ns        0.563 ns
BM_MakeHeap_pair<uint32, uint32>_Heap_262144                                 0.572 ns        0.561 ns
BM_MakeHeap_pair<uint32, uint32>_QuickSortAdversary_1                        0.304 ns        0.379 ns
BM_MakeHeap_pair<uint32, uint32>_QuickSortAdversary_4                        0.823 ns        0.430 ns
BM_MakeHeap_pair<uint32, uint32>_QuickSortAdversary_16                        1.08 ns         1.03 ns
BM_MakeHeap_pair<uint32, uint32>_QuickSortAdversary_64                        1.18 ns         1.23 ns
BM_MakeHeap_pair<uint32, uint32>_QuickSortAdversary_256                       1.39 ns         1.43 ns
BM_MakeHeap_pair<uint32, uint32>_QuickSortAdversary_1024                      1.36 ns         1.42 ns
BM_MakeHeap_pair<uint32, uint32>_QuickSortAdversary_16384                     1.28 ns         1.32 ns
BM_MakeHeap_pair<uint32, uint32>_QuickSortAdversary_262144                    1.34 ns         1.37 ns
BM_MakeHeap_tuple<uint32, uint64, uint32>_Random_1                           0.276 ns        0.511 ns
BM_MakeHeap_tuple<uint32, uint64, uint32>_Random_4                            4.25 ns         1.96 ns
BM_MakeHeap_tuple<uint32, uint64, uint32>_Random_16                           4.84 ns         3.77 ns
BM_MakeHeap_tuple<uint32, uint64, uint32>_Random_64                           5.53 ns         4.93 ns
BM_MakeHeap_tuple<uint32, uint64, uint32>_Random_256                          5.30 ns         5.06 ns
BM_MakeHeap_tuple<uint32, uint64, uint32>_Random_1024                         5.29 ns         5.02 ns
BM_MakeHeap_tuple<uint32, uint64, uint32>_Random_16384                        5.53 ns         5.31 ns
BM_MakeHeap_tuple<uint32, uint64, uint32>_Random_262144                       5.49 ns         5.29 ns
BM_MakeHeap_tuple<uint32, uint64, uint32>_Ascending_1                        0.275 ns        0.443 ns
BM_MakeHeap_tuple<uint32, uint64, uint32>_Ascending_4                         1.22 ns        0.764 ns
BM_MakeHeap_tuple<uint32, uint64, uint32>_Ascending_16                        1.39 ns         1.49 ns
BM_MakeHeap_tuple<uint32, uint64, uint32>_Ascending_64                        1.66 ns         1.76 ns
BM_MakeHeap_tuple<uint32, uint64, uint32>_Ascending_256                       1.85 ns         1.99 ns
BM_MakeHeap_tuple<uint32, uint64, uint32>_Ascending_1024                      1.90 ns         2.02 ns
BM_MakeHeap_tuple<uint32, uint64, uint32>_Ascending_16384                     2.15 ns         2.27 ns
BM_MakeHeap_tuple<uint32, uint64, uint32>_Ascending_262144                    2.25 ns         2.37 ns
BM_MakeHeap_tuple<uint32, uint64, uint32>_Descending_1                       0.274 ns        0.445 ns
BM_MakeHeap_tuple<uint32, uint64, uint32>_Descending_4                       0.939 ns        0.520 ns
BM_MakeHeap_tuple<uint32, uint64, uint32>_Descending_16                       1.02 ns        0.811 ns
BM_MakeHeap_tuple<uint32, uint64, uint32>_Descending_64                       1.01 ns        0.941 ns
BM_MakeHeap_tuple<uint32, uint64, uint32>_Descending_256                      1.03 ns         1.01 ns
BM_MakeHeap_tuple<uint32, uint64, uint32>_Descending_1024                    0.969 ns        0.947 ns
BM_MakeHeap_tuple<uint32, uint64, uint32>_Descending_16384                   0.882 ns        0.876 ns
BM_MakeHeap_tuple<uint32, uint64, uint32>_Descending_262144                  0.893 ns        0.871 ns
BM_MakeHeap_tuple<uint32, uint64, uint32>_SingleElement_1                    0.276 ns        0.443 ns
BM_MakeHeap_tuple<uint32, uint64, uint32>_SingleElement_4                     1.34 ns        0.870 ns
BM_MakeHeap_tuple<uint32, uint64, uint32>_SingleElement_16                    1.60 ns         1.59 ns
BM_MakeHeap_tuple<uint32, uint64, uint32>_SingleElement_64                    1.91 ns         2.00 ns
BM_MakeHeap_tuple<uint32, uint64, uint32>_SingleElement_256                   1.91 ns         2.08 ns
BM_MakeHeap_tuple<uint32, uint64, uint32>_SingleElement_1024                  1.91 ns         2.10 ns
BM_MakeHeap_tuple<uint32, uint64, uint32>_SingleElement_16384                 2.13 ns         2.35 ns
BM_MakeHeap_tuple<uint32, uint64, uint32>_SingleElement_262144                2.25 ns         2.48 ns
BM_MakeHeap_tuple<uint32, uint64, uint32>_PipeOrgan_1                        0.275 ns        0.446 ns
BM_MakeHeap_tuple<uint32, uint64, uint32>_PipeOrgan_4                         1.07 ns        0.671 ns
BM_MakeHeap_tuple<uint32, uint64, uint32>_PipeOrgan_16                        1.36 ns         1.44 ns
BM_MakeHeap_tuple<uint32, uint64, uint32>_PipeOrgan_64                        1.70 ns         1.80 ns
BM_MakeHeap_tuple<uint32, uint64, uint32>_PipeOrgan_256                       1.88 ns         2.05 ns
BM_MakeHeap_tuple<uint32, uint64, uint32>_PipeOrgan_1024                      1.92 ns         2.06 ns
BM_MakeHeap_tuple<uint32, uint64, uint32>_PipeOrgan_16384                     2.11 ns         2.26 ns
BM_MakeHeap_tuple<uint32, uint64, uint32>_PipeOrgan_262144                    2.18 ns         2.34 ns
BM_MakeHeap_tuple<uint32, uint64, uint32>_Heap_1                             0.274 ns        0.441 ns
BM_MakeHeap_tuple<uint32, uint64, uint32>_Heap_4                             0.938 ns        0.587 ns
BM_MakeHeap_tuple<uint32, uint64, uint32>_Heap_16                             1.01 ns        0.873 ns
BM_MakeHeap_tuple<uint32, uint64, uint32>_Heap_64                             1.08 ns         1.00 ns
BM_MakeHeap_tuple<uint32, uint64, uint32>_Heap_256                            1.21 ns         1.18 ns
BM_MakeHeap_tuple<uint32, uint64, uint32>_Heap_1024                           1.37 ns         1.29 ns
BM_MakeHeap_tuple<uint32, uint64, uint32>_Heap_16384                          1.31 ns         1.26 ns
BM_MakeHeap_tuple<uint32, uint64, uint32>_Heap_262144                         1.29 ns         1.25 ns
BM_MakeHeap_tuple<uint32, uint64, uint32>_QuickSortAdversary_1               0.275 ns        0.447 ns
BM_MakeHeap_tuple<uint32, uint64, uint32>_QuickSortAdversary_4                1.22 ns        0.764 ns
BM_MakeHeap_tuple<uint32, uint64, uint32>_QuickSortAdversary_16               1.35 ns         1.46 ns
BM_MakeHeap_tuple<uint32, uint64, uint32>_QuickSortAdversary_64               1.63 ns         1.73 ns
BM_MakeHeap_tuple<uint32, uint64, uint32>_QuickSortAdversary_256              1.83 ns         1.87 ns
BM_MakeHeap_tuple<uint32, uint64, uint32>_QuickSortAdversary_1024             1.81 ns         1.94 ns
BM_MakeHeap_tuple<uint32, uint64, uint32>_QuickSortAdversary_16384            2.06 ns         2.19 ns
BM_MakeHeap_tuple<uint32, uint64, uint32>_QuickSortAdversary_262144           2.14 ns         2.31 ns
BM_MakeHeap_string_Random_1                                                  0.289 ns        0.446 ns
BM_MakeHeap_string_Random_4                                                   7.43 ns         4.84 ns
BM_MakeHeap_string_Random_16                                                  9.73 ns         8.92 ns
BM_MakeHeap_string_Random_64                                                  11.5 ns         11.5 ns
BM_MakeHeap_string_Random_256                                                 12.6 ns         12.4 ns
BM_MakeHeap_string_Random_1024                                                13.2 ns         13.2 ns
BM_MakeHeap_string_Random_16384                                               15.4 ns         15.4 ns
BM_MakeHeap_string_Random_262144                                              21.4 ns         21.5 ns
BM_MakeHeap_string_Ascending_1                                               0.287 ns        0.447 ns
BM_MakeHeap_string_Ascending_4                                                3.22 ns         2.44 ns
BM_MakeHeap_string_Ascending_16                                               3.77 ns         3.62 ns
BM_MakeHeap_string_Ascending_64                                               4.84 ns         5.17 ns
BM_MakeHeap_string_Ascending_256                                              5.79 ns         6.04 ns
BM_MakeHeap_string_Ascending_1024                                             5.93 ns         6.60 ns
BM_MakeHeap_string_Ascending_16384                                            6.84 ns         7.25 ns
BM_MakeHeap_string_Ascending_262144                                           13.5 ns         14.3 ns
BM_MakeHeap_string_Descending_1                                              0.293 ns        0.447 ns
BM_MakeHeap_string_Descending_4                                               2.61 ns         1.83 ns
BM_MakeHeap_string_Descending_16                                              2.64 ns         2.60 ns
BM_MakeHeap_string_Descending_64                                              2.75 ns         2.74 ns
BM_MakeHeap_string_Descending_256                                             3.78 ns         3.57 ns
BM_MakeHeap_string_Descending_1024                                            3.20 ns         3.51 ns
BM_MakeHeap_string_Descending_16384                                           3.57 ns         3.85 ns
BM_MakeHeap_string_Descending_262144                                          6.27 ns         6.39 ns
BM_MakeHeap_string_SingleElement_1                                           0.291 ns        0.448 ns
BM_MakeHeap_string_SingleElement_4                                            3.88 ns         2.71 ns
BM_MakeHeap_string_SingleElement_16                                           5.08 ns         4.96 ns
BM_MakeHeap_string_SingleElement_64                                           6.14 ns         6.29 ns
BM_MakeHeap_string_SingleElement_256                                          6.13 ns         6.46 ns
BM_MakeHeap_string_SingleElement_1024                                         5.98 ns         6.60 ns
BM_MakeHeap_string_SingleElement_16384                                        5.88 ns         6.39 ns
BM_MakeHeap_string_SingleElement_262144                                       9.95 ns         10.2 ns
BM_MakeHeap_string_PipeOrgan_1                                               0.292 ns        0.447 ns
BM_MakeHeap_string_PipeOrgan_4                                                2.97 ns         2.51 ns
BM_MakeHeap_string_PipeOrgan_16                                               3.76 ns         3.91 ns
BM_MakeHeap_string_PipeOrgan_64                                               4.89 ns         5.20 ns
BM_MakeHeap_string_PipeOrgan_256                                              5.77 ns         6.09 ns
BM_MakeHeap_string_PipeOrgan_1024                                             6.14 ns         6.40 ns
BM_MakeHeap_string_PipeOrgan_16384                                            6.83 ns         7.32 ns
BM_MakeHeap_string_PipeOrgan_262144                                           13.8 ns         14.6 ns
BM_MakeHeap_string_Heap_1                                                    0.288 ns        0.515 ns
BM_MakeHeap_string_Heap_4                                                     3.62 ns         4.20 ns
BM_MakeHeap_string_Heap_16                                                    5.36 ns         5.23 ns
BM_MakeHeap_string_Heap_64                                                    5.79 ns         5.38 ns
BM_MakeHeap_string_Heap_256                                                   5.70 ns         5.40 ns
BM_MakeHeap_string_Heap_1024                                                  5.78 ns         5.37 ns
BM_MakeHeap_string_Heap_16384                                                 6.09 ns         5.67 ns
BM_MakeHeap_string_Heap_262144                                                6.37 ns         5.96 ns
BM_MakeHeap_string_QuickSortAdversary_1                                      0.282 ns        0.448 ns
BM_MakeHeap_string_QuickSortAdversary_4                                       7.45 ns         5.60 ns
BM_MakeHeap_string_QuickSortAdversary_16                                      9.76 ns         8.85 ns
BM_MakeHeap_string_QuickSortAdversary_64                                      11.5 ns         11.2 ns
BM_MakeHeap_string_QuickSortAdversary_256                                     12.0 ns         11.8 ns
BM_MakeHeap_string_QuickSortAdversary_1024                                    12.2 ns         12.0 ns
BM_MakeHeap_string_QuickSortAdversary_16384                                   13.7 ns         13.6 ns
BM_MakeHeap_string_QuickSortAdversary_262144                                  14.1 ns         14.8 ns
BM_MakeHeap_float_Random_1                                                   0.287 ns        0.287 ns
BM_MakeHeap_float_Random_4                                                    2.29 ns         2.60 ns
BM_MakeHeap_float_Random_16                                                   4.00 ns         2.48 ns
BM_MakeHeap_float_Random_64                                                   4.41 ns         1.92 ns
BM_MakeHeap_float_Random_256                                                  4.73 ns         2.05 ns
BM_MakeHeap_float_Random_1024                                                 4.90 ns         2.27 ns
BM_MakeHeap_float_Random_16384                                                4.42 ns         2.27 ns
BM_MakeHeap_float_Random_262144                                               4.72 ns         1.39 ns
BM_MakeHeap_float_Ascending_1                                                0.291 ns        0.293 ns
BM_MakeHeap_float_Ascending_4                                                0.633 ns        0.428 ns
BM_MakeHeap_float_Ascending_16                                               0.638 ns        0.874 ns
BM_MakeHeap_float_Ascending_64                                               0.614 ns        0.698 ns
BM_MakeHeap_float_Ascending_256                                              0.663 ns        0.713 ns
BM_MakeHeap_float_Ascending_1024                                             0.660 ns        0.761 ns
BM_MakeHeap_float_Ascending_16384                                            0.628 ns        0.725 ns
BM_MakeHeap_float_Ascending_262144                                           0.629 ns        0.814 ns
BM_MakeHeap_float_Descending_1                                               0.290 ns        0.290 ns
BM_MakeHeap_float_Descending_4                                               0.421 ns        0.316 ns
BM_MakeHeap_float_Descending_16                                              0.302 ns        0.225 ns
BM_MakeHeap_float_Descending_64                                              0.293 ns        0.212 ns
BM_MakeHeap_float_Descending_256                                             0.314 ns        0.246 ns
BM_MakeHeap_float_Descending_1024                                            0.300 ns        0.231 ns
BM_MakeHeap_float_Descending_16384                                           0.308 ns        0.205 ns
BM_MakeHeap_float_Descending_262144                                          0.309 ns        0.203 ns
BM_MakeHeap_float_SingleElement_1                                            0.289 ns        0.292 ns
BM_MakeHeap_float_SingleElement_4                                            0.569 ns        0.347 ns
BM_MakeHeap_float_SingleElement_16                                           0.538 ns        0.825 ns
BM_MakeHeap_float_SingleElement_64                                           0.585 ns        0.727 ns
BM_MakeHeap_float_SingleElement_256                                          0.603 ns        0.708 ns
BM_MakeHeap_float_SingleElement_1024                                         0.618 ns        0.760 ns
BM_MakeHeap_float_SingleElement_16384                                        0.599 ns        0.726 ns
BM_MakeHeap_float_SingleElement_262144                                       0.723 ns        0.820 ns
BM_MakeHeap_float_PipeOrgan_1                                                0.289 ns        0.291 ns
BM_MakeHeap_float_PipeOrgan_4                                                0.457 ns        0.420 ns
BM_MakeHeap_float_PipeOrgan_16                                               0.670 ns         1.32 ns
BM_MakeHeap_float_PipeOrgan_64                                               0.764 ns        0.889 ns
BM_MakeHeap_float_PipeOrgan_256                                              0.793 ns        0.757 ns
BM_MakeHeap_float_PipeOrgan_1024                                             0.755 ns        0.764 ns
BM_MakeHeap_float_PipeOrgan_16384                                            0.723 ns        0.723 ns
BM_MakeHeap_float_PipeOrgan_262144                                           0.654 ns        0.817 ns
BM_MakeHeap_float_Heap_1                                                     0.291 ns        0.289 ns
BM_MakeHeap_float_Heap_4                                                     0.388 ns        0.316 ns
BM_MakeHeap_float_Heap_16                                                    0.317 ns        0.225 ns
BM_MakeHeap_float_Heap_64                                                    0.353 ns        0.213 ns
BM_MakeHeap_float_Heap_256                                                   0.361 ns        0.246 ns
BM_MakeHeap_float_Heap_1024                                                  0.381 ns        0.233 ns
BM_MakeHeap_float_Heap_16384                                                 0.390 ns        0.205 ns
BM_MakeHeap_float_Heap_262144                                                0.379 ns        0.202 ns
BM_MakeHeap_float_QuickSortAdversary_1                                       0.295 ns        0.289 ns
BM_MakeHeap_float_QuickSortAdversary_4                                       0.640 ns        0.422 ns
BM_MakeHeap_float_QuickSortAdversary_16                                      0.658 ns        0.871 ns
BM_MakeHeap_float_QuickSortAdversary_64                                      0.574 ns        0.659 ns
BM_MakeHeap_float_QuickSortAdversary_256                                     0.631 ns        0.550 ns
BM_MakeHeap_float_QuickSortAdversary_1024                                    0.617 ns        0.552 ns
BM_MakeHeap_float_QuickSortAdversary_16384                                   0.424 ns        0.283 ns
BM_MakeHeap_float_QuickSortAdversary_262144                                  0.386 ns        0.219 ns
```

Fixes #120752
2025-09-08 12:00:04 +02:00
Nikolas Klauser
34d4f0c136
[libc++][NFC] Use llvm.org/PR to link to bug reports (#156288)
We've built up quite a few links directly to github within the code
base. We should instead use `llvm.org/PR<issue-number>` to link to bugs,
since that is resilient to the bug tracker changing in the future. This
is especially relevant for tests linking to bugs, since they will
probably be there for decades to come. A nice side effect is that these
links are significantly shorter than the GH links, making them much less
of an eyesore.

This patch also replaces a few links that linked to the old bugzilla
instance on llvm.org.
2025-09-04 09:20:02 +02:00
Louis Dionne
2ae4b92a1c
[libc++] Fix broken precondition of __bit_log2 (#155476)
In #135303, we started using `__bit_log2` instead of `__log2i` inside
`std::sort`. However, `__bit_log2` has a precondition that `__log2i`
didn't have, which is that the input is non-zero. While it technically
makes no sense to request the logarithm of 0, `__log2i` handled that
case and returned 0 without issues.

After switching to `__bit_log2`, passing 0 as an input results in an
unsigned integer overflow which can trigger
`-fsanitize=unsigned-integer-overflow`. While not technically UB in
itself, it's clearly not intended either.

To fix this, we add an internal assertion to `__bit_log2` which catches
the issue in our test suite, and we make sure not to violate
`__bit_log2`'s preconditions before we call it from `std::sort`.
2025-08-28 18:07:59 -04:00
Nikolas Klauser
cdb67e1131
[libc++][NFC] Make __is_segmented_iterator a variable template (#149976) 2025-07-25 16:27:34 +02:00
Louis Dionne
d145f716ae
[libc++] Bump Xcode support (#148651)
Libc++'s policy is to support only the latest released Xcode, which is
Xcode 16.x. We did update our CI jobs to Xcode 16.x, but we forgot to
update the documentation, which still mentioned Xcode 15. This patch
updates the documentation and cleans up outdated mentions of
apple-clang-15 in the test suite.
2025-07-15 10:45:37 -04:00
Peng Liu
9827440f1e
[libc++] Optimize ranges::{for_each, for_each_n} for segmented iterators (#132896)
Previously, the segmented iterator optimization was limited to `std::{for_each, for_each_n}`. This patch
extends the optimization to `std::ranges::for_each` and `std::ranges::for_each_n`, ensuring consistent
optimizations across these algorithms. This patch first generalizes the `std` algorithms by introducing
a `Projection` parameter, which is set to `__identity` for the `std` algorithms. Then we let the `ranges`
algorithms to directly call their `std` counterparts with a general `__proj` argument. Benchmarks
demonstrate performance improvements of up to 21.4x for ``std::deque::iterator`` and 22.3x for
``join_view`` of ``vector<vector<char>>``.

Addresses a subtask of #102817.
2025-06-18 12:22:47 -04:00
James Y Knight
c3656afdf1
Revert "[libc++] Introduce ABI sensitive areas to avoid requiring _LIBCPP_HIDE_FROM_ABI everywhere (#131156)" (#141756)
This reverts commit c861fe8a71e64f3d2108c58147e7375cd9314521.

Unfortunately, this use of hidden visibility attributes causes
user-defined specializations of standard-library types to also be marked
hidden by default, which is incorrect. See discussion thread on #131156.

...and also reverts the follow-up commits:

Revert "[libc++] Add explicit ABI annotations to functions from the block runtime declared in <__functional/function.h> (#140592)"
This reverts commit 3e4c9dc299c35155934688184319d391b298fff7.

Revert "[libc++] Make ABI annotations explicit for windows-specific code (#140507)"
This reverts commit f73287e623a6c2e4a3485832bc3e10860cd26eb5.

Revert "[libc++][NFC] Replace a few "namespace std" with the correct macro (#140510)"
This reverts commit 1d411f27c769a32cb22ce50b9dc4421e34fd40dd.
2025-05-28 12:04:51 -04:00
Peng Liu
09c266b75d
[libc++] Optimize std::for_each_n for segmented iterators (#135468)
This patch enhances the performance of `std::for_each_n` when used with
segmented iterators, leading to significant performance improvements,
summarized in the tables below. This addresses a subtask of
https://github.com/llvm/llvm-project/issues/102817.
2025-05-21 12:10:50 -04:00
Nikolas Klauser
c861fe8a71
[libc++] Introduce ABI sensitive areas to avoid requiring _LIBCPP_HIDE_FROM_ABI everywhere (#131156)
This patch introduces `_LIBCPP_{BEGIN,END}_EXPLICIT_ABI_ANNOTATIONS`,
which allow us to have implicit annotations for most functions, and just
where it's not "hide_from_abi everything" we add explicit annotations.
This allows us to drop the `_LIBCPP_HIDE_FROM_ABI` macro from most
functions in libc++.
2025-05-18 15:47:05 +02:00
Peng Liu
e9280a1d39
[libc++] Backport segmented iterator optimization for std::for_each to C++11 (#134960)
Previously, the segmented iterator optimization for `std::for_each` was restricted to C++23 and later due to its dependency on `__movable_box`, which is not available in earlier standards. This patch eliminates that restriction, enabling consistent optimizations starting from C++11. 

By backporting this enhancement, we improve performance across older standards and create opportunities to extend similar optimizations to other algorithms by forwarding their calls to `std::for_each`.
2025-04-19 07:12:43 -04:00
Peng Liu
9e3982d9ae
[libc++] Replace __libcpp_{ctz, clz} with __builtin_{ctzg, clzg} (#133920)
`__libcpp_{ctz, clz}` were previously used as fallbacks for `__builtin_{ctzg, clzg}` to ensure compatibility with older compilers (Clang 18 and earlier), as `__builtin_{ctzg, clzg}` became available in Clang 19. Now that support for Clang 18 has been officially dropped in #130142, we can now safely  replace all instances of `__libcpp_{ctz, clz}` with `__count{l,r}_zero` (which internally call `__builtin_{ctzg, clzg}` and eliminate the fallback logic.

Closes #131179.
2025-04-18 20:57:05 -04:00
Дмитрий Изволов
51b8c66b08
[libc++] Extend the scope of radix sorting inside std::stable_sort to floating-point types (#129452)
These changes speed up `std::stable_sort` in the case of sorting
floating-point types.
This applies only to IEEE 754 floats.
The speedup is similar to that achieved for integers in PR #104683 (see
benchmarks below).

Why does this worth doing?
Previously, `std::stable_sort` had almost no chance of beating
`std::sort`.
Now there are cases when `std::stable_sort` is preferrable, and the
difference is significant.
```
---------------------------------------------------------------------------
Benchmark             |  std::stable_sort  |   std::sort | std::stable_sort
                      | without radix_sort |             | with radix_sort 
---------------------------------------------------------------------------
float_Random_1        |       1.62 ns      |     2.15 ns |          1.61 ns
float_Random_4        |       18.0 ns      |     2.71 ns |          16.3 ns
float_Random_16       |        118 ns      |      113 ns |           112 ns
float_Random_64       |        751 ns      |      647 ns |           730 ns
float_Random_256      |       4715 ns      |     2937 ns |          4669 ns
float_Random_1024     |      25713 ns      |    13172 ns |          5959 ns <--
float_Random_4096     |     131307 ns      |    56870 ns |         19294 ns <--
float_Random_16384    |     624996 ns      |   242953 ns |         64264 ns <--
float_Random_65536    |    2895661 ns      |  1027279 ns |        288553 ns <--
float_Random_262144   |   13285372 ns      |  4342593 ns |       3022377 ns <--
float_Random_1048576  |   60595871 ns      | 19087591 ns |      18690457 ns <--
float_Random_2097152  |  131336117 ns      | 38800396 ns |      52325016 ns
float_Random_4194304  |  270043042 ns      | 79978019 ns |     102907726 ns
double_Random_1       |       1.60 ns      |     2.15 ns |          1.61 ns
double_Random_4       |       15.2 ns      |     2.70 ns |          16.9 ns
double_Random_16      |        104 ns      |      112 ns |           119 ns
double_Random_64      |        712 ns      |      614 ns |           755 ns
double_Random_256     |       4496 ns      |     2966 ns |          4820 ns
double_Random_1024    |      24722 ns      |    12679 ns |          6189 ns <--
double_Random_4096    |     126075 ns      |    54484 ns |         20999 ns <--
double_Random_16384   |     613782 ns      |   232557 ns |        110276 ns <--
double_Random_65536   |    2894972 ns      |   988531 ns |        774302 ns <--
double_Random_262144  |   13460273 ns      |  4278059 ns |       5115123 ns
double_Random_1048576 |   61119996 ns      | 18408462 ns |      27166574 ns
double_Random_2097152 |  132511525 ns      | 37986158 ns |      54423869 ns
double_Random_4194304 |  272949862 ns      | 77912616 ns |     147670834 ns
```

Comparison for only `std::stable_sort`:
```
Benchmark                                                         Time      Time Old      Time New
--------------------------------------------------------------------------------------------------
BM_StableSort_float_Random_1024                                -0.7997         25438          5096
BM_StableSort_float_Random_4096                                -0.8731        128157         16260
BM_StableSort_float_Random_16384                               -0.9024        621271         60623
BM_StableSort_float_Random_65536                               -0.9081       2922413        268619
BM_StableSort_float_Random_262144                              -0.7766      13386345       2990408
BM_StableSort_float_Random_1048576                             -0.6954      60673010      18481751
BM_StableSort_float_Random_2097152                             -0.6026     130977358      52052182
BM_StableSort_float_Random_4194304                             -0.6252     271556583     101770500
BM_StableSort_float_Ascending_1024                             -0.6430          6711          2396
BM_StableSort_float_Ascending_4096                             -0.7979         38460          7773
BM_StableSort_float_Ascending_16384                            -0.8471        191069         29222
BM_StableSort_float_Ascending_65536                            -0.8683        882321        116194
BM_StableSort_float_Ascending_262144                           -0.8346       3868552        639937
BM_StableSort_float_Ascending_1048576                          -0.7460      16521233       4195953
BM_StableSort_float_Ascending_2097152                          -0.5439      21757532       9922776
BM_StableSort_float_Ascending_4194304                          -0.7525      67847496      16791582
BM_StableSort_float_Descending_1024                            -0.6359         15038          5475
BM_StableSort_float_Descending_4096                            -0.7090         62810         18278
BM_StableSort_float_Descending_16384                           -0.7763        311844         69750
BM_StableSort_float_Descending_65536                           -0.7228       1270513        352202
BM_StableSort_float_Descending_262144                          -0.6785       5484173       1763045
BM_StableSort_float_Descending_1048576                         -0.5084      20223149       9941852
BM_StableSort_float_Descending_2097152                         -0.7646      60523254      14247014
BM_StableSort_float_Descending_4194304                         -0.5638      95706839      41748858
BM_StableSort_float_SingleElement_1024                         +0.3715          1732          2375
BM_StableSort_float_SingleElement_4096                         -0.1685          9357          7781
BM_StableSort_float_SingleElement_16384                        -0.3793         47307         29362
BM_StableSort_float_SingleElement_65536                        -0.4925        227666        115536
BM_StableSort_float_SingleElement_262144                       -0.4271       1075853        616387
BM_StableSort_float_SingleElement_1048576                      -0.3736       5097599       3193279
BM_StableSort_float_SingleElement_2097152                      -0.2470       9854161       7420158
BM_StableSort_float_SingleElement_4194304                      -0.3384      22175964      14670720
BM_StableSort_float_PipeOrgan_1024                             -0.4885         10664          5455
BM_StableSort_float_PipeOrgan_4096                             -0.6340         50095         18337
BM_StableSort_float_PipeOrgan_16384                            -0.7078        238700         69739
BM_StableSort_float_PipeOrgan_65536                            -0.6740       1102419        359378
BM_StableSort_float_PipeOrgan_262144                           -0.7460       4698739       1193511
BM_StableSort_float_PipeOrgan_1048576                          -0.5657      18493972       8032392
BM_StableSort_float_PipeOrgan_2097152                          -0.7116      41089206      11850349
BM_StableSort_float_PipeOrgan_4194304                          -0.6650      83445011      27955737
BM_StableSort_float_QuickSortAdversary_1024                    -0.6863         17402          5460
BM_StableSort_float_QuickSortAdversary_4096                    -0.7715         79864         18247
BM_StableSort_float_QuickSortAdversary_16384                   -0.7800        317480         69839
BM_StableSort_float_QuickSortAdversary_65536                   -0.7400       1357601        352967
BM_StableSort_float_QuickSortAdversary_262144                  -0.6450       5662094       2009769
BM_StableSort_float_QuickSortAdversary_1048576                 -0.5092      21173627      10392107
BM_StableSort_float_QuickSortAdversary_2097152                 -0.7333      61748178      16469993
BM_StableSort_float_QuickSortAdversary_4194304                 -0.5607      98459863      43250182
BM_StableSort_double_Random_1024                               -0.7657         24769          5802
BM_StableSort_double_Random_4096                               -0.8441        126449         19717
BM_StableSort_double_Random_16384                              -0.8269        614910        106447
BM_StableSort_double_Random_65536                              -0.7413       2905000        751427
BM_StableSort_double_Random_262144                             -0.6287      13449514       4994348
BM_StableSort_double_Random_1048576                            -0.5635      60863246      26568349
BM_StableSort_double_Random_2097152                            -0.5959     130293892      52654532
BM_StableSort_double_Random_4194304                            -0.4772     272616445     142526267
BM_StableSort_double_Ascending_1024                            -0.4870          6757          3466
BM_StableSort_double_Ascending_4096                            -0.7360         37592          9923
BM_StableSort_double_Ascending_16384                           -0.7971        183967         37324
BM_StableSort_double_Ascending_65536                           -0.7465        897116        227398
BM_StableSort_double_Ascending_262144                          -0.6764       4020980       1301033
BM_StableSort_double_Ascending_1048576                         -0.6407      16421799       5900751
BM_StableSort_double_Ascending_2097152                         -0.6380      29347139      10622419
BM_StableSort_double_Ascending_4194304                         -0.5934      70439925      28644185
BM_StableSort_double_Descending_1024                           -0.5988         15216          6105
BM_StableSort_double_Descending_4096                           -0.6857         65069         20449
BM_StableSort_double_Descending_16384                          -0.6922        329321        101381
BM_StableSort_double_Descending_65536                          -0.7038       1367970        405242
BM_StableSort_double_Descending_262144                         -0.6472       5361644       1891429
BM_StableSort_double_Descending_1048576                        -0.6656      22031404       7366459
BM_StableSort_double_Descending_2097152                        -0.7593      68922467      16591242
BM_StableSort_double_Descending_4194304                        -0.6392      96283643      34743223
BM_StableSort_double_SingleElement_1024                        +0.9128          1895          3625
BM_StableSort_double_SingleElement_4096                        +0.1475         10013         11490
BM_StableSort_double_SingleElement_16384                       -0.1901         52382         42424
BM_StableSort_double_SingleElement_65536                       -0.2096        254698        201313
BM_StableSort_double_SingleElement_262144                      -0.1833       1248478       1019648
BM_StableSort_double_SingleElement_1048576                     -0.1741       5703397       4710603
BM_StableSort_double_SingleElement_2097152                     -0.1751      10922197       9009835
BM_StableSort_double_SingleElement_4194304                     -0.1538      26571923      22485137
BM_StableSort_double_PipeOrgan_1024                            -0.4406         10752          6014
BM_StableSort_double_PipeOrgan_4096                            -0.5917         49456         20195
BM_StableSort_double_PipeOrgan_16384                           -0.6258        270515        101221
BM_StableSort_double_PipeOrgan_65536                           -0.7098       1159462        336457
BM_StableSort_double_PipeOrgan_262144                          -0.6591       4735711       1614433
BM_StableSort_double_PipeOrgan_1048576                         -0.6620      19353110       6541172
BM_StableSort_double_PipeOrgan_2097152                         -0.7288      49131812      13323391
BM_StableSort_double_PipeOrgan_4194304                         -0.5988      81958974      32878171
BM_StableSort_double_QuickSortAdversary_1024                   -0.6516         17948          6254
BM_StableSort_double_QuickSortAdversary_4096                   -0.7527         82359         20363
BM_StableSort_double_QuickSortAdversary_16384                  -0.7009        340410        101811
BM_StableSort_double_QuickSortAdversary_65536                  -0.6854       1487480        467928
BM_StableSort_double_QuickSortAdversary_262144                 -0.6386       5648460       2041377
BM_StableSort_double_QuickSortAdversary_1048576                -0.6127      22859142       8852587
BM_StableSort_double_QuickSortAdversary_2097152                -0.7161      68693975      19499381
BM_StableSort_double_QuickSortAdversary_4194304                -0.5909      95532179      39077491
OVERALL_GEOMEAN                                                -0.6472             0             0
```
2025-04-16 17:34:11 +08:00
A. Jiang
cfa322fa9a
[libc++][NFC] Reuse __bit_log2 for sort (#135303)
The `__log2i` function template in `<algorithm/sort.h>` is basically
equivalent to `__bit_log2` in `<__bit/bit_log2.h>`. It seems better to
avoid duplication.
2025-04-13 09:45:18 +08:00
James E T Smith
475cbf0ad6
[libc++] Implement ranges::iota (#68494)
# Overview

As a disclaimer, this is my first PR to LLVM and while I've tried to
ensure I've followed the LLVM and libc++ contributing guidelines,
there's probably a good chance I missed something. If I have, just let
me know and I'll try to correct it as soon as I can.

This PR implements `std::ranges::iota` and
`std::ranges::out_value_result` outlined in
[P2440r1](https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2021/p2440r1.html).

As outlined in the paper above, I've:
- Implemented `out_value_result` and added to `<algorithm>`
- Added `out_value_result`, `iota_result`, and two overloads of `iota`
to `std::ranges` in `<numeric>`
- Updated the version macro `__cpp_lib_ranges_iota` in `<version>`

I've also added tests for `ranges::iota` and `ranges::out_value_result`.
Lastly, I added those structs to the appropriate module files.

Partially implements #105184

EDIT: Forgot to mention in the original post, thanks to @hawkinsw for
taking a look at a preliminary version of this PR!

# TODOs
- [x] Updating the range [status
doc](https://github.com/jamesETsmith/llvm-project/blob/main/libcxx/docs/Status/RangesMajorFeatures.csv)
- [x] Ensure all comments from https://reviews.llvm.org/D121436 are
addressed here
- [X] EDIT (I'll do this in a separate PR). ~~I'm open to implementing
the rest of P2440r1 (`ranges::shift_left` and `ranges::shift_right`) if
that's ok, I just wanted to get feedback on `ranges::iota` first~~
- [x] I've been having trouble building the modules locally and want to
make sure that's working properly

Closes: #134060
2025-04-05 13:46:11 +02:00
Peng Liu
8fdfe3f2a7
[libc++] Refactor ranges::{min, max, min_element, max_element} to use std::__min_element (#132418)
Previously, ranges::min_element delegated to ranges::__min_element_impl, which
duplicated the definition of std::__min_element. This patch updates
ranges::min_element to directly call std::__min_element, which allows
removing the redundant code in ranges::__min_element_impl.

Upon removal of ranges::__min_element_impl, the other ranges algorithms
ranges::{min,max,max_element}, which previously delegated to ranges::__min_element_impl,
have been updated to call std::__min_element instead.

This refactoring unifies the implementation across these algorithms,
ensuring that future optimizations or maintenance work only need to be
applied in one place.
2025-03-27 09:05:37 -04:00
Louis Dionne
b0668d859b
[libc++] Make sure that __desugars_to isn't tripped up by reference_wrapper, const and ref qualifiers (#132092)
Previously, const and ref qualification on an operation would cause
__desugars_to to report false, which would lead to unnecessary
pessimizations. The same holds for reference_wrapper.

In practice, const and ref qualifications on the operation itself are
not relevant to determining whether an operation desugars to something
else or not, so can be ignored.

We are not stripping volatile qualifiers from operations in this patch
because we feel that this requires additional discussion.

Fixes #129312
2025-03-25 14:29:06 -04:00
Louis Dionne
aa80388cf9
[libc++] Ensure that we vectorize algorithms on all Clang-based compilers (#132090)
Otherwise, we wouldn't vectorize on compilers like AppleClang when in
reality we know perfectly well how to do it.
2025-03-24 13:22:40 -04:00
Nikolas Klauser
fb44f00641
[libc++] Add [[gnu::nodebug]] on type traits (#128502) 2025-03-23 21:01:25 +01:00
A. Jiang
053a714add
[libc++] Implement part of P2562R1: constexpr ranges::inplace_merge (#131947)
Drive-by changes:
- Consistently mark `std::__inplace_merge::__inplace_merge_impl`
`_LIBCPP_CONSTEXPR_SINCE_CXX26`.
- This function template is only called by other functions that becomes
constexpr since C++26, and it itself calls `std::__inplace_merge` that
is constexpr since C++26.
- Unblock related test coverage in constant evaluation for
`stable_partition`, `ranges::stable_sort`, `std::stable_sort`,
`std::stable_partition`, and `std::inplace_merge`.
2025-03-20 01:59:32 +08:00
Peng Liu
029cb8aff1
[libc++] Fix copy_backward for vector<bool> with small storage types (#131560)
This patch fixes an issue in libc++ where `std::copy_backward` and
`ranges::copy_backward` incorrectly copy `std::vector<bool>` with small
storage types (e.g., `uint8_t`, `uint16_t`). The problem arises from
flawed bit mask computations involving integral promotions and sign-bit
extension, leading to unintended zeroing of bits. This patch corrects
the bitwise operations to ensure correct bit-level copying.

Fixes #131718.
2025-03-19 11:58:02 -04:00
Peng Liu
a5b3d3a03f
[libc++] Fix {std, ranges}::copy for vector<bool> with small storage types (#131545)
The current implementation of `{std, ranges}::copy` fails to copy
`vector<bool>` correctly when the underlying storage type
(`__storage_type`) is smaller than `int`, such as `unsigned char`,
`unsigned short`, `uint8_t` and `uint16_t`. The root cause is that the
unsigned small storage type undergoes integer promotion to (signed)
`int`, which is then left and right shifted, leading to UB (before
C++20) and sign-bit extension (since C++20) respectively. As a result,
the underlying bit mask evaluations become incorrect, causing erroneous
copying behavior.

This patch resolves the issue by correcting the internal bitwise
operations, ensuring that `{std, ranges}::copy` operates correctly for
`vector<bool>` with any custom (unsigned) storage types.

Fixes #131692.
2025-03-19 11:55:51 -04:00
Peng Liu
c5195ae2d0
[libc++] Fix {std, ranges}::equal for vector<bool> with small storage types (#130394)
The current implementation of `{std, ranges}::equal` fails to correctly
compare `vector<bool>`s when the underlying storage type is smaller than
`int` (e.g., `unsigned char`, `unsigned short`, `uint8_t` and
`uint16_t`). See [demo](https://godbolt.org/z/j4s87s6b3)). The problem
arises due to integral promotions on the intermediate bitwise
operations, leading to incorrect final equality comparison results. This
patch fixes the issue by ensuring that `{std, ranges}::equal` operate
properly for both aligned and unaligned bits.
 
Fixes #126369.
2025-03-19 11:51:21 -04:00
Peng Liu
e53bea5182
[libc++] Fix ambiguous call in {ranges, std}::count (#122529)
This PR fixes an ambiguous call encountered while using the
`std::ranges::count` and `std::count` algorithms with `vector<bool>`
with small `size_type`s.

The ambiguity arises from integral promotions during the internal
bitwise arithmetic of the `count` algorithms for small integral types.
This results in multiple viable candidates:
`__libcpp_popcount(unsigned)`,` __libcpp_popcount(unsigned long)`, and
`__libcpp_popcount(unsigned long long)`, leading to an ambiguous call
error. To resolve this ambiguity, we introduce a dispatcher function,
`__popcount`, which directs calls to the appropriate overloads of
`__libcpp_popcount`. This closes #122528.
2025-03-19 11:36:29 -04:00
A. Jiang
854a4f2bbb
[libc++] Implement part of P2562R1: constexpr std::inplace_merge (#129008)
Drive-by:
- Adds `constexpr_random.h` for pseudo-randomizing or shuffling in tests
for constant evaluation.
2025-03-19 07:42:23 +08:00
Peng Liu
3bd71cbec7
[libc++] Fix ambiguous call in {ranges, std}::find (#122641)
This PR fixes an ambiguous call encountered when using the `std::ranges::find` or `std::find`
algorithms with `vector<bool>` with small `allocator_traits::size_type`s, an issue reported
in #122528. The ambiguity arises from integral promotions during the internal bitwise
arithmetic of the `find` algorithms when applied to `vector<bool>` with small integral
`size_type`s. This leads to multiple viable candidates for small integral types:
__libcpp_ctz(unsigned), __libcpp_ctz(unsigned long), and __libcpp_ctz(unsigned long long),
none of which represent a single best viable match, resulting in an ambiguous call error.

To resolve this, we propose invoking an internal function __countr_zero as a dispatcher
that directs the call to the appropriate overload of __libcpp_ctz. Necessary amendments
have also been made to __countr_zero.
2025-03-13 14:15:03 -04:00
Peng Liu
4baf1c03fa
[libc++] Optimize ranges::rotate for vector<bool>::iterator (#121168)
This PR optimizes the performance of `std::ranges::rotate` for
`vector<bool>::iterator`. The optimization yields a performance
improvement of up to 2096x.

Closes #64038.
2025-03-13 14:07:23 -04:00
A. Jiang
ba9aeedf8e
[libc++] Implement part of P2562R1: constexpr ranges::stable_sort (#128860)
Drive-by: Enables test coverage for `ranges::stable_sort` with proxy
iterators, and changes "constexpr in" to "constexpr since" in comments
in `<algorithm>`.
2025-03-07 01:27:48 +08:00
A. Jiang
c28c508962
[libc++] Implement part of P2562R1: constexpr ranges::stable_partition (#129839) 2025-03-06 09:23:55 +08:00
Peng Liu
a12744ff05
[libc++] Optimize ranges::swap_ranges for vector<bool>::iterator (#121150)
This PR optimizes the performance of `std::ranges::swap_ranges` for
`vector<bool>::iterator`, addressing a subtask outlined in issue #64038.
The optimizations yield performance improvements of up to **611x** for
aligned range swap and **78x** for unaligned range swap comparison.
Additionally, comprehensive tests covering up to 4 storage words (256
bytes) with odd and even bit sizes are provided, which validate the
proposed optimizations in this patch.
2025-03-04 17:15:36 -05:00
A. Jiang
bf9bf291a3
[libc++] Implement part of P2562R1: constexpr std::stable_partition (#128868)
Drive-by changes:
- Enables no-memory case for Clang.
- Enables `robust_re_difference_type.compile.pass.cpp` and
`robust_against_proxy_iterators_lifetime_bugs.pass.cpp` test coverage
for `std::stable_sort` in constant evaluation since C++26. The changes
were missing in the PR making `std::stable_sort` `constexpr`.
2025-03-04 09:23:29 +08:00
Nikolas Klauser
1a6f9fd87f
[libc++] Enable algorithm vectorization on arm neon (#128873)
Previously the wrong detection macro has been used to check whether arm
NEON is available. This fixes it, and removes a few unnecessary includes
from `__algorithm/simd_utils.h` as a drive-by.
2025-02-28 13:38:52 +01:00
Peng Liu
7717a549e9
[libc++] Optimize ranges::equal for vector<bool>::iterator (#121084)
This PR optimizes the performance of `std::ranges::equal` for
`vector<bool>::iterator`, addressing a subtask outlined in issue #64038.
The optimizations yield performance improvements of up to 188x for
aligned equality comparison and 82x for unaligned equality
comparison. Moreover, comprehensive tests covering up to 4 storage words
(256 bytes) with odd and even bit sizes are provided, which validate the
proposed optimizations in this patch.
2025-02-26 12:18:25 -05:00
Louis Dionne
5e26fb1699
[libc++] Qualify calls to nullary functions like __throw_foo (#122465)
This is technically not necessary in most cases to prevent issues with ADL,
but let's be consistent. This allows us to remove the libcpp-qualify-declval
clang-tidy check, which is now enforced by the robust-against-adl clang-tidy check.
2025-02-21 07:59:46 -05:00
Peng Liu
ab3d793982
[libc++] Optimize ranges::move{,_backward} for vector<bool>::iterator (#121109)
As a follow-up to #121013 (which optimized `ranges::copy`) and #121026
(which optimized `ranges::copy_backward`), this PR enhances the
performance of `std::ranges::{move, move_backward}` for
`vector<bool>::iterator`, addressing a subtask outlined in issue #64038.

The optimizations bring performance improvements analogous to those
achieved for the `{copy, copy_backward}` algorithms: up to 2000x for
aligned moves and 60x for unaligned moves. Moreover, comprehensive
tests covering up to 4 storage words (256 bytes) with odd and even bit
sizes are provided, which validate the proposed optimizations in this
patch.
2025-02-19 11:36:45 -05:00
Дмитрий Изволов
6e402f5121
[libc++] Support constexpr for std::stable_sort in radix sort branch (#125284)
`std::stable_sort` is `constexpr` since PR
https://github.com/llvm/llvm-project/pull/110320
But `radix_sort` branch is still non-`constexpr`.
This PR fixes it.

#119394
#105360
2025-02-06 09:07:25 +01:00
Peng Liu
cf9806eb4d
[libc++] Fix UB in bitwise logic of {std, ranges}::{fill, fill_n} algorithms (#122410)
This PR addresses an undefined behavior that arises when using the
`std::fill` and `std::fill_n` algorithms, as well as their ranges
counterparts `ranges::fill` and `ranges::fill_n`, with `vector<bool, Alloc>`
that utilizes a custom-sized allocator with small integral types.
2025-02-05 11:39:49 -05:00