Followup to c3d1dac96bdd10250aa37bb367d5ef8334a093a1. As pointed out by
Maciej W. Rozycki, the casts are obviously useless now.

Reviewed-by: H.J. Lu <hjl.tools@gmail.com>

Similar to a9944a52c967ce76a5894c30d0274b824df43c7a and
f9493a15ea9cfb63a815c00c23142369ec09d8ce, we need to hide calloc use from
the compiler to accommodate GCC's r15-6566-g804e9d55d9e54c change.

First, include tst-malloc-aux.h, but then use `volatile` variables
for size.

The test passes without the tst-malloc-aux.h change but IMO we want
it there for consistency and to avoid future problems (possibly silent).

Reviewed-by: H.J. Lu <hjl.tools@gmail.com>

I've updated copyright dates in glibc for 2025.  This is the patch for
the changes not generated by scripts/update-copyrights and subsequent
build / regeneration of generated files.

Add __attribute_optimization_barrier__ to disable inlining and cloning on a
function.  For Clang, expand it to

__attribute__ ((optnone))

Otherwise, expand it to

__attribute__ ((noinline, clone))

Co-Authored-By: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Sam James <sam@gentoo.org>

Reviewed-by: Sam James <sam@gentoo.org>

Since -1 isn't a power of two, compiler may reject it, hide memalign from
Clang 19 which issues an error:

tst-memalign.c:86:31: error: requested alignment is not a power of 2 [-Werror,-Wnon-power-of-two-alignment]
   86 |   p = memalign (-1, pagesize);
      |                 ^~
tst-memalign.c:86:31: error: requested alignment must be 4294967296 bytes or smaller; maximum alignment assumed [-Werror,-Wbuiltin-assume-aligned-alignment]
   86 |   p = memalign (-1, pagesize);
      |                 ^~

Update tst-malloc-aux.h to hide all malloc functions and include it in
all malloc tests to prevent compiler from optimizing out any malloc
functions.

Tested with Clang 19.1.5 and GCC 15 20241206 for BZ #32366.

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Sam James <sam@gentoo.org>

This commit add tcache support in calloc() which can largely improve
the performance of small size allocation, especially in multi-thread
scenario. tcache_available() and tcache_try_malloc() are split out as
a helper function for better reusing the code.

Also fix tst-safe-linking failure after enabling tcache. In previous,
calloc() is used as a way to by-pass tcache in memory allocation and
trigger safe-linking check in fastbins path. With tcache enabled, it
needs extra workarounds to bypass tcache.

Result of bench-calloc-thread benchmark

Test Platform: Xeon-8380
Ratio: New / Original time_per_iteration (Lower is Better)

Threads#   | Ratio
-----------|------
1 thread   | 0.656
4 threads  | 0.470
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>

GCC 15 introduces allocation dead code removal (DCE) for PR117370 in
r15-5255-g7828dc070510f8. This breaks various glibc tests which want
to assert various properties of the allocator without doing anything
obviously useful with the allocated memory.

Alexander Monakov rightly pointed out that we can and should do better
than passing -fno-malloc-dce to paper over the problem. Not least because
GCC 14 already does such DCE where there's no testing of malloc's return
value against NULL, and LLVM has such optimisations too.

Handle this by providing malloc (and friends) wrappers with a volatile
function pointer to obscure that we're calling malloc (et. al) from the
compiler.

Reviewed-by: Paul Eggert <eggert@cs.ucla.edu>

Add calloc-clear-memory.h to clear memory size up to 36 bytes (72 bytes
on 64-bit targets) for calloc.  Use repeated stores with 1 branch, instead
of up to 3 branches.  On x86-64, it is faster than memset since calling
memset needs 1 indirect branch, 1 broadcast, and up to 4 branches.

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Wilco Dijkstra  <Wilco.Dijkstra@arm.com>