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Andrew Burgess 5a22e042e4 gdb: fix libstdc++ assert caused by invalid use of std::clamp
After this commit:

  commit 33ae45434d
  Date:   Mon Dec 4 14:23:17 2023 +0000

      gdb: Enable early init of thread pool size

I am now seeing this assert from libstdc++:

  /usr/include/c++/9/bits/stl_algo.h:3715: constexpr const _Tp& std::clamp(const _Tp&, const _Tp&, const _Tp&) [with _Tp = int]: Assertion '!(__hi < __lo)' failed.

This may only be visible because I compile with:

  -D_GLIBCXX_DEBUG=1 -D_GLIBCXX_DEBUG_PEDANTIC=1

but I haven't checked.  The issue the assert is highlighting is real,
and is caused by this block of code:

  if (n_threads < 0)
    {
      const int hardware_threads = std:🧵:hardware_concurrency ();
      /* Testing in #29959 indicates that parallel efficiency drops between
         n_threads=5 to 8.  Therefore, clamp the default value to 8 to avoid an
         excessive number of threads in the pool on many-core systems.  */
      const int throttle = 8;
      n_threads = std::clamp (hardware_threads, hardware_threads, throttle);
    }

The arguments to std::clamp are VALUE, LOW, HIGH, but in the above, if
we have more than 8 hardware threads available the LOW will be greater
than the HIGH, which is triggering the assert I see above.

I believe std::clamp is the wrong tool to use here.  Instead std::min
would be a better choice; we want the smaller value of
HARDWARE_THREADS or THROTTLE.  If h/w threads is 2, then we want 2,
but if h/w threads is 16 we want 8, this is what std::min gives us.

After this commit, I no longer see the assert.
2023-12-06 11:25:00 +00:00
bfd Automatic date update in version.in 2023-12-06 00:00:14 +00:00
binutils PR31096, nm shows 32bit addresses as 64bit addresses 2023-12-06 12:23:05 +10:30
config libiberty: Disable hwcaps for sha1.o 2023-11-30 10:14:30 +01:00
contrib Import mklog.py from gcc repo 2020-09-25 10:24:44 -04:00
cpu sim --enable-cgen-maint 2023-08-19 12:41:32 +09:30
elfcpp MIPS: Change all E_MIPS_* to EF_MIPS_* 2023-11-10 14:03:17 +00:00
etc Update year range in gprofng copyright notices 2023-01-01 23:26:30 +10:30
gas gas: drop unused fields from struct segment_info_struct 2023-12-01 08:29:33 +01:00
gdb gdb: fix libstdc++ assert caused by invalid use of std::clamp 2023-12-06 11:25:00 +00:00
gdbserver Update fall-through comment in gdbserver 2023-12-04 08:23:34 -07:00
gdbsupport gdb: Enable early init of thread pool size 2023-12-04 14:23:17 +00:00
gnulib gnulib: mark configure +x 2023-11-28 12:55:29 -05:00
gold Gold/MIPS: Add targ_extra_size=64 for mips32 triples 2023-11-17 14:33:33 +00:00
gprof Finalized intl-update patches 2023-11-15 12:53:04 +00:00
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include Add basic support for RISC-V 64-bit EFI objects 2023-12-05 13:20:27 +01:00
ld aarch64-elf: FAIL: indirect call stub to BTI stub relaxation 2023-12-05 13:00:34 +10:30
libbacktrace regen config 2023-08-12 10:27:57 +09:30
libctf libctf: adding CU mappings should be idempotent 2023-11-20 12:31:41 +00:00
libdecnumber regen config 2023-08-12 10:27:57 +09:30
libiberty libiberty: Fix build with GCC < 7 2023-12-05 23:34:01 +01:00
libsframe regen config 2023-08-12 10:27:57 +09:30
opcodes s390: Support for jump visualization in disassembly 2023-12-04 17:13:33 +00:00
readline [readline] Fix double free in _rl_scxt_dispose 2023-05-28 10:17:57 +02:00
sim sim: warnings: sync some build logic from gdbsupport 2023-12-05 23:12:16 -07:00
texinfo
zlib regen config 2023-08-12 10:27:57 +09:30
.cvsignore
.editorconfig Add top-level .editorconfig file 2022-01-28 08:25:42 -05:00
.gitattributes binutils-gdb/git: highlight whitespace errors in source files 2022-07-25 14:35:41 +01:00
.gitignore Finalized intl-update patches 2023-11-15 12:53:04 +00:00
ar-lib
ChangeLog Finalized intl-update patches 2023-11-15 12:53:04 +00:00
compile
config-ml.in MSP430: Add -fno-exceptions multilib 2023-08-12 10:24:26 +09:30
config.guess kvx: New port. 2023-08-16 14:22:54 +01:00
config.rpath
config.sub kvx: New port. 2023-08-16 14:22:54 +01:00
configure Finalized intl-update patches 2023-11-15 12:53:04 +00:00
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COPYING
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libtool.m4 FDPIC: Handle arm*-*-uclinuxfdpiceabi in configure scripts 2023-08-12 10:25:06 +09:30
lt~obsolete.m4
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ltmain.sh Do not use HAVE_DOS_BASED_FILE_SYSTEM for Cygwin. 2023-08-12 10:25:06 +09:30
ltoptions.m4
ltsugar.m4
ltversion.m4
MAINTAINERS MAINTAINERS: Update path to readline config.{sub,guess} files 2021-05-24 18:11:49 +02:00
Makefile.def Finalized intl-update patches 2023-11-15 12:53:04 +00:00
Makefile.in Finalized intl-update patches 2023-11-15 12:53:04 +00:00
Makefile.tpl toplevel: Substitute GDCFLAGS instead of using CFLAGS 2023-08-12 10:27:44 +09:30
makefile.vms
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README-maintainer-mode Note that at least dejagnu version 1.5.3 is required in order to be ale to run the testsuites. 2022-10-04 10:54:19 +01:00
SECURITY.txt Add a SECURITY.txt file describing the GNU Binutils' project's stance on security related bugs. 2023-04-20 16:52:11 +01:00
setup.com
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symlink-tree
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