From: Jonathan Wakely <jwakely@redhat.com>
To: libstdc++@gcc.gnu.org, gcc-patches@gcc.gnu.org
Cc: Thomas Rodgers <trodgers@redhat.com>
Subject: [committed] libstdc++: Avoid use of hardware interference non-constant [PR102377]
Date: Thu, 7 Oct 2021 18:39:51 +0100 [thread overview]
Message-ID: <YV8w53DbsfRL3SRK@redhat.com> (raw)
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libstdc++-v3/ChangeLog:
PR libstdc++/102377
* include/bits/atomic_wait.h (__waiter_pool_base:_S_align):
Hardcode to 64 instead of using non-constant constant.
Tested x86_64-linux. Committed to trunk.
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commit 0e90799071ee78f712f3b58fca7000bc0a258ade
Author: Jonathan Wakely <jwakely@redhat.com>
Date: Thu Oct 7 18:28:04 2021
libstdc++: Avoid use of hardware interference non-constant [PR102377]
libstdc++-v3/ChangeLog:
PR libstdc++/102377
* include/bits/atomic_wait.h (__waiter_pool_base:_S_align):
Hardcode to 64 instead of using non-constant constant.
diff --git a/libstdc++-v3/include/bits/atomic_wait.h b/libstdc++-v3/include/bits/atomic_wait.h
index 35c92644146..2ac07ccd05e 100644
--- a/libstdc++-v3/include/bits/atomic_wait.h
+++ b/libstdc++-v3/include/bits/atomic_wait.h
@@ -190,11 +190,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
struct __waiter_pool_base
{
-#ifdef __cpp_lib_hardware_interference_size
- static constexpr auto _S_align = hardware_destructive_interference_size;
-#else
- static constexpr auto _S_align = 64;
-#endif
+ // Don't use std::hardware_destructive_interference_size here because we
+ // don't want the layout of library types to depend on compiler options.
+ static constexpr auto _S_align = 64;
alignas(_S_align) __platform_wait_t _M_wait = 0;
reply other threads:[~2021-10-07 18:00 UTC|newest]
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