AuroraMiddleware/qt5base-lts
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Avoid calling memmove() if it's a noop

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This speeds up some of the operations.

Change-Id: I5195ba79df92ead8e8003aa82681703e8c3afe99
Reviewed-by: Andrei Golubev <andrei.golubev@qt.io>
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
This commit is contained in:
Lars Knoll 2020-11-04 14:08:41 +01:00 committed by Andrei Golubev
parent b3a5ad40a7
commit 9ede51d214
1 changed files with 25 additions and 20 deletions
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45
src/corelib/tools/qarraydataops.h
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@ -187,8 +187,9 @@ struct QArrayExceptionSafetyPrimitives
Displacer(T *start, T *finish, qsizetype diff) noexcept
: begin(start), end(finish), displace(diff)
{
::memmove(static_cast<void *>(begin + displace), static_cast<void *>(begin),
(end - begin) * sizeof(T));
if (displace)
::memmove(static_cast<void *>(begin + displace), static_cast<void *>(begin),
(end - begin) * sizeof(T));
}
void commit() noexcept { displace = 0; }
~Displacer() noexcept
@ -216,8 +217,9 @@ struct QArrayExceptionSafetyPrimitives
{ }
~Mover() noexcept
{
::memmove(static_cast<void *>(destination), static_cast<const void *>(source),
n * sizeof(T));
if (destination != source)
::memmove(static_cast<void *>(destination), static_cast<const void *>(source),
n * sizeof(T));
size -= source > destination ? source - destination : destination - source;
}
};
@ -292,8 +294,9 @@ public:
Q_ASSERT(e <= where || b > this->end() || where == this->end()); // No overlap or append
Q_ASSERT((e - b) <= this->freeSpaceAtEnd());
::memmove(static_cast<void *>(where + (e - b)), static_cast<void *>(where),
(static_cast<const T*>(this->end()) - where) * sizeof(T));
if (where != this->end())
::memmove(static_cast<void *>(where + (e - b)), static_cast<void *>(where),
(static_cast<const T*>(this->end()) - where) * sizeof(T));
::memcpy(static_cast<void *>(where), static_cast<const void *>(b), (e - b) * sizeof(T));
this->size += (e - b);
}
@ -307,10 +310,11 @@ public:
Q_ASSERT(e <= where || b > this->end() || where == this->end()); // No overlap or append
Q_ASSERT((e - b) <= this->freeSpaceAtBegin());
auto oldBegin = this->begin();
const T *oldBegin = this->begin();
this->ptr -= (e - b);
::memmove(static_cast<void *>(this->begin()), static_cast<void *>(oldBegin),
(where - static_cast<const T*>(oldBegin)) * sizeof(T));
if (where != oldBegin)
::memmove(static_cast<void *>(this->begin()), static_cast<const void *>(oldBegin),
(where - oldBegin) * sizeof(T));
::memcpy(static_cast<void *>(where - (e - b)), static_cast<const void *>(b),
(e - b) * sizeof(T));
this->size += (e - b);
@ -326,8 +330,9 @@ public:
Q_ASSERT(where >= this->begin() && where <= this->end());
Q_ASSERT(size_t(this->freeSpaceAtEnd()) >= n);
::memmove(static_cast<void *>(where + n), static_cast<void *>(where),
(static_cast<const T*>(this->end()) - where) * sizeof(T));
if (where != this->end())
::memmove(static_cast<void *>(where + n), static_cast<void *>(where),
(static_cast<const T*>(this->end()) - where) * sizeof(T));
this->size += qsizetype(n); // PODs can't throw on copy
while (n--)
*where++ = t;
@ -340,10 +345,11 @@ public:
Q_ASSERT(where >= this->begin() && where <= this->end());
Q_ASSERT(size_t(this->freeSpaceAtBegin()) >= n);
auto oldBegin = this->begin();
const T *oldBegin = this->begin();
this->ptr -= n;
::memmove(static_cast<void *>(this->begin()), static_cast<void *>(oldBegin),
(where - static_cast<const T*>(oldBegin)) * sizeof(T));
if (where != oldBegin)
::memmove(static_cast<void *>(this->begin()), static_cast<const void *>(oldBegin),
(where - oldBegin) * sizeof(T));
this->size += qsizetype(n); // PODs can't throw on copy
where -= n;
while (n--)
@ -392,8 +398,7 @@ public:
auto oldBegin = this->begin();
--this->ptr;
::memmove(static_cast<void *>(this->begin()), static_cast<void *>(oldBegin),
(where - oldBegin) * sizeof(T));
::memmove(static_cast<void *>(this->begin()), static_cast<void *>(oldBegin), (where - oldBegin) * sizeof(T));
*(where - 1) = t;
}
@ -410,8 +415,8 @@ public:
Q_ASSERT(b >= this->begin() && b < this->end());
Q_ASSERT(e > this->begin() && e <= this->end());
::memmove(static_cast<void *>(b), static_cast<void *>(e),
(static_cast<T *>(this->end()) - e) * sizeof(T));
if (e != this->end())
::memmove(static_cast<void *>(b), static_cast<void *>(e), (static_cast<T *>(this->end()) - e) * sizeof(T));
this->size -= (e - b);
}
@ -424,8 +429,8 @@ public:
const auto oldBegin = this->begin();
this->ptr += (e - b);
::memmove(static_cast<void *>(this->begin()), static_cast<void *>(oldBegin),
(b - static_cast<T *>(oldBegin)) * sizeof(T));
if (b != oldBegin)
::memmove(static_cast<void *>(this->begin()), static_cast<void *>(oldBegin), (b - static_cast<T *>(oldBegin)) * sizeof(T));
this->size -= (e - b);
}