Original commit message:
SmallVector: Resolve a long-standing fixme by using the existing unitialized_copy dispatch.
This makes append() use memcpy for trivially copyable types.
llvm-svn: 229149
r221973 changed SmallVector::operator[] to use size_t instead of unsigned.
Before that, on 64bit platforms, when a large index (say -1) was passed,
truncating it to unsigned avoided an overflow when computing 'begin() + idx',
and failed the range checking assertion, as expected.
With r221973, idx isn't truncated, so the addition wraps to
'(char*)begin() - 1', and doesn't fire anymore when it should have done so.
This commit changes the comparison to instead compute 'end() - begin()'
(i.e., 'size()'), which avoids potentially overflowing additions, and
correctly triggers the assertion when values such as -1 are passed.
Note that the problem already existed before that revision, on platforms
where sizeof(size_t) == sizeof(unsigned).
llvm-svn: 225338
This matches std::vector and is more efficient as it avoids
truncations.
With this the text segment of opt goes from 19705442 bytes
to 19703930 bytes.
llvm-svn: 221973
Unfortunately there's no way to elegantly do this with pre-canned
algorithms. Using a generating iterator doesn't work because you default
construct for each element, then move construct into the actual slot
(bad for copy but non-movable types, and a little unneeded overhead even
in the move-only case), so just write it out manually.
This solution isn't exception safe (if one of the element's ctors calls
we don't fall back, destroy the constructed elements, and throw on -
which std::uninitialized_fill does do) but SmallVector (and LLVM) isn't
exception safe anyway.
llvm-svn: 210495
(& because it makes it easier to test, this also improves
correctness/performance slightly by moving the last element in an insert
operation, rather than copying it)
llvm-svn: 210429
This would cause the last element in a range to be in a moved-from state
after an insert at a non-end position, losing that value entirely in the
process.
Side note: move_backward is subtle. It copies [A, B) to C-1 and down.
(the fact that it decrements both the second and third iterators before
the first movement is the subtle part... kind of surprising, anyway)
llvm-svn: 210426
When we were moving from a larger vector to a smaller one but didn't
need to re-allocate, we would move-assign over uninitialized memory in
the target, then move-construct that same data again.
llvm-svn: 207663
r206916 was not logically the same as the previous code because the
goto statements did not create loop. This should be the same as the
previous code.
llvm-svn: 206918
Goto statements jumping into previous inner blocks are pretty confusing
to read even though in this case they are valid. No reason to not use
while loops there.
llvm-svn: 206916
This reverts commit r203374.
Ambiguities in assign... oh well. I'm just going to revert this and
probably not try to recommit it as it's not terribly important.
llvm-svn: 203375
Move a common utility (assign(iter, iter)) into SmallVector (some of the
others could be moved there too, but this one seemed particularly
generic) and replace repetitions overrides with using directives.
And simplify SmallVector::assign(num, element) while I'm here rather
than thrashing these files (that cause everyone to rebuild) again.
llvm-svn: 203374
This reverts commit 617330909f0c26a3f2ab8601a029b9bdca48aa61.
It broke the bots:
/home/clangbuild2/clang-ppc64-2/llvm.src/unittests/ADT/SmallVectorTest.cpp:150: PushPopTest
/home/clangbuild2/clang-ppc64-2/llvm.src/unittests/ADT/SmallVectorTest.cpp:118: Failure
Value of: v[i].getValue()
Actual: 0
Expected: value
Which is: 2
llvm-svn: 178334
Rationale:
1) This was the name in the comment block. ;]
2) It matches Clang's __has_feature naming convention.
3) It matches other compiler-feature-test conventions.
Sorry for the noise. =]
I've also switch the comment block to use a \brief tag and not duplicate
the name.
llvm-svn: 168996
* wrap code blocks in \code ... \endcode;
* refer to parameter names in paragraphs correctly (\arg is not what most
people want -- it starts a new paragraph).
llvm-svn: 163790
test more than a single instantiation of SmallVector.
Add testing for 0, 1, 2, and 4 element sized "small" buffers. These
appear to be essentially untested in the unit tests until now.
Fix several tests to be robust in the face of a '0' small buffer. As
a consequence of this size buffer, the growth patterns are actually
observable in the test -- yes this means that many tests never caused
a grow to occur before. For some tests I've merely added a reserve call
to normalize behavior. For others, the growth is actually interesting,
and so I captured the fact that growth would occur and adjusted the
assertions to not assume how rapidly growth occured.
Also update the specialization for a '0' small buffer length to have all
the same interface points as the normal small vector.
llvm-svn: 161001
The rationale here is that it's hard to write loops containing vector erases and
it only shows up if the vector contains non-trivial objects leading to crashes
when forming them out of garbage memory.
llvm-svn: 160854
It always returns the iterator for the first inserted element, or the passed in
iterator if the inserted range was empty. Flesh out the unit test more and fix
all the cases it uncovered so far.
llvm-svn: 158645
Note that support for rvalue references does not imply support
for the full set of move-related STL operations.
I've preserved support for an odd little thing in insert() where
we're trying to support inserting a new element from an existing
one. If we actually want to support that, there's a lot more we
need to do: insert can call either grow or push_back, neither of
which is safe against this particular use pattern.
llvm-svn: 155979
