[SLP] Vectorize for all-constant entries.
This should fix libc++'s iostream initialization SIGBUSing on amd64,
whenever the global cout symbol is not aligned to 16 bytes.
Some further explanation: libc++'s iostream.cpp contains the definitions
of std::cout, std::cerr and so on. These global objects are effectively
declared with an alignment of 8 bytes. When an executable is linked
against libc++.so, it can sometimes get a copy of the global object,
which is then at the same alignment.
However, with clang 3.7.0, the initialization of these global objects
will incorrectly use SSE instructions (e.g. movdqa), whenever the
optimization level is high enough, and SSE is enabled, such as on amd64.
When any of these objects is not aligned to 16 bytes, this will result
in a SIGBUS during iostream initialization. In contrast, clang 3.6.x
and earlier took the 8 byte alignment into consideration, and avoided
SSE for those particular operations.
After bisecting of upstream changes, I found that the above revision
caused the change of this behavior, so I am reverting it now as a
workaround, while a discussion and test case is being prepared for
upstream.
all of the features in the current working draft of the upcoming C++
standard, provisionally named C++1y.
The code generator's performance is greatly increased, and the loop
auto-vectorizer is now enabled at -Os and -O2 in addition to -O3. The
PowerPC backend has made several major improvements to code generation
quality and compile time, and the X86, SPARC, ARM32, Aarch64 and SystemZ
backends have all seen major feature work.
Release notes for llvm and clang can be found here:
<http://llvm.org/releases/3.4/docs/ReleaseNotes.html>
<http://llvm.org/releases/3.4/tools/clang/docs/ReleaseNotes.html>
MFC after: 1 month
LoopVectorize: LoopSimplify can't canonicalize loops with an
indirectbr in it, don't assert on those cases.
Fixes PR16139.
This should fix clang assertion failures when optimizing at -O3, similar
to:
Assertion failed: (TheLoop->getLoopPreheader() && "No preheader!!"),
function canVectorize, file
contrib/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp, line 2171.
Reported by: O. Hartmann <ohartman@zedat.fu-berlin.de>
PR: ports/178332, ports/178977
MFC after: 3 days
LoopVectorize: getConsecutiveVector must respect signed arithmetic
We were passing an i32 to ConstantInt::get where an i64 was needed and we must
also pass the sign if we pass negatives numbers. The start index passed to
getConsecutiveVector must also be signed.
Should fix PR15882.
This should fix Firefox crashes some people have been reporting, when it
is compiled with -O3.
LoopVectorizer: Fix 15830. When scalarizing and unrolling stores make
sure that the order in which the elements are scalarized is the same
as the original order.
This fixes a miscompilation in FreeBSD's regex library.
This should fix lib/libc/regex/regcomp.c at -O3 with clang 3.3 r178860
on CPUs with SSE. Before this change, the vectorizer could incorrectly
rearrange the second loop in computejumps(), leading to possibly invalid
entries in the re_gets::charjump table.
The net result was that for example "sed s/@CC@/foo/" failed to work
correctly, leading to trouble with many configure scripts.
upcoming 3.3 release (branching and freezing expected in a few weeks).
Preliminary release notes can be found at the usual location:
<http://llvm.org/docs/ReleaseNotes.html>
An MFC is planned once the actual 3.3 release is finished.
