GlobalDCE deletes global vars and updates their initializers to nullptr
while leaving underlying constants to be cleaned up later by its uses.
The clean up may never happen, fix this by forcing it every time it's
safe to destroy constants.
Final patch by Rafael Espindola
http://reviews.llvm.org/D4931
<rdar://problem/17523868>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216390 91177308-0d34-0410-b5e6-96231b3b80d8
This patch adds support to recognize division by uniform power of 2 and modifies the cost table to vectorize division by uniform power of 2 whenever possible.
Updates Cost model for Loop and SLP Vectorizer.The cost table is currently only updated for X86 backend.
Thanks to Hal, Andrea, Sanjay for the review. (http://reviews.llvm.org/D4971)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216371 91177308-0d34-0410-b5e6-96231b3b80d8
This was added in r134994, to fix a memory leak;
three days later, r135248 switched
ContainedTys from being new-allocated to being allocated
via BumpPtrAllocator, and the earlier fix was never
reverted.
The destructor doesn't seem to ever actually be called
on Types anyway, so it's harmless, but if it were,
this'd be an invalid pointer.
This reverts r134994.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216354 91177308-0d34-0410-b5e6-96231b3b80d8
This does nothing but remove the Record from the map, and
then re-add it, without actually changing it in between.
The Record's Name used to be changed before re-adding it
when the code was first committed in r137232, but the
name-changing lines were removed in r142510, and since
then this code seems to do nothing.
This was also the only caller of removeClass or removeDef,
so now RecordKeeper owns its Records unconditionally,
and could be unique_ptr-ified.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216349 91177308-0d34-0410-b5e6-96231b3b80d8
The switch statement would never fire due to the preceding break statement. Also, the switch statement has a default label with no case labels. Simplified the code, and allow it to execute.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216346 91177308-0d34-0410-b5e6-96231b3b80d8
CFE, with -03, would turn:
bool f(unsigned x) {
bool a = x & 1;
bool b = x & 2;
return a | b;
}
into:
%1 = lshr i32 %x, 1
%2 = or i32 %1, %x
%3 = and i32 %2, 1
%4 = icmp ne i32 %3, 0
This sort of thing exposes a nasty pathology in GCC, ICC and LLVM.
Instead, we would rather want:
%1 = and i32 %x, 3
%2 = icmp ne i32 %1, 0
Things get a bit more interesting in the following case:
%1 = lshr i32 %x, %y
%2 = or i32 %1, %x
%3 = and i32 %2, 1
%4 = icmp ne i32 %3, 0
Replacing it with the following sequence is better:
%1 = shl nuw i32 1, %y
%2 = or i32 %1, 1
%3 = and i32 %2, %x
%4 = icmp ne i32 %3, 0
This sequence is preferable because %1 doesn't involve %x and could
potentially be hoisted out of loops if it is invariant; only perform
this transform in the non-constant case if we know we won't increase
register pressure.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216343 91177308-0d34-0410-b5e6-96231b3b80d8
Adds code generation support for dcbtst (data cache prefetch for write) and
icbt (instruction cache prefetch for read - Book E cores only).
We still end up with a 'cannot select' error for the non-supported prefetch
intrinsic forms. This will be fixed in a later commit.
Fixes PR20692.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216339 91177308-0d34-0410-b5e6-96231b3b80d8
Based on the STL class of the same name, it guards a mutex
while also allowing it to be unlocked conditionally before
destruction.
This eliminates the last naked usages of mutexes in LLVM and
clang.
It also uncovered and fixed a bug in callExternalFunction()
when compiled without USE_LIBFFI, where the mutex would never
be unlocked if the end of the function was reached.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216338 91177308-0d34-0410-b5e6-96231b3b80d8
This test was testing nothing, as only -Werror was ever
being added to the compiler flags.
You can see the final nitty-gritty compiler invocation in
CMakeFiles/CMakeOutput.log (for successful tests) and
CMakeFiles/CMakeError.log (for failed tests).
Before:
Building C object CMakeFiles/cmTryCompileExec3385359576.dir/src.c.o
/usr/bin/clang -fPIC -Wall -W -Wno-unused-parameter -Wwrite-strings -Wmissing-field-initializers -pedantic -Wno-long-long -Wcovered-switch-default -DC_WCOMMENT_ALLOWS_LINE_WRAP -Werror -o CMakeFiles/cmTryCompileExec3385359576.dir/src.c.o -c /home/nobled/code/llvm-b9/CMakeFiles/CMakeTmp/src.c
After:
Building C object CMakeFiles/cmTryCompileExec3385359576.dir/src.c.o
/usr/bin/clang -fPIC -Wall -W -Wno-unused-parameter -Wwrite-strings -Wmissing-field-initializers -pedantic -Wno-long-long -Wcovered-switch-default -DC_WCOMMENT_ALLOWS_LINE_WRAP -Werror -Wcomment -o CMakeFiles/cmTryCompileExec3385359576.dir/src.c.o -c /home/nobled/code/llvm-b9/CMakeFiles/CMakeTmp/src.c
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216328 91177308-0d34-0410-b5e6-96231b3b80d8
clang has only been smart enough not to trigger -Wnon-virtual-dtor
warnings on final classes since r208449 (in clang 3.5). Building
with older versions is extremely noisy, so disable the warning
on those compilers.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216327 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts commit r215862 due to nightly failures. Will work on getting a
reduced test case, but I wanted to get our bots green in the meantime.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216325 91177308-0d34-0410-b5e6-96231b3b80d8
these DAG combines.
The DAG auto-CSE thing is truly terrible. Due to it, when RAUW-ing
a node with its operand, you can cause its uses to CSE to itself, which
then causes their uses to become your uses which causes them to be
picked up by the RAUW. For nodes that are determined to be "no-ops",
this is "fine". But if the RAUW is one of several steps to enact
a transformation, this causes the DAG to really silently eat an discard
nodes that you would never expect. It took days for me to actually
pinpoint a test case triggering this and a really frustrating amount of
time to even comprehend the bug because I never even thought about the
ability of RAUW to iteratively consume nodes due to CSE-ing them into
itself.
To fix this, we have to build up a brand-new chain of operations any
time we are combining across (potentially) intervening nodes. But once
the logic is added to do this, another issue surfaces: CombineTo eagerly
deletes the one node combined, *but no others*. This is... really
frustrating. If deleting it makes its operands become dead, those
operand nodes often won't go onto the worklist in the
order you would want -- they're already on it and not near the top. That
means things higher on the worklist will get combined prior to these
dead nodes being GCed out of the worklist, and if the chain is long, the
immediate users won't be enough to re-detect where the root of the chain
is that became single-use again after deleting the dead nodes. The
better way to do this is to never immediately delete nodes, and instead
to just enqueue them so we can recursively delete them. The
combined-from node is typically not on the worklist anyways by virtue of
having been popped off.... But that in turn breaks other tests that
*require* CombineTo to delete unused nodes. :: sigh ::
Fortunately, there is a better way. This whole routine should have been
returning the replacement rather than using CombineTo which is quite
hacky. Switch to that, and all the pieces fall together.
I suspect the same kind of miscompile is possible in the half-shuffle
folding code, and potentially the recursive folding code. I'll be
switching those over to a pattern more like this one for safety's sake
even though I don't immediately have any test cases for them. Note that
the only way I got a test case for this instance was with *heavily* DAG
combined 256-bit shuffle sequences generated by my fuzzer. ;]
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216319 91177308-0d34-0410-b5e6-96231b3b80d8
There are two parts to this. First, the plugin needs to tell gold the comdat by
setting comdat_key.
What gets things a bit more complicated is that gold only seems
symbols. In particular, if A is an alias to B, it only sees the symbols
A and B. It can then ask us to keep symbol A but drop symbol B. What
we have to do instead is to create an internal version of B and make A
an alias to that.
At some point some of this logic should be moved to lib/Linker so that
we don't map a Constant to an internal version just to have lib/Linker
map that again to the destination module.
The reason for implementing this in tools/gold for now is simplicity.
With it in place it should be possible to update clang to use comdats
for constructors and destructors on ELF without breaking the LTO
bootstrap. Once that is done I intend to come back and improve the
interface lib/Linker exposes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216302 91177308-0d34-0410-b5e6-96231b3b80d8
This commit expands llvm-cov's functionality by adding support for a new code coverage
tool that uses LLVM's coverage mapping format and clang's instrumentation based profiling.
The gcov compatible tool can be invoked by supplying the 'gcov' command as the first argument,
or by modifying the tool's name to end with 'gcov'.
Differential Revision: http://reviews.llvm.org/D4445
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216300 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Fixes PR20425.
During slice building, if all of the incoming values of a PHI node are the same, replace the PHI node with the common value. This simplification makes alloca's used by PHI nodes easier to promote.
Test Plan: Added three more tests in phi-and-select.ll
Reviewers: nlewycky, eliben, meheff, chandlerc
Reviewed By: chandlerc
Subscribers: zinovy.nis, hfinkel, baldrick, llvm-commits
Differential Revision: http://reviews.llvm.org/D4659
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216299 91177308-0d34-0410-b5e6-96231b3b80d8
There's no need to do this if the user doesn't call va_start. In the
future, we're going to have thunks that forward these register
parameters with musttail calls, and they won't need these spills for
handling va_start.
Most of the test suite changes are adding va_start calls to existing
tests to keep things working.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216294 91177308-0d34-0410-b5e6-96231b3b80d8
