[SCEV] limit recursion depth of CompareSCEVComplexity
Summary:
CompareSCEVComplexity goes too deep (50+ on a quite a big unrolled
loop) and runs almost infinite time.
Added cache of "equal" SCEV pairs to earlier cutoff of further
estimation. Recursion depth limit was also introduced as a parameter.
Reviewers: sanjoy
Subscribers: mzolotukhin, tstellarAMD, llvm-commits
Differential Revision: https://reviews.llvm.org/D26389
Pull in r296992 from upstream llvm trunk (by Sanjoy Das):
[SCEV] Decrease the recursion threshold for CompareValueComplexity
Fixes PR32142.
r287232 accidentally increased the recursion threshold for
CompareValueComplexity from 2 to 32. This change reverses that
change by introducing a separate flag for CompareValueComplexity's
threshold.
The latter revision fixes the excessive compile times for skein_block.c.
[SCEV] limit recursion depth of CompareSCEVComplexity
Summary:
CompareSCEVComplexity goes too deep (50+ on a quite a big unrolled
loop) and runs almost infinite time.
Added cache of "equal" SCEV pairs to earlier cutoff of further
estimation. Recursion depth limit was also introduced as a parameter.
Reviewers: sanjoy
Subscribers: mzolotukhin, tstellarAMD, llvm-commits
Differential Revision: https://reviews.llvm.org/D26389
This commit is the cause of excessive compile times on skein_block.c
(and possibly other files) during kernel builds on amd64.
We never saw the problematic behavior described in this upstream commit,
so for now it is better to revert it. An upstream bug has been filed
here: https://bugs.llvm.org/show_bug.cgi?id=32142
Reported by: mjg
[ValueTracking] avoid crashing from bad assumptions (PR31809)
A program may contain llvm.assume info that disagrees with other
analysis. This may be caused by UB in the program, so we must not
crash because of that.
As noted in the code comments:
https://llvm.org/bugs/show_bug.cgi?id=31809
...we can do better, but this at least avoids the assert/crash in the
bug report.
Differential Revision: https://reviews.llvm.org/D29395
This fixes an assertion when building editors/emacs-devel.
PR: 216614
Fix use-after-free bug in AffectedValueCallbackVH::allUsesReplacedWith
When transferring affected values in the cache from an old value,
identified by the value of the current callback, to the specified new
value we might need to insert a new entry into the DenseMap which
constitutes the cache. Doing so might delete the current callback
object. Move the copying logic into a new function, a member of the
assumption cache itself, so that we don't run into UB should the
callback handle itself be removed mid-copy.
Differential Revision: https://reviews.llvm.org/D28749
This should fix crashes when building lld (as part of the llvmXY ports).
Reported by: jbeich
PR: 216117
Add some shortcuts in LazyValueInfo to reduce compile time of
Correlated Value Propagation.
The patch is to partially fix PR10584. Correlated Value Propagation
queries LVI to check non-null for pointer params of each callsite. If
we know the def of param is an alloca instruction, we know it is
non-null and can return early from LVI. Similarly, CVP queries LVI to
check whether pointer for each mem access is constant. If the def of
the pointer is an alloca instruction, we know it is not a constant
pointer. These shortcuts can reduce the cost of CVP significantly.
Differential Revision: https://reviews.llvm.org/D18066
This significantly reduces memory usage and compilation time when
compiling a particular C++ source file of the graphics/colmap port.
PR: 215136
MFC after: 3 days
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
CaptureTracking: Plug a loophole in the "too many uses" heuristic.
The heuristic was added to avoid spending too much compile time in a
specially crafted test case (PR17461, PR16474) with many uses on a
select or bitcast instruction can still trigger the slow case. Add a
check for that case.
This only affects compile time, don't have a good way to test it.
This fixes the excessive compile time spent on a specific file of the
graphics/rawtherapee port.
Reported by: mandree
MFC after: 3 days
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.
Make sure always-inline functions get inlined. <rdar://problem/12423986>
Without this change, when the estimated cost for inlining a function with
an "alwaysinline" attribute was lower than the inlining threshold, the
getInlineCost function was returning that estimated cost rather than the
special InlineCost::AlwaysInlineCost value. That is fine in the normal
inlining case, but it can fail when the inliner considers the opportunity
cost of inlining into an internal or linkonce-odr function. It may decide
not to inline the always-inline function in that case. The fix here is just
to make getInlineCost always return the special value for always-inline
functions. I ran into this building clang with libc++. Tablegen failed to
link because of an always-inline function that was not inlined. I have been
unable to reduce the testcase down to a reasonable size.
This should fix the link errors that were reported when atf-run was
compiled with clang -stdlib=libc++. In this case, at -O3 optimization,
some calls to basic_ios::clear() were not inlined, even when the
function was marked __always_inline__.
Reported by: Jan Beich <jbeich@tormail.org>
MFC after: 1 week
