Summary:
There are several places in the codebase that try to calculate a maximum value in a Statistic object. We currently do this in one of two ways:
MaxNumFoo = std::max(MaxNumFoo, NumFoo);
or
MaxNumFoo = (MaxNumFoo > NumFoo) ? MaxNumFoo : NumFoo;
The first version reads from MaxNumFoo one time and uncontionally rwrites to it. The second version possibly reads it twice depending on the result of the first compare. But we have no way of knowing if the value was changed by another thread between the reads and the writes.
This patch adds a method to the Statistic object that can ensure that we only store if our value is the max and the previous max didn't change after we read it. If it changed we'll recheck if our value should still be the max or not and try again.
This spawned from an audit I'm trying to do of all places we uses the implicit conversion to unsigned on the Statistics objects. See my previous thread on llvm-dev https://groups.google.com/forum/#!topic/llvm-dev/yfvxiorKrDQ
Reviewers: dberlin, chandlerc, hfinkel, dblaikie
Reviewed By: chandlerc
Subscribers: llvm-commits, sanjoy
Differential Revision: https://reviews.llvm.org/D33301
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@303318 91177308-0d34-0410-b5e6-96231b3b80d8
Commits were:
"Use WeakVH instead of WeakTrackingVH in AliasSetTracker's UnkownInsts"
"Add a new WeakVH value handle; NFC"
"Rename WeakVH to WeakTrackingVH; NFC"
The changes assumed pointers are 8 byte aligned on all architectures.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@301429 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
I plan to use WeakVH to mean "nulls itself out on deletion, but does
not track RAUW" in a subsequent commit.
Reviewers: dblaikie, davide
Reviewed By: davide
Subscribers: arsenm, mehdi_amini, mcrosier, mzolotukhin, jfb, llvm-commits, nhaehnle
Differential Revision: https://reviews.llvm.org/D32266
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@301424 91177308-0d34-0410-b5e6-96231b3b80d8
Before, it would print a sequence of:
*** IR Dump After Function Integration/Inlining ******
*** IR Dump After Function Integration/Inlining ******
*** IR Dump After Function Integration/Inlining ******
...
for every single function in the module.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@292442 91177308-0d34-0410-b5e6-96231b3b80d8
Running tests with expensive checks enabled exhibits some problems with
verification of pass results.
First, the pass verification may require results of analysis that are not
available. For instance, verification of loop info requires results of dominator
tree analysis. A pass may be marked as conserving loop info but does not need to
be dependent on DominatorTreePass. When a pass manager tries to verify that loop
info is valid, it needs dominator tree, but corresponding analysis may be
already destroyed as no user of it remained.
Another case is a pass that is skipped. For instance, entities with linkage
available_externally do not need code generation and such passes are skipped for
them. In this case result verification must also be skipped.
To solve these problems this change introduces a special flag to the Pass
structure to mark passes that have valid results. If this flag is reset,
verifications dependent on the pass result are skipped.
Differential Revision: https://reviews.llvm.org/D27190
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@291882 91177308-0d34-0410-b5e6-96231b3b80d8
Add an option to enable the analysis of MachineFunction register
usage to extract the list of clobbered registers.
When enabled, the CodeGen order is changed to be bottom up on the Call
Graph.
The analysis is split in two parts, RegUsageInfoCollector is the
MachineFunction Pass that runs post-RA and collect the list of
clobbered registers to produce a register mask.
An immutable pass, RegisterUsageInfo, stores the RegMask produced by
RegUsageInfoCollector, and keep them available. A future tranformation
pass will use this information to update every call-sites after
instruction selection.
Patch by Vivek Pandya <vivekvpandya@gmail.com>
Differential Revision: http://reviews.llvm.org/D20769
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@272403 91177308-0d34-0410-b5e6-96231b3b80d8
This patch implements a optimization bisect feature, which will allow optimizations to be selectively disabled at compile time in order to track down test failures that are caused by incorrect optimizations.
The bisection is enabled using a new command line option (-opt-bisect-limit). Individual passes that may be skipped call the OptBisect object (via an LLVMContext) to see if they should be skipped based on the bisect limit. A finer level of control (disabling individual transformations) can be managed through an addition OptBisect method, but this is not yet used.
The skip checking in this implementation is based on (and replaces) the skipOptnoneFunction check. Where that check was being called, a new call has been inserted in its place which checks the bisect limit and the optnone attribute. A new function call has been added for module and SCC passes that behaves in a similar way.
Differential Revision: http://reviews.llvm.org/D19172
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@267022 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This patch implements "-print-funcs" option to support function filtering for IR printing like -print-after-all, -print-before etc.
Examples:
-print-after-all -print-funcs=foo,bar
Reviewers: mcrosier, joker.eph
Subscribers: tejohnson, joker.eph, llvm-commits
Differential Revision: http://reviews.llvm.org/D15776
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@256952 91177308-0d34-0410-b5e6-96231b3b80d8
folding the code into the main Analysis library.
There already wasn't much of a distinction between Analysis and IPA.
A number of the passes in Analysis are actually IPA passes, and there
doesn't seem to be any advantage to separating them.
Moreover, it makes it hard to have interactions between analyses that
are both local and interprocedural. In trying to make the Alias Analysis
infrastructure work with the new pass manager, it becomes particularly
awkward to navigate this split.
I've tried to find all the places where we referenced this, but I may
have missed some. I have also adjusted the C API to continue to be
equivalently functional after this change.
Differential Revision: http://reviews.llvm.org/D12075
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@245318 91177308-0d34-0410-b5e6-96231b3b80d8
