20 Commits

Author SHA1 Message Date
52ab0bc417 [PM/AA] Extract the ModRef enums from the AliasAnalysis class in
preparation for de-coupling the AA implementations.

In order to do this, they had to become fake-scoped using the
traditional LLVM pattern of a leading initialism. These can't be actual
scoped enumerations because they're bitfields and thus inherently we use
them as integers.

I've also renamed the behavior enums that are specific to reasoning
about the mod/ref behavior of functions when called. This makes it more
clear that they have a very narrow domain of applicability.

I think there is a significantly cleaner API for all of this, but
I don't want to try to do really substantive changes for now, I just
want to refactor the things away from analysis groups so I'm preserving
the exact original design and just cleaning up the names, style, and
lifting out of the class.

Differential Revision: http://reviews.llvm.org/D10564

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242963 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-22 23:15:57 +00:00
c1a9c38190 [PM/AA] Remove the addEscapingUse update API that won't be easy to
directly model in the new PM.

This also was an incredibly brittle and expensive update API that was
never fully utilized by all the passes that claimed to preserve AA, nor
could it reasonably have been extended to all of them. Any number of
places add uses of values. If we ever wanted to reliably instrument
this, we would want a callback hook much like we have with ValueHandles,
but doing this for every use addition seems *extremely* expensive in
terms of compile time.

The only user of this update mechanism is GlobalsModRef. The idea of
using this to keep it up to date doesn't really work anyways as its
analysis requires a symmetric analysis of two different memory
locations. It would be very hard to make updates be sufficiently
rigorous to *guarantee* symmetric analysis in this way, and it pretty
certainly isn't true today.

However, folks have been using GMR with this update for a long time and
seem to not be hitting the issues. The reported issue that the update
hook fixes isn't even a problem any more as other changes to
GetUnderlyingObject worked around it, and that issue stemmed from *many*
years ago. As a consequence, a prior patch provided a flag to control
the unsafe behavior of GMR, and this patch removes the update mechanism
that has questionable compile-time tradeoffs and is causing problems
with moving to the new pass manager. Note the lack of test updates --
not one test in tree actually requires this update, even for a contrived
case.

All of this was extensively discussed on the dev list, this patch will
just enact what that discussion decides on. I'm sending it for review in
part to show what I'm planning, and in part to show the *amazing* amount
of work this avoids. Every call to the AA here is something like three
to six indirect function calls, which in the non-LTO pipeline never do
any work! =[

Differential Revision: http://reviews.llvm.org/D11214

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242605 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-18 03:26:46 +00:00
c51f300513 [PM/AA] Completely remove the AliasAnalysis::copyValue interface.
No in-tree alias analysis used this facility, and it was not called in
any particularly rigorous way, so it seems unlikely to be correct.

Note that one of the only stateful AA implementations in-tree,
GlobalsModRef is completely broken currently (and any AA passes like it
are equally broken) because Module AA passes are not effectively
invalidated when a function pass that fails to update the AA stack runs.

Ultimately, it doesn't seem like we know how we want to build stateful
AA, and until then trying to support and maintain correctness for an
untested API is essentially impossible. To that end, I'm planning to rip
out all of the update API. It can return if and when we need it and know
how to build it on top of the new pass manager and as part of *tested*
stateful AA implementations in the tree.

Differential Revision: http://reviews.llvm.org/D10889

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@241975 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-11 04:39:00 +00:00
cd52a7a381 Revert r240137 (Fixed/added namespace ending comments using clang-tidy. NFC)
Apparently, the style needs to be agreed upon first.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240390 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-23 09:49:53 +00:00
cf0db29df2 Fixed/added namespace ending comments using clang-tidy. NFC
The patch is generated using this command:

tools/clang/tools/extra/clang-tidy/tool/run-clang-tidy.py -fix \
  -checks=-*,llvm-namespace-comment -header-filter='llvm/.*|clang/.*' \
  llvm/lib/


Thanks to Eugene Kosov for the original patch!



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240137 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-19 15:57:42 +00:00
4d7ed3960c [PM/AA] Remove the Location typedef from the AliasAnalysis class now
that it is its own entity in the form of MemoryLocation, and update all
the callers.

This is an entirely mechanical change. References to "Location" within
AA subclases become "MemoryLocation", and elsewhere
"AliasAnalysis::Location" becomes "MemoryLocation". Hope that helps
out-of-tree folks update.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239885 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-17 07:18:54 +00:00
dc967a97df [PM/AA] Start refactoring AliasAnalysis to remove the analysis group and
port it to the new pass manager.

All this does is extract the inner "location" class used by AA into its
own full fledged type. This seems *much* cleaner as MemoryDependence and
soon MemorySSA also use this heavily, and it doesn't make much sense
being inside the AA infrastructure.

This will also make it much easier to break apart the AA infrastructure
into something that stands on its own rather than using the analysis
group design.

There are a few places where this makes APIs not make sense -- they were
taking an AliasAnalysis pointer just to build locations. I'll try to
clean those up in follow-up commits.

Differential Revision: http://reviews.llvm.org/D10228

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239003 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-04 02:03:15 +00:00
4ea24c84fb MergedLoadStoreMotion preserves MemoryDependenceAnalysis, it does not require it.
(It already was coded assuming it can sometimes be null, so no other changes are necessary)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237978 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-22 00:13:05 +00:00
eef4a339b5 Another set of missing raw_ostream.h. Still no functional change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232993 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-23 18:45:56 +00:00
b70bdd9034 Fixed a bug in store sinking.
The problem was in store-sink barrier check.

Store sink barrier should be checked for ModRef (read-write) mode.

http://llvm.org/bugs/show_bug.cgi?id=22613



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229495 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-17 13:10:05 +00:00
eeeec3ce0d [PM] Separate the TargetLibraryInfo object from the immutable pass.
The pass is really just a means of accessing a cached instance of the
TargetLibraryInfo object, and this way we can re-use that object for the
new pass manager as its result.

Lots of delta, but nothing interesting happening here. This is the
common pattern that is developing to allow analyses to live in both the
old and new pass manager -- a wrapper pass in the old pass manager
emulates the separation intrinsic to the new pass manager between the
result and pass for analyses.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226157 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-15 10:41:28 +00:00
bda134910a [PM] Move TargetLibraryInfo into the Analysis library.
While the term "Target" is in the name, it doesn't really have to do
with the LLVM Target library -- this isn't an abstraction which LLVM
targets generally need to implement or extend. It has much more to do
with modeling the various runtime libraries on different OSes and with
different runtime environments. The "target" in this sense is the more
general sense of a target of cross compilation.

This is in preparation for porting this analysis to the new pass
manager.

No functionality changed, and updates inbound for Clang and Polly.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226078 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-15 02:16:27 +00:00
2f6d42351a Sink store based on alias analysis
- by Ella Bolshinsky
The alias analysis is used define whether the given instruction
is a barrier for store sinking. For 2 identical stores, following
instructions are checked in the both basic blocks, to determine
whether they are sinking barriers.

http://reviews.llvm.org/D6420



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224247 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-15 14:09:53 +00:00
01d89eee39 Use Alias Analysis to hoist 2 loads from diamond to the common predecessor basic block.
Alias Analysis allows to detect real barriers for load hoisting.

Review in http://reviews.llvm.org/D5991



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221091 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-02 08:03:05 +00:00
438b59883a [MergedLoadStoreMotion] Move pass enabling option to PassManagerBuilder
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217538 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-10 19:55:29 +00:00
5c488f48bd Removed misleading comment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217527 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-10 17:54:50 +00:00
d0f88d5381 Fix for multi-line comment warning
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215169 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-07 23:19:55 +00:00
10437f66fa Fix for regression: [Bug 20369] wrong code at -O3 on x86_64-linux-gnu in 64-bit mode
Prevents hoisting of loads above stores and sinking of stores below loads
in MergedLoadStoreMotion.cpp (rdar://15991737)



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213497 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-21 03:02:46 +00:00
f707267837 MergedLoadStoreMotion.cpp: Fix msc17 build. Member initializer is unavailable.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213448 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-19 03:29:25 +00:00
d94715e273 MergedLoadStoreMotion pass
Merges equivalent loads on both sides of a hammock/diamond
and hoists into into the header.
Merges equivalent stores on both sides of a hammock/diamond
and sinks it to the footer.
Can enable if conversion and tolerate better load misses
and store operand latencies.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213396 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-18 19:13:09 +00:00