MemorySSAUpdater::getPreviousDefRecursive is a recursive algorithm, for
each block, it computes the previous definition for each predecessor,
then takes those definitions and combines them. But currently it doesn't
remember results which it already computed; this means it can visit the
same block multiple times, which adds up to exponential time overall.
To fix this, this patch adds a cache. If we computed the result for a
block already, we don't need to visit it again because we'll come up
with the same result. Well, unless we RAUW a MemoryPHI; in that case,
the TrackingVH will be updated automatically.
This matches the original source paper for this algorithm.
The testcase isn't really a test for the bug, but it adds coverage for
the case where tryRemoveTrivialPhi erases an existing PHI node. (It's
hard to write a good regression test for a performance issue.)
Differential Revision: https://reviews.llvm.org/D44715
llvm-svn: 328577
Summary:
Check that the first access before one being tested is valid.
Before this patch, if there was no definition prior to the Use being tested,
the first time Iter was deferenced, it hit the sentinel.
Reviewers: dberlin, gbiv
Subscribers: sanjoy, Prazek, llvm-commits
Differential Revision: https://reviews.llvm.org/D33950
llvm-svn: 304926
I did this a long time ago with a janky python script, but now
clang-format has built-in support for this. I fed clang-format every
line with a #include and let it re-sort things according to the precise
LLVM rules for include ordering baked into clang-format these days.
I've reverted a number of files where the results of sorting includes
isn't healthy. Either places where we have legacy code relying on
particular include ordering (where possible, I'll fix these separately)
or where we have particular formatting around #include lines that
I didn't want to disturb in this patch.
This patch is *entirely* mechanical. If you get merge conflicts or
anything, just ignore the changes in this patch and run clang-format
over your #include lines in the files.
Sorry for any noise here, but it is important to keep these things
stable. I was seeing an increasing number of patches with irrelevant
re-ordering of #include lines because clang-format was used. This patch
at least isolates that churn, makes it easy to skip when resolving
conflicts, and gets us to a clean baseline (again).
llvm-svn: 304787
- Mark an internal function static
- Remove the llvm namespace (just holding on to the `using namespace
llvm;` Works on My Machine(TM))
llvm-svn: 300947
Analysis, it has Analysis passes, and once NewGVN is made an Analysis,
this removes the cross dependency from Analysis to Transform/Utils.
NFC.
llvm-svn: 299980
Eli Friedman