Commit Graph

6 Commits

Author SHA1 Message Date
Michael Zolotukhin 67cfbaac89 [MemorySSA] Don't sort IDF blocks.
Summary:
After r332167 we started to sort the IDF blocks inside IDF calculation, so
there is no need to re-sort them on the user site. The test changes are due to
a slightly different order we're using now (originally we used DFSInNumber and
now the blocks are sorted by a pair (LevelFromRoot, DFSInNumber)).

Reviewers: dberlin, mgrang

Subscribers: Prazek, hiraditya, george.burgess.iv, llvm-commits

Differential Revision: https://reviews.llvm.org/D46899

llvm-svn: 332385
2018-05-15 18:40:29 +00:00
Piotr Padlewski 5dde809404 Rename invariant.group.barrier to launder.invariant.group
Summary:
This is one of the initial commit of "RFC: Devirtualization v2" proposal:
https://docs.google.com/document/d/16GVtCpzK8sIHNc2qZz6RN8amICNBtvjWUod2SujZVEo/edit?usp=sharing

Reviewers: rsmith, amharc, kuhar, sanjoy

Subscribers: arsenm, nhaehnle, javed.absar, hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D45111

llvm-svn: 331448
2018-05-03 11:03:01 +00:00
Piotr Padlewski f801205e48 Mark invariant.group.barrier as inaccessiblememonly
It turned out that readonly argmemonly is not enough.

  store 42, %p
  %b = barrier(%p)
  store 43, %b
the first store is dead, but because barrier was marked as
reading argument memory, it was considered alive. With
inaccessiblememonly it doesn't read the argument, but
it also can't be CSEd.

based on: https://reviews.llvm.org/D32006

llvm-svn: 331338
2018-05-02 08:22:07 +00:00
Yaxun Liu 407ca36b27 Let llvm.invariant.group.barrier accepts pointer to any address space
llvm.invariant.group.barrier may accept pointers to arbitrary address space.

This patch let it accept pointers to i8 in any address space and returns
pointer to i8 in the same address space.

Differential Revision: https://reviews.llvm.org/D39973

llvm-svn: 318413
2017-11-16 16:32:16 +00:00
Piotr Padlewski 04aee46779 Remove readnone from invariant.group.barrier
Summary:
Readnone attribute would cause CSE of two barriers with
the same argument, which is invalid by example:

    struct Base {
          virtual int foo() { return 42; }
    };

    struct Derived1 : Base {
          int foo() override { return 50; }
    };

    struct Derived2 : Base {
          int foo() override { return 100; }
    };

    void foo() {
        Base *x = new Base{};
        new (x) Derived1{};
        int a = std::launder(x)->foo();
        new (x) Derived2{};
        int b = std::launder(x)->foo();
    }

Here 2 calls of std::launder will produce @llvm.invariant.group.barrier,
which would be merged into one call, causing devirtualization
to devirtualize second call into Derived1::foo() instead of
Derived2::foo()

Reviewers: chandlerc, dberlin, hfinkel

Subscribers: llvm-commits, rsmith, amharc

Differential Revision: https://reviews.llvm.org/D31531

llvm-svn: 300101
2017-04-12 20:45:12 +00:00
Daniel Berlin 554dcd8c89 MemorySSA: Move to Analysis, from Transforms/Utils. It's used as
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
2017-04-11 20:06:36 +00:00