Commit Graph

3 Commits

Author SHA1 Message Date
Yaxun Liu 35ad126c78 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


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@318413 91177308-0d34-0410-b5e6-96231b3b80d8
2017-11-16 16:32:16 +00:00
Piotr Padlewski 6f93f61542 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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@300101 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-12 20:45:12 +00:00
Daniel Berlin e0f5ddbc01 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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@299980 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-11 20:06:36 +00:00