Commit Graph

3 Commits

Author SHA1 Message Date
Arthur Eubanks 4103f4a936 [MSSA][NewPM] Handle tests with -print-memoryssa
-print-memoryssa in legacy PM is print<memoryssa> in NPM.
Pin tests with -print-memoryssa to legacy PM.
Add corresponding tests for NPM where missing.
This fixes "unknown pass name 'print-memoryssa'".

Some tests still fail in Analysis/MemorySSA due to other passes that
haven't been ported.

pr43427.ll and pr43438.ll required adding -aa-pipeline=basic-aa,
-loop-simplify (since it doesn't run on legacy PM by default), and
decrementing some of the MemoryPhi numbers.

Reviewed By: asbirlea

Differential Revision: https://reviews.llvm.org/D85333
2020-08-05 15:59:45 -07:00
Alina Sbirlea 6720ed851b [MemorySSA] Avoid adding Phis in the presence of unreachable blocks.
Summary:
If a block has all incoming values with the same MemoryAccess (ignoring
incoming values from unreachable blocks), then use that incoming
MemoryAccess and do not create a Phi in the first place.

Revert IDF work-around added in rL372673; it should not be required unless
the Def inserted is the first in its block.

The patch also cleans up a series of tests, added during the many
iterations on insertDef.

The patch also fixes PR43438.
The same issue that occurs in insertDef with "adding phis, hence the IDF of
Phis is needed", can also occur in fixupDefs: the `getPreviousRecursive`
call only adds Phis walking on the predecessor edges, which means there
may be the case of a Phi added walking the CFG "backwards" which
triggers the needs for an additional Phi in successor blocks.
Such Phis are added during fixupDefs only in the presence of unreachable
blocks.
Hence this highlights the need to avoid adding Phis in blocks with
unreachable predecessors in the first place.

Reviewers: george.burgess.iv

Subscribers: Prazek, sanjoy.google, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D67995

llvm-svn: 372932
2019-09-25 23:24:39 +00:00
Alina Sbirlea 0363c3b8bb [MemorySSA] Check that block is reachable when adding phis.
Summary:
Originally the insertDef method was only used when building MemorySSA, and was limiting the number of Phi nodes that it created.
Now it's used for updates as well, and it can create additional Phis needed for correctness.
Make sure no Phis are created in unreachable blocks (condition met during MSSA build), otherwise the renamePass will find a null DTNode.

Resolves PR41640.

Reviewers: george.burgess.iv

Subscribers: jlebar, Prazek, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D61410

llvm-svn: 359845
2019-05-02 23:41:58 +00:00