tree 37d3218bbdf3288998f6c831c4298c582aa16957
parent f3e5509deff24540e7ccac1ccec4012aa269fde9
author Michael Kruse <llvm-project@meinersbur.de> 1632549816 -0500
committer Copybara-Service <copybara-worker@google.com> 1632645325 -0700

[Polly] Use VirtualUse to determine references.

VirtualUse ensures consistency over different source of values with
Polly. In particular, this enables its use of instructions moved between
Statement. Before the patch, the code wrongly assumed that the BB's
instructions are also the ScopStmt's instructions. Reference are
determined for OpenMP outlining and GPGPU kernel extraction.

GPGPU CodeGen had some problems. For one, it generated GPU kernel
parameters for constants. Second, it emitted GPU-side invariant loads
which have already been loaded by the host. This has been partially
fixed, it still generates a store for the invariant load result, but
using the value that the host has already written.

WARNING: I did not test the generated PollyACC code on an actual GPU.

The improved consistency will be made use of in the next patch.

GitOrigin-RevId: d5c87162db7763c89160dc66894bebf3bd1e90d7