tree 5c873a52cff4b0633d4b0e77ccb2f975787fab87
parent d433ca92d445d857852f61117c02c9eccbf5491c
author Christoffer Quist Adamsen <christofferqa@google.com> 1578917252 +0100
committer Christoffer Quist Adamsen <christofferqa@google.com> 1578929181 +0000

Improve precision of field bit access analysis

In the field bit access analysis, we ignore the following pattern, because the value is not read except for the write to the same field:

  bitField = bitField | 1;

However, due to redundant field load elimination, the following code:

  bitField = bitField | 1;
  bitField = bitField | 2;

... may be optimized into:

  int x = bitField | 1;
  bitField = x;
  bitField = x | 2;

Therefore, this CL extends the analysis that determines if a read only flows into a write to allow the read to flow into a series of logical binop instructions, before it is assigned back into the field.

Change-Id: Ib06219a5ee1014095a7e4c10a158ed63e645512f