Commit Graph

3 Commits

Author SHA1 Message Date
Steven Perron
5d602abd66 Add global redundancy elimination
Adds a pass that looks for redundant instruction in a function, and
removes them.  The algorithm is a hash table based value numbering
algorithm that traverses the dominator tree.

This pass removes completely redundant instructions, not partially
redundant ones.
2017-12-07 18:35:38 -05:00
Steven Perron
b35b52f97b Compute value number when the value table is constructed.
Computing the value numbers on demand, as we do now, can lead to
different results depending on the order in which the users asks for
the value numbers.  To make things more stable, we compute them ahead
of time.
2017-12-04 11:02:04 -05:00
Steven Perron
28c415500d Create a local value numbering pass
Creates a pass that removes redundant instructions within the same basic
block.  This will be implemented using a hash based value numbering
algorithm.

Added a number of functions that check for the Vulkan descriptor types.
These are used to determine if we are variables are read-only or not.

Implemented a function to check if loads and variables are read-only.
Implemented kernel specific and shader specific versions.

A big change is that the Combinator analysis in ADCE is factored out
into the IRContext as an analysis. This was done because it is being
reused in the value number table.
2017-11-23 11:45:09 -05:00