tree a58774b4ac209e68ff5ecb2e12196ce7a8112865
parent 35f47d6a902ff2ee50a4d4a0a4552f07c23d8ea3
author David Neto <dneto@google.com> 1594051697 +0000
committer David Neto <dneto@google.com> 1594051697 +0000

[spirv-reader] Support OpPhi

For each OpPhi, make a variable to carry values from predecessor blocks
to the OpPhi.  Declare the variable at the smallest scope enclosing all
the predecessor blocks (where we write to it), and the OpPhi (where we
read from it).

Bug: tint:3
Change-Id: I7898b4b903d9ee1a25a7466e3c5aaf6840550e2d
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/24181
Reviewed-by: dan sinclair <dsinclair@google.com>