tree 0af9b277b2dff23c3331a76f9da7af653b97313c
parent 095cd1c25526016b649be527700f65ebfaecf6e4
author David Neto <dneto@google.com> 1618338937 +0000
committer Commit Bot service account <commit-bot@chromium.org> 1618338937 +0000

spirv-reader: fix overly aggressive dominance check

When finding the true-head, false-head, and potentially the
premerge-head blocks of an if-selection, there was an overly
aggressive check for the true-branch or false-branch landing
on a merge block interior to the if-selection. The check was
determining if the merge block actually corresponded to the selection
header in question.  If not, then it was throwing an error.

The bug was that this check must be performed only if the
target in question is actually inside the selection body.
There are cases where the target could represent a structured
exit, e.g. to an enclosing loop's merge or continue, or
an enclosing switch construct's merge.

There is still a latent bug: if either the true branch
or false branch represent such a kLoopBreak, kLoopContinue, or
kSwitchBreak edge, then those are not properly generated.
That will be fixed in a followup CL.

Bug: tint:243, tint:494
Change-Id: I141cce07fa0a1dfe5fad20dd2989315e4cd7b688
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/47482
Auto-Submit: David Neto <dneto@google.com>
Commit-Queue: Alan Baker <alanbaker@google.com>
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: Alan Baker <alanbaker@google.com>