tree 6002ed00b0e0efdbe167eb4be899c3554393197b
parent dc2966a15b0cdddf3085ad14b11e6d4dc526674f
author Nicolas Capens <capn@google.com> 1541523381 -0500
committer Nicolas Capens <nicolascapens@google.com> 1541539106 +0000

Fix deterministic loops within conditional blocks, again.

Deterministic loops use the first scalar of the SIMD register used as
the loop index, for addressing arrays. This means that operations on the
index register should not be masked (i.e. it should be treated as a
scalar).

Previously we were still masking it based on conditional statements, and
we didn't disable the masking altogether for the loop initialization and
initial test. A new shader assembly instruction 'SCALAR' was added for
doing this.

Previously this was conflated with the 'TEST' instruction, which should
independently disable/restore the 'continue' mask.

Bug swiftshader:93
Bug b/118009174

Change-Id: I4add1a6d74231f463217e57adfabdc81faf489ae
Reviewed-on: https://swiftshader-review.googlesource.com/c/22348
Tested-by: Nicolas Capens <nicolascapens@google.com>
Reviewed-by: Alexis Hétu <sugoi@google.com>