If sk_Caps.rewriteMatrixVectorMultiply is false, we generate the same
code as before.
If sk_Caps.rewriteMatrixVectorMultiply is true, and optimization is
enabled, medium-precision multiplication of `matrix * vector` is
rewritten in BinaryExpression as the sum of
(m[0]*v[0] + m[1]*v[1] + ... + m[N]*v[N]).
Change-Id: I9796158fd4203b5cd2278c0d0e9a2e8cda82b136
Bug: skia:11769
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/388460
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
On ARM GPUs, the Vulkan driver does not honor relaxed precision when
evaluating SpvOpMatrixTimesVector. This leads to reduced performance
(compared to GLSL, where mediump matrices and floats do evaluate all
intermediate values at mediump).
This caps bit will be enabled on ARM GPUs and, in a followup CL, will
be used to toggle a workaround where `m*v` is rewritten as the sum of
(m[0]*v[0] + m[1]*v[1] + ... + m[N]*v[N]).
Change-Id: I310fa73639b6498552c9672e76860f2eded15d0a
Bug: skia:11769
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/388459
Auto-Submit: John Stiles <johnstiles@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
