Use op cache to eliminate OpCompositeConstruct + OpCompositeExtract.
Previously, we only handled the simple case of extracting from an
OpConstantComposite. Now we also handle the complex case of extracting
from an OpCompositeConstruct, where vectors can be composed of other
vectors.
This is particularly challenging because OpCompositeConstruct can
contain SpvIds from almost any other instruction, so we need to be
able to decode those instructions and figure out their type. For
instance:
%5 = OpFAdd Vec2 %1 %2
%6 = OpFAdd Scalar %3 %4
%7 = OpCompositeConstruct FloatVec3 %5 %6
%8 = OpCompositeExtract %7 2
The %8 (OpCompositeExtract) could be replaced with %6 but we need to
peek at the type in *both* OpFAdd instructions to decode this. It
only works when the affected instructions are in-cache, so many
opportunities are currently not optimized because their code still
uses the original, uncached form of writeInstruction.
Change-Id: I5719ae6284f32e1d6f2c898eca282c22b94fc764
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/529743
Reviewed-by: Brian Osman <brianosman@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
10 files changed
