Commit Graph

3 Commits

Author SHA1 Message Date
John Stiles
2396fb8be5 Convert division-by-literal in SPIR-V to multiplication.
This is particularly relevant for "vector / scalar" divides, as these
end up generating an extra OpFDiv to take the reciprocal of the scalar.
This meant we were generating code to calculate "literal 1 / literal N"
at runtime whenever dividing vector V against scalar N. This fix moves
the reciprocal calculation to compile-time. And of course, it's a valid
strength reduction in all cases.

Change-Id: I0986057e516120fe872e70135f1ac365155d5377
Bug: skia:11792
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/389156
Commit-Queue: John Stiles <johnstiles@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
2021-03-26 02:30:54 +00:00
John Stiles
d94bfdd7d8 Fix codegen for integer vector-scalar arithmetic in SPIR-V.
Due to missing type-checks, we would emit `OpVectorTimesScalar` when
multiplying an ivec with an int, or an `OpFDiv` when dividing an ivec
against an int.

Change-Id: Idc214dbe0ec208cb44f28b22e585584ac2ab7dae
Bug: skia:11267, skia:11788
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/388742
Commit-Queue: John Stiles <johnstiles@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
2021-03-26 02:30:04 +00:00
John Stiles
2febb5b423 Add SkSL test for vector-scalar math.
We had constant-folding tests for vector-scalar arithmetic, but didn't
have an equivalent SkSL unit test for vector-scalar arithmetic that
actually needs to be computed at runtime.

This exposes two SPIR-V bugs: one was previously known, but the other
is a new discovery.

Change-Id: I28737128f20b445797c6c29872335d05f94cc95c
Bug: skia:11267, skia:11788
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/388739
Auto-Submit: John Stiles <johnstiles@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
2021-03-25 23:30:34 +00:00