[sksl] Special-case unary negation on matrix types in MSL/SPIR-V
MSL does not support the unary "-" operator on matrix types. Similarly
the SPIR-V OpFNegate/OpSNegate operations only work on scalar and vector
type.
* An expression such as "-<mat>" is now transformed to "-1.0 * <mat>" when
generating MSL.
* The same expression now generates a component-wise negation in SPIR-V,
matching what glslang outputs for GLSL.
* A unary "+" is now treated as NOP for MSL, matching the SPIR-V backend.
An expression such as "+<expr>" is now evaluated as "<expr>".
* The shared/Negation.sksl has been moved to folding/ as much of its
contents exercise constant-folding of comparison expressions.
* The shared/UnaryPositiveNegative.sksl test has been extended to
exercise scalar and matrix types.
NOTE: The SPIR-V backend changes have caused a minor re-ordering of SSA
IDs generated when writing out a prefix-expression. The affected gold
files have been updated.
Bug: skia:12627, skia:12992
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/513976
Auto-Submit: Arman Uguray <armansito@google.com>
Reviewed-by: John Stiles <johnstiles@google.com>
Commit-Queue: Arman Uguray <armansito@google.com>
Change-Id: I56f9366efdbf6b63921db45cd927d580ab4b2eac
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/522991
17 files changed
