Improve optimization of prefix expressions at IR time.
- Values from constant variables are folded in when it helps, e.g.:
const bool SHINY = true;
const float SHININESS = 2;
if (!SHINY) { // <-- optimizes directly to `false`
param = -SHININESS; // <-- optimizes to `-2`
- Doubled-up logical-not and negation are stripped:
y = -(-x); // <-- optimizes to `y = x;`
b = !!a; // <-- optimizes to `b = a;`
Removal of doubled-up negation and logical-not was actually never
implemented in the constant-propagation phase; I just noticed it while
I was here and thinking about it.
Change-Id: Ie28bb9b5af91376f03d926e26e37f4a131bbf550
Bug: skia:11343
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/379298
Auto-Submit: John Stiles <johnstiles@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
3 files changed