tint: Implement sem::Load
The resolver now wraps sem::Expression objects with a sem::Load object
anywhere that the load rule is invoked. sem::Expression provides an
`UnwrapLoad()` method that returns the inner expression (or
passthrough, if no load is present), which is analaguous to
Type::UnwrapRef().
The logic for alias analysis in `RegisterLoadIfNeeded` has been folded
into the new `Resolver::Load` method.
Fixed up many transforms and tests. The only difference in output is
for a single SPIR-V backend test, where some IDs have changed due to
slight re-ordering of when expressions are generated.
There may be further clean-ups possible (e.g. removing unnecessary
calls to `UnwrapRef`, and simplifying places in the SPIR-V writer or
transforms that deal with memory accesses), but these can be addressed
in future patches.
Fixed: tint:1654
Change-Id: I69adecfe9251faae46546b64d0cdc29eea26cd4e
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/99706
Commit-Queue: James Price <jrprice@google.com>
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: Antonio Maiorano <amaiorano@google.com>
Reviewed-by: Ben Clayton <bclayton@google.com>
diff --git a/src/tint/transform/multiplanar_external_texture.cc b/src/tint/transform/multiplanar_external_texture.cc
index e7d8327..f8c927b1 100644
--- a/src/tint/transform/multiplanar_external_texture.cc
+++ b/src/tint/transform/multiplanar_external_texture.cc
@@ -197,7 +197,8 @@
if (builtin && !builtin->Parameters().IsEmpty() &&
builtin->Parameters()[0]->Type()->Is<type::ExternalTexture>() &&
builtin->Type() != sem::BuiltinType::kTextureDimensions) {
- if (auto* var_user = sem.Get<sem::VariableUser>(expr->args[0])) {
+ if (auto* var_user =
+ sem.Get(expr->args[0])->UnwrapLoad()->As<sem::VariableUser>()) {
auto it = new_binding_symbols.find(var_user->Variable());
if (it == new_binding_symbols.end()) {
// If valid new binding locations were not provided earlier, we would have
@@ -222,7 +223,7 @@
// texture_external parameter. These need to be expanded out to multiple plane
// textures and the texture parameters structure.
for (auto* arg : expr->args) {
- if (auto* var_user = sem.Get<sem::VariableUser>(arg)) {
+ if (auto* var_user = sem.Get(arg)->UnwrapLoad()->As<sem::VariableUser>()) {
// Check if a parameter is a texture_external by trying to find
// it in the transform state.
auto it = new_binding_symbols.find(var_user->Variable());
