tint/hlsl+glsl: fix workgroupUniformLoad polyfills

The BuiltinPolyfill transform expects the DirectVariableAccess transform
to run after it, but this regressed as part of
https://dawn-review.googlesource.com/c/dawn/+/122203

Add unit test along with e2e 1926.wgsl test.

Bug: tint:1926
Change-Id: I5107453ce152b12e6f2f36930846e1fffa775708
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/131020
Reviewed-by: James Price <jrprice@google.com>
Commit-Queue: Antonio Maiorano <amaiorano@google.com>
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: Ben Clayton <bclayton@google.com>

src/tint/transform/builtin_polyfill_test.cc

@@ -16,6 +16,7 @@
 
 #include <utility>
 
+#include "src/tint/transform/direct_variable_access.h"
 #include "src/tint/transform/test_helper.h"
 
 namespace tint::transform {
@@ -3673,8 +3674,23 @@ fn f() {
 DataMap polyfillWorkgroupUniformLoad() {
     BuiltinPolyfill::Builtins builtins;
     builtins.workgroup_uniform_load = true;
+
     DataMap data;
     data.Add<BuiltinPolyfill::Config>(builtins);
+
+    return data;
+}
+
+DataMap polyfillWorkgroupUniformLoadWithDirectVariableAccess() {
+    DataMap data;
+
+    BuiltinPolyfill::Builtins builtins;
+    builtins.workgroup_uniform_load = true;
+    data.Add<BuiltinPolyfill::Config>(builtins);
+
+    DirectVariableAccess::Options options;
+    data.Add<DirectVariableAccess::Config>(options);
+
     return data;
 }
 
@@ -3830,6 +3846,50 @@ fn f() {
     EXPECT_EQ(expect, str(got));
 }
 
+TEST_F(BuiltinPolyfillTest, WorkgroupUniformLoad_DirectVariableAccess) {
+    auto* src = R"(
+var<workgroup> v : i32;
+var<workgroup> v2 : i32;
+
+fn f() {
+  let r = workgroupUniformLoad(&v);
+  let s = workgroupUniformLoad(&v2);
+}
+)";
+
+    auto* expect = R"(
+enable chromium_experimental_full_ptr_parameters;
+
+fn tint_workgroupUniformLoad_v() -> i32 {
+  workgroupBarrier();
+  let result = v;
+  workgroupBarrier();
+  return result;
+}
+
+fn tint_workgroupUniformLoad_v2() -> i32 {
+  workgroupBarrier();
+  let result = v2;
+  workgroupBarrier();
+  return result;
+}
+
+var<workgroup> v : i32;
+
+var<workgroup> v2 : i32;
+
+fn f() {
+  let r = tint_workgroupUniformLoad_v();
+  let s = tint_workgroupUniformLoad_v2();
+}
+)";
+
+    auto got = Run<BuiltinPolyfill, DirectVariableAccess>(
+        src, polyfillWorkgroupUniformLoadWithDirectVariableAccess());
+
+    EXPECT_EQ(expect, str(got));
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // quantizeToF16
 ////////////////////////////////////////////////////////////////////////////////

src/tint/writer/glsl/generator_impl.cc

@@ -170,7 +170,6 @@ SanitizedResult Sanitize(const Program* in,
     manager.Add<transform::PreservePadding>();  // Must come before DirectVariableAccess
 
     manager.Add<transform::Unshadow>();  // Must come before DirectVariableAccess
-    manager.Add<transform::DirectVariableAccess>();
 
     manager.Add<transform::PromoteSideEffectsToDecl>();
 
@@ -203,9 +202,11 @@ SanitizedResult Sanitize(const Program* in,
         polyfills.texture_sample_base_clamp_to_edge_2d_f32 = true;
         polyfills.workgroup_uniform_load = true;
         data.Add<transform::BuiltinPolyfill::Config>(polyfills);
-        manager.Add<transform::BuiltinPolyfill>();
+        manager.Add<transform::BuiltinPolyfill>();  // Must come before DirectVariableAccess
     }
 
+    manager.Add<transform::DirectVariableAccess>();
+
     if (!options.disable_workgroup_init) {
         // ZeroInitWorkgroupMemory must come before CanonicalizeEntryPointIO as
         // ZeroInitWorkgroupMemory may inject new builtin parameters.

src/tint/writer/hlsl/generator_impl.cc

@@ -176,8 +176,6 @@ SanitizedResult Sanitize(const Program* in, const Options& options) {
 
     manager.Add<transform::Unshadow>();  // Must come before DirectVariableAccess
 
-    manager.Add<transform::DirectVariableAccess>();
-
     // LocalizeStructArrayAssignment must come after:
     // * SimplifyPointers, because it assumes assignment to arrays in structs are
     // done directly, not indirectly.
@@ -229,9 +227,11 @@ SanitizedResult Sanitize(const Program* in, const Options& options) {
         polyfills.texture_sample_base_clamp_to_edge_2d_f32 = true;
         polyfills.workgroup_uniform_load = true;
         data.Add<transform::BuiltinPolyfill::Config>(polyfills);
-        manager.Add<transform::BuiltinPolyfill>();
+        manager.Add<transform::BuiltinPolyfill>();  // Must come before DirectVariableAccess
     }
 
+    manager.Add<transform::DirectVariableAccess>();
+
     if (!options.disable_workgroup_init) {
         // ZeroInitWorkgroupMemory must come before CanonicalizeEntryPointIO as
         // ZeroInitWorkgroupMemory may inject new builtin parameters.

src/tint/writer/spirv/generator_impl.cc

@@ -119,7 +119,7 @@ SanitizedResult Sanitize(const Program* in, const Options& options) {
         polyfills.quantize_to_vec_f16 = true;  // crbug.com/tint/1741
         polyfills.workgroup_uniform_load = true;
         data.Add<transform::BuiltinPolyfill::Config>(polyfills);
-        manager.Add<transform::BuiltinPolyfill>();
+        manager.Add<transform::BuiltinPolyfill>();  // Must come before DirectVariableAccess
     }
 
     bool disable_workgroup_init_in_sanitizer =