Cherry pick d274861 to actually fix the vector interleave bug in Vulkan . (#9075)

Cherry pick d274861 to actually fix the vulkan shuffle bug.

Author: mcourteaux

src/CodeGen_Vulkan_Dev.cpp

@@ -2086,31 +2086,21 @@ void CodeGen_Vulkan_Dev::SPIRV_Emitter::visit(const Shuffle *op) {
         debug(3) << "\n";
 
         if (arg_ids.size() == 1) {
-
             // 1 argument, just do a simple assignment via a cast
             SpvId result_id = cast_type(op->type, op->vectors[0].type(), arg_ids[0]);
             builder.update_id(result_id);
 
         } else if (arg_ids.size() == 2) {
-
-            // 2 arguments, use a composite insert to update even and odd indices
-            uint32_t even_idx = 0;
-            uint32_t odd_idx = 1;
-            SpvFactory::Indices even_indices;
-            SpvFactory::Indices odd_indices;
-            for (int i = 0; i < op_lanes; ++i) {
-                even_indices.push_back(even_idx);
-                odd_indices.push_back(odd_idx);
-                even_idx += 2;
-                odd_idx += 2;
+            // 2 arguments, use vector-shuffle with logical indices indexing into (vec1[0], vec1[1], ..., vec2[0], vec2[1], ...)
+            SpvFactory::Indices logical_indices;
+            for (int i = 0; i < arg_lanes; ++i) {
+                logical_indices.push_back(uint32_t(i));
+                logical_indices.push_back(uint32_t(i + arg_lanes));
             }
 
             SpvId type_id = builder.declare_type(op->type);
-            SpvId value_id = builder.declare_null_constant(op->type);
-            SpvId partial_id = builder.reserve_id(SpvResultId);
             SpvId result_id = builder.reserve_id(SpvResultId);
-            builder.append(SpvFactory::composite_insert(type_id, partial_id, arg_ids[0], value_id, even_indices));
-            builder.append(SpvFactory::composite_insert(type_id, result_id, arg_ids[1], partial_id, odd_indices));
+            builder.append(SpvFactory::vector_shuffle(type_id, result_id, arg_ids[0], arg_ids[1], logical_indices));
             builder.update_id(result_id);
 
         } else {
@@ -2140,7 +2130,7 @@ void CodeGen_Vulkan_Dev::SPIRV_Emitter::visit(const Shuffle *op) {
     } else if (op->is_extract_element()) {
         int idx = op->indices[0];
         internal_assert(idx >= 0);
-        internal_assert(idx <= op->vectors[0].type().lanes());
+        internal_assert(idx < op->vectors[0].type().lanes());
         if (op->vectors[0].type().is_vector()) {
             SpvFactory::Indices indices = {(uint32_t)idx};
             SpvId type_id = builder.declare_type(op->type);