[js/webgpu] minor fixes to make tinyllama work (#19564)

Author: guschmue

js/web/lib/wasm/jsep/webgpu/ops/concat.ts

@@ -154,7 +154,9 @@ const createConcatProgramInfo = (inputs: readonly TensorView[], axis: number): P
 
 export const concat = (context: ComputeContext, attributes: ConcatAttributes): void => {
   validateInputs(context.inputs);
-  context.compute(createConcatProgramInfo(context.inputs, attributes.axis));
+  // 0 length tensors are valid for concat, remove them
+  const nonEmptyInputs = context.inputs.filter(input => ShapeUtil.size(input.dims) > 0);
+  context.compute(createConcatProgramInfo(nonEmptyInputs, attributes.axis), {inputs: nonEmptyInputs});
 };
 
 export const parseConcatAttributes = (attributes: Record<string, unknown>): ConcatAttributes =>

js/web/lib/wasm/jsep/webgpu/ops/gather.ts

@@ -55,7 +55,7 @@ const createGatherProgramInfo = (inputs: readonly TensorView[], attributes: Gath
           if (idx${x} < 0) {
             idx${x} = idx${x} + uniforms.axisDimLimit;
           }
-          var dataIndices${x} = ${data.type.indices}(0);
+          var dataIndices${x} : ${data.type.indices};
         `;
       for (let i = 0, j = 0; i < inputRank; i++) {
         if (i === axis) {