webgpu: change matmul_webgpu tile size back to 16 (#1711)

kainino0x · annxingyuan · commit 5ed6901e084b · 2019-04-30T08:03:06.000-04:00
INTERNAL
Tile size of 32 is causing failures and weird stuff on Mac.

This was untested because WEBGPU_MATMUL_WORK_PER_THREAD defaults to 2
(and uses the packed version instead).
diff --git a/src/backends/webgpu/src/kernels/matmul_webgpu.ts b/src/backends/webgpu/src/kernels/matmul_webgpu.ts
@@ -23,7 +23,7 @@ export class MatMulProgram implements WebGPUProgram {
   dispatch: [number, number, number];
   variableNames = ['A', 'B'];
   uniforms = 'uint dimAOuter, dimInner, dimBOuter, batch;';
-  tileSize: [number, number] = [32, 32];  // Must be square.
+  tileSize: [number, number] = [16, 16];  // Must be square.
 
   constructor(outputShape: [number, number, number]) {
     this.outputShape = outputShape;
