"fix" backprop large bench on gpu

juno_samples/rodinia/backprop/benches/backprop_bench.rs

@@ -68,7 +68,7 @@ fn backprop_bench(c: &mut Criterion) {
     };
 
     bench("backprop bench small", 65536);
-    bench("backprop bench large", 33554432);
+    bench("backprop bench large", 1048576);
 }
 
 criterion_group!(benches, backprop_bench);

juno_samples/rodinia/backprop/src/gpu.sch

@@ -33,10 +33,10 @@ fixpoint {
 reduce-slf(*);
 simpl!(*);
 
-fork-extend[32](layer_forward@inner_loop);
+fork-extend[1024](layer_forward@inner_loop);
 clean-monoid-reduces(layer_forward);
 simpl!(layer_forward);
-fork-tile[32, 0, false, true](layer_forward@inner_loop);
+fork-tile[1024, 0, false, true](layer_forward@inner_loop);
 clean-monoid-reduces(layer_forward);
 let out = fork-split(layer_forward@inner_loop);
 clean-monoid-reduces(layer_forward);