Remove unnecessary usize casts (#34)

Author: LegNeato

blog/2024-11-21-optimizing-matrix-mul/code/crates/gpu/tiling_2d/src/lib.rs

@@ -14,8 +14,8 @@ pub fn matmul(
     #[spirv(storage_buffer, descriptor_set = 0, binding = 2)] b: &[f32],
     #[spirv(storage_buffer, descriptor_set = 0, binding = 3)] result: &mut [f32],
 ) {
-    let row = (global_id.y * TILE_M as u32) as usize;
-    let col = (global_id.x * TILE_N as u32) as usize;
+    let row = (global_id.y * TILE_M) as usize;
+    let col = (global_id.x * TILE_N) as usize;
 
     // Initialize sums array to zeros
     // Note: This is uglier than it needs to be to work around
@@ -33,7 +33,7 @@ pub fn matmul(
 
             for j in 0..TILE_N as usize {
                 let b_element = if col + j < dimensions.n as usize {
-                    b[k * dimensions.n as usize + (col + j as usize)]
+                    b[k * dimensions.n as usize + (col + j)]
                 } else {
                     0.0
                 };
@@ -46,8 +46,8 @@ pub fn matmul(
     // Write results
     for i in 0..TILE_M as usize {
         for j in 0..TILE_N as usize {
-            let output_row = row + i as usize;
-            let output_col = col + j as usize;
+            let output_row = row + i;
+            let output_col = col + j;
 
             if output_row < dimensions.m as usize && output_col < dimensions.n as usize {
                 result[output_row * dimensions.n as usize + output_col] = sums[i][j];