[benchmarks] Align buf to cache line for consistency

Author: jacobsandlund

src/benchmark/CodepointWidth.zig

@@ -109,7 +109,7 @@ fn stepWcwidth(ptr: *anyopaque) Benchmark.Error!void {
     const f = self.data_f orelse return;
     var r = std.io.bufferedReader(f.reader());
     var d: UTF8Decoder = .{};
-    var buf: [4096]u8 = undefined;
+    var buf: [4096]u8 align(std.atomic.cache_line) = undefined;
     while (true) {
         const n = r.read(&buf) catch |err| {
             log.warn("error reading data file err={}", .{err});
@@ -133,7 +133,7 @@ fn stepTable(ptr: *anyopaque) Benchmark.Error!void {
     const f = self.data_f orelse return;
     var r = std.io.bufferedReader(f.reader());
     var d: UTF8Decoder = .{};
-    var buf: [4096]u8 = undefined;
+    var buf: [4096]u8 align(std.atomic.cache_line) = undefined;
     while (true) {
         const n = r.read(&buf) catch |err| {
             log.warn("error reading data file err={}", .{err});
@@ -162,7 +162,7 @@ fn stepSimd(ptr: *anyopaque) Benchmark.Error!void {
     const f = self.data_f orelse return;
     var r = std.io.bufferedReader(f.reader());
     var d: UTF8Decoder = .{};
-    var buf: [4096]u8 = undefined;
+    var buf: [4096]u8 align(std.atomic.cache_line) = undefined;
     while (true) {
         const n = r.read(&buf) catch |err| {
             log.warn("error reading data file err={}", .{err});

src/benchmark/GraphemeBreak.zig

@@ -92,7 +92,7 @@ fn stepNoop(ptr: *anyopaque) Benchmark.Error!void {
     const f = self.data_f orelse return;
     var r = std.io.bufferedReader(f.reader());
     var d: UTF8Decoder = .{};
-    var buf: [4096]u8 = undefined;
+    var buf: [4096]u8 align(std.atomic.cache_line) = undefined;
     while (true) {
         const n = r.read(&buf) catch |err| {
             log.warn("error reading data file err={}", .{err});
@@ -114,7 +114,7 @@ fn stepTable(ptr: *anyopaque) Benchmark.Error!void {
     var d: UTF8Decoder = .{};
     var state: unicode.GraphemeBreakState = .{};
     var cp1: u21 = 0;
-    var buf: [4096]u8 = undefined;
+    var buf: [4096]u8 align(std.atomic.cache_line) = undefined;
     while (true) {
         const n = r.read(&buf) catch |err| {
             log.warn("error reading data file err={}", .{err});

src/benchmark/IsSymbol.zig

@@ -91,7 +91,7 @@ fn stepZiglyph(ptr: *anyopaque) Benchmark.Error!void {
     const f = self.data_f orelse return;
     var r = std.io.bufferedReader(f.reader());
     var d: UTF8Decoder = .{};
-    var buf: [4096]u8 = undefined;
+    var buf: [4096]u8 align(std.atomic.cache_line) = undefined;
     while (true) {
         const n = r.read(&buf) catch |err| {
             log.warn("error reading data file err={}", .{err});
@@ -115,7 +115,7 @@ fn stepTable(ptr: *anyopaque) Benchmark.Error!void {
     const f = self.data_f orelse return;
     var r = std.io.bufferedReader(f.reader());
     var d: UTF8Decoder = .{};
-    var buf: [4096]u8 = undefined;
+    var buf: [4096]u8 align(std.atomic.cache_line) = undefined;
     while (true) {
         const n = r.read(&buf) catch |err| {
             log.warn("error reading data file err={}", .{err});