From 113e89b389505ade3687c63b1de31a7647cead70 Mon Sep 17 00:00:00 2001
From: Jacob Sandlund <jacob@jacobsandlund.com>
Date: Sat, 6 Sep 2025 15:06:00 -0400
Subject: [PATCH] [benchmarks] Use std.mem.doNotOptimizeAway to avoid data
 collisions

---
 src/benchmark/CodepointWidth.zig | 20 ++++----------------
 src/benchmark/GraphemeBreak.zig  |  3 +--
 2 files changed, 5 insertions(+), 18 deletions(-)

diff --git a/src/benchmark/CodepointWidth.zig b/src/benchmark/CodepointWidth.zig
index e9207aed5..406603ceb 100644
--- a/src/benchmark/CodepointWidth.zig
+++ b/src/benchmark/CodepointWidth.zig
@@ -121,11 +121,7 @@ fn stepWcwidth(ptr: *anyopaque) Benchmark.Error!void {
             const cp_, const consumed = d.next(c);
             assert(consumed);
             if (cp_) |cp| {
-                const width = wcwidth(cp);
-
-                // Write the width to the buffer to avoid it being compiled
-                // away
-                buf[0] = @intCast(width);
+                std.mem.doNotOptimizeAway(wcwidth(cp));
             }
         }
     }
@@ -151,14 +147,10 @@ fn stepTable(ptr: *anyopaque) Benchmark.Error!void {
             if (cp_) |cp| {
                 // This is the same trick we do in terminal.zig so we
                 // keep it here.
-                const width = if (cp <= 0xFF)
+                std.mem.doNotOptimizeAway(if (cp <= 0xFF)
                     1
                 else
-                    table.get(@intCast(cp)).width;
-
-                // Write the width to the buffer to avoid it being compiled
-                // away
-                buf[0] = @intCast(width);
+                    table.get(@intCast(cp)).width);
             }
         }
     }
@@ -182,11 +174,7 @@ fn stepSimd(ptr: *anyopaque) Benchmark.Error!void {
             const cp_, const consumed = d.next(c);
             assert(consumed);
             if (cp_) |cp| {
-                const width = simd.codepointWidth(cp);
-
-                // Write the width to the buffer to avoid it being compiled
-                // away
-                buf[0] = @intCast(width);
+                std.mem.doNotOptimizeAway(simd.codepointWidth(cp));
             }
         }
     }
diff --git a/src/benchmark/GraphemeBreak.zig b/src/benchmark/GraphemeBreak.zig
index 57effebe4..86661f985 100644
--- a/src/benchmark/GraphemeBreak.zig
+++ b/src/benchmark/GraphemeBreak.zig
@@ -126,8 +126,7 @@ fn stepTable(ptr: *anyopaque) Benchmark.Error!void {
             const cp_, const consumed = d.next(c);
             assert(consumed);
             if (cp_) |cp2| {
-                const v = unicode.graphemeBreak(cp1, @intCast(cp2), &state);
-                buf[0] = @intCast(@intFromBool(v));
+                std.mem.doNotOptimizeAway(unicode.graphemeBreak(cp1, @intCast(cp2), &state));
                 cp1 = cp2;
             }
         }