From: Hans Kristian Rosbach <hk-git@circlestorm.org>
Date: Wed, 14 Jan 2026 20:18:56 +0000 (+0100)
Subject: Unify compare256/compare256_rle benchmarks and add rolling misalignment
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b7cd3d8d8589ad061b04fcb519e2c2d0212483f7;p=thirdparty%2Fzlib-ng.git

Unify compare256/compare256_rle benchmarks and add rolling misalignment
---

diff --git a/test/benchmarks/benchmark_compare256.cc b/test/benchmarks/benchmark_compare256.cc
index 6853ca2b1..4b616f5a5 100644
--- a/test/benchmarks/benchmark_compare256.cc
+++ b/test/benchmarks/benchmark_compare256.cc
@@ -3,19 +3,16 @@
  * For conditions of distribution and use, see copyright notice in zlib.h
  */
 
-#include <stdio.h>
-
 #include <benchmark/benchmark.h>
 
 extern "C" {
 #  include "zbuild.h"
-#  include "zutil_p.h"
 #  include "arch_functions.h"
 #  include "../test_cpu_features.h"
 #  include "arch/generic/compare256_p.h"
 }
 
-#define MAX_COMPARE_SIZE (256)
+#define MAX_COMPARE_SIZE (256 + 64)
 
 class compare256: public benchmark::Fixture {
 private:
@@ -23,41 +20,53 @@ private:
     uint8_t *str2;
 
 public:
-    void SetUp(const ::benchmark::State&) {
-        str1 = (uint8_t *)zng_alloc(MAX_COMPARE_SIZE);
-        assert(str1 != NULL);
-        memset(str1, 'a', MAX_COMPARE_SIZE);
+    void SetUp(::benchmark::State& state) {
+        str1 = (uint8_t *)malloc(MAX_COMPARE_SIZE);
+        str2 = (uint8_t *)malloc(MAX_COMPARE_SIZE);
+        if (str1 == NULL || str2 == NULL) {
+            state.SkipWithError("malloc failed");
+            return;
+        }
 
-        str2 = (uint8_t *)zng_alloc(MAX_COMPARE_SIZE);
-        assert(str2 != NULL);
+        memset(str1, 'a', MAX_COMPARE_SIZE);
         memset(str2, 'a', MAX_COMPARE_SIZE);
     }
 
+    // Benchmark compare256, with rolling buffer misalignment for consistent results
     void Bench(benchmark::State& state, compare256_func compare256) {
+        int misalign = 0;
         int32_t match_len = (int32_t)state.range(0) - 1;
         uint32_t len = 0;
 
-        str2[match_len] = 0;
         for (auto _ : state) {
-            len = compare256((const uint8_t *)str1, (const uint8_t *)str2);
+            str2[match_len + misalign] = 0;   // Set new match limit
+
+            len = compare256((const uint8_t *)str1 + misalign, (const uint8_t *)str2 + misalign);
+
+            str2[match_len + misalign] = 'a'; // Reset match limit
+
+            if (misalign >= 63)
+                misalign = 0;
+            else
+                misalign++;
         }
-        str2[match_len] = 'a';
 
+        // Prevent the result from being optimized away
         benchmark::DoNotOptimize(len);
     }
 
     void TearDown(const ::benchmark::State&) {
-        zng_free(str1);
-        zng_free(str2);
+        free(str1);
+        free(str2);
     }
 };
 
-#define BENCHMARK_COMPARE256(name, fptr, support_flag) \
+#define BENCHMARK_COMPARE256(name, comparefunc, support_flag) \
     BENCHMARK_DEFINE_F(compare256, name)(benchmark::State& state) { \
         if (!(support_flag)) { \
             state.SkipWithError("CPU does not support " #name); \
         } \
-        Bench(state, fptr); \
+        Bench(state, comparefunc); \
     } \
     BENCHMARK_REGISTER_F(compare256, name)->Arg(1)->Arg(10)->Arg(40)->Arg(80)->Arg(100)->Arg(175)->Arg(256);
 
diff --git a/test/benchmarks/benchmark_compare256_rle.cc b/test/benchmarks/benchmark_compare256_rle.cc
index c7da50511..7e6551dbd 100644
--- a/test/benchmarks/benchmark_compare256_rle.cc
+++ b/test/benchmarks/benchmark_compare256_rle.cc
@@ -3,17 +3,14 @@
  * For conditions of distribution and use, see copyright notice in zlib.h
  */
 
-#include <stdio.h>
-
 #include <benchmark/benchmark.h>
 
 extern "C" {
 #  include "zbuild.h"
-#  include "zutil_p.h"
 #  include "compare256_rle.h"
 }
 
-#define MAX_COMPARE_SIZE (256)
+#define MAX_COMPARE_SIZE (256 + 64)
 
 class compare256_rle: public benchmark::Fixture {
 private:
@@ -21,43 +18,55 @@ private:
     uint8_t *str2;
 
 public:
-    void SetUp(const ::benchmark::State&) {
-        str1 = (uint8_t *)zng_alloc(MAX_COMPARE_SIZE);
-        assert(str1 != NULL);
-        memset(str1, 'a', MAX_COMPARE_SIZE);
+    void SetUp(::benchmark::State& state) {
+        str1 = (uint8_t *)malloc(MAX_COMPARE_SIZE);
+        str2 = (uint8_t *)malloc(MAX_COMPARE_SIZE);
+        if (str1 == NULL || str2 == NULL) {
+            state.SkipWithError("malloc failed");
+            return;
+        }
 
-        str2 = (uint8_t *)zng_alloc(MAX_COMPARE_SIZE);
-        assert(str2 != NULL);
+        memset(str1, 'a', MAX_COMPARE_SIZE);
         memset(str2, 'a', MAX_COMPARE_SIZE);
     }
 
+    // Benchmark compare256_rle, with rolling buffer misalignment for consistent results
     void Bench(benchmark::State& state, compare256_rle_func compare256_rle) {
+        int misalign = 0;
         int32_t match_len = (int32_t)state.range(0) - 1;
         uint32_t len = 0;
 
-        str2[match_len] = 0;
         for (auto _ : state) {
-            len = compare256_rle((const uint8_t *)str1, (const uint8_t *)str2);
+            str2[match_len + misalign] = 0;   // Set new match limit
+
+            len = compare256_rle((const uint8_t *)str1 + misalign, (const uint8_t *)str2 + misalign);
+
+            str2[match_len + misalign] = 'a'; // Reset match limit
+
+            if (misalign >= 63)
+                misalign = 0;
+            else
+                misalign++;
         }
-        str2[match_len] = 'a';
 
+        // Prevent the result from being optimized away
         benchmark::DoNotOptimize(len);
     }
 
     void TearDown(const ::benchmark::State&) {
-        zng_free(str1);
-        zng_free(str2);
+        free(str1);
+        free(str2);
     }
 };
 
-#define BENCHMARK_COMPARE256_RLE(name, fptr, support_flag) \
+#define BENCHMARK_COMPARE256_RLE(name, comparefunc, support_flag) \
     BENCHMARK_DEFINE_F(compare256_rle, name)(benchmark::State& state) { \
         if (!(support_flag)) { \
             state.SkipWithError("CPU does not support " #name); \
         } \
-        Bench(state, fptr); \
+        Bench(state, comparefunc); \
     } \
-    BENCHMARK_REGISTER_F(compare256_rle, name)->Range(1, MAX_COMPARE_SIZE);
+    BENCHMARK_REGISTER_F(compare256_rle, name)->Arg(1)->Arg(10)->Arg(40)->Arg(80)->Arg(100)->Arg(175)->Arg(256);;
 
 BENCHMARK_COMPARE256_RLE(8, compare256_rle_8, 1);
 BENCHMARK_COMPARE256_RLE(16, compare256_rle_16, 1);