From f71bfa68f6bb92fd9ba6a0e997dbf713658037e5 Mon Sep 17 00:00:00 2001
From: Fabio Scotto di Santolo <fabio.scottodisantolo@gmail.com>
Date: Fri, 19 Dec 2025 16:05:45 +0100
Subject: [PATCH] Added extra runner on Makefile

---
 Makefile            | 11 +++++-
 example/alignment.c | 83 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 93 insertions(+), 1 deletion(-)
 create mode 100644 example/alignment.c

diff --git a/Makefile b/Makefile
index 08b0893..abac185 100644
--- a/Makefile
+++ b/Makefile
@@ -16,7 +16,7 @@ $(OUT): $(SRC) $(LD_SCRIPT)
 clean:
 	rm -f $(OUT) kernel.map
 
-run: $(OUT)
+run-container: $(OUT)
 	distrobox enter archlinux -- qemu-system-riscv32 \
 				-machine virt \
 				-bios default \
@@ -24,3 +24,12 @@ run: $(OUT)
 				-serial mon:stdio \
 				-no-reboot \
 				-kernel $(OUT)
+
+run: $(OUT)
+	qemu-system-riscv32 \
+		-machine virt \
+		-bios default \
+		-nographic \
+		-serial mon:stdio \
+		-no-reboot \
+		-kernel $(OUT)
diff --git a/example/alignment.c b/example/alignment.c
new file mode 100644
index 0000000..84ba251
--- /dev/null
+++ b/example/alignment.c
@@ -0,0 +1,83 @@
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+#include <assert.h>
+
+// Define the number of iterations for the benchmark
+#define ARRAY_SIZE 50000000 // 50 Million random data points
+
+size_t align_up(size_t value, size_t align)
+{
+  size_t remainder = value % align;
+  if (remainder == 0)
+    return value;
+  return value + (align - remainder);
+}
+
+size_t align_arithmetic(size_t value, size_t alignment)
+{
+  return ((value + alignment - 1) / alignment) * alignment;
+}
+
+size_t align_bitwise(size_t value, size_t alignment)
+{
+  // TODO: assumendo che alignment è una potenza di 2 
+  return (value + alignment - 1) & ~(alignment - 1);
+}
+
+void benchmark(const char *name,
+	       size_t (*func)(size_t, size_t),
+	       size_t alignment,
+	       const size_t *data_array,
+	       long long num_elements)
+{
+  clock_t start, end;
+  double cpu_time_used;
+  size_t result_checksum = 0;
+
+  start = clock();
+  for (long long i = 0; i < num_elements; i++) {
+    result_checksum += func(data_array[i], alignment);
+  }
+  end = clock();
+  cpu_time_used = ((double) (end - start)) / CLOCKS_PER_SEC;
+  printf("  %-30s: %.4f seconds (Checksum: %zu)\n", name, cpu_time_used, result_checksum);
+}
+
+int main(void)
+{
+  size_t alignment_pot = 16;
+  size_t alignment_non_pot = 7;
+
+  printf("Generating %lld random input values...\n", (long long)ARRAY_SIZE);
+  srand((unsigned int)time(NULL));
+  size_t *random_data = (size_t *)malloc(ARRAY_SIZE * sizeof(size_t));
+  if (random_data == NULL) {
+    fprintf(stderr, "Memory allocation failed!\n");
+    return 1;
+  }
+  for (long long i = 0; i < ARRAY_SIZE; i++) {
+    // pseudo-random values up to 1MB
+    random_data[i] = rand() % (1024 * 1204);
+  }
+  printf("Data generation complete. \n\n");
+  printf("--- Alignment Function Stress Benchmark (%lld Random Inputs) --\n\n", (long long)ARRAY_SIZE);
+
+  // ================================== SCENARIO 1: Power-of-Two Alignment ======================
+  printf("Scenario 1: Alignment = %zu (Power of Two, Stress Test)\n", alignment_pot);
+
+  benchmark("1. Bitwise (PoT Specialized)", align_bitwise, alignment_pot, random_data, ARRAY_SIZE);
+  benchmark("2. Arithmetic (General)", align_arithmetic, alignment_pot, random_data, ARRAY_SIZE);
+  benchmark("3. Modulo (General)", align_up, alignment_pot, random_data, ARRAY_SIZE);
+
+// ================================== SCENARIO 2: Non-Power-of-Two Alignment ======================
+  printf("Scenario 2: Alignment = %zu (Non-Power of Two, Stress Test)\n", alignment_non_pot);
+
+  //benchmark("1. Bitwise (PoT Specialized)", align_bitwise, alignment_pot, random_data, ARRAY_SIZE);
+  benchmark("2. Arithmetic (General)", align_arithmetic, alignment_non_pot, random_data, ARRAY_SIZE);
+  benchmark("3. Modulo (General)", align_up, alignment_non_pot, random_data, ARRAY_SIZE);
+
+  free(random_data);
+  return 0;
+}