1 files changed, 47 insertions, 0 deletions
diff --git a/research/experiments/045-proof-compiler/unit.c b/research/experiments/045-proof-compiler/unit.c
new file mode 100644
index 0000000..f85a4d9
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+++ b/research/experiments/045-proof-compiler/unit.c
@@ -0,0 +1,47 @@
+/* Research 045: an operation's cost in machine instructions and cycles, from small apps (the apps in units): each takes
+ * message go { n: u32 } and does its operation n times; MESSAGES messages, counted (perf_event_open, user mode).
+ *
+ *   cc -O2 -std=c17 -I../../../core unit.c ../../../build/libpure.a -lm -pthread -o unit
+ *   ./unit MODULE N MESSAGES     one JSON line: instructions and cycles an operation */
+#define _GNU_SOURCE
+#include "module.h"
+#include <linux/perf_event.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <sys/syscall.h>
+#include <unistd.h>
+
+static int counter(uint64_t config) {
+    struct perf_event_attr a;
+    memset(&a, 0, sizeof(a));
+    a.size = sizeof(a), a.type = PERF_TYPE_HARDWARE, a.config = config, a.disabled = 1, a.exclude_kernel = 1, a.exclude_hv = 1;
+    return (int)syscall(SYS_perf_event_open, &a, 0, -1, -1, 0);
+}
+
+int main(int argc, char **argv) {
+    if (argc != 4) { fprintf(stderr, "usage: %s MODULE N MESSAGES\n", argv[0]); return 2; }
+    uint32_t n = (uint32_t)atoi(argv[2]);
+    int messages = atoi(argv[3]);
+    PureModule module = {0};
+    char error[160];
+    if (pure_module_read(argv[1], &module, error, sizeof(error)) != PURE_OK) { fprintf(stderr, "%s\n", error); return 1; }
+    PureApp app;
+    if (pure_app_start(&app, &module, (PureData){0}) != PURE_OK) return 1;
+    int go = pure_module_input(&module, "go");
+    unsigned char payload[4];
+    memcpy(payload, &n, 4);
+    if (pure_app_message(&app, (uint32_t)go, (PureSpan){payload, 4}) != PURE_OK) { fprintf(stderr, "failed\n"); return 1; }
+    int ins = counter(PERF_COUNT_HW_INSTRUCTIONS), cyc = counter(PERF_COUNT_HW_CPU_CYCLES);
+    ioctl(ins, PERF_EVENT_IOC_ENABLE, 0), ioctl(cyc, PERF_EVENT_IOC_ENABLE, 0);
+    for (int k = 0; k < messages; ++k)
+        if (pure_app_message(&app, (uint32_t)go, (PureSpan){payload, 4}) != PURE_OK) return 1;
+    ioctl(ins, PERF_EVENT_IOC_DISABLE, 0), ioctl(cyc, PERF_EVENT_IOC_DISABLE, 0);
+    uint64_t i = 0, c = 0;
+    if (read(ins, &i, 8) != 8 || read(cyc, &c, 8) != 8) return 1;
+    double ops = (double)n * messages;
+    printf("{\"n\":%u,\"messages\":%d,\"instructions_per_op\":%.1f,\"cycles_per_op\":%.1f}\n", n, messages, i / ops, c / ops);
+    pure_app_stop(&app);
+    return 0;
+}