From: Victor Julien <vjulien@oisf.net>
Date: Mon, 26 Feb 2024 11:17:15 +0000 (+0100)
Subject: detect: optimize sig_cnt setting
X-Git-Tag: suricata-8.0.0-beta1~1672
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c4ac6cdc9a861973d3da5a4015c40210ebb6b3e0;p=thirdparty%2Fsuricata.git

detect: optimize sig_cnt setting

Utilize _popcnt64 where available.
---

diff --git a/configure.ac b/configure.ac
index c510e7fccb..1c0a39a5cc 100644
--- a/configure.ac
+++ b/configure.ac
@@ -219,6 +219,11 @@
         [], [
             #include <sys/random.h> 
             ])
+    AC_CHECK_DECL([_popcnt64],
+        AC_DEFINE([HAVE_POPCNT64], [1], [Use _popcnt64]),
+        [], [
+            #include <x86intrin.h> 
+            ])
 
     AC_CHECK_HEADERS([malloc.h])
     AC_CHECK_DECL([malloc_trim],
diff --git a/src/detect-engine-siggroup.c b/src/detect-engine-siggroup.c
index 4be0b1c264..b08218193a 100644
--- a/src/detect-engine-siggroup.c
+++ b/src/detect-engine-siggroup.c
@@ -437,6 +437,24 @@ error:
     return -1;
 }
 
+#ifdef HAVE_POPCNT64
+#include <x86intrin.h>
+static uint32_t Popcnt(const uint8_t *array, const uint32_t size)
+{
+    /* input needs to be a multiple of 8 for u64 casts to work */
+    DEBUG_VALIDATE_BUG_ON(size < 8);
+    DEBUG_VALIDATE_BUG_ON(size % 8);
+
+    uint32_t cnt = 0;
+    uint64_t *ptr = (uint64_t *)array;
+    for (uint64_t idx = 0; idx < size; idx += 8) {
+        cnt += _popcnt64(*ptr);
+        ptr++;
+    }
+    return cnt;
+}
+#endif
+
 /**
  * \brief Updates the SigGroupHead->sig_cnt with the total count of all the
  *        Signatures present in this SigGroupHead.
@@ -447,14 +465,17 @@ error:
  */
 void SigGroupHeadSetSigCnt(SigGroupHead *sgh, uint32_t max_idx)
 {
-    uint32_t sig;
     sgh->init->max_sig_id = MAX(max_idx, sgh->init->max_sig_id);
-    sgh->init->sig_cnt = 0;
-    for (sig = 0; sig < sgh->init->max_sig_id + 1; sig++) {
+#ifdef HAVE_POPCNT64
+    sgh->init->sig_cnt = Popcnt(sgh->init->sig_array, sgh->init->sig_size);
+#else
+    uint32_t cnt = 0;
+    for (uint32_t sig = 0; sig < sgh->init->max_sig_id + 1; sig++) {
         if (sgh->init->sig_array[sig / 8] & (1 << (sig % 8)))
-            sgh->init->sig_cnt++;
+            cnt++;
     }
-
+    sgh->init->sig_cnt = cnt;
+#endif
     return;
 }
 
diff --git a/src/suricata.c b/src/suricata.c
index 213f6d95e9..462537c14e 100644
--- a/src/suricata.c
+++ b/src/suricata.c
@@ -765,6 +765,9 @@ static void PrintBuildInfo(void)
     strlcat(features, "RUST ", sizeof(features));
 #if defined(SC_ADDRESS_SANITIZER)
     strlcat(features, "ASAN ", sizeof(features));
+#endif
+#if defined(HAVE_POPCNT64)
+    strlcat(features, "POPCNT64 ", sizeof(features));
 #endif
     if (strlen(features) == 0) {
         strlcat(features, "none", sizeof(features));