From a8d95fd51ab53f287ba107b1bdb792ab7edf05b9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kacper=20Michaj=C5=82ow?= <kasper93@gmail.com>
Date: Tue, 4 Jun 2024 20:55:33 +0200
Subject: [PATCH] bstr: use memchr and memrchr for bstrchr and bstrrchr

May be faster to use optimized variants instead of simple loop.
---
 meson.build |  2 ++
 misc/bstr.c | 15 +++++++++++----
 2 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/meson.build b/meson.build
index 0f692a8e87..d1eee06be4 100644
--- a/meson.build
+++ b/meson.build
@@ -428,6 +428,8 @@ endif
 
 features += {'ppoll': cc.has_function('ppoll', args: '-D_GNU_SOURCE',
                                       prefix: '#include <poll.h>')}
+features += {'memrchr': cc.has_function('memrchr', args: '-D_GNU_SOURCE',
+                                        prefix: '#include <string.h>')}
 
 cd_devices = {
     'windows': 'D:',
diff --git a/misc/bstr.c b/misc/bstr.c
index 379b2ed22d..b9a260f8e1 100644
--- a/misc/bstr.c
+++ b/misc/bstr.c
@@ -63,18 +63,25 @@ int bstrcasecmp(struct bstr str1, struct bstr str2)
 
 int bstrchr(struct bstr str, int c)
 {
-    for (int i = 0; i < str.len; i++)
-        if (str.start[i] == c)
-            return i;
-    return -1;
+    if (!str.len)
+        return -1;
+    unsigned char *pos = memchr(str.start, c, str.len);
+    return pos ? pos - str.start : -1;
 }
 
 int bstrrchr(struct bstr str, int c)
 {
+    if (!str.len)
+        return -1;
+#if HAVE_MEMRCHR
+    unsigned char *pos = memrchr(str.start, c, str.len);
+    return pos ? pos - str.start : -1;
+#else
     for (int i = str.len - 1; i >= 0; i--)
         if (str.start[i] == c)
             return i;
     return -1;
+#endif
 }
 
 int bstrcspn(struct bstr str, const char *reject)