From 88c62cc7f616cf95e4e5ff1035929b857e573ecc Mon Sep 17 00:00:00 2001
From: Dmitry Arkhipov <grisumbras@yandex.ru>
Date: Sat, 30 Sep 2023 14:30:36 +0300
Subject: [PATCH] temp

---
 include/boost/json/detail/sse2.hpp | 33 ++++++++++++++++++++++--------
 1 file changed, 25 insertions(+), 8 deletions(-)

diff --git a/include/boost/json/detail/sse2.hpp b/include/boost/json/detail/sse2.hpp
index da660274b..c334b5bae 100644
--- a/include/boost/json/detail/sse2.hpp
+++ b/include/boost/json/detail/sse2.hpp
@@ -315,17 +315,34 @@ inline int count_digits( char const* p ) noexcept
 
 inline uint64_t parse_unsigned( uint64_t r, char const * p, std::size_t n ) noexcept
 {
-    constexpr int N = 4;
-    auto const e = p + n;
-    for( ; (e - p) >= N; p += N )
+    while( n >= 4 )
     {
-        for( auto i = 0; i < N; ++i )
-            r = r * 10 + p[i] - '0';
-    }
+        r = r * 10 + p[0] - '0';
+        r = r * 10 + p[1] - '0';
+        r = r * 10 + p[2] - '0';
+        r = r * 10 + p[3] - '0';
 
-    for( ; p != e; ++p )
-        r = r * 10 + *p - '0';
+        p += 4;
+        n -= 4;
+    }
 
+    switch( n )
+    {
+    case 0:
+        break;
+    case 1:
+        r = r * 10 + p[0] - '0';
+        break;
+    case 2:
+        r = r * 10 + p[0] - '0';
+        r = r * 10 + p[1] - '0';
+        break;
+    case 3:
+        r = r * 10 + p[0] - '0';
+        r = r * 10 + p[1] - '0';
+        r = r * 10 + p[2] - '0';
+        break;
+    }
     return r;
 }