From: Jonathan Wakely <jwakely@redhat.com>
Date: Wed, 4 Jul 2018 14:31:56 +0000 (+0100)
Subject: Fix std::__rotl and std::__rotr
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=4e4120a27ac1e2abd4a5309aefcc4ba0dac45784;p=gcc.git

Fix std::__rotl and std::__rotr

2018-07-04  Jonathan Wakely  <jwakely@redhat.com>
	    Jakub Jelinek  <jakub@redhat.com>

	* include/std/bit (__rotl, __rotr): Fix for non-power of two sizes.

Co-Authored-By: Jakub Jelinek <jakub@redhat.com>

From-SVN: r262414
---

diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index fa92b4bb489..b1747e82cb8 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,8 @@
+2018-07-04  Jonathan Wakely  <jwakely@redhat.com>
+	    Jakub Jelinek  <jakub@redhat.com>
+
+	* include/std/bit (__rotl, __rotr): Fix for non-power of two sizes.
+
 2018-07-04  Jonathan Wakely  <jwakely@redhat.com>
 
 	PR libstdc++/86398
diff --git a/libstdc++-v3/include/std/bit b/libstdc++-v3/include/std/bit
index ace88954030..a23f2ba60d1 100644
--- a/libstdc++-v3/include/std/bit
+++ b/libstdc++-v3/include/std/bit
@@ -46,7 +46,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     {
       constexpr auto _Nd = numeric_limits<_Tp>::digits;
       const unsigned __sN = __s % _Nd;
-      return (__x << __sN) | (__x >> ((-__sN) % _Nd));
+      return (__x << __sN) | (__x >> ((_Nd - __sN) % _Nd));
     }
 
   template<typename _Tp>
@@ -55,7 +55,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     {
       constexpr auto _Nd = numeric_limits<_Tp>::digits;
       const unsigned __sN = __s % _Nd;
-      return (__x >> __sN) | (__x << ((-__sN) % _Nd));
+      return (__x >> __sN) | (__x << ((_Nd - __sN) % _Nd));
     }
 
   template<typename _Tp>