gcc-wwwdocs branch master updated. 9b8a31d640d1c508be86637b6d82fcabf4d31590

[Thomas Kﾃｶnig <tkoenig@sourceware.org>]

This is an automated email from the git hooks/post-receive script. It was
generated because a ref change was pushed to the repository containing
the project "gcc-wwwdocs".

The branch, master has been updated
       via  9b8a31d640d1c508be86637b6d82fcabf4d31590 (commit)
      from  eba7cee0b803743191e292eed135d7c910255afd (commit)

Those revisions listed above that are new to this repository have
not appeared on any other notification email; so we list those
revisions in full, below.

- Log -----------------------------------------------------------------
commit 9b8a31d640d1c508be86637b6d82fcabf4d31590
Author: Thomas Koenig <tkoenig@gcc.gnu.org>
Date:   Sun Mar 19 08:43:15 2023 +0100

    Fix "doesn't"; add chapter on integer overflow for Fortran.
    
    Removed stuff.

diff --git a/htdocs/gcc-13/porting_to.html b/htdocs/gcc-13/porting_to.html
index 0ee58802..db0bf2fa 100644
--- a/htdocs/gcc-13/porting_to.html
+++ b/htdocs/gcc-13/porting_to.html
@@ -203,11 +203,27 @@ class Alloc
 <p>
 Since C++20, there is no <code>rebind</code> member in
 <code>std::allocator</code>, so deriving your own allocator types from
-<code>std::allocator</code> is simpler and doesn't require the derived
+<code>std::allocator</code> is simpler and does not require the derived
 allocator to provide its own <code>rebind</code>.
 For compatibility with previous C++ standards, the member should still be
 provided. The converting constructor is still required even in C++20.
 </p>
 
+<h2 id="fortran">Fortran language issues</h2>
+<h3 id="overflow">Behavior on integer overflow</h3>
+<p>
+GCC 13 includes new optimizations which may change behavior on
+integer overflow.  Traditional code, like linear congruential
+pseudo-random number generators in old programs and relying on a
+specific, non-standard behavior may now generate unexpected results.
+The option <code>-fsanitize=undefined</code> can be used to detect
+such code at runtime.
+</p>
+<p>
+It is recommended to use the intrinsic subroutine
+<code>RANDOM_NUMBER</code> for random number generators
+or, if the old behavior is desired, to use the <code>-fwrapv</code>
+option.  Note that this option can impact performance.
+</p>
 </body>
 </html>

-----------------------------------------------------------------------

Summary of changes:
 htdocs/gcc-13/porting_to.html | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)


hooks/post-receive
-- 
gcc-wwwdocs