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From: "dflogeras2 at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c++/67309] New: Error compiling with -std=c++11 and -fsingle-precision-constant
Date: Fri, 21 Aug 2015 16:39:00 -0000	[thread overview]
Message-ID: <bug-67309-4@http.gcc.gnu.org/bugzilla/> (raw)

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67309

            Bug ID: 67309
           Summary: Error compiling with -std=c++11 and
                    -fsingle-precision-constant
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: dflogeras2 at gmail dot com
  Target Milestone: ---

The ARM people recommend using -fsingle-precision-constant for targeting their
microcontrollers, such as the Cortex M4.  I am experimenting with using parts
of modern C++ on my uC projects.

If I compile the following (not just with arm cross compilers, even my native
linux compiler):

#include <algorithm>
int main() {}

with:
gcc test.cpp -fsingle-precision-constant -std=c++11 -c

It fails, since c++11 templating will not promote float types, and there is an
ambiguous 6.0 floating point constant in the bowels of the STL, which ends up
with a call to std::max<T>( float, double ) which is illegal.

Not sure what the proper fix is, and I'm also not sure why this used to compile
for me (same flags, gcc-4.7.3), but no longer does.


             reply	other threads:[~2015-08-21 16:39 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-08-21 16:39 dflogeras2 at gmail dot com [this message]
2015-08-21 18:26 ` [Bug libstdc++/67309] " redi at gcc dot gnu.org
2015-08-21 18:28 ` redi at gcc dot gnu.org
2015-08-21 19:58 ` dflogeras2 at gmail dot com
2015-08-21 20:25 ` redi at gcc dot gnu.org
2015-08-21 20:52 ` dflogeras2 at gmail dot com
2015-08-21 21:07 ` dflogeras2 at gmail dot com
2015-08-24 13:44 ` redi at gcc dot gnu.org
2015-08-24 13:49 ` redi at gcc dot gnu.org

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