[Bug c++/106131] [10/11/12/13 Regression] -fstrict-aliasing breaks normal program that does not use any pointer or reference

2022-06-29 Thread mpolacek at gcc dot gnu.org via Gcc-bugs 
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106131

--- Comment #5 from Marek Polacek  ---
Started with

commit 8403c2cf5f66758fc78a01a675b0d218fded0202
Author: Richard Biener 
Date:   Mon Nov 24 14:07:18 2014 +

re PR target/63679 ([AArch64] Failure to constant fold.)

2014-11-24  Richard Biener  

PR tree-optimization/63679
* tree-ssa-sccvn.c: Include ipa-ref.h, plugin-api.h and cgraph.h.
(copy_reference_ops_from_ref): Fix non-constant ADDR_EXPR case
to properly leave off at -1.
(fully_constant_vn_reference_p): Generalize folding from
constant initializers.
(vn_reference_lookup_3): When looking through aggregate copies
handle offsetted reads and try simplifying the result to
a constant.
* gimple-fold.h (fold_ctor_reference): Export.
* gimple-fold.c (fold_ctor_reference): Likewise.

* gcc.dg/tree-ssa/ssa-fre-42.c: New testcase.
* gcc.dg/tree-ssa/20030807-5.c: Avoid folding read from global to
zero.
* gcc.target/i386/ssetype-1.c: Likewise.
* gcc.target/i386/ssetype-3.c: Likewise.
* gcc.target/i386/ssetype-5.c: Likewise.

From-SVN: r218019

[Bug c++/106131] [10/11/12/13 Regression] -fstrict-aliasing breaks normal program that does not use any pointer or reference

2022-06-29 Thread pinskia at gcc dot gnu.org via Gcc-bugs 
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106131

Andrew Pinski  changed:

   What|Removed |Added

   Target Milestone|12.2|10.5

[Bug c++/106131] [10/11/12/13 Regression] -fstrict-aliasing breaks normal program that does not use any pointer or reference

2022-06-29 Thread pinskia at gcc dot gnu.org via Gcc-bugs 
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106131

Andrew Pinski  changed:

   What|Removed |Added

   Target Milestone|--- |12.2
Summary|-fstrict-aliasing breaks|[10/11/12/13 Regression]
   |normal program that does|-fstrict-aliasing breaks
   |not use any pointer or  |normal program that does
   |reference   |not use any pointer or
   ||reference
   Keywords||needs-bisection,
   ||needs-reduction

--- Comment #4 from Andrew Pinski  ---
This feels like a front-end issue ...