http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58963
Bug ID: 58963
Summary: Does C++ need flag_complex_method = 2?
Product: gcc
Version: 4.9.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: congh at google dot com
In the patch http://gcc.gnu.org/ml/gcc-patches/2005-02/msg00560.html, the
builtin function is used to perform complex multiplication and division. This
is to comply with C99 standard, but I am wondering if C++ also needs this.
There is no complex keyword in C++, and no content in C++ standard of the
behavior of operations on complex types. <complex> header file is all written
in source code, including complex multiplication and division. GCC should not
do too much for them by using builtin calls by default (also we can set
-fcx-limited-range to prevent GCC doing this), which has a big impact on
performance (let alone there may exist vectorization opportunities).
So I propose to not set flag_complex_method to 2 for C++. Any comment?
thanks,
Cong
