I disabled putting the new global into the same COMDAT as the function for now.
There's a fundamental problem when we inline references to the global but still
have the global in a COMDAT linked to the inlined function. Since this is only
an optimization there may be other versions of the COMDAT around that are
missing the new global and hell breaks loose at link time.
I hope the chromium build doesn't break this time :)
llvm-svn: 231564
This broke the Chromium build. Links were failing with messages like:
obj/dbus/libdbus_test_support.a(obj/dbus/dbus_test_support.mock_object_proxy.o):../../dbus/mock_object_proxy.cc:function dbus::MockObjectProxy::Detach(): warning: relocation refers to discarded section
/usr/local/google/work/chromium/src/third_party/binutils/Linux_x64/Release/bin/ld.gold: error: treating warnings as errors
llvm-svn: 231541
Instead of creating a copy on the stack just stash them in a private
constant global. This saves both the copying overhead and the stack
space, and gives the optimizer more room to constant fold.
This tries to make array temporaries more similar to regular arrays,
they can't use the same logic because a temporary has no VarDecl to be
bound to so we roll our own version here.
The original use case for this optimization was code like
for (int i : {1, 2, 3, 4, 5, 6, 7, 8, 10})
foo(i);
where without this patch (assuming that the loop is not unrolled) we
would alloca an array on the stack, copy the 10 values over and
iterate on that. With this patch we put the array in .text use it
directly. Apart from that case this helps on virtually any passing of
a constant std::initializer_list as a function argument.
Differential Revision: http://reviews.llvm.org/D8034
llvm-svn: 231508
This supports single-element initializer lists for references according to DR1288, as well as creating temporaries and binding to them for other initializer lists.
llvm-svn: 145186
Benjamin Kramer