Commit Graph

5 Commits

Author SHA1 Message Date
Reid Kleckner
29f6900759 inalloca: *Really* fix the docs
llvm-svn: 204890
2014-03-27 01:38:48 +00:00
Reid Kleckner
98016cc9fe Remove unneeded stale type.
llvm-svn: 204889
2014-03-27 01:34:51 +00:00
Reid Kleckner
5602f267b5 inalloca: Fix incorrect example IR and remove LangRef warning
The LangRef warning wasn't formatting the way I intended it to anyway.

Surprisingly inalloca appears to work, even when optimizations are
enabled.  We generate very bad code for it, but we can self-host and run
lots of big tests.

llvm-svn: 204888
2014-03-27 01:32:22 +00:00
Reid Kleckner
e0ad0fd826 Change inalloca rules to make it only apply to the last parameter
This makes things a lot easier, because we can now talk about the
"argument allocation", which allocates all the memory for the call in
one shot.

The only functional change is to the verifier for a feature that hasn't
shipped yet.

llvm-svn: 199434
2014-01-16 22:59:24 +00:00
Reid Kleckner
f795c3e4a9 Begin adding docs and IR-level support for the inalloca attribute
The inalloca attribute is designed to support passing C++ objects by
value in the Microsoft C++ ABI.  It behaves the same as byval, except
that it always implies that the argument is in memory and that the bytes
are never copied.  This attribute allows the caller to take the address
of an outgoing argument's memory and execute arbitrary code to store
into it.

This patch adds basic IR support, docs, and verification.  It does not
attempt to implement any lowering or fix any possibly broken transforms.

When this patch lands, a complete description of this feature should
appear at http://llvm.org/docs/InAlloca.html .

Differential Revision: http://llvm-reviews.chandlerc.com/D2173

llvm-svn: 197645
2013-12-19 02:14:12 +00:00