Commit Graph

7 Commits

Author SHA1 Message Date
Chandler Carruth fcd33149b4 Cleanup the handling of noinline function attributes, -fno-inline,
-fno-inline-functions, -O0, and optnone.

These were really, really tangled together:
- We used the noinline LLVM attribute for -fno-inline
  - But not for -fno-inline-functions (breaking LTO)
  - But we did use it for -finline-hint-functions (yay, LTO is happy!)
  - But we didn't for -O0 (LTO is sad yet again...)
- We had weird structuring of CodeGenOpts with both an inlining
  enumeration and a boolean. They interacted in weird ways and
  needlessly.
- A *lot* of set smashing went on with setting these, and then got worse
  when we considered optnone and other inlining-effecting attributes.
- A bunch of inline affecting attributes were managed in a completely
  different place from -fno-inline.
- Even with -fno-inline we failed to put the LLVM noinline attribute
  onto many generated function definitions because they didn't show up
  as AST-level functions.
- If you passed -O0 but -finline-functions we would run the normal
  inliner pass in LLVM despite it being in the O0 pipeline, which really
  doesn't make much sense.
- Lastly, we used things like '-fno-inline' to manipulate the pass
  pipeline which forced the pass pipeline to be much more
  parameterizable than it really needs to be. Instead we can *just* use
  the optimization level to select a pipeline and control the rest via
  attributes.

Sadly, this causes a bunch of churn in tests because we don't run the
optimizer in the tests and check the contents of attribute sets. It
would be awesome if attribute sets were a bit more FileCheck friendly,
but oh well.

I think this is a significant improvement and should remove the semantic
need to change what inliner pass we run in order to comply with the
requested inlining semantics by relying completely on attributes. It
also cleans up tho optnone and related handling a bit.

One unfortunate aspect of this is that for generating alwaysinline
routines like those in OpenMP we end up removing noinline and then
adding alwaysinline. I tried a bunch of other approaches, but because we
recompute function attributes from scratch and don't have a declaration
here I couldn't find anything substantially cleaner than this.

Differential Revision: https://reviews.llvm.org/D28053

llvm-svn: 290398
2016-12-23 01:24:49 +00:00
James Molloy c16a60b63e [C++] Add the "norecurse" attribute to main() if in C++ mode
The C++ spec (3.6.1.3) says "The function `main` shall not be used within a program". This implies that it cannot recurse, so add the norecurse attribute to help the midend out a bit.

llvm-svn: 252902
2015-11-12 15:36:04 +00:00
Bill Wendling 2386bb130c Reapply r176133 with testcase fixes.
llvm-svn: 176145
2013-02-27 00:06:04 +00:00
Anna Zaks 0f424b029b Revert "Add more attributes from the command line to functions."
This reverts commit 176009.

The commit is a likely cause of several buildbot failures.

llvm-svn: 176044
2013-02-25 19:51:03 +00:00
Bill Wendling 87869db5f5 Add more attributes from the command line to functions.
This is an ongoing process. Any command line option which a back-end cares about
should be added here.

llvm-svn: 176009
2013-02-25 07:15:16 +00:00
Bill Wendling c33fc4c004 Modify the tests to use attribute group references instead of listing the
function attributes.

llvm-svn: 175606
2013-02-20 07:22:19 +00:00
Ted Kremenek e65b086e07 Add clang support for new Objective-C literal syntax for NSDictionary, NSArray,
NSNumber, and boolean literals.  This includes both Sema and Codegen support.
Included is also support for new Objective-C container subscripting.

My apologies for the large patch.  It was very difficult to break apart.
The patch introduces changes to the driver as well to cause clang to link
in additional runtime support when needed to support the new language features.

Docs are forthcoming to document the implementation and behavior of these features.

llvm-svn: 152137
2012-03-06 20:05:56 +00:00