halting analysis, it is illegal to delete a call to a read-only function.
The correct solution is almost certainly to add a "must halt" attribute and
only allow deletions in its presence.

XFAIL the relevant testcase for now.

llvm-svn: 102831

reflect that it includes all inlined calls now, not just
devirtualized ones.

llvm-svn: 102824

that appear due to inlining a callee as candidates for
futher inlining, but a recent patch made it do this if
those call sites were indirect and became direct.

Unfortunately, in bizarre cases (see testcase) doing this
can cause us to infinitely inline mutually recursive
functions into callers not in the cycle.  Fix this by
keeping track of the inline history from which callsite
inline candidates got inlined from.

This shouldn't affect any "real world" code, but is required
for a follow on patch that is coming up next.

llvm-svn: 102822

llvm-svn: 102296

the worklist, making them inline candidates.

llvm-svn: 102213

This fixes a bug where calls inlined into an invoke would get
changed into an invoke but the array would keep pointing to
the (now dead) call.  The improved inliner behavior is still
disabled for now.

llvm-svn: 102196

llvm-svn: 102153

that appear in the SCC as a result of inlining as candidates
for inlining.  Change this so that it *does* consider call 
sites that change from being indirect to being direct as a
result of inlining.  This allows it to completely 
"devirtualize" the testcase.

llvm-svn: 102146

arguments are handled with a new InlineFunctionInfo class.  This 
makes it easier to extend InlineFunction to return more info in the
future.

llvm-svn: 102137

llvm-svn: 101846

to CallGraphSCCPass's instead of passing around a
std::vector<CallGraphNode*>.  No functionality change,
but now we have a much tidier interface.

llvm-svn: 101558

The Caller cost info would be reset everytime a callee was inlined. If the
caller has lots of calls and there is some mutual recursion going on, the
caller cost info could be calculated many times.

This patch reduces inliner runtime from 240s to 0.5s for a function with 20000
small function calls.

This is a more conservative version of r98089 that doesn't break the clang
test CodeGenCXX/temp-order.cpp. That test relies on rather extreme inlining
for constant folding.

llvm-svn: 98099

llvm-svn: 98094

The Caller cost info would be reset everytime a callee was inlined. If the
caller has lots of calls and there is some mutual recursion going on, the
caller cost info could be calculated many times.

This patch reduces inliner runtime from 240s to 0.5s for a function with 20000
small function calls.

llvm-svn: 98089

llvm-svn: 98024

Functions explicitly marked inline will get an inlining threshold slightly
more aggressive than the default for -O3. This means than -O3 builds are
mostly unaffected while -Os builds will be a bit bigger and faster.

The difference depends entirely on how many 'inline's are sprinkled on the
source.

In the CINT2006 suite, only these tests are significantly affected under -Os:

               Size   Time
471.omnetpp   +1.63% -1.85%
473.astar     +4.01% -6.02%
483.xalancbmk +4.60%  0.00%

Note that 483.xalancbmk runs too quickly to give useful timing results.

llvm-svn: 96066

This time it's for real! I am going to hook this up in the frontends as well.

The inliner has some experimental heuristics for dealing with the inline hint.
When given a -respect-inlinehint option, functions marked with the inline
keyword are given a threshold just above the default for -O3.

We need some experiments to determine if that is the right thing to do.

llvm-svn: 95466

This makes the inliner about as agressive as it was before my changes to the
inliner cost calculations. These levels give the same performance and slightly
smaller code than before.

llvm-svn: 95320

No functional change except the forgotten test for
InlineLimit.getNumOccurrences() == 0 in the CurrentThreshold2 calculation.

llvm-svn: 94007

llvm-svn: 92625

llvm-svn: 87035

running IPSCCP early, and we run functionattrs interlaced with the inliner,
we often (particularly for small or noop functions) completely propagate
all of the information about a call to its call site in IPSSCP (making a call
dead) and functionattrs is smart enough to realize that the function is
readonly (because it is interlaced with inliner).

To improve compile time and make the inliner threshold more accurate, realize
that we don't have to inline dead readonly function calls.  Instead, just 
delete the call.  This happens all the time for C++ codes, here are some
counters from opt/llvm-ld counting the number of times calls were deleted vs
inlined on various apps:

Tramp3d opt:
  5033 inline                - Number of call sites deleted, not inlined
 24596 inline                - Number of functions inlined
llvm-ld:
  667 inline           - Number of functions deleted because all callers found
  699 inline           - Number of functions inlined

483.xalancbmk opt:
  8096 inline                - Number of call sites deleted, not inlined
 62528 inline                - Number of functions inlined
llvm-ld:
   217 inline           - Number of allocas merged together
  2158 inline           - Number of functions inlined

471.omnetpp:
  331 inline                - Number of call sites deleted, not inlined
 8981 inline                - Number of functions inlined
llvm-ld:
  171 inline           - Number of functions deleted because all callers found
  629 inline           - Number of functions inlined


Deleting a call is much faster than inlining it, and is insensitive to the
size of the callee. :)

llvm-svn: 86975

llvm-svn: 83998

constants used in inlining heuristics (especially
those used in more than one file).  No functional change.

llvm-svn: 83675

and that will make Caller too big to inline, see if it
might be better to inline Caller into its callers instead.
This situation is described in PR 2973, although I haven't
tried the specific case in SPASS.

llvm-svn: 83602

llvm-svn: 83274

llvm-svn: 80540

indirect function pointer, inline it, then go to delete the body.
The problem is that the callgraph had other references to the function,
though the inliner had no way to know it, so we got a dangling pointer
and an invalid iterator out of the deal.

The fix to this is pretty simple: stop the inliner from deleting the
function by knowing that there are references to it.  Do this by making
CallGraphNodes contain a refcount.  This requires moving deletion of 
available_externally functions to the module-level cleanup sweep where
it belongs.

llvm-svn: 80533

argpromotion and structretpromote.  Basically, when replacing
a function, they used the 'changeFunction' api which changes
the entry in the function map (and steals/reuses the callgraph
node).

This has some interesting effects: first, the problem is that it doesn't
update the "callee" edges in any callees of the function in the call graph.
Second, this covers for a major problem in all the CGSCC pass stuff, which 
is that it is completely broken when functions are deleted if they *don't*
reuse a CGN.  (there is a cute little fixme about this though :).

This patch changes the protocol that CGSCC passes must obey: now the CGSCC 
pass manager copies the SCC and preincrements its iterator to avoid passes
invalidating it.  This allows CGSCC passes to mutate the current SCC.  However
multiple passes may be run on that SCC, so if passes do this, they are now
required to *update* the SCC to be current when they return.

Other less interesting parts of this patch are that it makes passes update
the CG more directly, eliminates changeFunction, and requires clients of
replaceCallSite to specify the new callee CGN if they are changing it.

llvm-svn: 80527

llvm-svn: 80334

calls into a function and if the calls bring in arrays, try to merge
them together to reduce stack size.  For example, in the testcase
we'd previously end up with 4 allocas, now we end up with 2 allocas.

As described in the comments, this is not really the ideal solution
to this problem, but it is surprisingly effective.  For example, on
176.gcc, we end up eliminating 67 arrays at "gccas" time and another
24 at "llvm-ld" time.

One piece of concern that I didn't look into: at -O0 -g with
forced inlining this will almost certainly result in worse debug
info.  I think this is acceptable though given that this is a case
of "debugging optimized code", and we don't want debug info to
prevent the optimizer from doing things anyway.

llvm-svn: 80215

llvm-svn: 80204

and other code cleanups.  No functionality change.

llvm-svn: 80199

the command line.  This gives llvm-gcc developers
a way to control inlining (documented as "not intended
for end users").

llvm-svn: 79966

- One formatting change.

No intended functionality change.

llvm-svn: 77717

 - Some clients which used DOUT have moved to DEBUG. We are deprecating the
   "magic" DOUT behavior which avoided calling printing functions when the
   statement was disabled. In addition to being unnecessary magic, it had the
   downside of leaving code in -Asserts builds, and of hiding potentially
   unnecessary computations.

llvm-svn: 77019

instead of getAnalysis<TargetData>().

llvm-svn: 76982

llvm-svn: 76284

and it wasn't generating calls through @PLT for these functions.
hasLocalLinkage() is now false for available_externally,
I attempted to fix the inliner and dce to handle available_externally properly.
It passed make check.

llvm-svn: 72328

llvm-svn: 67578