Commit Graph

438 Commits

Author SHA1 Message Date
Eric Christopher
04bcc11905 Move DataLayout back to the TargetMachine from TargetSubtargetInfo
derived classes.

Since global data alignment, layout, and mangling is often based on the
DataLayout, move it to the TargetMachine. This ensures that global
data is going to be layed out and mangled consistently if the subtarget
changes on a per function basis. Prior to this all targets(*) have
had subtarget dependent code moved out and onto the TargetMachine.

*One target hasn't been migrated as part of this change: R600. The
R600 port has, as a subtarget feature, the size of pointers and
this affects global data layout. I've currently hacked in a FIXME
to enable progress, but the port needs to be updated to either pass
the 64-bitness to the TargetMachine, or fix the DataLayout to
avoid subtarget dependent features.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@227113 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-26 19:03:15 +00:00
Chandler Carruth
6f409cbc05 [PM] Rework how the TargetLibraryInfo pass integrates with the new pass
manager to support the actual uses of it. =]

When I ported instcombine to the new pass manager I discover that it
didn't work because TLI wasn't available in the right places. This is
a somewhat surprising and/or subtle aspect of the new pass manager
design that came up before but I think is useful to be reminded of:

While the new pass manager *allows* a function pass to query a module
analysis, it requires that the module analysis is already run and cached
prior to the function pass manager starting up, possibly with
a 'require<foo>' style utility in the pass pipeline. This is an
intentional hurdle because using a module analysis from a function pass
*requires* that the module analysis is run prior to entering the
function pass manager. Otherwise the other functions in the module could
be in who-knows-what state, etc.

A somewhat surprising consequence of this design decision (at least to
me) is that you have to design a function pass that leverages
a module analysis to do so as an optional feature. Even if that means
your function pass does no work in the absence of the module analysis,
you have to handle that possibility and remain conservatively correct.
This is a natural consequence of things being able to invalidate the
module analysis and us being unable to re-run it. And it's a generally
good thing because it lets us reorder passes arbitrarily without
breaking correctness, etc.

This ends up causing problems in one case. What if we have a module
analysis that is *definitionally* impossible to invalidate. In the
places this might come up, the analysis is usually also definitionally
trivial to run even while other transformation passes run on the module,
regardless of the state of anything. And so, it follows that it is
natural to have a hard requirement on such analyses from a function
pass.

It turns out, that TargetLibraryInfo is just such an analysis, and
InstCombine has a hard requirement on it.

The approach I've taken here is to produce an analysis that models this
flexibility by making it both a module and a function analysis. This
exposes the fact that it is in fact safe to compute at any point. We can
even make it a valid CGSCC analysis at some point if that is useful.
However, we don't want to have a copy of the actual target library info
state for each function! This state is specific to the triple. The
somewhat direct and blunt approach here is to turn TLI into a pimpl,
with the state and mutators in the implementation class and the query
routines primarily in the wrapper. Then the analysis can lazily
construct and cache the implementations, keyed on the triple, and
on-demand produce wrappers of them for each function.

One minor annoyance is that we will end up with a wrapper for each
function in the module. While this is a bit wasteful (one pointer per
function) it seems tolerable. And it has the advantage of ensuring that
we pay the absolute minimum synchronization cost to access this
information should we end up with a nice parallel function pass manager
in the future. We could look into trying to mark when analysis results
are especially cheap to recompute and more eagerly GC-ing the cached
results, or we could look at supporting a variant of analyses whose
results are specifically *not* cached and expected to just be used and
discarded by the consumer. Either way, these seem like incremental
enhancements that should happen when we start profiling the memory and
CPU usage of the new pass manager and not before.

The other minor annoyance is that if we end up using the TLI in both
a module pass and a function pass, those will be produced by two
separate analyses, and thus will point to separate copies of the
implementation state. While a minor issue, I dislike this and would like
to find a way to cleanly allow a single analysis instance to be used
across multiple IR unit managers. But I don't have a good solution to
this today, and I don't want to hold up all of the work waiting to come
up with one. This too seems like a reasonable thing to incrementally
improve later.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226981 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-24 02:06:09 +00:00
Chandler Carruth
eeeec3ce0d [PM] Separate the TargetLibraryInfo object from the immutable pass.
The pass is really just a means of accessing a cached instance of the
TargetLibraryInfo object, and this way we can re-use that object for the
new pass manager as its result.

Lots of delta, but nothing interesting happening here. This is the
common pattern that is developing to allow analyses to live in both the
old and new pass manager -- a wrapper pass in the old pass manager
emulates the separation intrinsic to the new pass manager between the
result and pass for analyses.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226157 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-15 10:41:28 +00:00
NAKAMURA Takumi
20b033eae5 Update libdeps since TLI was moved from Target to Analysis in r226078.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226126 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-15 05:21:00 +00:00
Chandler Carruth
bda134910a [PM] Move TargetLibraryInfo into the Analysis library.
While the term "Target" is in the name, it doesn't really have to do
with the LLVM Target library -- this isn't an abstraction which LLVM
targets generally need to implement or extend. It has much more to do
with modeling the various runtime libraries on different OSes and with
different runtime environments. The "target" in this sense is the more
general sense of a target of cross compilation.

This is in preparation for porting this analysis to the new pass
manager.

No functionality changed, and updates inbound for Clang and Polly.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226078 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-15 02:16:27 +00:00
Craig Topper
e34c5782a8 Remove an unnecessary reference variable that pointed to a unique_ptr variable. Just use the unique_ptr variable directly.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224104 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-12 07:52:06 +00:00
Craig Topper
2a4988e8fc Use unique_ptr operator= instead of constructor to make it explicit that there's no conversion occurring.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224103 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-12 07:52:00 +00:00
Craig Topper
4fca0dd75f Just use the Module unique_ptr object directly in many places instead of separate pointer that's kept in sync with it.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224004 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-11 07:04:52 +00:00
Craig Topper
11043f9faf Use unique_ptr to remove an explicit delete. Change return type to pass the unique_ptr to caller.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224003 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-11 07:04:46 +00:00
Rafael Espindola
3b670550ad Add doInitialization/doFinalization to DataLayoutPass.
With this a DataLayoutPass can be reused for multiple modules.

Once we have doInitialization/doFinalization, it doesn't seem necessary to pass
a Module to the constructor.

Overall this change seems in line with the idea of making DataLayout a required
part of Module. With it the only way of having a DataLayout used is to add it
to the Module.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217548 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-10 21:27:43 +00:00
Craig Topper
847998f0dd Use StringRef to avoid copies and simplify code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216822 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-30 16:48:22 +00:00
Rafael Espindola
81e49922a8 Return a std::unique_ptr from the IRReader.h functions. NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216466 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-26 17:29:46 +00:00
Rafael Espindola
8c96862847 Modernize raw_fd_ostream's constructor a bit.
Take a StringRef instead of a "const char *".
Take a "std::error_code &" instead of a "std::string &" for error.

A create static method would be even better, but this patch is already a bit too
big.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216393 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-25 18:16:47 +00:00
Eric Christopher
9f85dccfc6 Remove the TargetMachine forwards for TargetSubtargetInfo based
information and update all callers. No functional change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214781 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-04 21:25:23 +00:00
Eric Christopher
d1b5bdaebd Move MCOptions that aren't shared between programs into their specific
program and have them initialize the MCOptions struct explicitly.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209321 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-21 21:05:09 +00:00
Eric Christopher
9a37986328 Make a couple of command lines static and remove an unnecessary
initialization.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209320 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-21 21:05:05 +00:00
Eric Christopher
4f6d26dbe8 Move the verbose asm option to be part of the options struct and
set appropriately.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209258 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-20 23:59:50 +00:00
Eric Christopher
475ac5d302 Unify command line handling of MCTargetOptions and remove extra
options and code. No functional change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208833 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-15 01:10:50 +00:00
Eric Christopher
bfc3f301b6 Have the SubtargetFeature help routine just not return a number and
fall back to the normal path without a cpu. While doing this fix
llc to just exit when we don't have a module to process instead of
asserting.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208102 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-06 16:29:50 +00:00
Rafael Espindola
c6e42b5590 Remove the -disable-cfi option.
This also add a release note about it. If this stays I will cleanup MC
next week.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207977 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-05 17:33:26 +00:00
Benjamin Kramer
7259f14839 raw_ostream: Forward declare OpenFlags and include FileSystem.h only where necessary.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207593 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-29 23:26:49 +00:00
Craig Topper
573faecacf [C++] Use 'nullptr'. Tools edition.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207176 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-25 04:24:47 +00:00
Jim Grosbach
d023e14a5e llc: Add support for -mcpu=native.
When -mcpu=native is passed, autodetect the host CPU and pass that
as the CPU name to the TargetMachine factory method.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206095 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-12 01:34:31 +00:00
Ahmed Charles
f4ccd11075 Replace OwningPtr<T> with std::unique_ptr<T>.
This compiles with no changes to clang/lld/lldb with MSVC and includes
overloads to various functions which are used by those projects and llvm
which have OwningPtr's as parameters. This should allow out of tree
projects some time to move. There are also no changes to libs/Target,
which should help out of tree targets have time to move, if necessary.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203083 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-06 05:51:42 +00:00
Rafael Espindola
356deb5ecd Use DataLayout from the module when easily available.
Eventually DataLayoutPass should go away, but for now that is the only easy
way to get a DataLayout in some APIs. This patch only changes the ones that
have easy access to a Module.

One interesting issue with sometimes using DataLayoutPass and sometimes
fetching it from the Module is that we have to make sure they are equivalent.
We can get most of the way there by always constructing the pass with a Module.
In fact, the pass could be changed to point to an external DataLayout instead
of owning one to make this stricter.

Unfortunately, the C api passes a DataLayout, so it has to be up to the caller
to make sure the pass and the module are in sync.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@202204 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-25 23:25:17 +00:00
Rafael Espindola
57edc9d4ff Make DataLayout a plain object, not a pass.
Instead, have a DataLayoutPass that holds one. This will allow parts of LLVM
don't don't handle passes to also use DataLayout.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@202168 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-25 17:30:31 +00:00
Rafael Espindola
ac69459e0f Replace the F_Binary flag with a F_Text one.
After this I will set the default back to F_None. The advantage is that
before this patch forgetting to set F_Binary would corrupt a file on windows.
Forgetting to set F_Text produces one that cannot be read in notepad, which
is a better failure mode :-)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@202052 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-24 18:20:12 +00:00
Rafael Espindola
9f5066c72c Make DisableIntegratedAS a TargetOption.
This replaces the old NoIntegratedAssembler with at TargetOption. This is
more flexible and will be used to forward clang's -no-integrated-as option.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201836 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-21 03:13:54 +00:00
Rafael Espindola
ed6718d228 One last pass of DataLayout variable renaming.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201834 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-21 02:01:42 +00:00
Eli Bendersky
cf42174647 Refactor TargetOptions initialization into a single place.
The same code (~20 lines) for initializing a TargetOptions object from CodeGen
cmdline flags is duplicated 4 times in 4 different tools. This patch moves it
into a utility function.

Since the CodeGen/CommandFlags.h file defines cl::opt flags in a header, it's
a bit of a touchy situation because we should only link them into tools. So this
patch puts the init function in the header.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201699 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-19 17:09:35 +00:00
Rafael Espindola
f39297678b Remove support for not using .loc directives.
Clang itself was not using this. The only way to access it was via llc.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200862 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-05 18:00:21 +00:00
Juergen Ributzka
9ce88db752 Add target analysis passes to the codegen pipeline for MCJIT.
This patch adds the target analysis passes (usually TargetTransformInfo) to the
codgen pipeline. We also expose now the AddAnalysisPasses method through the C
API, because the optimizer passes would also benefit from better target-specific
cost models.

Reviewed by Andrew Kaylor

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199926 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-23 19:23:28 +00:00
Chandler Carruth
9f20a4c6ce Re-sort #include lines again, prior to moving headers around.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199080 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-13 08:04:33 +00:00
Chandler Carruth
8a5351f0f5 [PM] Rename the IR printing pass header to a more generic and correct
name to match the source file which I got earlier. Update the include
sites. Also modernize the comments in the header to use the more
recommended doxygen style.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199041 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-12 11:10:32 +00:00
Chandler Carruth
bc65a8d518 Move the LLVM IR asm writer header files into the IR directory, as they
are part of the core IR library in order to support dumping and other
basic functionality.

Rename the 'Assembly' include directory to 'AsmParser' to match the
library name and the only functionality left their -- printing has been
in the core IR library for quite some time.

Update all of the #includes to match.

All of this started because I wanted to have the layering in good shape
before I started adding support for printing LLVM IR using the new pass
infrastructure, and commandline support for the new pass infrastructure.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198688 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-07 12:34:26 +00:00
Nico Weber
94d1e67cb5 Port r198087 and r198089 (strip dead code by default) from make to cmake.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198198 91177308-0d34-0410-b5e6-96231b3b80d8
2013-12-30 03:36:05 +00:00
Nico Weber
5e7c782b29 Strip dead code when linking by default with BFD ld (linux, ...) and ld64 (os x).
This reduces the size of clang-format from 22 MB to 1.8 MB, diagtool goes from
21 MB to 2.8 MB, libclang.so goes from 29 MB to 20 MB, etc.  The size of the
bin/ folder shrinks from 270 MB to 200 MB.

Targets that support plugins and don't already use EXPORTED_SYMBOL_FILE
(which libclang and libLTO already do) can set NO_DEAD_STRIP to opt out.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198087 91177308-0d34-0410-b5e6-96231b3b80d8
2013-12-27 22:38:59 +00:00
NAKAMURA Takumi
3aabdebde2 [CMake] Update LLVM_LINK_COMPONENTS for each CMakeLists.txt.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@196908 91177308-0d34-0410-b5e6-96231b3b80d8
2013-12-10 11:13:32 +00:00
Will Dietz
7437feefbb Export symbols in tools that support loading plugins.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@196447 91177308-0d34-0410-b5e6-96231b3b80d8
2013-12-05 01:01:58 +00:00
Bill Wendling
61fc8d670f Use function attributes to indicate that we don't want to realign the stack.
Function attributes are the future! So just query whether we want to realign the
stack directly from the function instead of through a random target options
structure.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187618 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-01 21:42:05 +00:00
Bill Wendling
f245ae5a4a Replace the "NoFramePointerElimNonLeaf" target option with a function attribute.
There's no need to specify a flag to omit frame pointer elimination on non-leaf
nodes...(Honestly, I can't parse that option out.) Use the function attribute
stuff instead.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187093 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-25 00:34:29 +00:00
Bill Wendling
0dcba2fadb Recommit r186217 with testcase fix:
Use the function attributes to pass along the stack protector buffer size.

 Now that we have robust function attributes, don't use a command line option to
 specify the stack protecto buffer size.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186863 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-22 20:15:21 +00:00
Rafael Espindola
c1b49b56d4 Add a wrapper for open.
This centralizes the handling of O_BINARY and opens the way for hiding more
differences (like how open behaves with directories).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186447 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-16 19:44:17 +00:00
Chandler Carruth
12c74dc2c2 Revert commit r186217 -- this is breaking bots:
http://lab.llvm.org:8013/builders/clang-x86_64-darwin11-nobootstrap-RAincremental/builds/4328

Original commit log:
  Use the function attributes to pass along the stack protector buffer
  size.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186234 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-13 01:00:17 +00:00
Bill Wendling
8a50013cc2 Use the function attributes to pass along the stack protector buffer size.
Now that we have robust function attributes, don't use a command line option to
specify the stack protecto buffer size.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186217 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-12 22:25:20 +00:00
Wan Xiaofei
1b11a1925e Test commit access.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184278 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-19 02:26:00 +00:00
Andy Gibbs
200241e4de Replace uses of the deprecated std::auto_ptr with OwningPtr.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179373 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-12 10:56:28 +00:00
Chandler Carruth
0f3e4b1495 Manually update the dependencies in the Makefiles. It turns out that all
that work on the LLVMBuild based dependency specification didn't
actually work, we just now maintain dependencies in *3* places instead
of 2. Yay.

There may still be some missing dependencies, I'm still sifting through
the bots and my builds, but this is a step in the right direction.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177988 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-26 03:45:47 +00:00
Chandler Carruth
7fc162f893 Split out the IRReader header and the utility functions it provides into
its own library. These functions are bridging between the bitcode reader
and the ll parser which are in different libraries. Previously we didn't
have any good library to do this, and instead played fast and loose with
a "header only" set of interfaces in the Support library. This really
doesn't work well as evidenced by the recent attempt to add timing logic
to the these routines.

As part of this, make them normal functions rather than weird inline
functions, and sink the implementation into the library. Also clean up
the header to be nice and minimal.

This requires updating lots of build system dependencies to specify that
the IRReader library is needed, and several source files to not
implicitly rely upon the header file to transitively include all manner
of other headers.

If you are using IRReader.h, this commit will break you (the header
moved) and you'll need to also update your library usage to include
'irreader'. I will commit the corresponding change to Clang momentarily.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177971 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-26 02:25:37 +00:00
Chandler Carruth
aeef83c6af Switch TargetTransformInfo from an immutable analysis pass that requires
a TargetMachine to construct (and thus isn't always available), to an
analysis group that supports layered implementations much like
AliasAnalysis does. This is a pretty massive change, with a few parts
that I was unable to easily separate (sorry), so I'll walk through it.

The first step of this conversion was to make TargetTransformInfo an
analysis group, and to sink the nonce implementations in
ScalarTargetTransformInfo and VectorTargetTranformInfo into
a NoTargetTransformInfo pass. This allows other passes to add a hard
requirement on TTI, and assume they will always get at least on
implementation.

The TargetTransformInfo analysis group leverages the delegation chaining
trick that AliasAnalysis uses, where the base class for the analysis
group delegates to the previous analysis *pass*, allowing all but tho
NoFoo analysis passes to only implement the parts of the interfaces they
support. It also introduces a new trick where each pass in the group
retains a pointer to the top-most pass that has been initialized. This
allows passes to implement one API in terms of another API and benefit
when some other pass above them in the stack has more precise results
for the second API.

The second step of this conversion is to create a pass that implements
the TargetTransformInfo analysis using the target-independent
abstractions in the code generator. This replaces the
ScalarTargetTransformImpl and VectorTargetTransformImpl classes in
lib/Target with a single pass in lib/CodeGen called
BasicTargetTransformInfo. This class actually provides most of the TTI
functionality, basing it upon the TargetLowering abstraction and other
information in the target independent code generator.

The third step of the conversion adds support to all TargetMachines to
register custom analysis passes. This allows building those passes with
access to TargetLowering or other target-specific classes, and it also
allows each target to customize the set of analysis passes desired in
the pass manager. The baseline LLVMTargetMachine implements this
interface to add the BasicTTI pass to the pass manager, and all of the
tools that want to support target-aware TTI passes call this routine on
whatever target machine they end up with to add the appropriate passes.

The fourth step of the conversion created target-specific TTI analysis
passes for the X86 and ARM backends. These passes contain the custom
logic that was previously in their extensions of the
ScalarTargetTransformInfo and VectorTargetTransformInfo interfaces.
I separated them into their own file, as now all of the interface bits
are private and they just expose a function to create the pass itself.
Then I extended these target machines to set up a custom set of analysis
passes, first adding BasicTTI as a fallback, and then adding their
customized TTI implementations.

The fourth step required logic that was shared between the target
independent layer and the specific targets to move to a different
interface, as they no longer derive from each other. As a consequence,
a helper functions were added to TargetLowering representing the common
logic needed both in the target implementation and the codegen
implementation of the TTI pass. While technically this is the only
change that could have been committed separately, it would have been
a nightmare to extract.

The final step of the conversion was just to delete all the old
boilerplate. This got rid of the ScalarTargetTransformInfo and
VectorTargetTransformInfo classes, all of the support in all of the
targets for producing instances of them, and all of the support in the
tools for manually constructing a pass based around them.

Now that TTI is a relatively normal analysis group, two things become
straightforward. First, we can sink it into lib/Analysis which is a more
natural layer for it to live. Second, clients of this interface can
depend on it *always* being available which will simplify their code and
behavior. These (and other) simplifications will follow in subsequent
commits, this one is clearly big enough.

Finally, I'm very aware that much of the comments and documentation
needs to be updated. As soon as I had this working, and plausibly well
commented, I wanted to get it committed and in front of the build bots.
I'll be doing a few passes over documentation later if it sticks.

Commits to update DragonEgg and Clang will be made presently.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171681 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-07 01:37:14 +00:00