- Consistency with opt (which supports the same option with the same meaning and
  description).
- Debugging gold plugin-based linking without optimizations getting in the way.
- Debugging programs linked with the gold plugin while preserving the original
  debug info.
- Fine-grained control over LTO passes using the gold plugin in combination with
  opt (or clang/dragonegg).

Patch by Cristiano Giuffrida!

llvm-svn: 176257

llvm-svn: 172499

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.

llvm-svn: 171681

Sorry for the noise here, 'make check' doesn't build this code. =/

llvm-svn: 171623

into their new header subdirectory: include/llvm/IR. This matches the
directory structure of lib, and begins to correct a long standing point
of file layout clutter in LLVM.

There are still more header files to move here, but I wanted to handle
them in separate commits to make tracking what files make sense at each
layer easier.

The only really questionable files here are the target intrinsic
tablegen files. But that's a battle I'd rather not fight today.

I've updated both CMake and Makefile build systems (I think, and my
tests think, but I may have missed something).

I've also re-sorted the includes throughout the project. I'll be
committing updates to Clang, DragonEgg, and Polly momentarily.

llvm-svn: 171366

llvm-svn: 171363

llvm-svn: 169817

The linker will call `lto_codegen_add_must_preserve_symbol' on all globals that
should be kept around. The linker will pretend that a dylib is being created.
<rdar://problem/12528059>

llvm-svn: 169770

llvm-svn: 169720

This function sets the `_exportDynamic' ivar. When that's set, we export all
symbols (e.g. we don't run the internalize pass). This is equivalent to the
`--export-dynamic' linker flag in GNU land:

--export-dynamic
  When creating a dynamically linked executable, add all symbols to the dynamic
  symbol table. The dynamic symbol table is the set of symbols which are visible
  from dynamic objects at run time. If you do not use this option, the dynamic
  symbol table will normally contain only those symbols which are referenced by
  some dynamic object mentioned in the link. If you use dlopen to load a dynamic
  object which needs to refer back to the symbols defined by the program, rather
  than some other dynamic object, then you will probably need to use this option
  when linking the program itself.

The Darwin linker will support this via the `-export_dynamic' flag. We should
modify clang to support this via the `-rdynamic' flag.

llvm-svn: 169656

Again, tools are trickier to pick the main module header for than
library source files. I've started to follow the pattern of using
LLVMContext.h when it is included as a stub for program source files.

llvm-svn: 169252

start up and clean up module passes, now that ASAN and TSAN are fixed the
tests pass

llvm-svn: 168905

Revert r168635 "Step towards implementation of pass manager with doInitialization and doFinalization per module detangled from runOn?? calls, still has temporary code not to break ASAN to be removed when that pass conforms to the proposed model".
It appears to have broken at least one buildbot.

llvm-svn: 168654

Step towards implementation of pass manager with doInitialization and doFinalization per module detangled from runOn?? calls, still has temporary code not to break ASAN to be removed when that pass conforms to the proposed model

Patch by Pedro Artigas, with feedback from by Chandler Carruth.

llvm-svn: 168635

Add doInitialization and doFinalization methods to ModulePass's, to allow them to be re-initialized and reused on multiple Module's.

Patch by Pedro Artigas.

llvm-svn: 168008

llvm-svn: 166248

The TargetTransform changes are breaking LTO bootstraps of clang.  I am
working with Nadav to figure out the problem, but I am reverting it for now
to get our buildbots working.

This reverts svn commits: 165665 165669 165670 165786 165787 165997
and I have also reverted clang svn 165741

llvm-svn: 166168

llvm-svn: 165997

This is a temporary hack until Bill's project to record command line options
in the LLVM IR is ready. Clang currently sets a default CPU but that isn't
recorded anywhere and it doesn't get used in the final LTO compilation.

llvm-svn: 165809

llvm-svn: 165403

llvm-svn: 163349

llvm-svn: 161530

llvm-svn: 161356

When the command line target options were removed from the LLVM libraries, LTO
lost its ability to specify things like `-disable-fp-elim'. Add this back by
adding the command line variables to the `lto' project.
<rdar://problem/12038729>

llvm-svn: 161353

This broke in r144788 when the CodeGenOpt option was moved from everywhere else
(specifically, from addPassesToEmitFile) to createTargetMachine. Since
LTOCodeGenerator wasn't passing the 4th argument, when the 4th parameter became
the 3rd, it silently continued to compile (int->bool conversion) but meant
something completely different.

This change preserves the existing (accidental) and previous (default)
semantics of the addPassesToEmitFile and restores the previous/intended
CodeGenOpt argument by passing it appropriately to createTargetMachine.

(discovered by pending changes to -Wconversion to catch constant->bool
conversions)

llvm-svn: 157705

so we don't want it to show up in the stable 3.1 interface.

While at it, add a comment about why LTOCodeGenerator manually creates the
internalize pass.

llvm-svn: 154807

Revert the 'EnableInitializing' flag. There is debate on whether we should run that pass by default in LTO.

llvm-svn: 154356

Apply the scope restrictions after parsing the command line options. There may be some which are used in that function.

llvm-svn: 154348

llvm-svn: 154306

Consider the following program:

$ cat main.c
void foo(void) { }

int main(int argc, char *argv[]) {
    foo();
    return 0;
}
$ cat bundle.c 
extern void foo(void);

void bar(void) {
     foo();
}
$ clang -o main main.c
$ clang -o bundle.so bundle.c -bundle -bundle_loader ./main
$ nm -m bundle.so
0000000000000f40 (__TEXT,__text) external _bar
                 (undefined) external _foo (from executable)
                 (undefined) external dyld_stub_binder (from libSystem)
$ clang -o main main.c -O4
$ clang -o bundle.so bundle.c -bundle -bundle_loader ./main
Undefined symbols for architecture x86_64:
  "_foo", referenced from:
      _bar in bundle-elQN6d.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

The linker was told that the 'foo' in 'main' was 'internal' and had no uses, so
it was dead stripped.

Another situation is something like:

define void @foo() {
  ret void
}

define void @bar() {
  call asm volatile "call _foo" ...
  ret void
}

The only use of 'foo' is inside of an inline ASM call. Since we don't look
inside those for uses of functions, we don't specify this as a "use."

Get around this by not invoking the 'internalize' pass by default. This is an
admitted hack for LTO correctness.
<rdar://problem/11185386>

llvm-svn: 154124

llvm-svn: 153902

llvm-svn: 153810

llvm-svn: 153809

llvm-svn: 153808

llvm-svn: 153807

llvm-svn: 153805

llvm-svn: 153804

llvm-svn: 153803

llvm-svn: 148578

change, now you need a TargetOptions object to create a TargetMachine. Clang
patch to follow.

One small functionality change in PTX. PTX had commented out the machine
verifier parts in their copy of printAndVerify. That now calls the version in
LLVMTargetMachine. Users of PTX who need verification disabled should rely on
not passing the command-line flag to enable it.

llvm-svn: 145714