Commit Graph

428 Commits

Author SHA1 Message Date
Andrey Turetskiy 2396c38a8a [X86] Fix stack alignment for MCU target, by Anton Nadolskiy.
This patch fixes stack alignments for MCU (should be aligned to 4 bytes).

Differential Revision: http://reviews.llvm.org/D15646

llvm-svn: 260375
2016-02-10 11:57:06 +00:00
Yunzhong Gao eb959722a7 Revert r259576: Disable the vzeroupper insertion pass on PS4.
Will re-implement based on review feedback.

llvm-svn: 259615
2016-02-03 01:25:12 +00:00
Yunzhong Gao b76ccacfb1 Disable the vzeroupper insertion pass on PS4.
See comments in test/CodeGen/X86/avx-vzeroupper.ll for more explanation.

Original patch by: Sean Silva

llvm-svn: 259576
2016-02-02 21:39:23 +00:00
Alexey Bataev 7cf324772f LEA code size optimization pass (Part 1): Remove redundant address recalculations, by Andrey Turetsky
Add new x86 pass which replaces address calculations in load or store instructions with def register of existing LEA (must be in the same basic block), if the LEA calculates address that differs only by a displacement. Works only with -Os or -Oz.
Differential Revision: http://reviews.llvm.org/D13294

llvm-svn: 254712
2015-12-04 10:53:15 +00:00
Reid Kleckner ae44e871cd Revert "Revert "Revert r248959, "[WinEH] Emit int3 after noreturn calls on Win64"""
This reverts commit r249794.

Apparently my checkouts are full of unexpected surprises today.

llvm-svn: 249796
2015-10-09 01:13:17 +00:00
Reid Kleckner b510401785 Revert "Revert r248959, "[WinEH] Emit int3 after noreturn calls on Win64""
This reverts commit r249032.

TODO write commit msg

llvm-svn: 249794
2015-10-09 01:11:37 +00:00
NAKAMURA Takumi 1ed20db720 Revert r248959, "[WinEH] Emit int3 after noreturn calls on Win64"
It broke; LLVM :: CodeGen__Generic__2009-11-16-BadKillsCrash.ll

llvm-svn: 249032
2015-10-01 17:00:56 +00:00
Reid Kleckner 6dec87a8a0 [WinEH] Emit int3 after noreturn calls on Win64
The Win64 unwinder disassembles forwards from each PC to try to
determine if this PC is in an epilogue. If so, it skips calling the EH
personality function for that frame. Typically, this means you cannot
catch an exception in the same frame that you threw it, because 'throw'
calls a noreturn runtime function.

Previously we avoided this problem with the TrapUnreachable
TargetOption, but that's a much bigger hammer than we need. All we need
is a 1 byte non-epilogue instruction right after the call.  Instead,
what we got was an unconditional branch to a shared block containing the
ud2, potentially 7 bytes instead of 1. So, this reverts r206684, which
added TrapUnreachable, and replaces it with something better.

The new code pattern matches for invoke/call followed by unreachable and
inserts an int3 into the DAG. To be 100% watertight, we would need to
insert SEH_Epilogue instructions into all basic blocks ending in a call
with no terminators or successors, but in practice this is unlikely to
come up.

llvm-svn: 248959
2015-09-30 23:09:23 +00:00
Eric Christopher a4e5d3cf8e constify the Function parameter to the TTI creation callback and
propagate to all callers/users/etc.

llvm-svn: 247864
2015-09-16 23:38:13 +00:00
David Majnemer 0ad363eebc [WinEH] Calculate state numbers for the new EH representation
State numbers are calculated by performing a walk from the innermost
funclet to the outermost funclet.   Rudimentary support for the new EH
constructs has been added to the assembly printer, just enough to test
the new machinery.

Differential Revision: http://reviews.llvm.org/D12098

llvm-svn: 245331
2015-08-18 19:07:12 +00:00
Pat Gavlin b399095c3f Add a target environment for CoreCLR.
Although targeting CoreCLR is similar to targeting MSVC, there are
certain important differences that the backend must be aware of
(e.g. differences in stack probes, EH, and library calls).

Differential Revision: http://reviews.llvm.org/D11012

llvm-svn: 245115
2015-08-14 22:41:43 +00:00
Sanjay Patel 09b2c890af [x86] set default reciprocal (division and square root) codegen to match GCC
D8982 ( checked in at http://reviews.llvm.org/rL239001 ) added command-line 
options to allow reciprocal estimate instructions to be used in place of
divisions and square roots.

This patch changes the default settings for x86 targets to allow that recip
codegen (except for scalar division because that breaks too much code) when
using -ffast-math or its equivalent. 

This matches GCC behavior for this kind of codegen.

Differential Revision: http://reviews.llvm.org/D10396

llvm-svn: 240310
2015-06-22 18:29:44 +00:00
Daniel Sanders c81f450f1a Clean up redundant copies of Triple objects. NFC
Summary:

Reviewers: rengolin

Reviewed By: rengolin

Subscribers: llvm-commits, rengolin, jholewinski

Differential Revision: http://reviews.llvm.org/D10382

llvm-svn: 239823
2015-06-16 15:44:21 +00:00
Daniel Sanders 3e5de88dac Replace string GNU Triples with llvm::Triple in TargetMachine. NFC.
Summary:
For the moment, TargetMachine::getTargetTriple() still returns a StringRef.

This continues the patch series to eliminate StringRef forms of GNU triples
from the internals of LLVM that began in r239036.

Reviewers: rengolin

Reviewed By: rengolin

Subscribers: ted, llvm-commits, rengolin, jholewinski

Differential Revision: http://reviews.llvm.org/D10362

llvm-svn: 239554
2015-06-11 19:41:26 +00:00
Sanjay Patel 08829bac81 [x86] Add a reassociation optimization to increase ILP via the MachineCombiner pass
This is a reimplementation of D9780 at the machine instruction level rather than the DAG.

Use the MachineCombiner pass to reassociate scalar single-precision AVX additions (just a
starting point; see the TODO comments) to increase ILP when it's safe to do so.

The code is closely based on the existing MachineCombiner optimization that is implemented
for AArch64.

This patch should not cause the kind of spilling tragedy that led to the reversion of r236031.

Differential Revision: http://reviews.llvm.org/D10321

llvm-svn: 239486
2015-06-10 20:32:21 +00:00
Daniel Sanders a73f1fdb19 Replace string GNU Triples with llvm::Triple in MCSubtargetInfo and create*MCSubtargetInfo(). NFC.
Summary:
This continues the patch series to eliminate StringRef forms of GNU triples
from the internals of LLVM that began in r239036.

Reviewers: rafael

Reviewed By: rafael

Subscribers: rafael, ted, jfb, llvm-commits, rengolin, jholewinski

Differential Revision: http://reviews.llvm.org/D10311

llvm-svn: 239467
2015-06-10 12:11:26 +00:00
Sanjay Patel 667a7e2a0f make reciprocal estimate code generation more flexible by adding command-line options (3rd try)
The first try (r238051) to land this was reverted due to ExecutionEngine build failure;
that was hopefully addressed by r238788.

The second try (r238842) to land this was reverted due to BUILD_SHARED_LIBS failure;
that was hopefully addressed by r238953.

This patch adds a TargetRecip class for processing many recip codegen possibilities.
The class is intended to handle both command-line options to llc as well
as options passed in from a front-end such as clang with the -mrecip option.

The x86 backend is updated to use the new functionality.
Only -mcpu=btver2 with -ffast-math should see a functional change from this patch.
All other x86 CPUs continue to *not* use reciprocal estimates by default with -ffast-math.

Differential Revision: http://reviews.llvm.org/D8982

llvm-svn: 239001
2015-06-04 01:32:35 +00:00
Rafael Espindola cf8beece97 Revert "make reciprocal estimate code generation more flexible by adding command-line options (2nd try)"
This reverts commit r238842.

It broke -DBUILD_SHARED_LIBS=ON build.

llvm-svn: 238900
2015-06-03 05:32:44 +00:00
Sanjay Patel 6f031d848e make reciprocal estimate code generation more flexible by adding command-line options (2nd try)
The first try (r238051) to land this was reverted due to bot failures
that were hopefully addressed by r238788.

This patch adds a TargetRecip class for processing many recip codegen possibilities.
The class is intended to handle both command-line options to llc as well
as options passed in from a front-end such as clang with the -mrecip option.

The x86 backend is updated to use the new functionality.
Only -mcpu=btver2 with -ffast-math should see a functional change from this patch.
All other x86 CPUs continue to *not* use reciprocal estimates by default with -ffast-math.

Differential Revision: http://reviews.llvm.org/D8982

llvm-svn: 238842
2015-06-02 15:28:15 +00:00
Reid Kleckner 5b8ebfbc25 Only add the EH state insertion pass on 32-bit Windows
llvm-svn: 238612
2015-05-29 20:43:10 +00:00
Rafael Espindola 445712264d Revert "make reciprocal estimate code generation more flexible by adding command-line options"
This reverts commit r238051.

It broke some bots:

http://lab.llvm.org:8011/builders/llvm-ppc64-linux1/builds/18190

llvm-svn: 238075
2015-05-23 00:22:44 +00:00
Sanjay Patel ba2ba80302 make reciprocal estimate code generation more flexible by adding command-line options
This patch adds a class for processing many recip codegen possibilities.
The TargetRecip class is intended to handle both command-line options to llc as well
as options passed in from a front-end such as clang with the -mrecip option.

The x86 backend is updated to use the new functionality.
Only -mcpu=btver2 with -ffast-math should see a functional change from this patch.
All other CPUs continue to *not* use reciprocal estimates by default with -ffast-math.

Differential Revision: http://reviews.llvm.org/D8982

llvm-svn: 238051
2015-05-22 21:10:06 +00:00
Quentin Colombet 494eb606cd Reapply r238011 with a fix for the trap instruction.
The problem was that I slipped a change required for shrink-wrapping, namely I
used getFirstTerminator instead of the getLastNonDebugInstr that was here before
the refactoring, whereas the surrounding code is not yet patched for that.

Original message:
[X86] Refactor the prologue emission to prepare for shrink-wrapping.

- Add a late pass to expand pseudo instructions (tail call and EH returns).
 Instead of doing it in the prologue emission.
- Factor some static methods in X86FrameLowering to ease code sharing.

NFC.

Related to <rdar://problem/20821487>

llvm-svn: 238035
2015-05-22 18:10:47 +00:00
Tamas Berghammer 466692abdc Revert "[X86] Fix a variable name for r237977 so that it works with every compilers."
Revert "[X86] Refactor the prologue emission to prepare for shrink-wrapping."

This reverts commit 6b3b93fc8b68a2c806aa992ee4bd3d7f61898d4b.
This reverts commit ab0b15dff8539826283a59c2dd700a18a9680e0f.

llvm-svn: 238011
2015-05-22 10:01:56 +00:00
Quentin Colombet faf4b57e1d [X86] Refactor the prologue emission to prepare for shrink-wrapping.
- Add a late pass to expand pseudo instructions (tail call and EH returns).
  Instead of doing it in the prologue emission.
- Factor some static methods in X86FrameLowering to ease code sharing.

NFC.

Related to <rdar://problem/20821487>

llvm-svn: 237977
2015-05-22 00:12:31 +00:00
Eric Christopher 149d37abd4 Remove setting FloatABIType from the X86 port, nothing uses it.
llvm-svn: 237398
2015-05-14 22:26:54 +00:00
Eric Christopher 824f42f209 Migrate existing backends that care about software floating point
to use the information in the module rather than TargetOptions.

We've had and clang has used the use-soft-float attribute for some
time now so have the backends set a subtarget feature based on
a particular function now that subtargets are created based on
functions and function attributes.

For the one middle end soft float check go ahead and create
an overloadable TargetLowering::useSoftFloat function that
just checks the TargetSubtargetInfo in all cases.

Also remove the command line option that hard codes whether or
not soft-float is set by using the attribute for all of the
target specific test cases - for the generic just go ahead and
add the attribute in the one case that showed up.

llvm-svn: 237079
2015-05-12 01:26:05 +00:00
Reid Kleckner 0738a9c02e Re-land "[WinEH] Add an EH registration and state insertion pass for 32-bit x86"
This reverts commit r236360.

This change exposed a bug in WinEHPrepare by opting win32 code into EH
preparation. We already knew that WinEHPrepare has bugs, and is the
status quo for x64, so I don't think that's a reason to hold off on this
change. I disabled exceptions in the sanitizer tests in r236505 and an
earlier revision.

llvm-svn: 236508
2015-05-05 17:44:16 +00:00
Reid Kleckner 83d89fa546 Revert "[WinEH] Add an EH registration and state insertion pass for 32-bit x86"
This reverts commit r236359. Things are still broken despite testing. :(

llvm-svn: 236360
2015-05-01 22:50:14 +00:00
Reid Kleckner 51476acd77 Re-land "[WinEH] Add an EH registration and state insertion pass for 32-bit x86"
This reverts commit r236340.

llvm-svn: 236359
2015-05-01 22:40:25 +00:00
Reid Kleckner 2747d3d55a Revert "[WinEH] Add an EH registration and state insertion pass for 32-bit x86"
This reverts commit r236339, it breaks the win32 clang-cl self-host.

llvm-svn: 236340
2015-05-01 20:14:04 +00:00
Reid Kleckner 4856fc61b4 [WinEH] Add an EH registration and state insertion pass for 32-bit x86
This pass is responsible for constructing the EH registration object
that gets linked into fs:00, which is all it does in this change. In the
future, it will also insert stores to update the EH state number.

I considered keeping this functionality in WinEHPrepare, but it's pretty
separable and X86 specific. It has conceptually very little to do with
the task of WinEHPrepare, which is currently outlining.  WinEHPrepare is
also in theory useful on ARM, but this logic is pretty x86 specific.

Reviewers: andrew.w.kaylor, majnemer

Differential Revision: http://reviews.llvm.org/D9422

llvm-svn: 236339
2015-05-01 20:04:54 +00:00
Reid Kleckner 60d5232be2 [X86] Use 4 byte preferred aggregate alignment on Win32
This helps reduce the frequency of stack realignment prologues in 32-bit
X86 Windows code. Before this change and the corresponding clang change,
we would take the max of the type preferred alignment and the explicit
alignment on the alloca.

If you don't override aggregate alignment in datalayout, you get a
default of 8. This dates back to 2007 / r34356, and changing it seems
prohibitively difficult at this point.

llvm-svn: 236270
2015-04-30 22:11:59 +00:00
Mehdi Amini 93e1ea167e Move the DataLayout to the generic TargetMachine, making it mandatory.
Summary:
I don't know why every singled backend had to redeclare its own DataLayout.
There was a virtual getDataLayout() on the common base TargetMachine, the
default implementation returned nullptr. It was not clear from this that
we could assume at call site that a DataLayout will be available with
each Target.

Now getDataLayout() is no longer virtual and return a pointer to the
DataLayout member of the common base TargetMachine. I plan to turn it into
a reference in a future patch.

The only backend that didn't have a DataLayout previsouly was the CPPBackend.
It now initializes the default DataLayout. This commit is NFC for all the
other backends.

Test Plan: clang+llvm ninja check-all

Reviewers: echristo

Subscribers: jfb, jholewinski, llvm-commits

Differential Revision: http://reviews.llvm.org/D8243

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 231987
2015-03-12 00:07:24 +00:00
Derek Schuff 072f93fe72 Make NaCl's use of .init_array for static constructors match Linux
Summary:
The generic ELF TargetObjectFile defaults to .ctors, but Linux's
defaults to .init_array by calling InitializeELF with the value of
UseInitArray from TargetMachine. Make NaCl's behavior match.

Reviewers: jvoung
Differential Revision: http://reviews.llvm.org/D8240

llvm-svn: 231934
2015-03-11 16:16:09 +00:00
Paul Robinson 06a8eb8343 [X86][ELF] Correct relocation for DWARF TLS references
Previously we had only Linux using DTPOFF for these; all X86 ELF
targets should. Fixes a side issue mentioned in PR21077.

Differential Revision: http://reviews.llvm.org/D8011

llvm-svn: 231130
2015-03-03 21:01:27 +00:00
Paul Robinson 9f4cfc574e Revert r230979, should apply to all X86 ELF.
llvm-svn: 230985
2015-03-02 18:50:18 +00:00
Paul Robinson 10ae2e52de [PS4] Correct relocation for DWARF TLS references.
llvm-svn: 230979
2015-03-02 17:44:52 +00:00
Duncan P. N. Exon Smith 5975a703e6 X86: Canonicalize access to function attributes, NFC
Canonicalize access to function attributes to use the simpler API.

getAttributes().getAttribute(AttributeSet::FunctionIndex, Kind)
  => getFnAttribute(Kind)

getAttributes().hasAttribute(AttributeSet::FunctionIndex, Kind)
  => hasFnAttribute(Kind)

llvm-svn: 229214
2015-02-14 01:59:52 +00:00
Chandler Carruth 30d69c2e36 [PM] Remove the old 'PassManager.h' header file at the top level of
LLVM's include tree and the use of using declarations to hide the
'legacy' namespace for the old pass manager.

This undoes the primary modules-hostile change I made to keep
out-of-tree targets building. I sent an email inquiring about whether
this would be reasonable to do at this phase and people seemed fine with
it, so making it a reality. This should allow us to start bootstrapping
with modules to a certain extent along with making it easier to mix and
match headers in general.

The updates to any code for users of LLVM are very mechanical. Switch
from including "llvm/PassManager.h" to "llvm/IR/LegacyPassManager.h".
Qualify the types which now produce compile errors with "legacy::". The
most common ones are "PassManager", "PassManagerBase", and
"FunctionPassManager".

llvm-svn: 229094
2015-02-13 10:01:29 +00:00
Eric Christopher 24f3f65196 Remove the use of getSubtarget in the creation of the X86
PassManager instance. In one case we can make the determination
from the Triple, in the other (execution dependency pass) the
pass will avoid running if we don't have any code that uses that
register class so go ahead and add it to the pipeline.

llvm-svn: 228334
2015-02-05 19:27:04 +00:00
Michael Kuperstein 13fbd45263 [X86] Convert esp-relative movs of function arguments to pushes, step 2
This moves the transformation introduced in r223757 into a separate MI pass.
This allows it to cover many more cases (not only cases where there must be a 
reserved call frame), and perform rudimentary call folding. It still doesn't 
have a heuristic, so it is enabled only for optsize/minsize, with stack 
alignment <= 8, where it ought to be a fairly clear win.

(Re-commit of r227728)

Differential Revision: http://reviews.llvm.org/D6789

llvm-svn: 227752
2015-02-01 16:56:04 +00:00
Michael Kuperstein e86aa9a8a4 Revert r227728 due to bad line endings.
llvm-svn: 227746
2015-02-01 16:15:07 +00:00
Chandler Carruth 8b04c0d26a [multiversion] Switch all of the targets over to use the
TargetIRAnalysis access path directly rather than implementing getTTI.

This even removes getTTI from the interface. It's more efficient for
each target to just register a precise callback that creates their
specific TTI.

As part of this, all of the targets which are building their subtargets
individually per-function now build their TTI instance with the function
and thus look up the correct subtarget and cache it. NVPTX, R600, and
XCore currently don't leverage this functionality, but its trivial for
them to add it now.

llvm-svn: 227735
2015-02-01 13:20:00 +00:00
Michael Kuperstein bd57186c76 [X86] Convert esp-relative movs of function arguments to pushes, step 2
This moves the transformation introduced in r223757 into a separate MI pass.
This allows it to cover many more cases (not only cases where there must be a 
reserved call frame), and perform rudimentary call folding. It still doesn't 
have a heuristic, so it is enabled only for optsize/minsize, with stack 
alignment <= 8, where it ought to be a fairly clear win.

Differential Revision: http://reviews.llvm.org/D6789

llvm-svn: 227728
2015-02-01 11:44:44 +00:00
Chandler Carruth 93dcdc47db [PM] Switch the TargetMachine interface from accepting a pass manager
base which it adds a single analysis pass to, to instead return the type
erased TargetTransformInfo object constructed for that TargetMachine.

This removes all of the pass variants for TTI. There is now a single TTI
*pass* in the Analysis layer. All of the Analysis <-> Target
communication is through the TTI's type erased interface itself. While
the diff is large here, it is nothing more that code motion to make
types available in a header file for use in a different source file
within each target.

I've tried to keep all the doxygen comments and file boilerplate in line
with this move, but let me know if I missed anything.

With this in place, the next step to making TTI work with the new pass
manager is to introduce a really simple new-style analysis that produces
a TTI object via a callback into this routine on the target machine.
Once we have that, we'll have the building blocks necessary to accept
a function argument as well.

llvm-svn: 227685
2015-01-31 11:17:59 +00:00
Chandler Carruth 705b185f90 [PM] Change the core design of the TTI analysis to use a polymorphic
type erased interface and a single analysis pass rather than an
extremely complex analysis group.

The end result is that the TTI analysis can contain a type erased
implementation that supports the polymorphic TTI interface. We can build
one from a target-specific implementation or from a dummy one in the IR.

I've also factored all of the code into "mix-in"-able base classes,
including CRTP base classes to facilitate calling back up to the most
specialized form when delegating horizontally across the surface. These
aren't as clean as I would like and I'm planning to work on cleaning
some of this up, but I wanted to start by putting into the right form.

There are a number of reasons for this change, and this particular
design. The first and foremost reason is that an analysis group is
complete overkill, and the chaining delegation strategy was so opaque,
confusing, and high overhead that TTI was suffering greatly for it.
Several of the TTI functions had failed to be implemented in all places
because of the chaining-based delegation making there be no checking of
this. A few other functions were implemented with incorrect delegation.
The message to me was very clear working on this -- the delegation and
analysis group structure was too confusing to be useful here.

The other reason of course is that this is *much* more natural fit for
the new pass manager. This will lay the ground work for a type-erased
per-function info object that can look up the correct subtarget and even
cache it.

Yet another benefit is that this will significantly simplify the
interaction of the pass managers and the TargetMachine. See the future
work below.

The downside of this change is that it is very, very verbose. I'm going
to work to improve that, but it is somewhat an implementation necessity
in C++ to do type erasure. =/ I discussed this design really extensively
with Eric and Hal prior to going down this path, and afterward showed
them the result. No one was really thrilled with it, but there doesn't
seem to be a substantially better alternative. Using a base class and
virtual method dispatch would make the code much shorter, but as
discussed in the update to the programmer's manual and elsewhere,
a polymorphic interface feels like the more principled approach even if
this is perhaps the least compelling example of it. ;]

Ultimately, there is still a lot more to be done here, but this was the
huge chunk that I couldn't really split things out of because this was
the interface change to TTI. I've tried to minimize all the other parts
of this. The follow up work should include at least:

1) Improving the TargetMachine interface by having it directly return
   a TTI object. Because we have a non-pass object with value semantics
   and an internal type erasure mechanism, we can narrow the interface
   of the TargetMachine to *just* do what we need: build and return
   a TTI object that we can then insert into the pass pipeline.
2) Make the TTI object be fully specialized for a particular function.
   This will include splitting off a minimal form of it which is
   sufficient for the inliner and the old pass manager.
3) Add a new pass manager analysis which produces TTI objects from the
   target machine for each function. This may actually be done as part
   of #2 in order to use the new analysis to implement #2.
4) Work on narrowing the API between TTI and the targets so that it is
   easier to understand and less verbose to type erase.
5) Work on narrowing the API between TTI and its clients so that it is
   easier to understand and less verbose to forward.
6) Try to improve the CRTP-based delegation. I feel like this code is
   just a bit messy and exacerbating the complexity of implementing
   the TTI in each target.

Many thanks to Eric and Hal for their help here. I ended up blocked on
this somewhat more abruptly than I expected, and so I appreciate getting
it sorted out very quickly.

Differential Revision: http://reviews.llvm.org/D7293

llvm-svn: 227669
2015-01-31 03:43:40 +00:00
Eric Christopher 8b7706517c 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.

llvm-svn: 227113
2015-01-26 19:03:15 +00:00
Matthias Braun b2f2388a76 Enable MachineVerifier in debug mode for X86, ARM, AArch64, Mips.
llvm-svn: 224075
2014-12-11 23:18:03 +00:00
Matthias Braun 7e37a5f523 [CodeGen] Add print and verify pass after each MachineFunctionPass by default
Previously print+verify passes were added in a very unsystematic way, which is
annoying when debugging as you miss intermediate steps and allows bugs to stay
unnotice when no verification is performed.

To make this change practical I added the possibility to explicitely disable
verification. I used this option on all places where no verification was
performed previously (because alot of places actually don't pass the
MachineVerifier).
In the long term these problems should be fixed properly and verification
enabled after each pass. I'll enable some more verification in subsequent
commits.

This is the 2nd attempt at this after realizing that PassManager::add() may
actually delete the pass.

llvm-svn: 224059
2014-12-11 21:26:47 +00:00