Commit Graph

18743 Commits

Author SHA1 Message Date
Sanjay Patel
7ddee6601d propagate IR-level fast-math-flags to DAG nodes, disabled by default
This is an updated version of the patch that was checked in at:
http://reviews.llvm.org/rL237046

but subsequently reverted because it exposed a bug in the DAG Combiner:
http://reviews.llvm.org/D9893

This time, there's an enablement flag ("EnableFMFInDAG") around the code in
SelectionDAGBuilder where we copy the set of FP optimization flags from IR
instructions to DAG nodes. So, in theory, there should be no functional change
from this patch as-is, but it will allow testing with the added functionality
to proceed via "-enable-fmf-dag" passed to llc.

This patch adds the minimum plumbing necessary to use IR-level
fast-math-flags (FMF) in the backend without actually using
them for anything yet. This is a follow-on to:
http://reviews.llvm.org/rL235997

Differential Revision: http://reviews.llvm.org/D10403



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239828 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-16 16:25:43 +00:00
Matt Arsenault
5202cab841 Revert "Revert "Fix merges of non-zero vector stores""
Reapply r239539. Don't assume the collected number of
stores is the same vector size. Just take the first N
stores to fill the vector.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239825 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-16 15:51:48 +00:00
Daniel Sanders
7f5b833aa3 Replace string GNU Triples with llvm::Triple in TargetMachine::getTargetTriple(). NFC.
Summary:
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: llvm-commits, rengolin

Differential Revision: http://reviews.llvm.org/D10381


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239815 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-16 13:15:50 +00:00
Arnaud A. de Grandmaison
443838d8aa [MachineSink] Address post-commit review comments
The successors cache is now a local variable, making it more visible that it
is only valid for the MBB being processed.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239807 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-16 08:57:21 +00:00
Alex Lorenz
00b6413c97 MIR Serialization: Print and parse simple machine function attributes.
This commit serializes the simple, scalar attributes from the 
'MachineFunction' class.

Reviewers: Duncan P. N. Exon Smith

Differential Revision: http://reviews.llvm.org/D10449


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239790 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-16 00:10:47 +00:00
Alex Lorenz
b3607cdd97 MIR Serialization: move the MIR printer out of the MIR printing pass.
This commit decouples the MIR printer and the MIR printing pass so
that it will be possible to move the MIR printer into a separate 
machine IR library later on.

Reviewers: Duncan P. N. Exon Smith


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239788 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-15 23:52:35 +00:00
Adrian Prantl
0f80e47db3 Debug Info IR: Switch DIObjCProperty to use DITypeRef.
This is a prerequisite for turning on ODR type uniquing for ObjC++.

rdar://problem/21377883

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239780 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-15 23:18:03 +00:00
Alex Lorenz
034945e8fe MIR Serialization: Create dummy functions when the MIR file doesn't have LLVM IR.
This commit creates a dummy LLVM IR function with one basic block and an unreachable
instruction for each parsed machine function when the MIR file doesn't have LLVM IR.
This change is required as the machine function analysis pass creates machine
functions only for the functions that are defined in the current LLVM module.

Reviewers: Duncan P. N. Exon Smith

Differential Revision: http://reviews.llvm.org/D10135


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239778 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-15 23:07:38 +00:00
Alex Lorenz
185789e9a0 MIR Serialization: Report an error when machine functions have the same name.
This commit reports an error when the MIR parser encounters a machine
function with the name that is the same as the name of a different
machine function.

Reviewers: Duncan P. N. Exon Smith

Differential Revision: http://reviews.llvm.org/D10130


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239774 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-15 22:23:23 +00:00
Peter Collingbourne
7ffec838a2 Protection against stack-based memory corruption errors using SafeStack
This patch adds the safe stack instrumentation pass to LLVM, which separates
the program stack into a safe stack, which stores return addresses, register
spills, and local variables that are statically verified to be accessed
in a safe way, and the unsafe stack, which stores everything else. Such
separation makes it much harder for an attacker to corrupt objects on the
safe stack, including function pointers stored in spilled registers and
return addresses. You can find more information about the safe stack, as
well as other parts of or control-flow hijack protection technique in our
OSDI paper on code-pointer integrity (http://dslab.epfl.ch/pubs/cpi.pdf)
and our project website (http://levee.epfl.ch).

The overhead of our implementation of the safe stack is very close to zero
(0.01% on the Phoronix benchmarks). This is lower than the overhead of
stack cookies, which are supported by LLVM and are commonly used today,
yet the security guarantees of the safe stack are strictly stronger than
stack cookies. In some cases, the safe stack improves performance due to
better cache locality.

Our current implementation of the safe stack is stable and robust, we
used it to recompile multiple projects on Linux including Chromium, and
we also recompiled the entire FreeBSD user-space system and more than 100
packages. We ran unit tests on the FreeBSD system and many of the packages
and observed no errors caused by the safe stack. The safe stack is also fully
binary compatible with non-instrumented code and can be applied to parts of
a program selectively.

This patch is our implementation of the safe stack on top of LLVM. The
patches make the following changes:

- Add the safestack function attribute, similar to the ssp, sspstrong and
  sspreq attributes.

- Add the SafeStack instrumentation pass that applies the safe stack to all
  functions that have the safestack attribute. This pass moves all unsafe local
  variables to the unsafe stack with a separate stack pointer, whereas all
  safe variables remain on the regular stack that is managed by LLVM as usual.

- Invoke the pass as the last stage before code generation (at the same time
  the existing cookie-based stack protector pass is invoked).

- Add unit tests for the safe stack.

Original patch by Volodymyr Kuznetsov and others at the Dependable Systems
Lab at EPFL; updates and upstreaming by myself.

Differential Revision: http://reviews.llvm.org/D6094

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239761 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-15 21:07:11 +00:00
Alex Lorenz
a15d888abf MIR Serialization: Connect the machine function analysis pass to the MIR parser.
This commit connects the machine function analysis pass (which creates machine
functions) to the MIR parser, which will initialize the machine functions 
with the state from the MIR file and reconstruct the machine IR.

This commit introduces a new interface called 'MachineFunctionInitializer',
which can be used to provide custom initialization for the machine functions.

This commit also introduces a new diagnostic class called 
'DiagnosticInfoMIRParser' which is used for MIR parsing errors.
This commit modifies the default diagnostic handling in LLVMContext - now the
the diagnostics are printed directly into llvm::errs() so that the MIR parsing 
errors can be printed with colours.  

Reviewers: Justin Bogner

Differential Revision: http://reviews.llvm.org/D9928


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239753 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-15 20:30:22 +00:00
Sanjoy Das
18a05df213 Unbreak the build from r239740.
Do not re-use an enum name as a field name.  Some bots don't like this.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239746 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-15 19:29:44 +00:00
Sanjoy Das
8d5b28507b [CodeGen] Add a pass to fold null checks into nearby memory operations.
Summary:
This change adds an "ImplicitNullChecks" target dependent pass.  This
pass folds null checks into memory operation using the FAULTING_LOAD
pseudo-op introduced in previous patches.

Depends on D10197
Depends on D10199
Depends on D10200

Reviewers: reames, rnk, pgavlin, JosephTremoulet, atrick

Reviewed By: atrick

Subscribers: ab, JosephTremoulet, llvm-commits

Differential Revision: http://reviews.llvm.org/D10201

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239743 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-15 18:44:27 +00:00
Sanjoy Das
319c91bbb0 [TargetInstrInfo] Rename getLdStBaseRegImmOfs and implement for x86.
Summary:

TargetInstrInfo::getLdStBaseRegImmOfs to
TargetInstrInfo::getMemOpBaseRegImmOfs and implement for x86.  The
implementation only handles a few easy cases now and will be made more
sophisticated in the future.

This is NFCI: the only user of `getLdStBaseRegImmOfs` (now
`getmemOpBaseRegImmOfs`) is `LoadClusterMotion` and `LoadClusterMotion`
is disabled for x86.

Reviewers: reames, ab, MatzeB, atrick

Reviewed By: MatzeB, atrick

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D10199

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239741 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-15 18:44:14 +00:00
Sanjoy Das
1991e2a4df [CodeGen] Introduce a FAULTING_LOAD_OP pseudo-op.
Summary:
This instruction encodes a loading operation that may fault, and a label
to branch to if the load page-faults.  The locations of potentially
faulting loads and their "handler" destinations are recorded in a
FaultMap section, meant to be consumed by LLVM's clients.

Nothing generates FAULTING_LOAD_OP instructions yet, but they will be
used in a future change.

The documentation (FaultMaps.rst) needs improvement and I will update
this diff with a more expanded version shortly.

Depends on D10196

Reviewers: rnk, reames, AndyAyers, ab, atrick, pgavlin

Reviewed By: atrick, pgavlin

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D10197

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239740 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-15 18:44:08 +00:00
Arnaud A. de Grandmaison
981ffd1bc4 [MachineSink] Improve runtime performance. NFC.
This patch fixes a compilation time issue, when MachineSink faces PHIs
with a huge number of operands. This can happen for example in goto table
based interpreters, where some basic blocks can have several of those PHIs,
each one with several hundreds operands. MachineSink was spending a
significant time re-building and re-sorting the list of successors of
the current MachineBasicBlock. The computing and sorting of the current
MachineBasicBlock successors is now cached.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239720 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-15 09:09:06 +00:00
NAKAMURA Takumi
145cdc632a AsmPrinter.cpp: Avoid crashes for targeting like "arm-mingw32". CurrentFnSym might not be <MCSymbolELF> here.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239692 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-14 00:23:40 +00:00
NAKAMURA Takumi
82b72bed60 Reformat.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239691 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-14 00:23:33 +00:00
Simon Pilgrim
4692cb1303 [DAGCombiner] Added BSWAP(BSWAP(x)) -> x combine pattern.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239682 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-13 16:25:12 +00:00
Sanjay Patel
75975e2a29 hoist loop-invariant; NFCI
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239681 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-13 15:33:15 +00:00
Sanjay Patel
ea58c7de01 remove function names from comments and clean up; NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239680 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-13 15:32:45 +00:00
Simon Pilgrim
4a9a71e3ec [SelectionDAG] Added assertions + UNDEF handling for BSWAP node creation.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239679 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-13 15:23:58 +00:00
Sanjay Patel
4aeeb9e5dc remove unnecessary casts; NFCI
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239678 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-13 15:06:33 +00:00
Simon Pilgrim
d8b27b1cb1 [DAGCombiner] Added BSWAP vector constant folding support.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239675 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-13 14:08:15 +00:00
Simon Pilgrim
6b520d01a2 Stripped trailing whitespace. NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239674 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-13 12:57:36 +00:00
Matthias Braun
8ce6c58e41 Rename TargetSubtargetInfo::enablePostMachineScheduler() to enablePostRAScheduler()
r213101 changed the behaviour of this method to not only affect the
PostMachineScheduler scheduler but also the PostRAScheduler scheduler,
renaming should make this fact clear. Also document that the preferred
way is to specify this in the scheduling model instead of overriding
this method.

Differential Revision: http://reviews.llvm.org/D10427

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239659 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-13 03:42:16 +00:00
Matthias Braun
6fee0b00e2 MachineLICM: Use TargetSchedModel instead of just itineraries
This will use Itinieraries if available, but will also work if just a
MCSchedModel is available.

Differential Revision: http://reviews.llvm.org/D10428

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239658 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-13 03:42:11 +00:00
Reid Kleckner
2bd0221fa4 [WinEH] Put finally pointers in the handler scope table field
We were putting them in the filter field, which is correct for 64-bit
but wrong for 32-bit.

Also switch the order of scope table entry emission so outermost entries
are emitted first, and fix an obvious state assignment bug.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239574 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-11 23:37:18 +00:00
Reid Kleckner
3e16bd3aaf [WinEH] Create an llvm.x86.seh.exceptioninfo intrinsic
This intrinsic is like framerecover plus a load. It recovers the EH
registration stack allocation from the parent frame and loads the
exception information field out of it, giving back a pointer to an
EXCEPTION_POINTERS struct. It's designed for clang to use in SEH filter
expressions instead of accessing the EXCEPTION_POINTERS parameter that
is available on x64.

This required a minor change to MC to allow defining a label variable to
another absolute framerecover label variable.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239567 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-11 22:32:23 +00:00
Daniel Sanders
4ddb0ced90 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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239554 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-11 19:41:26 +00:00
Ahmed Bougacha
fd83cb21ce [CodeGen] ArrayRef'ize cond/pred in various TII APIs. NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239553 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-11 19:30:37 +00:00
Rafael Espindola
6c56decee0 Generalize emitAbsoluteSymbolDiff.
This makes emitAbsoluteSymbolDiff always succeed and moves logic from the asm
printer to it.

The object one now also works on ELF. If two symbols are in the same fragment,
we will never move them apart.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239552 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-11 18:58:08 +00:00
Reid Kleckner
cd354fa84d Revert "Fix merges of non-zero vector stores"
This reverts commit r239539.

It was causing SDAG assertions while building freetype.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239543 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-11 17:25:24 +00:00
Matt Arsenault
564ff6478c Fix merges of non-zero vector stores
Now actually stores the non-zero constant instead of 0.
I somehow forgot to include this part of r238108.

The test change was just an independent instruction order swap,
so just add another check line to satisfy CHECK-NEXT.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239539 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-11 16:03:52 +00:00
Sanjay Patel
6b71bf10b6 remove function names from comments; NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239532 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-11 14:26:49 +00:00
Arnaud A. de Grandmaison
3b8d35fb8d [LiveVariables] Improve isLiveOut runtime performances. NFC.
On large goto table based interpreters, where phi nodes can have (very) large
fan-ins, isLiveOut exhibited poor performances: about 40% of the full
codegen time was spent in PHIElim, sorting MachineBasicBlock addresses.

This patch improve the performances for such cases, and does not show
compile time regressions on the LNT, at bootstrap (llvm+clang+lldb) or
any other benchmarks we have in-house.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239510 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-11 07:50:21 +00:00
Arnaud A. de Grandmaison
a2cdb8ca59 [PHIElim] Use ranges and const-ify, NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239508 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-11 07:45:05 +00:00
Pete Cooper
5a118340dd Remove MachineModuleInfo::UsedFunctions as it has no users.
It hasn't been used since r130964.

This also removes MachineModuleInfo::isUsedFunction and
MachineModuleInfo::AnalyzeModule, both of which were only
there to support UsedFunctions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239501 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-11 01:04:56 +00:00
Sanjay Patel
bb79423d0f punctuation policing; NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239484 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-10 19:52:58 +00:00
Reid Kleckner
3de99b70aa [WinEH] _except_handlerN uses 0 instead of 1 to indicate catch-all
Our usage of 1 was a holdover from __C_specific_handler.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239482 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-10 18:14:07 +00:00
Sanjay Patel
708de57fee fix typo in comment; NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239478 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-10 17:08:12 +00:00
Igor Laevsky
544d686bc0 [StatepointLowering] Reuse stack slots across basic blocks
During statepoint lowering we can sometimes avoid spilling of the value if we know that it was already spilled for previous statepoint.
We were doing this by checking if incoming statepoint value was lowered into load from stack slot. This was working only in boundaries of one basic block.

But instead of looking at the lowered node we can look directly at the llvm-ir value and if it was gc.relocate (or some simple modification of it) look up stack slot for it's derived pointer and reuse stack slot from it. This allows us to look across basic block boundaries.

Differential Revision: http://reviews.llvm.org/D10251



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239472 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-10 12:31:53 +00:00
Reid Kleckner
6d7e69b227 Remove safeseh debug print and remove extra braces
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239449 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-10 01:13:44 +00:00
Reid Kleckner
c8e72e9126 [WinEH] Emit .safeseh directives for all 32-bit exception handlers
Use a "safeseh" string attribute to do this. You would think we chould
just accumulate the set of personalities like we do on dwarf, but this
fails to account for the LSDA-loading thunks we use for
__CxxFrameHandler3. Each of those needs to make it into .sxdata as well.
The string attribute seemed like the most straightforward approach.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239448 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-10 01:02:30 +00:00
Reid Kleckner
a8c0a9b042 Fix -Wsign-compare warning in WinException.cpp
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239445 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-10 00:04:53 +00:00
Tobias Edler von Koch
cbe2100f7e [RegisterScavenger] Fix handling of predicated instructions
Summary:
The RegisterScavenger explicitly ignores <kill> flags on operands of
predicated instructions and therefore assumes that such registers remain
live. When it then scavenges such a register, it inserts a spill of this
(killed) register. This is invalid code and gets flagged up by the 
verifier.

Nowadays kill flags are set correctly on predicated instructions. This
patch makes the Scavenger respect them.

The bug has so far only been triggered by an internal pass, so I don't
have a test case unfortunately.

Fixes PR23119.

Reviewers: hfinkel, tobiasvk_caf

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D9039

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239439 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-09 22:10:58 +00:00
Reid Kleckner
bdcbc426af [WinEH] Add 32-bit SEH state table emission prototype
This gets all the handler info through to the asm printer and we can
look at the .xdata tables now. I've convinced one small catch-all test
case to work, but other than that, it would be a stretch to say this is
functional.

The state numbering algorithm avoids doing any scope reconstruction as
we do for C++ to simplify the implementation.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239433 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-09 21:42:19 +00:00
David Blaikie
6eee2375d9 Revert "[DWARF] Fix a few corner cases in expression emission"
This reverts commit r239380 due to apparently GDB regressions:
http://lab.llvm.org:8011/builders/clang-x86_64-ubuntu-gdb-75/builds/22562

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239420 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-09 18:01:51 +00:00
Keno Fischer
b4863a99c9 [DWARF] Fix a few corner cases in expression emission
Summary: I noticed an object file with `DW_OP_reg4 DW_OP_breg4 0` as a DWARF expression,
which I traced to a missing break (and `++I`) in this code snippet.
While I was at it, I also added support for a few other corner cases
along the same lines that I could think of.

Test Plan: Hand-crafted test case to exercises these cases is included.

Reviewers: echristo, dblaikie, aprantl

Reviewed By: aprantl

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D10302

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239380 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-09 01:53:59 +00:00
Matt Arsenault
d2f17c4e2b Implement computeKnownBits for min/max nodes
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239378 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-09 00:52:41 +00:00