Commit Graph

17028 Commits

Author SHA1 Message Date
Rafael Espindola
8fa6f94ebb Refactor duplicated code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214328 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-30 19:42:16 +00:00
Louis Gerbarg
5fb3c84898 Retain alignment requirements for load->selects modified by DAGCombine
DAGCombine may choose to rewrite graphs where two loads feed a select into
graphs where a select of two addresses feed a load. While it sanity checks the
loads to make sure they are broadly equivalent it currently just uses the
alignment restriction of the left node. In cases where the right node has
stronger alignment requiresment this may lead to bad codegen, such as generating
an aligned load where an unaligned load is required. This patch makes the
combine generate a load with an alignment that is the same as whichever is more
restrictive of the two alignments.

Tests included.

rdar://17762530

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214322 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-30 18:24:41 +00:00
Rafael Espindola
4366b6cede Add the missing hasLinkOnceODRLinkage predicate.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214312 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-30 15:57:51 +00:00
Chandler Carruth
840b5d58c3 Don't manually (and forcibly) run the verifier on the entire module from
the jump instruction table pass. First, the verifier is already built
into all the tools. The test case is adapted to just run llvm-as
demonstrating that we still catch the broken module. Second, the
verifier is *extremely* slow. This was responsible for very significant
compile time regressions.

If you have deployed a Clang binary anywhere from r210280 to this
commit, you really want to re-deploy.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214287 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-30 05:44:04 +00:00
Petar Jovanovic
278da370ce Add support for scalarizing ctlz_zero_undef
Fix the missing case in ScalarizeVectorResult() that was exposed with
libclcore.bc in Android.

Differential Revision: http://reviews.llvm.org/D4645


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214266 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-30 00:44:03 +00:00
Richard Smith
0630cb25a1 Header hygiene: remove using directive and #undef DEBUG_TYPE once we're done.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214263 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-30 00:25:24 +00:00
Manman Ren
70626f555c Feedback on r214189, no functionality change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214240 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-29 22:58:13 +00:00
Manman Ren
23ab342d96 [Debug Info] remove DITrivialType and use null to represent unspecified param.
Per feedback on r214111, we are going to use null to represent unspecified
parameter. If the type array is {null}, it means a function that returns void;
If the type array is {null, null}, it means a variadic function that returns
void. In summary if we have more than one element in the type array and the last
element is null, it is a variadic function.

rdar://17628609


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214189 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-29 18:20:39 +00:00
Tim Northover
6f800f7333 CodeGenPrep: fall back to MVT::Other if instruction's type isn't an EVT.
The test being performed is just an approximation anyway, so it really
shouldn't crash when things don't go entirely as expected.

Should fix PR20474.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214177 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-29 10:20:22 +00:00
Tim Northover
b1692ad2c3 ARM: fix @llvm.convert.from.fp16 on softfloat targets.
We need to make sure we use the softened version of all appropriate operands in
the libcall, or things go horribly wrong. This may entail actually executing a
1-stage softening.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214175 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-29 09:56:38 +00:00
Jiangning Liu
f3224d0617 Add TargetInstrInfo interface isAsCheapAsAMove.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214158 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-29 01:55:19 +00:00
Manman Ren
2bd885aa97 [Debug Info] unique MDNodes in the enum types of each compile unit.
The enum types array by design contains pointers to MDNodes rather than DIRefs.
Unique them when handling the enum types in DwarfDebug.

rdar://17628609


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214139 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-28 23:04:20 +00:00
Manman Ren
807538b567 [Debug Info] add DISubroutineType and its creation takes DITypeArray.
DITypeArray is an array of DITypeRef, at its creation, we will create
DITypeRef (i.e use the identifier if the type node has an identifier).

This is the last patch to unique the type array of a subroutine type.

rdar://17628609


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214132 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-28 22:24:06 +00:00
Manman Ren
8e8c1ac702 [Debug Info] rename getTypeArray to getElements, setTypeArray to setArrays.
This is the second of a series of patches to handle type uniqueing of the
type array for a subroutine type.

For vector and array types, getElements returns the array of subranges, so it
is a better name than getTypeArray. Even for class, struct and enum types,
getElements returns the members, which can be subprograms.

setArrays can set up to two arrays, the second is the templates.

This commit should have no functionality change.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214112 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-28 19:14:13 +00:00
Chandler Carruth
d9d33c92a7 [SDAG] Add DEBUG logging to the legalizer, fixing a "bug" found by
inspection in the proccess, and shuffle the logging in the DAG combiner
around a bit.

With this it is much easier to follow what the legalizer is doing. It
should even accurately present most of the strange legalization
operations where a single node is replaced by multiple nodes, etc. There
is still some information lost (we log SDNodes not SDValues so we don't
log which result is used for which thing), but I think this is much
closer to a usable system. Notably, this will make it *much* more
apparant when legalization is actually happening inside the combiner, or
when there is a cycle caused by interactions of the legalizer and the
combiner.

The "bug" I fixed here I'm not sure is remotely possible to trigger. We
were only adding one of the nodes in a replacement to the updated set
rather than all of the nodes in the replacement. Realistically, the
worst result of this are nodes not getting back onto the worklist in the
DAG combiner. I doubt it is possible to trigger this today, and
I certainly don't have any ideas about how, but this at least brings the
code into alignment with the principled operation of the routine.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214105 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-28 17:55:07 +00:00
Matt Arsenault
2dd264c8a3 Add alignment value to allowsUnalignedMemoryAccess
Rename to allowsMisalignedMemoryAccess.

On R600, 8 and 16 byte accesses are mostly OK with 4-byte alignment,
and don't need to be split into multiple accesses. Vector loads with
an alignment of the element type are not uncommon in OpenCL code.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214055 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-27 17:46:40 +00:00
Chandler Carruth
f1ce818bef [SDAG] Add an assert that we don't mess up the number of values when
replacing nodes in the legalizer.

This caught a number of bugs for me during development.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214022 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-26 05:53:16 +00:00
Chandler Carruth
722419ef52 [SDAG] Simplify the code for handling single-value nodes and add
a missing transfer of debug information (without which tests fail).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214021 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-26 05:52:51 +00:00
Chandler Carruth
69359ed45b [SDAG] When performing post-legalize DAG combining, run the legalizer
over each node in the worklist prior to combining.

This allows the combiner to produce new nodes which need to go back
through legalization. This is particularly useful when generating
operands to target specific nodes in a post-legalize DAG combine where
the operands are significantly easier to express as pre-legalized
operations. My immediate use case will be PSHUFB formation where we need
to build a constant shuffle mask with a build_vector node.

This also refactors the relevant functionality in the legalizer to
support this, and updates relevant tests. I've spoken to the R600 folks
and these changes look like improvements to them. The avx512 change
needs to be investigated, I suspect there is a disagreement between the
legalizer and the DAG combiner there, but it seems a minor issue so
leaving it to be re-evaluated after this patch.

Differential Revision: http://reviews.llvm.org/D4564

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214020 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-26 05:49:40 +00:00
Hal Finkel
8ef7b17dfc Add @llvm.assume, lowering, and some basic properties
This is the first commit in a series that add an @llvm.assume intrinsic which
can be used to provide the optimizer with a condition it may assume to be true
(when the control flow would hit the intrinsic call). Some basic properties are added here:

 - llvm.invariant(true) is dead.
 - llvm.invariant(false) is unreachable (this directly corresponds to the
   documented behavior of MSVC's __assume(0)), so is llvm.invariant(undef).

The intrinsic is tagged as writing arbitrarily, in order to maintain control
dependencies. BasicAA has been updated, however, to return NoModRef for any
particular location-based query so that we don't unnecessarily block code
motion.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213973 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-25 21:13:35 +00:00
Akira Hatanaka
0651a556fe [stack protector] Fix a potential security bug in stack protector where the
address of the stack guard was being spilled to the stack.

Previously the address of the stack guard would get spilled to the stack if it
was impossible to keep it in a register. This patch introduces a new target
independent node and pseudo instruction which gets expanded post-RA to a
sequence of instructions that load the stack guard value. Register allocator
can now just remat the value when it can't keep it in a register. 

<rdar://problem/12475629>


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213967 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-25 19:31:34 +00:00
David Blaikie
fcfd56262b Reapply "DebugInfo: Don't put fission type units in comdat sections."
This recommits r208930, r208933, and r208975 (by reverting r209338) and
reverts r209529 (the FIXME to readd this functionality once the tools
were fixed) now that DWP has been fixed to cope with a single section
for all fission type units.

Original commit message:

"Since type units in the dwo file are handled by a debug aware tool,
they don't need to leverage the ELF comdat grouping to implement
deduplication. Avoid creating all the .group sections for these as a
space optimization."

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213956 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-25 17:11:58 +00:00
David Blaikie
e27d5a0047 Recommit r212203: Don't try to construct debug LexicalScopes hierarchy for functions that do not have top level debug information.
Reverted by Eric Christopher (Thanks!) in r212203 after Bob Wilson
reported LTO issues. Duncan Exon Smith and Aditya Nandakumar helped
provide a reduced reproduction, though the failure wasn't too hard to
guess, and even easier with the example to confirm.

The assertion that the subprogram metadata associated with an
llvm::Function matches the scope data referenced by the DbgLocs on the
instructions in that function is not valid under LTO. In LTO, a C++
inline function might exist in multiple CUs and the subprogram metadata
nodes will refer to the same llvm::Function. In this case, depending on
the order of the CUs, the first intance of the subprogram metadata may
not be the one referenced by the instructions in that function and the
assertion will fail.

A test case (test/DebugInfo/cross-cu-linkonce-distinct.ll) is added, the
assertion removed and a comment added to explain this situation.

This was then reverted again in r213581 as it caused PR20367. The root
cause of this was the early exit in LiveDebugVariables meant that
spurious DBG_VALUE intrinsics that referenced dead variables were not
removed, causing an assertion/crash later on. The fix is to have
LiveDebugVariables strip all DBG_VALUE intrinsics in functions without
debug info as they're not needed anyway. Test case added to cover this
situation (that occurs when a debug-having function is inlined into a
nodebug function) in test/DebugInfo/X86/nodebug_with_debug_loc.ll

Original commit message:

If a function isn't actually in a CU's subprogram list in the debug info
metadata, ignore all the DebugLocs and don't try to build scopes, track
variables, etc.

While this is possibly a minor optimization, it's also a correctness fix
for an incoming patch that will add assertions to LexicalScopes and the
debug info verifier to ensure that all scope chains lead to debug info
for the current function.

Fix up a few test cases that had broken/incomplete debug info that could
violate this constraint.

Add a test case where this occurs by design (inlining a
debug-info-having function in an attribute nodebug function - we want
this to work because /if/ the nodebug function is then inlined into a
debug-info-having function, it should be fine (and will work fine - we
just stitch the scopes up as usual), but should the inlining not happen
we need to not assert fail either).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213952 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-25 16:10:16 +00:00
Chandler Carruth
38ccfe9761 [SDAG] Don't insert the VRBase into a mapping from SDValues when the def
doesn't actually correspond to an SDValue at all. Fixes most of the
remaining asserts on out-of-range SDValue result numbers.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213930 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-25 09:19:18 +00:00
Matt Arsenault
068898df79 Store nodes only have 1 result.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213928 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-25 07:56:42 +00:00
Chandler Carruth
72d4fa9cc6 [SDAG] Start plumbing an assert into SDValues that we don't form one
with a result number outside the range of results for the node.

I don't know how we managed to not really check this very basic
invariant for so long, but the code is *very* broken at this point.
I have over 270 test failures with the assert enabled. I'm committing it
disabled so that others can join in the cleanup effort and reproduce the
issues. I've also included one of the obvious fixes that I already
found. More fixes to come.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213926 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-25 07:23:23 +00:00
Chandler Carruth
d24d326705 [SDAG] Introduce a combined set to the DAG combiner which tracks nodes
which have successfully round-tripped through the combine phase, and use
this to ensure all operands to DAG nodes are visited by the combiner,
even if they are only added during the combine phase.

This is critical to have the combiner reach nodes that are *introduced*
during combining. Previously these would sometimes be visited and
sometimes not be visited based on whether they happened to end up on the
worklist or not. Now we always run them through the combiner.

This fixes quite a few bad codegen test cases lurking in the suite while
also being more principled. Among these, the TLS codegeneration is
particularly exciting for programs that have this in the critical path
like TSan-instrumented binaries (although I think they engineer to use
a different TLS that is faster anyways).

I've tried to check for compile-time regressions here by running llc
over a merged (but not LTO-ed) clang bitcode file and observed at most
a 3% slowdown in llc. Given that this is essentially a worst case (none
of opt or clang are running at this phase) I think this is tolerable.
The actual LTO case should be even less costly, and the cost in normal
compilation should be negligible.

With this combining logic, it is possible to re-legalize as we combine
which is necessary to implement PSHUFB formation on x86 as
a post-legalize DAG combine (my ultimate goal).

Differential Revision: http://reviews.llvm.org/D4638

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213898 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-24 22:15:28 +00:00
Chandler Carruth
1b1fbccf49 [x86] Make vector legalization of extloads work more like the "normal"
vector operation legalization with support for custom target lowering
and fallback to expand when it fails, and use this to implement sext and
anyext load lowering for x86 in a more principled way.

Previously, the x86 backend relied on a target DAG combine to "combine
away" sextload and extload nodes prior to legalization, or would expand
them during legalization with terrible code. This is particularly
problematic because the DAG combine relies on running over non-canonical
DAG nodes at just the right time to match several common and important
patterns. It used a combine rather than lowering because we didn't have
good lowering support, and to expose some tricks being employed to more
combine phases.

With this change it becomes a proper lowering operation, the backend
marks that it can lower these nodes, and I've added support for handling
the canonical forms that don't have direct legal representations such as
sextload of a v4i8 -> v4i64 on AVX1. With this change, our test cases
for this behavior continue to pass even after the DAG combiner beigns
running more systematically over every node.

There is some noise caused by this in the test suite where we actually
use vector extends instead of subregister extraction. This doesn't
really seem like the right thing to do, but is unlikely to be a critical
regression. We do regress in one case where by lowering to the
target-specific patterns early we were able to combine away extraneous
legal math nodes. However, this regression is completely addressed by
switching to a widening based legalization which is what I'm working
toward anyways, so I've just switched the test to that mode.

Differential Revision: http://reviews.llvm.org/D4654

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213897 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-24 22:09:56 +00:00
Lang Hames
b96e833817 [X86] Optimize stackmap shadows on X86.
This patch minimizes the number of nops that must be emitted on X86 to satisfy
stackmap shadow constraints.

To minimize the number of nops inserted, the X86AsmPrinter now records the
size of the most recent stackmap's shadow in the StackMapShadowTracker class,
and tracks the number of instruction bytes emitted since the that stackmap
instruction was encountered. Padding is emitted (if it is required at all)
immediately before the next stackmap/patchpoint instruction, or at the end of
the basic block.

This optimization should reduce code-size and improve performance for people
using the llvm stackmap intrinsic on X86.

<rdar://problem/14959522>



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213892 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-24 20:40:55 +00:00
Hal Finkel
16fd27b2c3 Add scoped-noalias metadata
This commit adds scoped noalias metadata. The primary motivations for this
feature are:
  1. To preserve noalias function attribute information when inlining
  2. To provide the ability to model block-scope C99 restrict pointers

Neither of these two abilities are added here, only the necessary
infrastructure. In fact, there should be no change to existing functionality,
only the addition of new features. The logic that converts noalias function
parameters into this metadata during inlining will come in a follow-up commit.

What is added here is the ability to generally specify noalias memory-access
sets. Regarding the metadata, alias-analysis scopes are defined similar to TBAA
nodes:

!scope0 = metadata !{ metadata !"scope of foo()" }
!scope1 = metadata !{ metadata !"scope 1", metadata !scope0 }
!scope2 = metadata !{ metadata !"scope 2", metadata !scope0 }
!scope3 = metadata !{ metadata !"scope 2.1", metadata !scope2 }
!scope4 = metadata !{ metadata !"scope 2.2", metadata !scope2 }

Loads and stores can be tagged with an alias-analysis scope, and also, with a
noalias tag for a specific scope:

... = load %ptr1, !alias.scope !{ !scope1 }
... = load %ptr2, !alias.scope !{ !scope1, !scope2 }, !noalias !{ !scope1 }

When evaluating an aliasing query, if one of the instructions is associated
with an alias.scope id that is identical to the noalias scope associated with
the other instruction, or is a descendant (in the scope hierarchy) of the
noalias scope associated with the other instruction, then the two memory
accesses are assumed not to alias.

Note that is the first element of the scope metadata is a string, then it can
be combined accross functions and translation units. The string can be replaced
by a self-reference to create globally unqiue scope identifiers.

[Note: This overview is slightly stylized, since the metadata nodes really need
to just be numbers (!0 instead of !scope0), and the scope lists are also global
unnamed metadata.]

Existing noalias metadata in a callee is "cloned" for use by the inlined code.
This is necessary because the aliasing scopes are unique to each call site
(because of possible control dependencies on the aliasing properties). For
example, consider a function: foo(noalias a, noalias b) { *a = *b; } that gets
inlined into bar() { ... if (...) foo(a1, b1); ... if (...) foo(a2, b2); } --
now just because we know that a1 does not alias with b1 at the first call site,
and a2 does not alias with b2 at the second call site, we cannot let inlining
these functons have the metadata imply that a1 does not alias with b2.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213864 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-24 14:25:39 +00:00
Hal Finkel
2c7c54c86c AA metadata refactoring (introduce AAMDNodes)
In order to enable the preservation of noalias function parameter information
after inlining, and the representation of block-level __restrict__ pointer
information (etc.), additional kinds of aliasing metadata will be introduced.
This metadata needs to be carried around in AliasAnalysis::Location objects
(and MMOs at the SDAG level), and so we need to generalize the current scheme
(which is hard-coded to just one TBAA MDNode*).

This commit introduces only the necessary refactoring to allow for the
introduction of other aliasing metadata types, but does not actually introduce
any (that will come in a follow-up commit). What it does introduce is a new
AAMDNodes structure to hold all of the aliasing metadata nodes associated with
a particular memory-accessing instruction, and uses that structure instead of
the raw MDNode* in AliasAnalysis::Location, etc.

No functionality change intended.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213859 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-24 12:16:19 +00:00
Eric Christopher
0bebd31dce Fix indenting.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213811 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-23 22:34:13 +00:00
Eric Christopher
ba08e46435 Reorganize and simplify local variables.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213809 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-23 22:27:10 +00:00
Eric Christopher
3322b7eef1 Remove the query for TargetMachine and TargetInstrInfo since we're
already inside TargetInstrInfo.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213806 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-23 22:12:03 +00:00
Jim Grosbach
df48c93ef0 DAG: fp->int conversion for non-splat constants.
Constant fold the lanes of the input constant build_vector individually
so we correctly handle when the vector elements are not all the same
constant value.

PR20394

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213798 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-23 20:41:31 +00:00
Chad Rosier
67c325e9f0 [AArch64] Lower sdiv x, pow2 using add + select + shift.
The target-independent DAGcombiner will generate:
asr w1, X, #31 w1 = splat sign bit.
add X, X, w1, lsr #28 X = X + 0 or pow2-1
asr w0, X, asr #4 w0 = X/pow2

However, the add + shifts is expensive, so generate:
add w0, X, 15 w0 = X + pow2-1
cmp X, wzr X - 0
csel X, w0, X, lt X = (X < 0) ? X + pow2-1 : X;
asr w0, X, asr 4 w0 = X/pow2

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213758 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-23 14:57:52 +00:00
James Molloy
ed10064699 Enable partial libcall inlining for all targets by default.
This pass attempts to speculatively use a sqrt instruction if one exists on the target, falling back to a libcall if the target instruction returned NaN.

This was enabled for MIPS and System-Z, but is well guarded and is good for most targets - GCC does this for (that I've checked) X86, ARM and AArch64.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213752 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-23 13:33:00 +00:00
Chandler Carruth
a6425604c2 [SDAG] Make the DAGCombine worklist not grow endlessly due to duplicate
insertions.

The old behavior could cause arbitrarily bad memory usage in the DAG
combiner if there was heavy traffic of adding nodes already on the
worklist to it. This commit switches the DAG combine worklist to work
the same way as the instcombine worklist where we null-out removed
entries and only add new entries to the worklist. My measurements of
codegen time shows slight improvement. The memory utilization is
unsurprisingly dominated by other factors (the IR and DAG itself
I suspect).

This change results in subtle, frustrating churn in the particular order
in which DAG combines are applied which causes a number of minor
regressions where we fail to match a pattern previously matched by
accident. AFAICT, all of these should be using AddToWorklist to directly
or should be written in a less brittle way. None of the changes seem
drastically bad, and a few of the changes seem distinctly better.

A major change required to make this work is to significantly harden the
way in which the DAG combiner handle nodes which become dead
(zero-uses). Previously, we relied on the ability to "priority-bump"
them on the combine worklist to achieve recursive deletion of these
nodes and ensure that the frontier of remaining live nodes all were
added to the worklist. Instead, I've introduced a routine to just
implement that precise logic with no indirection. It is a significantly
simpler operation than that of the combiner worklist proper. I suspect
this will also fix some other problems with the combiner.

I think the x86 changes are really minor and uninteresting, but the
avx512 change at least is hiding a "regression" (despite the test case
being just noise, not testing some performance invariant) that might be
looked into. Not sure if any of the others impact specific "important"
code paths, but they didn't look terribly interesting to me, or the
changes were really minor. The consensus in review is to fix any
regressions that show up after the fact here.

Thanks to the other reviewers for checking the output on other
architectures. There is a specific regression on ARM that Tim already
has a fix prepped to commit.

Differential Revision: http://reviews.llvm.org/D4616

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213727 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-23 07:08:53 +00:00
Chandler Carruth
3f1ae7f58c [SDAG] Refactor the code for inserting a newly allocated SDNode into the
DAG into a helper function.

This adds a trip through the (very minimal) verification logic in
a bunch of places that were missing it, but shouldn't have any other
impact outside of refactoring. I'm hoping to use this to do more clever
things when DAG nodes are inserted into the graph.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213612 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-22 04:07:55 +00:00
Chandler Carruth
3c249a5a67 [SDAG] Remove a giant pile of asserts that may have helped track down
a bug in 2010 when they were added but are adding no value today.

In fact, they are utter lies. NodeAllocator is used to allocate almost
all of these node types. I don't know what we were trying to assert
here, and the docs don't give any answer. Until we once again stumble
upon a bug needing help, let's clear the path for improvements.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213610 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-22 04:03:22 +00:00
David Blaikie
529165298e Revert "Recommit r212203: Don't try to construct debug LexicalScopes hierarchy for functions that do not have top level debug information."
This reverts commit r212649 while I investigate/reduce/etc PR20367.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213581 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-21 20:45:59 +00:00
Logan Chien
8c4cf40507 Replace the result usages while legalizing cmpxchg.
We should update the usages to all of the results;
otherwise, we might get assertion failure or SEGV during
the type legalization of ATOMIC_CMP_SWAP_WITH_SUCCESS
with two or more illegal types.

For example, in the following sequence, both i8 and i1
might be illegal in some target, e.g. armv5, mipsel, mips64el,

    %0 = cmpxchg i8* %ptr, i8 %desire, i8 %new monotonic monotonic
    %1 = extractvalue { i8, i1 } %0, 1

Since both i8 and i1 should be legalized, the corresponding
ATOMIC_CMP_SWAP_WITH_SUCCESS dag will be checked/replaced/updated
twice.

If we don't update the usage to *ALL* of the results in the
first round, the DAG for extractvalue might be processed earlier.
The GetPromotedInteger() will result in assertion failure,
because its operand (i.e. the success bit of cmpxchg) is not
promoted beforehand.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213569 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-21 17:33:44 +00:00
Duncan P. N. Exon Smith
facdfc6781 Revert "[C++11] Add predecessors(BasicBlock *) / successors(BasicBlock *) iterator ranges."
This reverts commit r213474 (and r213475), which causes a miscompile on
a stage2 LTO build.  I'll reply on the list in a moment.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213562 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-21 17:06:51 +00:00
Tim Northover
f8d927f22b CodeGen: emit IR-level f16 conversion intrinsics as fptrunc/fpext
This makes the first stage DAG for @llvm.convert.to.fp16 an fptrunc,
and correspondingly @llvm.convert.from.fp16 an fpext. The legalisation
path is now uniform, regardless of the input IR:

  fptrunc -> FP_TO_FP16 (if f16 illegal) -> libcall
  fpext -> FP16_TO_FP (if f16 illegal) -> libcall

Each target should be able to select the version that best matches its
operations and not be required to duplicate patterns for both fptrunc
and FP_TO_FP16 (for example).

As a result we can remove some redundant AArch64 patterns.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213507 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-21 09:13:56 +00:00
Chandler Carruth
d4cde8670c [SDAG,cleanup] Switch the DAG combiner over to use the spelling
'Worklist' consistently rather than a deeply confusing mixture of
'WorkList' and 'Worklist'.

Notably, the very 'WorkList' of the DAG combiner was exposed to target
specific DAG combines under an interface 'AddToWorklist' which was
implemented by in turn calling 'AddToWorkList' in the combiner. This has
sent me circling with the wrong case in grep one too many times.

I chose to normalize on 'Worklist' because that one won the grep-vote
for llvm/lib/... by a hundered hits or so, and it is used in places
relatively "canonical" such as InstCombine's Worklist. Let's all jsut
pick this casing, whether "correct", "good", or "bad" and be
consistent...

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213506 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-21 08:56:44 +00:00
Chandler Carruth
0c991ec57a [SDAG] Rather than using a narrow test against the one dummy node on the
stack, filter all handle nodes from the DAG combiner worklist.

This will also handle cases where other handle nodes might be
(erroneously) added to the worklist and then cause bugs and explosions
when deleted. For example, when running the legalizer within the DAG
combiner, there are times when other handle nodes are used and can end
up here.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213505 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-21 08:32:31 +00:00
Andrea Di Biagio
19e39c6f12 [DAGCombiner] Improve the shuffle-vector folding logic.
Canonicalize shuffles according to rules:
 *  shuffle(A, shuffle(A, B)) -> shuffle(shuffle(A,B), A)
 *  shuffle(B, shuffle(A, B)) -> shuffle(shuffle(A,B), B)
 *  shuffle(B, shuffle(A, Undef)) -> shuffle(shuffle(A, Undef), B)

This patch helps identifying more shuffle pairs that could be combined reusing
the already existing rules in the DAGCombiner.

Added new test 'combine-vec-shuffle-5.ll' to verify that the canonicalized
shuffles are now folded into a single shuffle node by the DAGCombiner.
Added more test cases to 'combine-vec-shuffle-4.ll'.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213504 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-21 07:30:54 +00:00
Andrea Di Biagio
3d1975d44b [DAG] Refactor some logic. No functional change.
This patch removes function 'CommuteVectorShuffle' from X86ISelLowering.cpp
and moves its logic into SelectionDAG.cpp as method 'getCommutedVectorShuffles'.
This refactoring is in preperation of an upcoming change to the DAGCombiner.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213503 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-21 07:28:51 +00:00
NAKAMURA Takumi
1d55cc6828 MachineRegionInfo.cpp: Another fix on MachineRegionInfo::MachineRegionInfo::recalculate() to appease msc17.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213476 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-20 11:14:55 +00:00
Manuel Jacob
a4697dad19 [C++11] Add predecessors(BasicBlock *) / successors(BasicBlock *) iterator ranges.
Summary: This patch introduces two new iterator ranges and updates existing code to use it.  No functional change intended.

Test Plan: All tests (make check-all) still pass.

Reviewers: dblaikie

Reviewed By: dblaikie

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D4481

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213474 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-20 09:10:11 +00:00