Commit Graph

18108 Commits

Author SHA1 Message Date
Paul Robinson
107918efa2 Emit correct linkage-name attribute based on DWARF version.
There are still 4 tests that check for DW_AT_MIPS_linkage_name,
because they specify DWARF 2 or 3 in the module metadata. So, I didn't
create an explicit version-based test for the attribute.

Differential Revision: http://reviews.llvm.org/D8227


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231880 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-10 22:44:45 +00:00
Eric Christopher
57849e3bb4 Remove the use of the subtarget in MCCodeEmitter creation and
update all ports accordingly. Required a couple of small rewrites
in handling subtarget features during creation in PPC.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231861 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-10 22:03:14 +00:00
Rafael Espindola
f3d745cdc9 Create symbols marking the start of a section earlier.
This lets us pass the symbol to the constructor and avoid the mutable field.

This also opens the way for outputting the symbol only when needed, instead
of outputting them at the start of the file.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231859 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-10 22:00:25 +00:00
Quentin Colombet
7775242da3 [CodeGenPrepare] Refine the cost model provided by the promotion helper.
- Use TargetLowering to check for the actual cost of each extension.
- Provide a factorized method to check for the cost of an extension:
  TargetLowering::isExtFree.
- Provide a virtual method TargetLowering::isExtFreeImpl for targets to be able
  to tune the cost of non-free extensions.

This refactoring offers a better granularity to model what really happens on
different targets.

No performance changes and very few code differences.

Part of <rdar://problem/19267165> 


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231855 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-10 21:48:15 +00:00
Chad Rosier
09fc12a14e Don't evaluate rend() on every iteration of the loop.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231837 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-10 20:29:59 +00:00
Bruno Cardoso Lopes
84e6358ea0 [AsmPrinter][TLOF] Reintroduce AArch64 test
Follow up from r231505.

Fix the non-determinism by using a MapVector and reintroduce the AArch64
testcase. Defer deleting the got candidates up to the end and remove
them in a bulk, avoiding linear time removal of each element.

Thanks to Renato Golin for trying it out on other platforms.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231830 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-10 20:05:23 +00:00
Adrian Prantl
e753b17efe Change the datatype of DwarfExpression::Emit(Un)Signed to (u)int64_t
so it matches the one used by ByteStreamer::Emit(U|S)LEB128.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231823 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-10 19:23:37 +00:00
Rafael Espindola
0f4df6dc6f Store an optional section start label in MCSection.
This makes code that uses section relative expressions (debug info) simpler and
less brittle.

This is still a bit awkward as the symbol is created late and has to be
stored in a mutable field.

I will move the symbol creation earlier in the next patch.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231802 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-10 16:58:10 +00:00
Igor Laevsky
68beb2a9ec Teach lowering to correctly handle invoke statepoint and gc results tied to them. Note that we still can not lower gc.relocates for invoke statepoints.
Also it extracts getCopyFromRegs helper function in SelectionDAGBuilder as we need to be able to customize type of the register exported from basic block during lowering of the gc.result.
(Resubmitting this change after not being able to reproduce buildbot failure)

Differential Revision: http://reviews.llvm.org/D7760



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231800 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-10 16:26:48 +00:00
Chad Rosier
e891f49ad5 [BranchFolding] Remove MMOs during tail merge to preserve dependencies.
When tail merging it may be necessary to remove MMOs from memory operations to
ensures later passes (e.g., MI sched) conservatively compute dependencies.
Currently, we only remove the MMO from the common tail if the MMO doesn't match
with the relative instruction in the non-common tail(s).

A more robust solution would be to add multiple MMOs from the duplicate MIs to
the new MI. Currently ScheduleDAGInstrs.cpp ignores all MMOs on instructions
with multiple MMOs, so this solution is equivalent for the time being.

No test case included as this is incredibly difficult to reproduce.

Patch was a collaborative effort between Ana Pazos and myself.
Phabricator: http://reviews.llvm.org/D7769

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231799 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-10 16:22:52 +00:00
Sanjay Patel
137e1f3f28 [X86, AVX] replace vinsertf128 intrinsics with generic shuffles
We want to replace as much custom x86 shuffling via intrinsics
as possible because pushing the code down the generic shuffle
optimization path allows for better codegen and less complexity
in LLVM.

This is the sibling patch for the Clang half of this change:
http://reviews.llvm.org/D8088

Differential Revision: http://reviews.llvm.org/D8086



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231794 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-10 16:08:36 +00:00
Rafael Espindola
71653f3324 Remove effectively dead code.
Switching back and forth between sections does nothing (other than producing
larger .s files).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231790 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-10 14:48:01 +00:00
Daniel Sanders
b02d16e0e7 The operand flag word used in ISD::INLINEASM is an i32 not a pointer. NFC.
Summary:
This is part of the work to support memory constraints that behave
differently to 'm'. The subsequent patches will expand on the existing
encoding (which is a 32-bit int) and as a result in some flag words will no
longer fit into an i16. This problem only affected the MSP430 target which
appears to have 16-bit pointers.

Reviewers: hfinkel

Reviewed By: hfinkel

Subscribers: hfinkel, llvm-commits

Differential Revision: http://reviews.llvm.org/D8168

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231783 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-10 10:42:59 +00:00
Rafael Espindola
cf08570476 Move variable into assert to fix -Asserts builds.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231753 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-10 04:28:09 +00:00
Rafael Espindola
774ad7aeb3 Remove incredibly confusing isBaseAddressKnownZero.
When referring to a symbol in a dwarf section on ELF we should use

.long foo

instead of

.long foo - .debug_something

because ELF is unaware of the content of the sections and therefore needs
relocations. This has nothing to do with optimizing a -0.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231751 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-10 04:11:52 +00:00
Rafael Espindola
44292e80ac Use a better name for compile unit labels.
They mark the start of a compile unit, so name them .Lcu_*. Using
Section->getLabelBeginName() makes it looks like they mark the start of the
section.

While at it, switch to createTempSymbol to avoid collisions with labels
created in inline assembly. Not sure if a "don't crash" test is worth it.

With this getLabelBeginName is dead, delete it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231750 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-10 03:58:36 +00:00
Frederic Riss
d8b587de3b DwarfAccelTable: remove unneeded bucket terminators.
Last commit fixed the handling of hash collisions, but it introdcuced
unneeded bucket terminators in some places. The generated table was
correct, it can just be a tiny bit smaller. As the previous table was
correct, the test doesn't need updating. If we really wanted to test
this, I could add the section size to the dwarf dump and test for a
precise value there. IMO the correctness test is sufficient.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231748 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-10 03:47:55 +00:00
Rafael Espindola
810c3f5ef9 Move label creation close to emission. NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231744 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-10 03:11:11 +00:00
Mehdi Amini
529919ff31 DataLayout is mandatory, update the API to reflect it with references.
Summary:
Now that the DataLayout is a mandatory part of the module, let's start
cleaning the codebase. This patch is a first attempt at doing that.

This patch is not exactly NFC as for instance some places were passing
a nullptr instead of the DataLayout, possibly just because there was a
default value on the DataLayout argument to many functions in the API.
Even though it is not purely NFC, there is no change in the
validation.

I turned as many pointer to DataLayout to references, this helped
figuring out all the places where a nullptr could come up.

I had initially a local version of this patch broken into over 30
independant, commits but some later commit were cleaning the API and
touching part of the code modified in the previous commits, so it
seemed cleaner without the intermediate state.

Test Plan:

Reviewers: echristo

Subscribers: llvm-commits

From: Mehdi Amini <mehdi.amini@apple.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231740 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-10 02:37:25 +00:00
Frederic Riss
14bd47ef85 DwarfAccelTable: Fix handling of hash collisions.
It turns out accelerator tables where totally broken if they contained
entries with colliding hashes. The failure mode is pretty bad, as it not
only impacted the colliding entries, but would basically make all the
entries after the first hash collision pointing in the wrong place.

The testcase uses the symbol names that where found to collide during a
clang build.

From a performance point of view, the patch adds a sort and a linear
walk over each bucket contents. While it has a measurable impact on the
accelerator table emission, it's not showing up significantly in clang
profiles (and I'd argue that correctness is priceless :-)).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231732 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-10 00:46:31 +00:00
Ahmed Bougacha
55a060641f [CodeGen] Replace the reused stores' chain for extractelt expansion.
This fixes a subtle issue that was introduced in r205153.

When reusing a store for the extractelement expansion (to load directly
from it, inserting of going through the stack), later stores to the
same location might have overwritten the data we were expecting to
extract from.

To fix that, we need to explicitly replace the chain going out of the
reused store, so that later stores also have an explicit dependency on
the generated element-extracting loads, and can't clobber them.

rdar://20066785
Differential Revision: http://reviews.llvm.org/D8180


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231721 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-09 22:51:05 +00:00
Reid Kleckner
4c27f8d49e Reland r229944: EH: Prune unreachable resume instructions during Dwarf EH preparation
Fix the double-deletion of AnalysisResolver when delegating through to
Dwarf EH preparation by creating one from scratch. Hopefully the new
pass manager simplifies this.

This reverts commit r229952.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231719 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-09 22:45:16 +00:00
Rafael Espindola
9e065f52fc Use a MapVector instead of an extra sort.
This also has the advantage of not depending on the brittle getLabelBeginName.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231714 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-09 22:08:37 +00:00
Frederic Riss
be25211e4f DwarfAccelTable: fix obvious typo.
I have a test for that issue, but I didn't include it in the commit as it's
a 200KB file for a pretty minor issue. (The reason the file is so big is
that it needs > 1024 variables/functions to trigger and that with debug
information.

The issue/fix on the other side is totally trivial. If poeple want the test
commited, I can do that. It just didn't seem worth it to me.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231701 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-09 21:09:50 +00:00
Rafael Espindola
905c6fb424 Don't prime the section map.
This was just creating unused labels for .text when the module had no
functions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231694 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-09 20:09:58 +00:00
Rafael Espindola
be886690bd Print jump tables before exception tables.
In the case where just tables are part of the function section, this produces
more readable assembly by avoiding switching to the eh section and back
to .text.

This would also break with non unique section names, as trying to switch to
a unique section actually creates a new one.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231677 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-09 18:29:12 +00:00
Rafael Espindola
ce9ee4e050 Don't repeat name in comment. NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231676 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-09 18:11:42 +00:00
Rafael Espindola
a32448cb94 Remove dummy method implementations.
These are pure virtual in the base class, so the compiler checks that they
are implemented.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231673 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-09 17:58:49 +00:00
David Blaikie
da4471d726 Simplify expressions involving boolean constants with clang-tidy
Patch by Richard (legalize at xmission dot com).

Differential Revision: http://reviews.llvm.org/D8154

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231617 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-09 01:57:13 +00:00
Benjamin Kramer
c8a95a8bf4 Make static variables const if possible. Makes them go into a read-only section.
Or fold them into a initializer list which has the same effect. NFC.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231598 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-08 16:07:39 +00:00
Simon Pilgrim
b8056be62c [DAGCombiner] Add a shuffle mask commutation helper function. NFCI.
We have an increasing number of cases where we are creating commuted shuffle masks - all implementing nearly the same code.

This patch adds a static helper function - ShuffleVectorSDNode::commuteMask() and replaces a number of cases to use it.

Differential Revision: http://reviews.llvm.org/D8139

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231581 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-07 22:33:11 +00:00
Benjamin Kramer
ed0266d8ee Make constant arrays that are passed to functions as const.
In theory this allows the compiler to skip materializing the array on
the stack. In practice clang often fails to do that, but that's a
different story. NFC.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231571 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-07 17:41:00 +00:00
Simon Pilgrim
62ffaaac7c Use SDValue bool check to tidyup some possible combines. NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231569 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-07 16:34:55 +00:00
Andrea Di Biagio
15d2c3fb00 [DAGCombiner] Fix wrong folding of AND dag nodes.
This patch fixes the logic in the DAGCombiner that folds an AND node according
to rule: (and (X (load V)), C) -> (X (load V))

An AND between a vector load 'X' and a constant build_vector 'C' can be folded
into the load itself only if we can prove that the AND operation is redundant.
The algorithm implemented by 'visitAND' firstly computes the splat value 'S'
from C, and then checks if S has the lower 'B' bits set (where B is the size in
bits of the vector element type). The algorithm takes into account also the
'undef' bits in the splat mask.

Unfortunately, the algorithm only worked under the assumption that the size of S
is a multiple of the vector element type. With this patch, we conservatively
avoid folding the AND if the splat bits are not compatible with the vector
element type.

Added X86 test and-load-fold.ll

Differential Revision: http://reviews.llvm.org/D8085


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231563 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-07 12:24:55 +00:00
Simon Pilgrim
62ba058dea [DAGCombiner] SCALAR_TO_VECTOR(EXTRACT_VECTOR_ELT(V,C)) -> VECTOR_SHUFFLE
This patch attempts to convert a SCALAR_TO_VECTOR using an operand from an EXTRACT_VECTOR_ELT into a VECTOR_SHUFFLE.

This prevents many cases of spilling scalar data between the gpr + simd registers. 

At present the optimization only accepts cases where there is no TRUNC of the scalar type (i.e. all types must match).

Differential Revision: http://reviews.llvm.org/D8132

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231554 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-07 05:52:42 +00:00
Matthias Braun
47941aa098 DAGCombiner: Canonicalize select(and/or,x,y) depending on target.
This is based on the following equivalences:
select(C0 & C1, X, Y) <=> select(C0, select(C1, X, Y), Y)
select(C0 | C1, X, Y) <=> select(C0, X, select(C1, X, Y))

Many target cannot perform and/or on the CPU flags and therefore the
right side should be choosen to avoid materializign the i1 flags in an
integer register. If the target can perform this operation efficiently
we normalize to the left form.

Differential Revision: http://reviews.llvm.org/D7622

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231507 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-06 19:49:10 +00:00
Matthias Braun
fdd8f37dc6 DAGCombiner: Factor out some and/or combines.
This is in preparation for changing visitSELECT to normalize towards
select(Cond0, select(Cond1, X, Y), Y);
select(Cond0, X, select(Cond1, X, Y)) which perfom an implicit and/or of
the conditions.

The factored function contains all DAGCombine rules which reduce two values
combined by an And/Or operation to a single value. This does not include rules
involving constants as visitSELECT already handles that case.

Differential Revision: http://reviews.llvm.org/D8026

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231506 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-06 19:49:06 +00:00
Matthias Braun
ae6bbac733 ExecutionDepsFix: Indizes -> Indices.
Translate german to english.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231500 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-06 18:56:20 +00:00
Eric Christopher
be76ce0ca1 Fix typo.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231495 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-06 18:20:23 +00:00
Bruno Cardoso Lopes
dfc6383227 [AsmPrinter][TLOF] 32-bit MachO support for replacing GOT equivalents
Add MachO 32-bit (i.e. arm and x86) support for replacing global GOT equivalent
symbol accesses. Unlike 64-bit targets, there's no GOTPCREL relocation, and
access through a non_lazy_symbol_pointers section is used instead.

-- before

    _extgotequiv:
       .long _extfoo

    _delta:
       .long _extgotequiv-_delta

-- after

    _delta:
       .long L_extfoo$non_lazy_ptr-_delta

       .section __IMPORT,__pointers,non_lazy_symbol_pointers
    L_extfoo$non_lazy_ptr:
       .indirect_symbol _extfoo
       .long 0

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231475 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-06 13:49:05 +00:00
Bruno Cardoso Lopes
66aa390799 [AsmPrinter][TLOF] ARM64 MachO support for replacing GOT equivalents
Follow up r230264 and add ARM64 support for replacing global GOT
equivalent symbol accesses by references to the GOT entry for the final
symbol instead, example:

-- before

   .globl  _foo
  _foo:
   .long   42

   .globl  _gotequivalent
  _gotequivalent:
   .quad   _foo

   .globl  _delta
  _delta:
   .long   _gotequivalent-_delta

-- after

   .globl  _foo
  _foo:
   .long   42

   .globl  _delta
  Ltmp3:
   .long _foo@GOT-Ltmp3

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231474 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-06 13:48:45 +00:00
Michael Zolotukhin
6023ad2d37 LegalizeTypes: Handle shift by 0 in ExpandShiftByConstant.
Though such shifts are usually optimized away by combiner, we still can
encounter them after a vector shift is legalized.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231443 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-06 01:13:01 +00:00
Benjamin Kramer
7dc13e4d4b SelectionDAGBuilder: Merge 3 copies of the limited precision exp2 emission code.
NFC intended.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231406 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-05 21:13:08 +00:00
Andrew Kaylor
18296bdf03 Fix uninitialized memory references in WinEHPrepare
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231405 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-05 21:06:42 +00:00
Benjamin Kramer
f74b5c6198 SDAG: Merge the meat of two ExpandAtomic implementations.
The copies already diverged, don't let them become any worse. Reduce
redundancy in code with a little macro metaprogramming.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231401 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-05 20:04:29 +00:00
Rafael Espindola
2f76abe7d7 Use the correct func begin symbol in all places in ppc.
I missed an occurrence of the old symbol in my previous patch.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231398 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-05 19:47:50 +00:00
Rafael Espindola
2e2dbc35da Use the generic Lfunc_begin label on ppc.
This removes yet another custom label to mark the start of a function.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231390 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-05 18:55:50 +00:00
David Majnemer
42fcf79f36 X86: Optimize address mode matching for FRAME_ALLOC_RECOVER nodes
We know that the absolute symbol will be less than 2GB and thus will
always fit.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231389 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-05 18:50:12 +00:00
Reid Kleckner
9f7c861416 Replace llvm.frameallocate with llvm.frameescape
Turns out it's pretty straightforward and simplifies the implementation.

Reviewers: andrew.w.kaylor

Differential Revision: http://reviews.llvm.org/D8051

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231386 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-05 18:26:34 +00:00
Simon Pilgrim
a744a15e97 [DagCombiner] Allow shuffles to merge through bitcasts
Currently shuffles may only be combined if they are of the same type, despite the fact that bitcasts are often introduced in between shuffle nodes (e.g. x86 shuffle type widening).

This patch allows a single input shuffle to peek through bitcasts and if the input is another shuffle will merge them, shuffling using the smallest sized type, and re-applying the bitcasts at the inputs and output instead.

Dropped old ShuffleToZext test - this patch removes the use of the zext and vector-zext.ll covers these anyhow.

Differential Revision: http://reviews.llvm.org/D7939

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231380 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-05 17:14:04 +00:00