121418 Commits

Author SHA1 Message Date
Sanjay Patel
ec44710063 [x86] fix allowsMisalignedMemoryAccesses() for 8-byte and smaller accesses
This is a continuation of the fix from:
http://reviews.llvm.org/D10662

and discussion in:
http://reviews.llvm.org/D12154

Here, we distinguish slow unaligned SSE (128-bit) accesses from slow unaligned
scalar (64-bit and under) accesses. Other lowering (eg, getOptimalMemOpType) 
assumes that unaligned scalar accesses are always ok, so this changes 
allowsMisalignedMemoryAccesses() to match that behavior.

Differential Revision: http://reviews.llvm.org/D12543


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246658 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-02 15:42:49 +00:00
Rafael Espindola
3c4c9334b2 Pass a symbol table to getRelocationSymbol instead of returning one.
This removes a report_fatal_error from library and avoids checking a
section property for every section entry.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246656 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-02 15:07:39 +00:00
Asaf Badouh
05859c7cbb [X86][AVX512VLBW] add support in byte shift and SAD
add byte shift left/right
add SAD - compute sum of absolute differences

Differential Revision: http://reviews.llvm.org/D12479

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246654 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-02 14:21:54 +00:00
Chad Rosier
f8f78cdf6d Add newline to test. NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246653 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-02 14:06:16 +00:00
Joseph Tremoulet
16c6479624 [TableGen] Allow TokenTy in intrinsic signatures
Summary:
Add the necessary plumbing so that llvm_token_ty can be used as an
argument/return type in intrinsic definitions and correspondingly require
TokenTy in function types.  TokenTy is an opaque type that has no target
lowering, but can be used in machine-independent intrinsics.  It is
required for the upcoming llvm.eh.padparam intrinsic.

Reviewers: majnemer, rnk

Subscribers: stoklund, llvm-commits

Differential Revision: http://reviews.llvm.org/D12532

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246651 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-02 13:36:25 +00:00
Igor Breger
1b50f7132b AVX512: Implemented encoding and intrinsics for VGETMANTPD/S , VGETMANTSD/S instructions
Added tests for intrinsics and encoding.

Differential Revision: http://reviews.llvm.org/D11593

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246642 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-02 11:18:55 +00:00
NAKAMURA Takumi
3a491e5d33 Suppress llvm/test/tools/gold/X86/parallel.ll while investigating.
For me,

  Program received signal SIGSEGV, Segmentation fault.
  0x00007ffff7deb0dc in _dl_fixup () from /lib64/ld-linux-x86-64.so.2

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246641 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-02 10:59:21 +00:00
Igor Breger
191108c6b8 AVX512: Implemented encoding and intrinsics for vshufps/d.
Added tests for intrinsics and encoding.

Differential Revision: http://reviews.llvm.org/D11709

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246640 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-02 10:50:58 +00:00
James Molloy
6ce50a6980 [LV] Don't bail to MiddleBlock if a runtime check fails, bail to ScalarPH instead
We were bailing to two places if our runtime checks failed. If the initial overflow check failed, we'd go to ScalarPH. If any other check failed, we'd go to MiddleBlock. This caused us to have to have an extra PHI per induction and reduction as the vector loop's exit block was not dominated by its latch.

There's no need to have this behavior - if we just always go to ScalarPH we can get rid of a bunch of complexity.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246637 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-02 10:15:39 +00:00
James Molloy
e2568a81dc [LV] Move some code around slightly to make the intent of the function more clear.
NFC.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246636 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-02 10:15:32 +00:00
James Molloy
4718dafb69 [LV] Cleanup: Sink an IRBuilder closer to its uses.
NFC.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246635 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-02 10:15:27 +00:00
James Molloy
2b7433d981 [LV] Refactor all runtime check emissions into helper functions.
This reduces the complexity of createEmptyBlock() and will open the door to further refactoring.

The test change is simply because we're now constant folding a trivial test.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246634 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-02 10:15:22 +00:00
James Molloy
f6d9948d5a [LV] Pull creation of trip counts into a helper function.
... and do a tad of tidyup while we're at it. Because StartIdx must now be zero, there's no difference between Count and EndIdx.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246633 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-02 10:15:16 +00:00
James Molloy
cf062a0a18 [LV] Factor the creation of the loop induction variable out of createEmptyLoop()
It makes things easier to understand if this is in a helper method. This is part of my ongoing spaghetti-removal operation on createEmptyLoop.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246632 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-02 10:15:09 +00:00
James Molloy
fe89784bf1 [LV] Never widen an induction variable.
There's no need to widen canonical induction variables. It's just as efficient to create a *new*, wide, induction variable.

Consider, if we widen an indvar, then we'll have to truncate it before its uses anyway (1 trunc). If we create a new indvar instead, we'll have to truncate that instead (1 trunc) [besides which IndVars should go and clean up our mess after us anyway on principle].

This lets us remove a ton of special-casing code.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246631 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-02 10:15:05 +00:00
James Molloy
390bcc0ac8 [LV] Switch to using canonical induction variables.
Vectorized loops only ever have one induction variable. All induction PHIs from the scalar loop are rewritten to be in terms of this single indvar.

We were trying very hard to pick an indvar that already existed, even if that indvar wasn't canonical (didn't start at zero). But trying so hard is really fruitless - creating a new, canonical, indvar only results in one extra add in the worst case and that add is trivially easy to push through the PHI out of the loop by instcombine.

If we try and be less clever here and instead let instcombine clean up our mess (as we do in many other places in LV), we can remove unneeded complexity.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246630 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-02 10:14:54 +00:00
NAKAMURA Takumi
11caed9e12 [CMake] Don't use OBJLIB on Xcode.
I got a few reports it didn't work.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246629 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-02 10:11:26 +00:00
Elena Demikhovsky
e1bb461f27 AVX-512: store <4 x i1> and <2 x i1> values in memory
Enabled DAG pattern lowering for SKX with DQI predicate.

Differential Revision: http://reviews.llvm.org/D12550



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246625 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-02 09:20:58 +00:00
Elena Demikhovsky
d4b64f7e66 Optimization for Gather/Scatter with uniform base
Vector 'getelementptr' with scalar base is an opportunity for gather/scatter intrinsic to generate a better sequence.
While looking for uniform base, we want to use the scalar base pointer of GEP, if exists.

Differential Revision: http://reviews.llvm.org/D11121



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246622 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-02 08:39:13 +00:00
Yaron Keren
e53e7dcf09 Move createEliminateAvailableExternallyPass earlier in the pass pipeline
to save running many ModulePasses on available external functions that
are thrown away anyhow.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246619 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-02 06:34:11 +00:00
Vedant Kumar
ec0cd29de8 [CodeGen] Fix FREM on 32-bit MSVC on x86
Patch by Dylan McKay!

Differential Revision: http://reviews.llvm.org/D12099

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246615 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-02 01:31:58 +00:00
David Majnemer
6ad37ecd02 [MC] Generate a timestamp for COFF object files
The MS incremental linker seems to inspect the timestamp written into
the object file to determine whether or not it's contents need to be
considered.  Failing to set the timestamp to a date newer than the
executable will result in the object file not participating in
subsequent links.  To ameliorate this, write the current time into the
object file's TimeDateStamp field.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246607 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-01 23:46:11 +00:00
David Majnemer
dc2d216543 [MC] Remove MCAssembler's copy of OS
We can just ask the ObjectWriter for it's stream instead of caching
around our own reference to it.  No functionality change is intended.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246604 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-01 23:19:38 +00:00
Ahmed Bougacha
fc98f116be [ARM] Don't abort on variable-idx extractelt in ReconstructShuffle.
The code introduced in r244314 assumed that EXTRACT_VECTOR_ELT only
takes constant indices, but it does accept variables.
Bail out for those: we can't use them, as the shuffles we want to
reconstruct do require constant masks.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246594 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-01 21:56:00 +00:00
David Majnemer
3d58bd6369 [MC] Add support for generating COFF CRCs
COFF sections are accompanied with an auxiliary symbol which includes a
checksum.  This checksum used to be filled with just zero but this seems
to upset LINK.exe when it is processing a /INCREMENTAL link job.
Instead, fill the CheckSum field with the JamCRC of the section
contents.  This matches MSVC's behavior.

This fixes PR19666.

N.B.  A rather simple implementation of JamCRC is given.  It implements
a byte-wise calculation using the method given by Sarwate.  There are
implementations with higher throughput like slice-by-eight and making
use of PCLMULQDQ.  We can switch to one of those techniques if it turns
out to be a significant use of time.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246590 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-01 21:23:58 +00:00
Nico Weber
bb93db26e4 Make trunk release notes point to 3.7, not 3.6
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246588 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-01 21:10:56 +00:00
Sanjay Patel
ac515c4087 rename "slow-unaligned-mem-under-32" to slow-unaligned-mem-16" (NFCI)
This is a follow-on suggested by:
http://reviews.llvm.org/D12154 ( http://reviews.llvm.org/rL245729 )
http://reviews.llvm.org/D10662 ( http://reviews.llvm.org/rL245075 )

This makes the attribute name match most of the existing lowering logic
and regression test expectations.

But the current use of this attribute is inconsistent; see the FIXME
comment for "allowsMisalignedMemoryAccesses()". That change will
result in functional changes and should be coming soon.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246585 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-01 20:51:51 +00:00
Peter Collingbourne
0a1d37b2e8 gold-plugin: Implement parallel LTO code generation using llvm::splitCodeGen.
Parallelism can be enabled using a new plugin option, jobs=N, where N is
the number of code generation threads.

Differential Revision: http://reviews.llvm.org/D12308

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246584 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-01 20:40:22 +00:00
Benjamin Kramer
374ff4e100 Remove OutputBuffer.
This was last used by the pre-MC object emitter and has been dead for
quite a while. We have better ways to emit endian-dependent stuff now.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246571 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-01 18:25:34 +00:00
Hans Wennborg
e1478f87af DeadArgElim: don't eliminate arguments from naked functions
Differential Revision: http://reviews.llvm.org/D12534

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246564 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-01 18:06:46 +00:00
Artem Belevich
20264d6c67 New bitcode linker flags:
-only-needed -- link in only symbols needed by destination module
-internalize -- internalize linked symbols

Differential Revision: http://reviews.llvm.org/D12459

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246561 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-01 17:55:55 +00:00
Davide Italiano
70b9edea77 [llvm-readobj] MachO -- correctly dump section field 'Reserved3'
Before we incorrectly ignored it.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246556 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-01 16:29:02 +00:00
Ahmed Bougacha
37d12daa3a [AArch64] Lower READCYCLECOUNTER using MRS PMCCTNR_EL0.
This matches the ARM behavior. In both cases, the register is part
of the optional Performance Monitors extension, so, add the feature,
and enable it for the A-class processors we support.

Differential Revision: http://reviews.llvm.org/D12425



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246555 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-01 16:23:45 +00:00
David Majnemer
919f1f47e4 [MC] Allow MCObjectWriter's output stream to be swapped out
There are occasions where it is useful to consider the entirety of the
contents of a section.  For example, compressed debug info needs the
entire section available before it can compress it and write it out.
The compressed debug info scenario was previously implemented by
mirroring the implementation of writeSectionData in the ELFObjectWriter.

Instead, allow the output stream to be swapped on demand.  This lets
callers redirect the output stream to a more convenient location before
it hits the object file.

No functionality change is intended.

Differential Revision: http://reviews.llvm.org/D12509

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246554 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-01 16:19:03 +00:00
Igor Breger
c02bfc6060 AVX512: Implemented intrinsics for valign.
Differential Revision: http://reviews.llvm.org/D12526

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246551 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-01 15:27:18 +00:00
Sanjay Patel
aae58931bb use CHECK-LABEL for more precision
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246547 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-01 14:35:05 +00:00
Silviu Baranga
9258bce088 [AArch64] Turn on by default interleaved access vectorization
Summary:
This change turns on by default interleaved access vectorization
for AArch64.

We also clean up some tests which were spedifically enabling this
behaviour.

Reviewers: rengolin

Subscribers: aemerson, llvm-commits, rengolin

Differential Revision: http://reviews.llvm.org/D12149

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246542 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-01 11:26:46 +00:00
Silviu Baranga
ed8658c508 [ARM] Turn on by default interleaved access vectorization
Summary:
This change turns on by default interleaved access vectorization on ARM,
as it has shown to be beneficial on ARM.

Reviewers: rengolin

Subscribers: aemerson, llvm-commits, rengolin

Differential Revision: http://reviews.llvm.org/D12146

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246541 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-01 11:19:15 +00:00
Silviu Baranga
bbdc83dd12 [ARM][AArch64] Turn on by default interleaved access lowering
Summary:
Interleaved access lowering removes a memory operation and a
sequence of vector shuffles and replaces it with a series of
memory operations. This should be always beneficial.

This pass in only enabled on ARM/AArch64.

Reviewers: rengolin

Subscribers: aemerson, llvm-commits, rengolin

Differential Revision: http://reviews.llvm.org/D12145

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246540 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-01 11:12:35 +00:00
Yaron Keren
7e374d84bc Fix typo.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246538 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-01 10:13:49 +00:00
Rui Ueyama
5c1fa7fc49 Object: Fix COFF import file's symbols.
If a symbol is marked as "data", the symbol should be exported
with __imp_ prefix. Previously, the symbol was exported as-is.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246532 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-01 06:01:53 +00:00
Justin Bogner
06fdb30196 cmake: Error instead of warning and dropping invalid LLVM_USE_SANITIZER
Currently, if you call cmake with a typo in an LLVM_USE_SANITIZER
value, there's a cmake warning and the build goes on with no
sanitizers at all. This isn't a good behaviour, since cmake warnings
are fairly easy to miss and the resulting behaviour is that it looks
like the build is sanitizer clean.

Upgrade these warnings to errors so misconfigurations are more
obvious.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246531 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-01 05:45:07 +00:00
Andrew Wilkins
10add60748 Enable linking tools, shared libraries against libLLVM
Summary:
Three closely related changes, to have a mode in which we link all
executables and shared libraries against libLLVM. 

1. Add a new LLVM_LINK_LLVM_DYLIB cmake option, which, when ON, will link
   executables and shared libraries against libLLVM. For this to work, it
   is necessary to also set LLVM_BUILD_LLVM_DYLIB and LLVM_DYLIB_EXPORT_ALL.

   It is not strictly necessary to set LLVM_DISABLE_LLVM_DYLIB_ATEXIT, but
   we also default to OFF in this mode, or tools tend to misbehave (e.g.
   stdout may not flush on exit when output is buffered.)

   llvm-config and Tablegen do not use libLLVM, as they are dependencies of
   libLLVM.

2. Modify llvm-go to take a new flag, "linkmode=component-libs|dylib".
   Depending on which one is passed (default is component-libs), we link
   with the individual libraries or libLLVM respectively. We pass in dylib
   when LLVM_LINK_LLVM_DYLIB is ON.

3. Fix LLVM_DYLIB_EXPORT_ALL on Linux, and expand the symbols exported to
   actually export all. Don't strip leading underscore from symbols on Linux,
   and make sure we get all exported symbols and weak-with-default symbols
   ("W" in nm output). Without these changes, passes won't load because
   the "Annotate..." symbols defined in lib/Support/Valigrind.cpp are not
   found.

Testing:
 - Ran default build ("ninja") with LLVM, clang, compiler-rt, llgo, lldb.
 - Ran "check", "check-clang", "check-tsan", "check-libgo" targets. I've
   never had much success with LLDB tests, and llgoi is currently broken
   so check-llgo fails for an unrelated reason.
 - Ran "lldb" to ensure it loads.

Reviewers: chandlerc, beanz, pcc, rnk

Subscribers: rnk, chapuni, sylvestre.ledru, llvm-commits

Differential Revision: http://reviews.llvm.org/D12488

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246527 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-01 03:14:31 +00:00
Matt Arsenault
6bf871423e AMDGPU: Fix adding redundant implicit operands
These are already added during the MachineInstr construction,
so this was adding the implicit registers twice.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246525 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-01 02:02:21 +00:00
Cong Hou
715dbbbc3c Distribute the weight on the edge from switch to default statement to edges generated in lowering switch.
Currently, when edge weights are assigned to edges that are created when lowering switch statement, the weight on the edge to default statement (let's call it "default weight" here) is not considered. We need to distribute this weight properly. However, without value profiling, we have no idea how to distribute it. In this patch, I applied the heuristic that this weight is evenly distributed to successors.

For example, given a switch statement with cases 1,2,3,5,10,11,20, and every edge from switch to each successor has weight 10. If there is a binary search tree built to test if n < 10, then its two out-edges will have weight 4x10+10/2 = 45 and 3x10 + 10/2 = 35 respectively (currently they are 40 and 30 without considering the default weight). Each distribution (which is 5 here) will be stored in each SwitchWorkListItem for further distribution.

There are some exceptions:

For a jump table header which doesn't have any edge to default statement, we don't distribute the default weight to it.
For a bit test header which covers a contiguous range and hence has no edges to default statement, we don't distribute the default weight to it.
When the branch checks a single value or a contiguous range with no edge to default statement, we don't distribute the default weight to it.
In other cases, the default weight is evenly distributed to successors.

Differential Revision: http://reviews.llvm.org/D12418



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246522 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-01 01:42:16 +00:00
Sanjay Patel
51bbd6f3be remove unnecessary/conflicting target info
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246514 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-01 00:27:36 +00:00
Sanjay Patel
806b965072 fixed test to specify triple rather than arch and CPU
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246513 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-01 00:25:23 +00:00
Duncan P. N. Exon Smith
680ff33b17 LTO: Cleanup parameter names and header docs, NFC
Follow LLVM style for the parameter names (`CamelCase` not `camelCase`),
and surface the header docs in doxygen.  No functionality change
intended.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246509 91177308-0d34-0410-b5e6-96231b3b80d8
2015-08-31 23:44:06 +00:00
Hal Finkel
9e983241c9 [DAGCombine] Fixup SETCC legality checking
SETCC is one of those special node types for which operation actions (legality,
etc.) is keyed off of an operand type, not the node's value type. This makes
sense because the value type of a legal SETCC node is determined by its
operands' value type (via the TLI function getSetCCResultType). When the
SDAGBuilder creates SETCC nodes, it either creates them with an MVT::i1 value
type, or directly with the value type provided by TLI.getSetCCResultType.

The first problem being fixed here is that DAGCombine had several places
querying TLI.isOperationLegal on SETCC, but providing the return of
getSetCCResultType, instead of the operand type directly. This does not mean
what the author thought, and "luckily", most in-tree targets have SETCC with
Custom lowering, instead of marking them Legal, so these checks return false
anyway.

The second problem being fixed here is that two of the DAGCombines could create
SETCC nodes with arbitrary (integer) value types; specifically, those that
would simplify:

  (setcc a, b, op1) and|or (setcc a, b, op2) -> setcc a, b, op3
     (which is possible for some combinations of (op1, op2))

If the operands of the and|or node are actual setcc nodes, then this is not an
issue (because the and|or must share the same type), but, the relevant code in
DAGCombiner::visitANDLike and DAGCombiner::visitORLike actually calls
DAGCombiner::isSetCCEquivalent on each operand, and that function will
recognise setcc-like select_cc nodes with other return types. And, thus, when
creating new SETCC nodes, we need to be careful to respect the value-type
constraint. This is even true before type legalization, because it is quite
possible for the SELECT_CC node to have a legal type that does not happen to
match the corresponding TLI.getSetCCResultType type.

To be explicit, there is nothing that later fixes the value types of SETCC
nodes (if the type is legal, but does not happen to match
TLI.getSetCCResultType). Creating SETCCs with an MVT::i1 value type seems to
work only because, either MVT::i1 is not legal, or it is what
TLI.getSetCCResultType returns if it is legal. Fixing that is a larger change,
however. For the time being, restrict the relevant transformations to produce
only SETCC nodes with a value type matching TLI.getSetCCResultType (or MVT::i1
prior to type legalization).

Fixes PR24636.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246507 91177308-0d34-0410-b5e6-96231b3b80d8
2015-08-31 23:15:04 +00:00
Sanjay Patel
b113c5eb7f don't set a legal vector type if we know we can't use that type (NFCI)
Added benefit: the 'if' logic now matches the text of the comment that describes it.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246506 91177308-0d34-0410-b5e6-96231b3b80d8
2015-08-31 22:59:03 +00:00