llvm dev - Jul 2016 - Hitting assertion failure related to vectorization + instcombine

Sure. David, what do you think about merging this to 3.9?

Sanjay: are you saying I'd just apply that diff to
InstructionSimplify.cpp, not InstCombineSelect.cpp?

On Fri, Jul 22, 2016 at 7:08 AM, Sanjay Patel <spatel at rotateright.com>
wrote:
> Hi Hans -
>
> Yes, I think this is a good patch for 3.9 (cc'ing David Majnemer as
code
> owner). The functional change was r276209. I made an NFC refactoring in
> InstSimplify at r275911 that isn't in the branch, so I don't think
the patch
> will apply as-is. For safety, you could apply the one-line fix without
> pulling the refactoring into the branch with this diff:
>
> -    unsigned BitWidth = Q.DL.getTypeSizeInBits(TrueVal->getType());
> +    unsigned BitWidth > +       
Q.DL.getTypeSizeInBits(TrueVal->getType()->getScalarType());
>
>
>
>
> On Fri, Jul 22, 2016 at 7:45 AM, Hans Wennborg <hans at chromium.org>
wrote:
>>
>> Sanjay: let me know if this is something that will apply to 3.9.
>>
>> Thanks,
>> Hans
>>
>> On Wed, Jul 20, 2016 at 5:59 PM, Sanjay Patel via llvm-dev
>> <llvm-dev at lists.llvm.org> wrote:
>> > Quick update - the bug existed before I refactored that chunk in
>> > InstSimplify with:
>> > https://reviews.llvm.org/rL275911
>> >
>> > In fact, as discussed in https://reviews.llvm.org/D22537 - because
we
>> > have a
>> > big pile of lazily copied code, the bug has an identical twin that
>> > exists in
>> > InstCombine. I swear I didn't touch that code...yet. :)
>> >
>> > define <2 x i32> @select_icmp_vec(<2 x i32> %x) {
>> >   %cmp = icmp slt <2 x i32> %x, zeroinitializer
>> >   %xor = xor <2 x i32> %x, <i32 2147483648, i32
2147483648>
>> >   %x.xor = select <2 x i1> %cmp, <2 x i32> %x, <2 x
i32> %xor
>> >   ret <2 x i32> %x.xor
>> > }
>> >
>> > $ ./opt -instcombine selvec.ll -S
>> > Assertion failed: (BitWidth == RHS.BitWidth &&
"Comparison requires
>> > equal
>> > bit widths"), function operator==, file
>> > /Users/spatel/myllvm/llvm/include/llvm/ADT/APInt.h, line 983.
>> >
>> > I should have a patch up for review shortly.
>> >
>> >
>> > On Wed, Jul 20, 2016 at 2:03 PM, Sanjay Patel <spatel at
rotateright.com>
>> > wrote:
>> >>
>> >> Thanks for notifying me. Yes, this was a recent change. Taking
a look
>> >> now.
>> >>
>> >> On Wed, Jul 20, 2016 at 1:49 PM, Michael Kuperstein <mkuper
at google.com>
>> >> wrote:
>> >>>
>> >>> +Sanjay, who touched this last. :-)
>> >>>
>> >>> On Wed, Jul 20, 2016 at 12:44 PM, Ismail Badawi (ibadawi)
via llvm-dev
>> >>> <llvm-dev at lists.llvm.org> wrote:
>> >>>>
>> >>>> Hi folks,
>> >>>>
>> >>>> I'm hitting the below assertion failure when
compiling this small
>> >>>> piece
>> >>>> of C code (repro.c, attached).
>> >>>>
>> >>>> My command line is:
>> >>>>
>> >>>> bin/clang --target=aarch64-linux-gnu -c -O2 repro.c
>> >>>>
>> >>>> clang is built from top of trunk as of this morning.
It only happens
>> >>>> at
>> >>>> -O2, and it doesn't happen with the default target
(x86_64). I tried
>> >>>> to
>> >>>> reproduce using just 'llc -O2' but didn't
manage -- but I do have
>> >>>> this
>> >>>> reduced opt command line (repro.ll also attached, just
generated from
>> >>>> repro.c at -O0):
>> >>>>
>> >>>> bin/opt -instcombine -licm -simplifycfg -instcombine
-loop-rotate
>> >>>> -loop-vectorize -instcombine < repro.ll
>> >>>>
>> >>>> The failure is:
>> >>>>
>> >>>> opt:
/scratch/1/ismail/llvm-upstream/include/llvm/ADT/APInt.h:983:
>> >>>> bool
>> >>>> llvm::APInt::operator==(const llvm::APInt&) const:
Assertion
>> >>>> `BitWidth =>> >>>> RHS.BitWidth
&& "Comparison requires equal bit widths"' failed.
>> >>>> ...snip...
>> >>>> #8 0x00000000013a8553
llvm::APInt::operator==(llvm::APInt const&)
>> >>>> const
>> >>>>
/scratch/1/ismail/llvm-upstream/include/llvm/ADT/APInt.h:984:0
>> >>>> #9 0x0000000001f875b0
simplifySelectBitTest(llvm::Value*,
>> >>>> llvm::Value*,
>> >>>> llvm::Value*, llvm::APInt const*, bool)
>> >>>>
>> >>>>
/scratch/1/ismail/llvm-upstream/lib/Analysis/InstructionSimplify.cpp:3388:0
>> >>>> #10 0x0000000001f87ad5
simplifySelectWithICmpCond(llvm::Value*,
>> >>>> llvm::Value*, llvm::Value*, (anonymous
namespace)::Query const&,
>> >>>> unsigned
>> >>>> int)
>> >>>>
>> >>>>
/scratch/1/ismail/llvm-upstream/lib/Analysis/InstructionSimplify.cpp:3434:0
>> >>>> #11 0x0000000001f87f6a
SimplifySelectInst(llvm::Value*, llvm::Value*,
>> >>>> llvm::Value*, (anonymous namespace)::Query const&,
unsigned int)
>> >>>>
>> >>>>
/scratch/1/ismail/llvm-upstream/lib/Analysis/InstructionSimplify.cpp:3515:0
>> >>>> #12 0x0000000001f87fe3
llvm::SimplifySelectInst(llvm::Value*,
>> >>>> llvm::Value*, llvm::Value*, llvm::DataLayout
const&,
>> >>>> llvm::TargetLibraryInfo
>> >>>> const*, llvm::DominatorTree const*,
llvm::AssumptionCache*,
>> >>>> llvm::Instruction const*)
>> >>>>
>> >>>>
/scratch/1/ismail/llvm-upstream/lib/Analysis/InstructionSimplify.cpp:3528:0
>> >>>> ...snip...
>> >>>> Stack dump:
>> >>>> 0.  Program arguments: debugbuild/bin/opt -instcombine
-licm
>> >>>> -simplifycfg -instcombine -loop-rotate -loop-vectorize
-instcombine
>> >>>> 1.  Running pass 'Function Pass Manager' on
module '<stdin>'.
>> >>>> 2.  Running pass 'Combine redundant
instructions' on function
>> >>>> '@strsave'
>> >>>>
>> >>>> ---
>> >>>>
>> >>>> Looking at the code, the issue is with this line:
>> >>>>
>> >>>>   if (TrueVal == X && match(FalseVal,
m_And(m_Specific(X),
>> >>>> m_APInt(C)))
>> >>>> &&
>> >>>>         *Y == ~*C)
>> >>>>
>> >>>> In this case Y is a 128-bit APInt, and so is the value
that C is
>> >>>> extracted from, but the m_APInt matcher has code that
calls
>> >>>> getSplatValue()
>> >>>> if the matched expression has vector type. So C ends
up as an 8-bit
>> >>>> value,
>> >>>> triggering the assertion failure on the call to ==.
>> >>>>
>> >>>> The issue is clear but I'm not sure what the
correct fix should be --
>> >>>> whether this code is just not meant to work with
vector types, or
>> >>>> whether
>> >>>> the call to getSplatValue() doesn't belong in the
matcher, or whether
>> >>>> there
>> >>>> should be a corresponding call to getSplatValue() on
the caller side,
>> >>>> or
>> >>>> something else.
>> >>>>
>> >>>> Any help from someone with more context would be
appreciated.
>> >>>>
>> >>>> Thanks,
>> >>>> Ismail
>> >>>>
>> >>>>
>> >>>> _______________________________________________
>> >>>> LLVM Developers mailing list
>> >>>> llvm-dev at lists.llvm.org
>> >>>>
http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>> >>>>
>> >>>
>> >>
>> >
>> >
>> > _______________________________________________
>> > LLVM Developers mailing list
>> > llvm-dev at lists.llvm.org
>> > http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>> >
>
>

David, Sanjay: ping?

On Mon, Jul 25, 2016 at 11:07 AM, Hans Wennborg <hans at chromium.org>
wrote:
> Sure. David, what do you think about merging this to 3.9?
>
> Sanjay: are you saying I'd just apply that diff to
> InstructionSimplify.cpp, not InstCombineSelect.cpp?
>
> On Fri, Jul 22, 2016 at 7:08 AM, Sanjay Patel <spatel at
rotateright.com> wrote:
>> Hi Hans -
>>
>> Yes, I think this is a good patch for 3.9 (cc'ing David Majnemer as
code
>> owner). The functional change was r276209. I made an NFC refactoring in
>> InstSimplify at r275911 that isn't in the branch, so I don't
think the patch
>> will apply as-is. For safety, you could apply the one-line fix without
>> pulling the refactoring into the branch with this diff:
>>
>> -    unsigned BitWidth = Q.DL.getTypeSizeInBits(TrueVal->getType());
>> +    unsigned BitWidth >> +       
Q.DL.getTypeSizeInBits(TrueVal->getType()->getScalarType());
>>
>>
>>
>>
>> On Fri, Jul 22, 2016 at 7:45 AM, Hans Wennborg <hans at
chromium.org> wrote:
>>>
>>> Sanjay: let me know if this is something that will apply to 3.9.
>>>
>>> Thanks,
>>> Hans
>>>
>>> On Wed, Jul 20, 2016 at 5:59 PM, Sanjay Patel via llvm-dev
>>> <llvm-dev at lists.llvm.org> wrote:
>>> > Quick update - the bug existed before I refactored that chunk
in
>>> > InstSimplify with:
>>> > https://reviews.llvm.org/rL275911
>>> >
>>> > In fact, as discussed in https://reviews.llvm.org/D22537 -
because we
>>> > have a
>>> > big pile of lazily copied code, the bug has an identical twin
that
>>> > exists in
>>> > InstCombine. I swear I didn't touch that code...yet. :)
>>> >
>>> > define <2 x i32> @select_icmp_vec(<2 x i32> %x) {
>>> >   %cmp = icmp slt <2 x i32> %x, zeroinitializer
>>> >   %xor = xor <2 x i32> %x, <i32 2147483648, i32
2147483648>
>>> >   %x.xor = select <2 x i1> %cmp, <2 x i32> %x,
<2 x i32> %xor
>>> >   ret <2 x i32> %x.xor
>>> > }
>>> >
>>> > $ ./opt -instcombine selvec.ll -S
>>> > Assertion failed: (BitWidth == RHS.BitWidth &&
"Comparison requires
>>> > equal
>>> > bit widths"), function operator==, file
>>> > /Users/spatel/myllvm/llvm/include/llvm/ADT/APInt.h, line 983.
>>> >
>>> > I should have a patch up for review shortly.
>>> >
>>> >
>>> > On Wed, Jul 20, 2016 at 2:03 PM, Sanjay Patel <spatel at
rotateright.com>
>>> > wrote:
>>> >>
>>> >> Thanks for notifying me. Yes, this was a recent change.
Taking a look
>>> >> now.
>>> >>
>>> >> On Wed, Jul 20, 2016 at 1:49 PM, Michael Kuperstein
<mkuper at google.com>
>>> >> wrote:
>>> >>>
>>> >>> +Sanjay, who touched this last. :-)
>>> >>>
>>> >>> On Wed, Jul 20, 2016 at 12:44 PM, Ismail Badawi
(ibadawi) via llvm-dev
>>> >>> <llvm-dev at lists.llvm.org> wrote:
>>> >>>>
>>> >>>> Hi folks,
>>> >>>>
>>> >>>> I'm hitting the below assertion failure when
compiling this small
>>> >>>> piece
>>> >>>> of C code (repro.c, attached).
>>> >>>>
>>> >>>> My command line is:
>>> >>>>
>>> >>>> bin/clang --target=aarch64-linux-gnu -c -O2
repro.c
>>> >>>>
>>> >>>> clang is built from top of trunk as of this
morning. It only happens
>>> >>>> at
>>> >>>> -O2, and it doesn't happen with the default
target (x86_64). I tried
>>> >>>> to
>>> >>>> reproduce using just 'llc -O2' but
didn't manage -- but I do have
>>> >>>> this
>>> >>>> reduced opt command line (repro.ll also attached,
just generated from
>>> >>>> repro.c at -O0):
>>> >>>>
>>> >>>> bin/opt -instcombine -licm -simplifycfg
-instcombine -loop-rotate
>>> >>>> -loop-vectorize -instcombine < repro.ll
>>> >>>>
>>> >>>> The failure is:
>>> >>>>
>>> >>>> opt:
/scratch/1/ismail/llvm-upstream/include/llvm/ADT/APInt.h:983:
>>> >>>> bool
>>> >>>> llvm::APInt::operator==(const llvm::APInt&)
const: Assertion
>>> >>>> `BitWidth =>>> >>>>
RHS.BitWidth && "Comparison requires equal bit widths"'
failed.
>>> >>>> ...snip...
>>> >>>> #8 0x00000000013a8553
llvm::APInt::operator==(llvm::APInt const&)
>>> >>>> const
>>> >>>>
/scratch/1/ismail/llvm-upstream/include/llvm/ADT/APInt.h:984:0
>>> >>>> #9 0x0000000001f875b0
simplifySelectBitTest(llvm::Value*,
>>> >>>> llvm::Value*,
>>> >>>> llvm::Value*, llvm::APInt const*, bool)
>>> >>>>
>>> >>>>
/scratch/1/ismail/llvm-upstream/lib/Analysis/InstructionSimplify.cpp:3388:0
>>> >>>> #10 0x0000000001f87ad5
simplifySelectWithICmpCond(llvm::Value*,
>>> >>>> llvm::Value*, llvm::Value*, (anonymous
namespace)::Query const&,
>>> >>>> unsigned
>>> >>>> int)
>>> >>>>
>>> >>>>
/scratch/1/ismail/llvm-upstream/lib/Analysis/InstructionSimplify.cpp:3434:0
>>> >>>> #11 0x0000000001f87f6a
SimplifySelectInst(llvm::Value*, llvm::Value*,
>>> >>>> llvm::Value*, (anonymous namespace)::Query
const&, unsigned int)
>>> >>>>
>>> >>>>
/scratch/1/ismail/llvm-upstream/lib/Analysis/InstructionSimplify.cpp:3515:0
>>> >>>> #12 0x0000000001f87fe3
llvm::SimplifySelectInst(llvm::Value*,
>>> >>>> llvm::Value*, llvm::Value*, llvm::DataLayout
const&,
>>> >>>> llvm::TargetLibraryInfo
>>> >>>> const*, llvm::DominatorTree const*,
llvm::AssumptionCache*,
>>> >>>> llvm::Instruction const*)
>>> >>>>
>>> >>>>
/scratch/1/ismail/llvm-upstream/lib/Analysis/InstructionSimplify.cpp:3528:0
>>> >>>> ...snip...
>>> >>>> Stack dump:
>>> >>>> 0.  Program arguments: debugbuild/bin/opt
-instcombine -licm
>>> >>>> -simplifycfg -instcombine -loop-rotate
-loop-vectorize -instcombine
>>> >>>> 1.  Running pass 'Function Pass Manager'
on module '<stdin>'.
>>> >>>> 2.  Running pass 'Combine redundant
instructions' on function
>>> >>>> '@strsave'
>>> >>>>
>>> >>>> ---
>>> >>>>
>>> >>>> Looking at the code, the issue is with this line:
>>> >>>>
>>> >>>>   if (TrueVal == X && match(FalseVal,
m_And(m_Specific(X),
>>> >>>> m_APInt(C)))
>>> >>>> &&
>>> >>>>         *Y == ~*C)
>>> >>>>
>>> >>>> In this case Y is a 128-bit APInt, and so is the
value that C is
>>> >>>> extracted from, but the m_APInt matcher has code
that calls
>>> >>>> getSplatValue()
>>> >>>> if the matched expression has vector type. So C
ends up as an 8-bit
>>> >>>> value,
>>> >>>> triggering the assertion failure on the call to
==.
>>> >>>>
>>> >>>> The issue is clear but I'm not sure what the
correct fix should be --
>>> >>>> whether this code is just not meant to work with
vector types, or
>>> >>>> whether
>>> >>>> the call to getSplatValue() doesn't belong in
the matcher, or whether
>>> >>>> there
>>> >>>> should be a corresponding call to getSplatValue()
on the caller side,
>>> >>>> or
>>> >>>> something else.
>>> >>>>
>>> >>>> Any help from someone with more context would be
appreciated.
>>> >>>>
>>> >>>> Thanks,
>>> >>>> Ismail
>>> >>>>
>>> >>>>
>>> >>>> _______________________________________________
>>> >>>> LLVM Developers mailing list
>>> >>>> llvm-dev at lists.llvm.org
>>> >>>>
http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>>> >>>>
>>> >>>
>>> >>
>>> >
>>> >
>>> > _______________________________________________
>>> > LLVM Developers mailing list
>>> > llvm-dev at lists.llvm.org
>>> > http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>>> >
>>
>>

LGTM

On Wednesday, July 27, 2016, Hans Wennborg <hans at chromium.org> wrote:
> David, Sanjay: ping?
>
> On Mon, Jul 25, 2016 at 11:07 AM, Hans Wennborg <hans at chromium.org
> <javascript:;>> wrote:
> > Sure. David, what do you think about merging this to 3.9?
> >
> > Sanjay: are you saying I'd just apply that diff to
> > InstructionSimplify.cpp, not InstCombineSelect.cpp?
> >
> > On Fri, Jul 22, 2016 at 7:08 AM, Sanjay Patel <spatel at
rotateright.com
> <javascript:;>> wrote:
> >> Hi Hans -
> >>
> >> Yes, I think this is a good patch for 3.9 (cc'ing David
Majnemer as code
> >> owner). The functional change was r276209. I made an NFC
refactoring in
> >> InstSimplify at r275911 that isn't in the branch, so I
don't think the
> patch
> >> will apply as-is. For safety, you could apply the one-line fix
without
> >> pulling the refactoring into the branch with this diff:
> >>
> >> -    unsigned BitWidth =
Q.DL.getTypeSizeInBits(TrueVal->getType());
> >> +    unsigned BitWidth > >> +       
Q.DL.getTypeSizeInBits(TrueVal->getType()->getScalarType());
> >>
> >>
> >>
> >>
> >> On Fri, Jul 22, 2016 at 7:45 AM, Hans Wennborg <hans at
chromium.org
> <javascript:;>> wrote:
> >>>
> >>> Sanjay: let me know if this is something that will apply to
3.9.
> >>>
> >>> Thanks,
> >>> Hans
> >>>
> >>> On Wed, Jul 20, 2016 at 5:59 PM, Sanjay Patel via llvm-dev
> >>> <llvm-dev at lists.llvm.org <javascript:;>> wrote:
> >>> > Quick update - the bug existed before I refactored that
chunk in
> >>> > InstSimplify with:
> >>> > https://reviews.llvm.org/rL275911
> >>> >
> >>> > In fact, as discussed in https://reviews.llvm.org/D22537
- because
> we
> >>> > have a
> >>> > big pile of lazily copied code, the bug has an identical
twin that
> >>> > exists in
> >>> > InstCombine. I swear I didn't touch that code...yet.
:)
> >>> >
> >>> > define <2 x i32> @select_icmp_vec(<2 x i32>
%x) {
> >>> >   %cmp = icmp slt <2 x i32> %x, zeroinitializer
> >>> >   %xor = xor <2 x i32> %x, <i32 2147483648, i32
2147483648>
> >>> >   %x.xor = select <2 x i1> %cmp, <2 x i32>
%x, <2 x i32> %xor
> >>> >   ret <2 x i32> %x.xor
> >>> > }
> >>> >
> >>> > $ ./opt -instcombine selvec.ll -S
> >>> > Assertion failed: (BitWidth == RHS.BitWidth &&
"Comparison requires
> >>> > equal
> >>> > bit widths"), function operator==, file
> >>> > /Users/spatel/myllvm/llvm/include/llvm/ADT/APInt.h, line
983.
> >>> >
> >>> > I should have a patch up for review shortly.
> >>> >
> >>> >
> >>> > On Wed, Jul 20, 2016 at 2:03 PM, Sanjay Patel <
> spatel at rotateright.com <javascript:;>>
> >>> > wrote:
> >>> >>
> >>> >> Thanks for notifying me. Yes, this was a recent
change. Taking a
> look
> >>> >> now.
> >>> >>
> >>> >> On Wed, Jul 20, 2016 at 1:49 PM, Michael Kuperstein
<
> mkuper at google.com <javascript:;>>
> >>> >> wrote:
> >>> >>>
> >>> >>> +Sanjay, who touched this last. :-)
> >>> >>>
> >>> >>> On Wed, Jul 20, 2016 at 12:44 PM, Ismail Badawi
(ibadawi) via
> llvm-dev
> >>> >>> <llvm-dev at lists.llvm.org
<javascript:;>> wrote:
> >>> >>>>
> >>> >>>> Hi folks,
> >>> >>>>
> >>> >>>> I'm hitting the below assertion failure
when compiling this small
> >>> >>>> piece
> >>> >>>> of C code (repro.c, attached).
> >>> >>>>
> >>> >>>> My command line is:
> >>> >>>>
> >>> >>>> bin/clang --target=aarch64-linux-gnu -c -O2
repro.c
> >>> >>>>
> >>> >>>> clang is built from top of trunk as of this
morning. It only
> happens
> >>> >>>> at
> >>> >>>> -O2, and it doesn't happen with the
default target (x86_64). I
> tried
> >>> >>>> to
> >>> >>>> reproduce using just 'llc -O2' but
didn't manage -- but I do have
> >>> >>>> this
> >>> >>>> reduced opt command line (repro.ll also
attached, just generated
> from
> >>> >>>> repro.c at -O0):
> >>> >>>>
> >>> >>>> bin/opt -instcombine -licm -simplifycfg
-instcombine -loop-rotate
> >>> >>>> -loop-vectorize -instcombine < repro.ll
> >>> >>>>
> >>> >>>> The failure is:
> >>> >>>>
> >>> >>>> opt:
/scratch/1/ismail/llvm-upstream/include/llvm/ADT/APInt.h:983:
> >>> >>>> bool
> >>> >>>> llvm::APInt::operator==(const
llvm::APInt&) const: Assertion
> >>> >>>> `BitWidth => >>> >>>>
RHS.BitWidth && "Comparison requires equal bit widths"'
failed.
> >>> >>>> ...snip...
> >>> >>>> #8 0x00000000013a8553
llvm::APInt::operator==(llvm::APInt const&)
> >>> >>>> const
> >>> >>>>
/scratch/1/ismail/llvm-upstream/include/llvm/ADT/APInt.h:984:0
> >>> >>>> #9 0x0000000001f875b0
simplifySelectBitTest(llvm::Value*,
> >>> >>>> llvm::Value*,
> >>> >>>> llvm::Value*, llvm::APInt const*, bool)
> >>> >>>>
> >>> >>>>
> /scratch/1/ismail/llvm-upstream/lib/Analysis/InstructionSimplify.cpp:3388:0
> >>> >>>> #10 0x0000000001f87ad5
simplifySelectWithICmpCond(llvm::Value*,
> >>> >>>> llvm::Value*, llvm::Value*, (anonymous
namespace)::Query const&,
> >>> >>>> unsigned
> >>> >>>> int)
> >>> >>>>
> >>> >>>>
> /scratch/1/ismail/llvm-upstream/lib/Analysis/InstructionSimplify.cpp:3434:0
> >>> >>>> #11 0x0000000001f87f6a
SimplifySelectInst(llvm::Value*,
> llvm::Value*,
> >>> >>>> llvm::Value*, (anonymous namespace)::Query
const&, unsigned int)
> >>> >>>>
> >>> >>>>
> /scratch/1/ismail/llvm-upstream/lib/Analysis/InstructionSimplify.cpp:3515:0
> >>> >>>> #12 0x0000000001f87fe3
llvm::SimplifySelectInst(llvm::Value*,
> >>> >>>> llvm::Value*, llvm::Value*, llvm::DataLayout
const&,
> >>> >>>> llvm::TargetLibraryInfo
> >>> >>>> const*, llvm::DominatorTree const*,
llvm::AssumptionCache*,
> >>> >>>> llvm::Instruction const*)
> >>> >>>>
> >>> >>>>
> /scratch/1/ismail/llvm-upstream/lib/Analysis/InstructionSimplify.cpp:3528:0
> >>> >>>> ...snip...
> >>> >>>> Stack dump:
> >>> >>>> 0.  Program arguments: debugbuild/bin/opt
-instcombine -licm
> >>> >>>> -simplifycfg -instcombine -loop-rotate
-loop-vectorize
> -instcombine
> >>> >>>> 1.  Running pass 'Function Pass
Manager' on module '<stdin>'.
> >>> >>>> 2.  Running pass 'Combine redundant
instructions' on function
> >>> >>>> '@strsave'
> >>> >>>>
> >>> >>>> ---
> >>> >>>>
> >>> >>>> Looking at the code, the issue is with this
line:
> >>> >>>>
> >>> >>>>   if (TrueVal == X && match(FalseVal,
m_And(m_Specific(X),
> >>> >>>> m_APInt(C)))
> >>> >>>> &&
> >>> >>>>         *Y == ~*C)
> >>> >>>>
> >>> >>>> In this case Y is a 128-bit APInt, and so is
the value that C is
> >>> >>>> extracted from, but the m_APInt matcher has
code that calls
> >>> >>>> getSplatValue()
> >>> >>>> if the matched expression has vector type. So
C ends up as an
> 8-bit
> >>> >>>> value,
> >>> >>>> triggering the assertion failure on the call
to ==.
> >>> >>>>
> >>> >>>> The issue is clear but I'm not sure what
the correct fix should
> be --
> >>> >>>> whether this code is just not meant to work
with vector types, or
> >>> >>>> whether
> >>> >>>> the call to getSplatValue() doesn't
belong in the matcher, or
> whether
> >>> >>>> there
> >>> >>>> should be a corresponding call to
getSplatValue() on the caller
> side,
> >>> >>>> or
> >>> >>>> something else.
> >>> >>>>
> >>> >>>> Any help from someone with more context would
be appreciated.
> >>> >>>>
> >>> >>>> Thanks,
> >>> >>>> Ismail
> >>> >>>>
> >>> >>>>
> >>> >>>>
_______________________________________________
> >>> >>>> LLVM Developers mailing list
> >>> >>>> llvm-dev at lists.llvm.org
<javascript:;>
> >>> >>>>
http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
> >>> >>>>
> >>> >>>
> >>> >>
> >>> >
> >>> >
> >>> > _______________________________________________
> >>> > LLVM Developers mailing list
> >>> > llvm-dev at lists.llvm.org <javascript:;>
> >>> > http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
> >>> >
> >>
> >>
>
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