As suggested on D53258, this patch shares common CTLZ expansion code between VectorLegalizer and SelectionDAGLegalize by putting it in TargetLowering.
Extension to D53474
llvm-svn: 345060
As suggested on D53258, this patch demonstrates sharing common CTTZ expansion code between VectorLegalizer and SelectionDAGLegalize by putting it in TargetLowering.
I intend to move CTLZ and (scalar) CTPOP over as well and then update D53258 accordingly.
Differential Revision: https://reviews.llvm.org/D53474
llvm-svn: 345039
Add an intrinsic that takes 2 integers and perform unsigned saturation
addition on them.
This is a part of implementing fixed point arithmetic in clang where some of
the more complex operations will be implemented as intrinsics.
Differential Revision: https://reviews.llvm.org/D53340
llvm-svn: 344971
Introduce new versions that follow the IEEE semantics
to help with legalization that may need quieted inputs.
There are some regressions from inserting unnecessary
canonicalizes when these are matched from fast math
fcmp + select which should be fixed in a future commit.
llvm-svn: 344914
Add an intrinsic that takes 2 integers and perform saturation addition on them.
This is a part of implementing fixed point arithmetic in clang where some of
the more complex operations will be implemented as intrinsics.
Differential Revision: https://reviews.llvm.org/D53053
llvm-svn: 344629
This is intended to make the backend on par with functionality that was
added to the IR version of SimplifyDemandedVectorElts in:
rL343727
...and the original motivation is that we need to improve demanded-vector-elements
in several ways to avoid problems that would be exposed in D51553.
Differential Revision: https://reviews.llvm.org/D52912
llvm-svn: 344541
Similar to what already happens in the DAGCombiner wrappers, this patch adds the root nodes back onto the worklist if the DCI wrappers' SimplifyDemandedBits/SimplifyDemandedVectorElts were successful.
Differential Revision: https://reviews.llvm.org/D53026
llvm-svn: 344132
rL343913 was using SimplifyDemandedBits's original demanded mask instead of the adjusted 'NewMask' that accounts for multiple uses of the op (those variable names really need improving....).
Annoyingly many of the test changes (back to pre-rL343913 state) are actually safe - but only because their multiple uses are all by PMULDQ/PMULUDQ.
Thanks to Jan Vesely (@jvesely) for bisecting the bug.
llvm-svn: 343935
This patch enables SimplifyDemandedBits to call SimplifyDemandedVectorElts in cases where the demanded bits mask covers entire elements of a bitcasted source vector.
There are a couple of cases here where simplification at a deeper level (such as through bitcasts) prevents further simplification - CommitTargetLoweringOpt only adds immediate uses/users back to the worklist when we might want to combine the original caller again to see what else it can simplify.
As well as that I had to disable handling of bool vector until SimplifyDemandedVectorElts better supports some of their opcodes (SETCC, shifts etc.).
Fixes PR39178
Differential Revision: https://reviews.llvm.org/D52935
llvm-svn: 343913
Adding NonNull as attributes to returned pointers has the unfortunate side
effect of disabling tail calls. This patch ignores the NonNull attribute when
we decide whether to tail merge, in the same way that we ignore the NoAlias
attribute, as it has no affect on the call sequence.
Differential Revision: https://reviews.llvm.org/D52238
llvm-svn: 343091
This is the DAG equivalent of D51433.
If we know we're not using all vector lanes, use that knowledge to potentially simplify a vselect condition.
The reduction/horizontal tests show that we are eliminating AVX1 operations on the upper half of 256-bit
vectors because we don't need those anyway.
I'm not sure what the pr34592 test is showing. That's run with -O0; is SimplifyDemandedVectorElts supposed
to be running there?
Differential Revision: https://reviews.llvm.org/D51696
llvm-svn: 341762
Summary:
A follow-up for D49266 / rL337166 + D49497 / rL338044.
This is still the same pattern to check for the [lack of]
signed truncation, but in this case the constants and the predicate
are negated.
https://rise4fun.com/Alive/BDVhttps://rise4fun.com/Alive/n7Z
Reviewers: spatel, craig.topper, RKSimon, javed.absar, efriedma, dmgreen
Reviewed By: spatel
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D51532
llvm-svn: 341287
This reduces most of the sdiv stages (the MULHS, shifts etc.) to just zero/identity values and use the numerator scale factor to multiply by +1/-1.
llvm-svn: 340260
This patch refactors the existing TargetLowering::BuildSDIV base implementation to support non-uniform constant vector denominators.
This is the last patch necessary to close PR36545
Differential Revision: https://reviews.llvm.org/D50765
llvm-svn: 339908
This patch refactors the existing BuildExactSDIV implementation to support non-uniform constant vector denominators.
Differential Revision: https://reviews.llvm.org/D50392
llvm-svn: 339756
We were checking for all bits being Known by checking Known.Zero|Known.One, but if all the bits are known then the value should be a Constant and we can just check for that instead.
llvm-svn: 339509
Provide a pass-through of the numerator for divide by one cases - this is the same approach we take in DAGCombiner::visitSDIVLike.
I investigated whether we could achieve this by magic MULHU/SRL values but nothing appeared to work as we don't have a way for MULHU(x,c) -> x
llvm-svn: 339254
As requested in D50392, this is a minor refactor to BuildExactSDIV to stop taking the uniform constant APInt divisor and instead extract it locally.
I also cleanup the operands and valuetypes to better match BuildUDiv (and BuildSDIV in the near future).
llvm-svn: 339246
This patch refactors the existing TargetLowering::BuildUDIV base implementation to support non-uniform constant vector denominators.
It also includes a fold for MULHU by pow2 constants to SRL which can now more readily occur from BuildUDIV.
Differential Revision: https://reviews.llvm.org/D49248
llvm-svn: 339121
Add a parameter for testing specifically for
sNaNs - at least one instruction pattern on AMDGPU
needs to check specifically for this.
Also handle more cases, and add a target hook
for custom nodes, similar to the hooks for known
bits.
llvm-svn: 338910
First step towards a BuildSDIV equivalent to D49248 for non-uniform vector support - this just pushes the splat detection down into TargetLowering::BuildSDIV where its still used.
Differential Revision: https://reviews.llvm.org/D50185
llvm-svn: 338838
The vector contains the SDNodes that these functions create. The number of nodes is always a small number so we should use SmallVector to avoid a heap allocation.
llvm-svn: 338329
This removes the need for an assert to ensure the pointer isn't null.
Years ago we had ifs the checked the pointer was non-null before very access to the vector. These checks were removed and replaced with a single assert. But a reference seems more suitable here.
llvm-svn: 338205
Summary:
A follow-up for D49266 / rL337166.
At least one of these cases is more canonical,
so we really do have to handle it.
https://godbolt.org/g/pkzP3Xhttps://rise4fun.com/Alive/pQyhZZ
We won't get to these cases with I1 being -1,
as that will be constant-folded to true or false.
I'm also not sure we actually hit the 'ule' case,
but i think the worst think that could happen is that being dead code.
Reviewers: spatel, craig.topper, RKSimon, javed.absar, efriedma
Reviewed By: spatel
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D49497
llvm-svn: 338044
Summary:
[[ https://bugs.llvm.org/show_bug.cgi?id=38149 | PR38149 ]]
As discussed in https://reviews.llvm.org/D49179#1158957 and later,
the IR for 'check for [no] signed truncation' pattern can be improved:
https://rise4fun.com/Alive/gBf
^ that pattern will be produced by Implicit Integer Truncation sanitizer,
https://reviews.llvm.org/D48958https://bugs.llvm.org/show_bug.cgi?id=21530
in signed case, therefore it is probably a good idea to improve it.
But the IR-optimal patter does not lower efficiently, so we want to undo it..
This handles the simple pattern.
There is a second pattern with predicate and constants inverted.
NOTE: we do not check uses here. we always do the transform.
Reviewers: spatel, craig.topper, RKSimon, javed.absar
Reviewed By: spatel
Subscribers: kristof.beyls, llvm-commits
Differential Revision: https://reviews.llvm.org/D49266
llvm-svn: 337166
As discussed on PR37989, this patch adds EXTRACT_SUBVECTOR handling to TargetLowering::SimplifyDemandedVectorElts and calls it from DAGCombiner::visitEXTRACT_SUBVECTOR.
Differential Revision: https://reviews.llvm.org/D48825
llvm-svn: 336490
We've been running doxygen with the autobrief option for a couple of
years now. This makes the \brief markers into our comments
redundant. Since they are a visual distraction and we don't want to
encourage more \brief markers in new code either, this patch removes
them all.
Patch produced by
for i in $(git grep -l '\\brief'); do perl -pi -e 's/\\brief //g' $i & done
Differential Revision: https://reviews.llvm.org/D46290
llvm-svn: 331272
This supports things like
(setcc ugt X, 0) -> (setcc ne X, 0)
I've restricted to only make changes to vectors before legalize ops because I doubt all targets have accurate condition code legality information for vectors given how little we did before.
Differential Revision: https://reviews.llvm.org/D42948
llvm-svn: 326495
isCondCodeLegal internally checked Legal or Custom which is misleading. Though no targets set any cond code action to Custom today.
So I've renamed isCondCodeLegal to isCondCodeLegalOrCustom and added a real isCondCodeLegal that only checks Legal.
I've changed legalization code to use isCondCodeLegalOrCustom and left things reachable via DAG combine as isCondCodeLegal. I've also changed some places that called getCondCodeAction and compared to Legal to just use isCondCodeLegal.
I'm looking at trying to keep SETCC all the way to isel for the AVX512 integer comparisons and I suspect I'll need to make some condition codes Custom to stop DAG combine from changing things post LegalizeOps. Prior to this only Expand stopped DAG combine, but that causes LegalizeOps to try to swap operands or invert rather than calling our Custom handler.
Differential Revision: https://reviews.llvm.org/D43607
llvm-svn: 325829
This is split off from D42948 and includes just the cases that constant fold to true or false. It also includes some refactoring to keep predicate checks together.
This supports things like
(setcc uge X, 0) -> true
Differential Revision: https://reviews.llvm.org/D43489
llvm-svn: 325627
DAGCombiner and SimplifySetCC both use getPointerTy for shift amounts pre-legalization. DAGCombiner uses a single helper function to hide this. SimplifySetCC does it in multiple places.
This patch adds a defaulted parameter to getShiftAmountTy that can make it return getPointerTy for scalar types. Use this parameter to simplify the SimplifySetCC and DAGCombiner.
Additionally, there were two places in SimplifySetCC that were creating shifts using the target's preferred shift amount pre-legalization. If the target uses a narrow type and the type is illegal, this can cause SimplfiySetCC to create a shift with an amount that can't represent all possible shift values for the type. To fix this we should use pointer type there too.
Alternatively we could make getScalarShiftAmountTy for each target return a safe value for large types as proposed in D43445. And maybe we should still do that, but fixing the SimplifySetCC code keeps other targets from tripping over this in the future.
Fixes PR36250.
Differential Revision: https://reviews.llvm.org/D43449
llvm-svn: 325602
Based off the DemandedElts mask the and UNDEF elements returned from the SimplifyDemandedVectorElts calls to the shuffle operands, we can attempt to simplify the shuffle mask.
I had to be very conservative here as accepting post-legalized shuffle masks could cause problems for targets that legalize UNDEF mask elements back to inrange values (PowerPC), similarly combining to identity shuffle masks could cause too much UNDEF information to disappear for later combines.
llvm-svn: 325354
This is mainly a move of simplifyShuffleOperands from DAGCombiner::visitVECTOR_SHUFFLE to create a more general purpose TargetLowering::SimplifyDemandedVectorElts implementation.
Further features can be moved/added in future patches.
Differential Revision: https://reviews.llvm.org/D42896
llvm-svn: 325232
This reverses instcombine's demanded bits' transform which always tries to clear bits in constants.
As noted in PR35792 and shown in the test diffs:
https://bugs.llvm.org/show_bug.cgi?id=35792
...we can do better in codegen by trying to form -1. The x86 sub test shows a missed opportunity.
I did investigate changing instcombine's behavior, but it would be more work to change
canonicalization in IR. Clearing bits / shrinking constants can allow killing instructions,
so we'd have to figure out how to not regress those cases.
Differential Revision: https://reviews.llvm.org/D42986
llvm-svn: 324839
SelectionDAG::getBoolConstant was recently introduced. At the time I didn't know getConstTrueVal existed, but I think getBoolConstant is better as it will use the source VT to make sure it can properly detect floating point if it is configured differently.
llvm-svn: 324832
Many in SimplifySetCC and FoldSetCC try to create true or false constants. Some of them query getBooleanContents to figure out whether to use all ones or just 1 for true. But many places do not check and just use 1 without ensuring the VT has an i1 scalar type. Note sure if those places only trigger before type legalization so they only see an i1
type?
To cleanup the inconsistency and reduce some duplicated code, this patch adds a getBoolConstant method to SelectionDAG that takes are of querying getBooleanContents and doing the right thing.
Differential Revision: https://reviews.llvm.org/D43037
llvm-svn: 324634
When handling vectors with non byte-sized elements, reverse the order of the
elements in the built integer if the target is Big-Endian.
SystemZ tests updated.
Review: Eli Friedman, Ulrich Weigand.
https://reviews.llvm.org/D42786
llvm-svn: 324063
This was completely broken, but hopefully fixed by this patch.
In cases where it is needed, a vector with non byte-sized elements is stored
by extracting, zero-extending, shift:ing and or:ing the elements into an
integer of the same width as the vector, which is then stored.
Review: Eli Friedman, Ulrich Weigand
https://reviews.llvm.org/D42100#inline-369520https://bugs.llvm.org/show_bug.cgi?id=35520
llvm-svn: 323042
Allow SimplifyDemandedBits to use TargetLoweringOpt::computeKnownBits to look through bitcasts. This can help simplifying in some cases where bitcasts of constants generated during or after legalization can't be folded away, and thus didn't get picked up by SimplifyDemandedBits. This fixes PR34620, where a redundant pand created during legalization from lowering and lshr <16xi8> wasn't being simplified due to the presence of a bitcasted build_vector as an operand.
Committed on the behalf of @sameconrad (Sam Conrad)
Differential Revision: https://reviews.llvm.org/D41643
llvm-svn: 321969
This seems to improve X86's ability to match this into an address computation. Otherwise the other operand gets assigned to the base register and the stack pointer + frame index ends up in the index register. But index registers can't encode ESP/RSP so we end up having to move it into another register to meet the constraint.
I could try to improve the address matcher in X86, but swapping the producer seemed easier. Several other places already have the operands in this order so this is at least consistent.
llvm-svn: 321370
Two issues found when doing codegen for splitting vector with non-zero alloca addr space:
DAGTypeLegalizer::SplitVecRes_INSERT_VECTOR_ELT/SplitVecOp_EXTRACT_VECTOR_ELT uses dummy pointer info for creating
SDStore. Since one pointer operand contains multiply and add, InferPointerInfo is unable to
infer the correct pointer info, which ends up with a dummy pointer info for the target to lower
store and results in isel failure. The fix is to introduce MachinePointerInfo::getUnknownStack to
represent MachinePointerInfo which is known in alloca address space but without other information.
TargetLowering::getVectorElementPointer uses value type of pointer in addr space 0 for
multiplication of index and then add it to the pointer. However the pointer may be in an addr
space which has different size than addr space 0. The fix is to use the pointer value type for
index multiplication.
Differential Revision: https://reviews.llvm.org/D39758
llvm-svn: 319622
The object can't straddle the address space
wrap around, so I think it's OK to assume any
offsets added to the base object pointer can't
overflow. Similar logic already appears to be
applied in SelectionDAGBuilder when lowering
aggregate returns.
llvm-svn: 319272
This is needed for cases when the memory access is not as big as the width of
the data type. For instance, storing i1 (1 bit) would be done in a byte (8
bits).
Using 'BitSize >> 3' (or '/ 8') would e.g. give the memory access of an i1 a
size of 0, which for instance makes alias analysis return NoAlias even when
it shouldn't.
There are no tests as this was done as a follow-up to the bugfix for the case
where this was discovered (r318824). This handles more similar cases.
Review: Björn Petterson
https://reviews.llvm.org/D40339
llvm-svn: 319173
All these headers already depend on CodeGen headers so moving them into
CodeGen fixes the layering (since CodeGen depends on Target, not the
other way around).
llvm-svn: 318490
Some of the AMDGPU stack addressing modes require knowing the sign
bit is zero. We used to accomplish this by custom lowering
frame indexes, and then putting an AssertZext around a
TargetFrameIndex. This required specifically looking for
the AssextZext + frame index pattern which was moderately
disgusting. The same could probably be accomplished
with a target specific node, but would still
require special handling of frame indexes.
llvm-svn: 317671
Summary:
We shouldn't recurse any further but it doesn't mean we shouldn't be able to give the known bits for a constant. The caller would probably like that we always return the right answer for a constant RHS. This matches what InstCombine does in this case.
I don't have a test case because this showed up while trying to revive D31724.
Reviewers: RKSimon, spatel
Reviewed By: RKSimon
Subscribers: arsenm, llvm-commits
Differential Revision: https://reviews.llvm.org/D38967
llvm-svn: 316255
Currently expandUnalignedLoad/Store uses place holder pointer info for temporary memory operand
in stack, which does not have correct address space. This causes unaligned private double16 load/store to be
lowered to flat_load instead of buffer_load for amdgcn target.
This fixes failures of OpenCL conformance test basic/vload_private/vstore_private on target amdgcn---amdgizcl.
Differential Revision: https://reviews.llvm.org/D35361
llvm-svn: 314566
This teach simplifyDemandedBits to handle constant splat vector shifts.
This required changing some uses of getZExtValue to getLimitedValue since we can't rely on legalization using getShiftAmountTy for the shift amount.
I believe there may have been a bug in the ((X << C1) >>u ShAmt) handling where we didn't check if the inner shift was too large. I've fixed that here.
I had to add new patterns to ARM because the zext/sext the patterns were trying to look for got turned into an any_extend with this patch. Happy to split that out too, but not sure how to test without this change.
Differential Revision: https://reviews.llvm.org/D37665
llvm-svn: 314139
This adds routines for reseting KnownBits to unknown, making the value all zeros or all ones. It also adds methods for querying if the value is zero, all ones or unknown.
Differential Revision: https://reviews.llvm.org/D32637
llvm-svn: 302262
