13061 Commits

Author SHA1 Message Date
Simon Pilgrim
84447c044f [DAG] Add SelectionDAG::isADDLike helper. NFC.
Make the DAGCombine helper global so we can more easily reuse it.
2023-09-06 16:54:25 +01:00
Simon Pilgrim
e4d0e12099 [DAG] Fold (shl (sext (add_nsw x, c1)), c2) -> (add (shl (sext x), c2), c1 << c2) (REAPPLIED)
Assuming the ADD is nsw then it may be sign-extended to merge with a SHL op in a similar fold to the existing (shl (add x, c1), c2) -> (add (shl x, c2), c1 << c2) fold.

This is most useful for helping to expose address math for X86, but has also touched several aarch64 test cases as well.

Alive2: https://alive2.llvm.org/ce/z/2UpSbJ

Differential Revision: https://reviews.llvm.org/D159198
2023-09-06 13:19:42 +01:00
Dmitri Gribenko
97bf104d97 Revert "[DAG] Fold (shl (sext (add_nsw x, c1)), c2) -> (add (shl (sext x), c2), c1 << c2)"
This reverts commit b027ce0ab93060bc6cb79d5402d21520e8b93fb7.

This commit breaks Transforms/InferAddressSpaces/AMDGPU/flat_atomic.ll.
2023-09-06 11:28:55 +02:00
Simon Pilgrim
b027ce0ab9 [DAG] Fold (shl (sext (add_nsw x, c1)), c2) -> (add (shl (sext x), c2), c1 << c2)
Assuming the ADD is nsw then it may be sign-extended to merge with a SHL op in a similar fold to the existing (shl (add x, c1), c2) -> (add (shl x, c2), c1 << c2) fold.

This is most useful for helping to expose address math for X86, but has also touched several aarch64 test cases as well.

Alive2: https://alive2.llvm.org/ce/z/2UpSbJ

Differential Revision: https://reviews.llvm.org/D159198
2023-09-06 10:06:21 +01:00
Ting Wang
71be020dda [SelectionDAG][PowerPC] Memset reuse vector element for tail store
On PPC there are instructions to store element from vector(e.g.
stxsdx/stxsiwx), and these instructions can be leveraged to avoid tail
constant in memset and constant splat array initialization.

This patch tries to explore these opportunities.

Reviewed By: shchenz

Differential Revision: https://reviews.llvm.org/D138883
2023-09-06 01:52:38 -04:00
Simon Pilgrim
5463503ae1 [DAG] Move scalar BITCAST constant folds from getNode to FoldConstantArithmetic 2023-09-05 13:11:20 +01:00
David Sherwood
50598f0ff4 [DAGCombiner][SVE] Add support for illegal extending masked loads
In some cases where the same mask is used for multiple
extending masked loads it can be more efficient to combine
the zero- or sign-extend into the load even if it's not a
legal or custom operation. This leads to splitting up the
extending load into smaller parts, which also requires
splitting the mask. For SVE at least this improves the
performance of the SPEC benchmark x264 slightly on
neoverse-v1 (~0.3%), and at least one other benchmark
improves by around 30%. The uplift for SVE seems due to
removing the dependencies (vector unpacks) introduced
between the loads and the vector operations, since this
should increase the level of parallelism.

See tests:

  CodeGen/AArch64/sve-masked-ldst-sext.ll
  CodeGen/AArch64/sve-masked-ldst-zext.ll

https://reviews.llvm.org/D159191
2023-09-05 10:41:21 +00:00
Kazu Hirata
5fb990ac51 [SelectionDAG] Use isNullConstant (NFC) 2023-09-02 09:32:43 -07:00
Fangrui Song
111fcb0df0 [llvm] Fix duplicate word typos. NFC
Those fixes were taken from https://reviews.llvm.org/D137338
2023-09-01 18:25:16 -07:00
Matt Arsenault
b14e83d1a4 IR: Add llvm.exp10 intrinsic
We currently have log, log2, log10, exp and exp2 intrinsics. Add exp10
to fix this asymmetry. AMDGPU already has most of the code for f32
exp10 expansion implemented alongside exp, so the current
implementation is duplicating nearly identical effort between the
compiler and library which is inconvenient.

https://reviews.llvm.org/D157871
2023-09-01 19:45:03 -04:00
Philip Reames
685e1909e9 [LegalizeDAG] Use scalable aware idiom for checking for single element vector
NFC for fixed vectors (all that reaches here currently), and future proofing for scalable vectors.
2023-09-01 11:56:03 -07:00
Simon Pilgrim
15b561ed38 [DAG] Move STEP_VECTOR constant fold from getNode to FoldConstantArithmetic 2023-09-01 15:47:37 +01:00
Simon Pilgrim
1d47d5d67c [DAG] Move F16<->FP constant folds from getNode to FoldConstantArithmetic 2023-09-01 15:47:36 +01:00
Simon Pilgrim
4b9c2cf0a7 [DAG] Move INT<->FP constant folds from getNode to FoldConstantArithmetic 2023-09-01 14:02:02 +01:00
Simon Pilgrim
2a81396b1b [DAG] SimplifyDemandedBits - add SMIN/SMAX KnownBits comparison analysis
Followup to D158364

Also, final fix for Issue #59902 which noted that the snippet should just return 1
2023-09-01 12:42:30 +01:00
Simon Pilgrim
aca8b9d0d5 [DAG] SimplifyDemandedBits - if we're only demanding the signbits, a MIN/MAX node can be simplified to a OR or AND node
Extension to the signbit case, if the signbits extend down through all the demanded bits then SMIN/SMAX/UMIN/UMAX nodes can be simplified to a OR/AND/AND/OR.

Alive2: https://alive2.llvm.org/ce/z/mFVFAn (general case)

Differential Revision: https://reviews.llvm.org/D158364
2023-09-01 10:56:32 +01:00
Matt Arsenault
ad9d13d535 SelectionDAG: Swap operands of atomic_store
Irritatingly, atomic_store had operands in the opposite order from
regular store. This made it difficult to share patterns between
regular and atomic stores.

There was a previous incomplete attempt to move atomic_store into the
regular StoreSDNode which would be better.

I think it was a mistake for all atomicrmw to swap the operand order,
so maybe it's better to take this one step further.

https://reviews.llvm.org/D123143
2023-08-31 17:30:10 -04:00
Daniel Paoliello
0c5c7b52f0 Emit the CodeView S_ARMSWITCHTABLE debug symbol for jump tables
The CodeView `S_ARMSWITCHTABLE` debug symbol is used to describe the layout of a jump table, it contains the following information:

* The address of the branch instruction that uses the jump table.
* The address of the jump table.
* The "base" address that the values in the jump table are relative to.
* The type of each entry (absolute pointer, a relative integer, a relative integer that is shifted).

Together this information can be used by debuggers and binary analysis tools to understand what an jump table indirect branch is doing and where it might jump to.

Documentation for the symbol can be found in the Microsoft PDB library dumper: 0fe89a942f/cvdump/dumpsym7.cpp (L5518)

This change adds support to LLVM to emit the `S_ARMSWITCHTABLE` debug symbol as well as to dump it out (for testing purposes).

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D149367
2023-08-31 12:06:50 -07:00
Konstantina Mitropoulou
17fc78e7a4 [DAGCombiner] Change foldAndOrOfSETCC() to optimize and/or patterns with floating points.
This reverts commit 48fa79a503a7cf380f98b6335fbd349afae1bd86.

Reviewed By: brooksmoses

Differential Revision: https://reviews.llvm.org/D159240
2023-08-31 11:36:50 -07:00
Nick Desaulniers
2fad6e6985 [InlineAsm] wrap Kind in enum class NFC
Should add some minor type safety to the use of this information, since
there's quite a bit of metadata being laundered through an `unsigned`.

I'm looking to potentially add more bitfields to that `unsigned`, but I
find InlineAsm's big ol' bag of enum values and usage of `unsigned`
confusing, type-unsafe, and un-ergonomic. These can probably be better
abstracted.

I think the lack of static_cast outside of InlineAsm indicates the prior
code smell fixed here.

Reviewed By: qcolombet

Differential Revision: https://reviews.llvm.org/D159242
2023-08-31 08:54:51 -07:00
Luke Lau
3a4ad45a2c [DAGCombiner] Combine trunc (splat_vector x) -> splat_vector (trunc x)
From the discussion in https://reviews.llvm.org/D158853, moving the truncate
into the splat helps more splatted scalar operands get selected on RISC-V, and
also avoids the need for splat_vector_parts on RV32.

Reviewed By: RKSimon

Differential Revision: https://reviews.llvm.org/D159147
2023-08-30 15:22:57 +01:00
Simon Pilgrim
376050db9f [DAG] Move some unary constant folds from getNode() to FoldConstantArithmetic()
We need to clean up some type handling before the remainder (int<->fp and bitcasts) can be moved over.
2023-08-30 13:59:28 +01:00
Simon Pilgrim
d037445f3a [DAG] visitSHL - use FoldConstantArithmetic to fold constants in (shl (add x, c1), c2) -> (add (shl x, c2), c1 << c2) fold
Matches what we do in the (shl (mul x, c1), c2) -> (mul x, c1 << c2) fold as well as inside visitShiftByConstant
2023-08-29 18:52:24 +01:00
Craig Topper
299b1b4071 [SelectionDAG][RISCV] Teach getConstant to use SPLAT_VECTOR_PARTS if vXi64 SPLAT_VECTOR is legal but i64 scalars are not.
That matches how such a SPLAT_VECTOR would have been type legalized
so assume it is ok to use for creating constants after type legalization.

Still need some improvements to SPLAT_VECTOR lowering.

This overlaps with some of what D158742 was trying to fix.

Reviewed By: luke

Differential Revision: https://reviews.llvm.org/D158870
2023-08-29 09:22:17 -07:00
Luke Lau
8f1d1e2b61 [SDAG] Add computeKnownBits support for ISD::SPLAT_VECTOR_PARTS
We can work out the known bits for a given lane by concatenating the known bits of each scalar operand.

In the description of ISD::SPLAT_VECTOR_PARTS in ISDOpcodes.h it says that the
total size of the scalar operands must cover the output element size, but I've
added a stricter assertion here that the total width of the scalar operands
must be exactly equal to the element size. It doesn't seem to trigger, and I'm
not sure if there any targets that use SPLAT_VECTOR_PARTS for anything other
than v4i32 -> v2i64 splats.

We also need to include it in isTargetCanonicalConstantNode, otherwise
returning the known bits introduces an infinite combine loop.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D158852
2023-08-28 10:35:58 +01:00
Luke Lau
6e4860f5d0 [SDAG] Add SimplifyDemandedBits support for ISD::SPLAT_VECTOR
This improves some cases where a splat_vector uses a build_pair that can be
simplified, e.g:

(rotl x:i64, splat_vector (build_pair x1:i32, x2:i32))

rotl only demands the bottom 6 bits, so this patch allows it to simplify it to:

(rotl x:i64, splat_vector (build_pair x1:i32, undef:i32))

Which in turn improves some cases where a splat_vector_parts is lowered on
RV32.

Reviewed By: RKSimon

Differential Revision: https://reviews.llvm.org/D158839
2023-08-28 10:35:56 +01:00
Arthur Eubanks
0a4fc4ac1c Revert "Emit the CodeView S_ARMSWITCHTABLE debug symbol for jump tables"
This reverts commit 8d0c3db388143f4e058b5f513a70fd5d089d51c3.

Causes crashes, see comments in https://reviews.llvm.org/D149367.

Some follow-up fixes are also reverted:

This reverts commit 636269f4fca44693bfd787b0a37bb0328ffcc085.
This reverts commit 5966079cf4d4de0285004eef051784d0d9f7a3a6.
This reverts commit e7294dbc85d24a08c716d9babbe7f68390cf219b.
2023-08-25 18:34:15 -07:00
Danila Malyutin
e036ba50a7 [StatepointLowering] Fix possible nullptr access in debug output
Differential Revision: https://reviews.llvm.org/D158866
2023-08-25 22:56:17 +03:00
Daniel Paoliello
8d0c3db388 Emit the CodeView S_ARMSWITCHTABLE debug symbol for jump tables
The CodeView `S_ARMSWITCHTABLE` debug symbol is used to describe the layout of a jump table, it contains the following information:

* The address of the branch instruction that uses the jump table.
* The address of the jump table.
* The "base" address that the values in the jump table are relative to.
* The type of each entry (absolute pointer, a relative integer, a relative integer that is shifted).

Together this information can be used by debuggers and binary analysis tools to understand what an jump table indirect branch is doing and where it might jump to.

Documentation for the symbol can be found in the Microsoft PDB library dumper: 0fe89a942f/cvdump/dumpsym7.cpp (L5518)

This change adds support to LLVM to emit the `S_ARMSWITCHTABLE` debug symbol as well as to dump it out (for testing purposes).

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D149367
2023-08-25 10:19:17 -07:00
LiaoChunyu
1b12427c01 [VP][RISCV] Add vp.is.fpclass and RISC-V support
There is no vp.fpclass after FCLASS_VL(D151176), try to support vp.fpclass.

Reviewed By: arsenm

Differential Revision: https://reviews.llvm.org/D152993
2023-08-25 15:40:55 +08:00
Konstantina Mitropoulou
48fa79a503 Revert "[DAGCombiner] Change foldAndOrOfSETCC() to optimize and/or patterns with floating points."
This reverts commit 5ec13535235d07eafd64058551bc495f87c283b1.
2023-08-24 20:39:04 -07:00
Konstantina Mitropoulou
5ec1353523 [DAGCombiner] Change foldAndOrOfSETCC() to optimize and/or patterns with floating points.
CMP(A,C)||CMP(B,C) => CMP(MIN/MAX(A,B), C)
CMP(A,C)&&CMP(B,C) => CMP(MIN/MAX(A,B), C)

If the operands are proven to be non NaN, then the optimization can be applied
for all predicates.

We can apply the optimization for the following predicates for FMINNUM/FMAXNUM
(for quiet and signaling NaNs) and for FMINNUM_IEEE/FMAXNUM_IEEE if we can prove
that the operands are not signaling NaNs.
- ordered lt/le and ||
- ordered gt/ge and ||
- unordered lt/le and &&
- unordered gt/ge and &&

Reviewed By: arsenm

Differential Revision: https://reviews.llvm.org/D155267
2023-08-24 10:48:56 -07:00
Simon Pilgrim
d254014fdb [DAG] Add willNotOverflowAdd/willNotOverflowSub helper functions.
Matches similar instructions on InstCombine
2023-08-24 17:52:54 +01:00
Felipe de Azevedo Piovezan
35f4ef1fee [SelectionDAG][DebugInfo] Handle entry_value dbg.value DIExprs earlier
When SelectiondDAG converts dbg.value intrinsics, it first ensures we have
already generated code for the value operator of the intrinsic. The rationale
being that if we haven't had the need to generate code for this value, it won't
be a debug value that causes the generation.

For example, if the first use the physical register of an argument is a
dbg.value, we are going to hit this code path.  However, this is irrelevant for
entry value expressions: by definition we are not interested in the _current_
value of the physical register, but rather on its value at the start of the
function. To deal with this, this patch changes lowering to handle this case as
early as possible.

Differential Revision: https://reviews.llvm.org/D158649
2023-08-24 09:33:53 -04:00
Serge Pavlov
6862f0fab1 [FPEnv] Intrinsics for access to FP control modes
The change introduces intrinsics 'get_fpmode', 'set_fpmode' and
'reset_fpmode'. They manage all target dynamic floating-point control
modes, which include, for instance, rounding direction, precision,
treatment of denormals and so on. The intrinsics do the same
operations as the C library functions 'fegetmode' and 'fesetmode'. By
default they are lowered to calls to these functions.

Two main use cases are supported by this implementation.

1. Local modification of the control modes. In this case the code
usually has a pattern (in pseudocode):

    saved_modes = get_fpmode()
    set_fpmode(<new_modes>)
    ...
    <do operations under the new modes>
    ...
    set_fpmode(saved_modes)

In the case when it is known that the current FP environment is default,
the code may be shorter:

    set_fpmode(<new_modes>)
    ...
    <do operations under the new modes>
    ...
    reset_fpmode()

Such patterns appear not only in user code but also in implementations
of various FP controlling pragmas. In particular, the implementation of
`#pragma STDC FENV_ROUND` requires similar code if the target does not
support static rounding mode.

2. Portable control of FP modes. Usually FP control modes are set by
writing to some control register. Different targets have different
layout of this register, the way the register is accessed also may be
different. Using set of target-specific definitions for the control
register bits together with these intrinsic functions provides enough
portable way to handle control modes across wide range of hardware.

This change defines only llvm intrinsic function, which implement the
access required for the aforementioned use cases.

Differential Revision: https://reviews.llvm.org/D82525
2023-08-24 15:52:19 +07:00
Craig Topper
2ad50f354a [DAGCombiner][RISCV][AArch64][PowerPC] Restrict foldAndOrOfSETCC from using SMIN/SMAX where and OR/AND would do.
This removes some diffs created by D153502.

I'm assuming an AND/OR won't be worse than an SMIN/SMAX. For
RISC-V at least, AND/OR can be a shorter encoding than SMIN/SMAX.

It's weird that we have two different functions responsible for
folding logic of setccs, but I'm not ready to try to untangle that.

I'm unclear if the PowerPC chang is a regression or not. It looks
like it might use more registers, but I don't understand PowerPC
register so I'm not sure.

Reviewed By: arsenm

Differential Revision: https://reviews.llvm.org/D158292
2023-08-23 20:26:23 -07:00
Yingwei Zheng
d6639f83a9
[SDAG][RISCV] Avoid folding setcc (xor C1, -1), C2, cond into setcc (xor C2, -1), C1, cond
This patch fixes https://github.com/llvm/llvm-project/issues/64935.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D158654
2023-08-24 04:18:17 +08:00
Peter Rong
f58fbfc746 [X86][CodeGen] Add a dag pattern to fix #64323
After recent patch D30189, #64323's error message become a new one.
When DAGCombiner was optimizing `(vextract (scalar_to_vector val, 0) -> val`, it didn't
consider the possibility that the inserted value type has less bit than the dest type.
This patch fixes that.

Reviewed By: pengfei

Differential Revision: https://reviews.llvm.org/D158355
2023-08-23 10:50:32 -07:00
Felipe de Azevedo Piovezan
88417098bb [CodeGen][DebugInfo] Append OP_deref when converting an EntryValue dbg.declare
When we convert an EntryValue dbg.declare into an entry of the MF side table, we
currently copy its DIExpression as is, and rely on subsequent layers to "know"
that this expression is implicitly indirect. This is bad because it adds an
implicit assumption to the IR representation, and requires subsequent layers to
know about this assumption. This also limits the reusability of this table:
what if, in the future, we want to use this table for dbg.values?

This patch changes existing behavior so that the entities converting
dbg_declares explicitly add an OP_deref when converting EntryValue dbg.declares.

Differential Revision: https://reviews.llvm.org/D158437
2023-08-23 12:25:12 -04:00
Jianjian GUAN
879e801a91 [RISCV] Apply promotion for f16 vector ops when only have zvfhmin
For most fp16 vector ops, we could promote it to fp32 vector when zvfhmin is enable but zvfh is not.
But for nxv32f16, we need to split it first since nxv32f32 is not a valid MVT.

Reviewed By: michaelmaitland

Differential Revision: https://reviews.llvm.org/D153848
2023-08-23 16:49:20 +08:00
Simon Pilgrim
ba818c4019 [DAG] replaceStoreOfInsertLoad - don't fold if the inserted element is implicitly truncated
D152276 wasn't handling the case where the inserted element is implicitly truncated into the vector - resulting in a i1 element (implicitly truncated from i8) overwriting 8 bits instead of 1 bit.

This patch is intended to be merged into 17.x so I've just disallowed any vector element vs inserted element type mismatch - technically we could be more elegant and permit truncated stores (as long as the store is still byte sized), but the use cases for that are so limited I'd prefer to play it safe for now.

Candidate patch for #64655 17.x merge

Differential Revision: https://reviews.llvm.org/D158366
2023-08-21 11:22:07 +01:00
Kazu Hirata
134115618a [CodeGen] Use isAllOnesConstant and isNullConstant (NFC) 2023-08-20 22:56:40 -07:00
Simon Pilgrim
95865e5138 [DAG] SimplifyDemandedBits - if we're only demanding the signbit, a SMIN/SMAX node can be simplified to a OR/AND node respectively.
Alive2: https://alive2.llvm.org/ce/z/MehvFB

REAPPLIED from 54d663d5896008 with fix for using the correct DemandedBits mask.
2023-08-20 14:20:49 +01:00
Jim Lin
18f5ada244 [DAGCombiner] Don't reduce BUILD_VECTOR to BITCAST before LegalizeTypes if VT is legal.
Targets may lose some optimization opportunities for certain vector operation
if we reduce BUILD_VECTOR to BITCAST early.

And if VT is not legal, reduce BUILD_VECTOR to BITCAST before LegailizeTypes
can get benefit. Because type-legalizer often scalarizes illegal type of vectors.

Reviewed By: sebastian-ne

Differential Revision: https://reviews.llvm.org/D156645
2023-08-19 12:53:50 +08:00
Philip Reames
92e0c0dc1a [DAG] Restrict insert_subvector undef, splat_veector, dontcare transform
On the extract_subvector side, we already have the restriction. With D158201, we'd start getting unprofitable splat combines unless we add the same one on the extract_subvector side.

Differential Revision: https://reviews.llvm.org/D158202
2023-08-18 12:44:09 -07:00
Philip Reames
67b71ad04a [DAG] Fold insert_subvector undef, (extract_subvector X, 0), 0 with non-matching types
We have an existing DAG combine for when an insert/extract subvector pair is entirely a nop, but we hadn't handled the case where the net result was either an insert or an extract (but not both). The transform is restricted to index = 0 to avoid having to adjust indices after the transform.

Differential Revision: https://reviews.llvm.org/D158201
2023-08-18 12:28:27 -07:00
Craig Topper
bbbb93eb48 Revert "[DAG] Fold insert_subvector undef, (extract_subvector X, 0), 0 with non-matching types"
This reverts commit 770be43f6782dab84d215d01b37396d63a9c2b6e.

Forgot to remove from my tree while experimenting.
2023-08-18 12:00:07 -07:00
Craig Topper
0a5347f40d [DAG] SimplifyDemandedBits - Use DemandedBits intead of OriginalDemandedBits to when simplifying UMIN/UMAX to AND/OR.
DemandedBits is forced to all ones if there are multiple users.

The changes X86 test cases looks like they were miscompiles before.
The value of eax/rax from the cmov is returned from the function in
addition to being used by the sar. That usage needs all bits even
though the sar doesn't.
2023-08-18 11:59:18 -07:00
Craig Topper
770be43f67 [DAG] Fold insert_subvector undef, (extract_subvector X, 0), 0 with non-matching types
We have an existing DAG combine for when an insert/extract subvector pair is entirely a nop, but we hadn't handled the case where the net result was either an insert or an extract (but not both).  The transform is restricted to index = 0 to avoid having to adjust indices after the transform.

Reviews, a couple comments on the test changes:
* Mostly RISCV, mostly schedule reordering.
* One real regression in splats-with-mixed-vl.ll due to a different overly aggressive combine, fix in a follow up patch.
* The test/CodeGen/X86/vector-replicaton-i1-mask.ll diff looked concerning at first, but not the mask size at most 4 i1s.  I think the type changes on the mask loads are correct, but would welcome a second opinion with someone more familiar with AVX512 codegen.

Differential Revision: https://reviews.llvm.org/D158201
2023-08-18 11:59:18 -07:00
Thurston Dang
29b2009061 Revert "[DAG] SimplifyDemandedBits - if we're only demanding the signbit, a SMIN/SMAX node can be simplified to a OR/AND node respectively."
This reverts commit 54d663d5896008c09c938f80357e2a056454bc65, which breaks the test CodeGen/SystemZ/ctpop-01.ll for stage2-ubsan check (see https://lab.llvm.org/buildbot/#/builders/85/builds/18410)

I manually confirmed that the test had been passing immediately prior to that commit
(BUILDBOT_REVISION=4772c66cfb00d60f8f687930e9dd3aa1b6872228 llvm-zorg/zorg/buildbot/builders/sanitizers/buildbot_bootstrap_ubsan.sh)
2023-08-18 18:08:10 +00:00