42810 Commits

Author SHA1 Message Date
Kristina Bessonova
0ac75e82ff Reland [DwarfDebug] Move emission of global vars, types and imports to endModule()
This patch proposes to move emission of global variables, types,
imported entities, etc from DwarfDebug::beginModule() to DwarfDebug::endModule().
Effectively, this changes nothing but the order of debug entities which
will be as follows:
* subprograms (including related context, local variables/labels,
  local imported entities; related types can be created as a part of
  the emission of local entities of an abstract subprogram);
* global variables (including related context and types);
* retained types and enums;
* non-local-scoped imported entities;
* basic types;
* other types left (as a part of local variables attributes emission).

Note that the order of emitted compile units may also be changed as now we emit
units that contain subprograms first and then all other non-empty units.

The motivation behind this change is the following:
(1) DwarfDebug::beginModule() is run at the very beginning of backend's pipeline,
    from this time IR can be significantly changed by target-specific passes.
    If it happens for debug metadata of global entities, those changes will not
    be reflected in the emitted DWARF.
(2) imported subprogram names should refer to an abstract subprogram if it exists,
    but it isn't known in DwarfDebug::beginModule() (it's possible to make some
    guesses based on location info, but it's not quite reliable);
(3) aforementioned entities if they are scoped within a bracketed block
    (subject of D113741) couldn't be emitted in DwarfDebug::beginModule()
    (they need parent emitted first). Another problem is if to try to gather
    some information about local entities and defer their emission
    (till subprogram's processing or DwarfDebug::endModule()) all the gathered
    details might be irrelevant / invalid by the time the entities are being
    emitted (because of (1)).

Reviewed By: dblaikie

Differential Revision: https://reviews.llvm.org/D114705
2021-12-05 13:56:45 +02:00
Phoebe Wang
f37d9b4112 [X86][FP16] Replace vXi16 to vXf16 instead of v8f16
Fixes pr52561

Reviewed By: LuoYuanke

Differential Revision: https://reviews.llvm.org/D114304
2021-12-05 19:19:11 +08:00
David Green
57ff805a6d [DAG] Create fptoui.sat from clamped fptosi
As an extension to D111976, this converts clamp fptosi, clamped between
0 and (2^n)-1 to a fptoui.sat. This can greatly help on targets with
conversions that naturally saturate, such as Arm.

X86 disables the transform as some of the test cases increases in size.
A fptoui.sat necessitates a fp clamp without native support, so there is
little use in converting if the instruction is just going to be
expanded.

Differential Revision: https://reviews.llvm.org/D112428
2021-12-05 09:25:52 +00:00
Kristina Bessonova
a961604819 Revert "[DwarfDebug] Support emitting function-local declaration for a lexical block"
This reverts commits
* ee691970a9a85470948ada623c31f0ab8773617c (D113741),
* 79d3132998b2828be8f7d2ec411f91fb11b3e01f (D114705)

due to lldb and dexter test failures.
2021-12-04 18:06:57 +02:00
Matt Arsenault
729bf9b26b AMDGPU: Enable fixed function ABI by default
Code using indirect calls is broken without this, and there isn't
really much value in supporting the old attempt to vary the argument
placement based on uses. This resulted in more argument shuffling code
anyway.

Also have the option stop implying all inputs need to be passed. This
will no rely on the amdgpu-no-* attributes to avoid passing
unnecessary values.
2021-12-04 10:49:18 -05:00
Matt Arsenault
2959e082e1 AMDGPU: Assume all amdhsa kernarg passed implicit arguments by default
Previously we would require adding an attribute to kernels to enable
the inputs passed in the kernarg segment, accessed by
llvm.amdgcn.implicitarg.ptr. This violates the principle of being
correct by default. Some OpenMP testcases were broken recently since
it wasn't correctly setting this attribute, and no known frontends are
setting this to anything other than the maximum.

Most of the test changes are from load widening of argument loads
since there now more implied dereferenceable bytes.
2021-12-04 10:38:25 -05:00
Matt Arsenault
ae0ba7dedd AMDGPU: Optimize out implicit kernarg argument allocation if unused
We already annotate whether llvm.amdgcn.implicitarg.ptr is known to be
unused. Start using it to avoid allocating the implicit arguments if
unneeded.
2021-12-04 10:38:25 -05:00
Kristina Bessonova
79d3132998 [DwarfDebug] Move emission of global vars, types and imports to endModule()
This patch proposes to move emission of global variables, types,
imported entities, etc from DwarfDebug::beginModule() to DwarfDebug::endModule().
Effectively, this changes nothing but the order of debug entities which
will be as follows:
* subprograms (including related context, local variables/labels,
  local imported entities; related types can be created as a part of
  the emission of local entities of an abstract subprogram);
* global variables (including related context and types);
* retained types and enums;
* non-local-scoped imported entities;
* basic types;
* other types left (as a part of local variables attributes emission).

Note that the order of emitted compile units may also be changed as now we emit
units that contain subprograms first and then all other non-empty units.

The motivation behind this change is the following:
(1) DwarfDebug::beginModule() is run at the very beginning of backend's pipeline,
    from this time IR can be significantly changed by target-specific passes.
    If it happens for debug metadata of global entities, those changes will not
    be reflected in the emitted DWARF.
(2) imported subprogram names should refer to an abstract subprogram if it exists,
    but it isn't known in DwarfDebug::beginModule() (it's possible to make some
    guesses based on location info, but it's not quite reliable);
(3) aforementioned entities if they are scoped within a bracketed block
    (subject of D113741) couldn't be emitted in DwarfDebug::beginModule()
    (they need parent emitted first). Another problem is if to try to gather
    some information about local entities and defer their emission
    (till subprogram's processing or DwarfDebug::endModule()) all the gathered
    details might be irrelevant / invalid by the time the entities are being
    emitted (because of (1)).

Reviewed By: dblaikie

Differential Revision: https://reviews.llvm.org/D114705
2021-12-04 14:10:01 +02:00
Jay Foad
2774bad112 [AMDGPU] Change llvm.amdgcn.image.bvh.intersect.ray to take vec3 args
The ray_origin, ray_dir and ray_inv_dir arguments should all be vec3 to
match how the hardware instruction works.

Don't change the API of the corresponding OpenCL builtins.

Differential Revision: https://reviews.llvm.org/D115032
2021-12-04 10:32:11 +00:00
Jay Foad
bc7dacf589 [AMDGPU] Generate checks for llvm.amdgcn.image.bvh.intersect.ray
Differential Revision: https://reviews.llvm.org/D114955
2021-12-04 10:32:11 +00:00
Choongwoo Han
181c4ba467 [CFG] Handle calls with funclet bundle
When Control Flow Guard Check is inserted, funclet bundle was not checked. Therefore, it didn't generate code correctly when a target function has "funclet" bundle.

Reviewed By: rnk

Differential Revision: https://reviews.llvm.org/D114914
2021-12-03 10:51:10 -08:00
Stanislav Mekhanoshin
e1d6306815 [AMDGPU] Fixed incomplete definitions in twoaddr-fma.mir. NFC. 2021-12-03 10:18:03 -08:00
Stanislav Mekhanoshin
3b17cb1506 [AMDGPU] Kill def when folding immediate in two-addr pass
Two-address pass works right before RA and if an immediate
was folded into an instruction there is nothing to remove
the dead def. We end up with something like:

	v_mov_b32_e32 v14, 0xc1700000
	v_mov_b32_e32 v14, 0x41200000
	v_fmaak_f32 v51, s67, v19, 0xc1700000
	v_fmaak_f32 v38, v51, v19, 0x4120000

The patch kills the dead move instruction right in the folding.

Differential Revision: https://reviews.llvm.org/D114999
2021-12-03 09:37:49 -08:00
Stephen Tozer
98a021fcbf [DebugInfo] Attempt to preserve more information during tail duplication
Prior to this patch, tail duplication handled debug info poorly -
specifically, debug instructions would be dropped instead of being set
undef, potentially extending the lifetimes of prior debug values that
should be killed. The pass was also very aggressive with dropping debug
info, dropping debug info even when the SSA value it referred to was
still present. This patch attempts to handle debug info more carefully,
checking to see whether each affected debug value can still be live,
setting it undef if not.

Reviewed By: jmorse

Differential Revision: https://reviews.llvm.org/D106875
2021-12-03 15:30:05 +00:00
David Green
ab0c5cea0b [ARM] Use v2i1 for MVE and CDE intrinsics
This adjusts all the MVE and CDE intrinsics now that v2i1 is a legal
type, to use a <2 x i1> as opposed to emulating the predicate with a
<4 x i1>. The v4i1 workarounds have been removed leaving the natural
v2i1 types, notably in vctp64 which now generates a v2i1 type.

AutoUpgrade code has been added to upgrade old IR, which needs to
convert the old v4i1 to a v2i1 be converting it back and forth to an
integer with arm.mve.v2i and arm.mve.i2v intrinsics. These should be
optimized away in the final assembly.

Differential Revision: https://reviews.llvm.org/D114455
2021-12-03 15:27:58 +00:00
Nemanja Ivanovic
d6c0ef7887 [PowerPC] Handle base load with reservation mnemonic
The Power ISA defined l[bhwdq]arx as both base and
extended mnemonics. The base mnemonic takes the EH
bit as an operand and the extended mnemonic omits
it, making it implicitly zero. The existing
implementation only handles the base mnemonic when
EH is 1 and internally produces a different
instruction. There are historical reasons for this.
This patch simply removes the limitation introduced
by this implementation that disallows the base
mnemonic with EH = 0 in the ASM parser.

This resolves an issue that prevented some files
in the Linux kernel from being built with
-fintegrated-as.

Also fix a crash if the value is not an integer immediate.
2021-12-03 09:13:02 -06:00
David Green
255ad73424 [ARM] Make MVE v2i1 predicates legal
MVE can treat v16i1, v8i1, v4i1 and v2i1 as different views onto the
same 16bit VPR.P0 register, with v2i1 holding two 8 bit values for the
two halves. This was never treated as a legal type in llvm in the past
as there are not many 64bit instructions and no 64bit compares. There
are a few instructions that could use it though, notably a VSELECT (as
it can handle any size using the underlying v16i8 VPSEL), AND/OR/XOR for
similar reasons, some gathers/scatter and long multiplies and VCTP64
instructions.

This patch goes through and makes v2i1 a legal type, handling all the
cases that fall out of that. It also makes VSELECT legal for v2i64 as a
side benefit. A lot of the codegen changes as a result - usually in way
that is a little better or a little worse, but still expensive. Costs
can change a little too in the process, again in a way that expensive
things remain expensive. A lot of the tests that changed are mainly to
ensure correctness - the code can hopefully be improved in the future
where it comes up in practice.

The intrinsics currently remain using the v4i1 they previously did to
emulate a v2i1. This will be changed in a followup patch but this one
was already large enough.

Differential Revision: https://reviews.llvm.org/D114449
2021-12-03 14:05:41 +00:00
Jay Foad
b670dcb81b [AMDGPU] Add some more GFX10 test coverage 2021-12-03 14:03:31 +00:00
Jay Foad
b29b6f92af [AMDGPU] Add some more GFX10 GlobalISel test coverage 2021-12-03 13:40:27 +00:00
Simon Pilgrim
e85667a2fb [PowerPC] Add non-constant fcopysign f128 test coverage
As discussed on D114589 as the constant case gets affected by SimplifyDemandedBits a lot - the non-constant case currently falls back to copysignl libcalls
2021-12-03 12:04:06 +00:00
Petar Avramovic
0b34ffe4a6 AMDGPU/GlobalISel: Add clamp combine
Add clamp combine. Source is fminnum(fmaxnum(Val, 0.0), 1.0) or
fmaxnum(fminnum(Val, 1.0), 0.0) or fmed3 intrinsic with 0.0 and
1.0 as two out of three operands.

Differential Revision: https://reviews.llvm.org/D90052
2021-12-03 12:49:39 +01:00
Petar Avramovic
ec54867d75 AMDGPU/GlobalISel: Add floating point med3 combine
Add floating point version of med3 combine.
Source is fminnum(fmaxnum(Val, K0), K1) or fmaxnum(fminnum(Val, K1), K0)
where K0 and K1 are constants and K0 <= K1.

Differential Revision: https://reviews.llvm.org/D90051
2021-12-03 12:49:39 +01:00
Petar Avramovic
ab01f4d264 AMDGPU/GlobalISel: Do not fcanonicalize const splat padded with undef
Recognize constant splat padded with undef in isCanonicalized.
Fcanonicalize will be removed by RemoveFcanonicalize in post-legalizer
combiner. We will treat undef as value that will result in a splat
in clamp combine after regbankselect.

Differential Revision: https://reviews.llvm.org/D104408
2021-12-03 12:49:38 +01:00
Victor Perez
9eb7322748 [RISCV][VP] Add RVV codegen for vp.select
Lower vp.select instrinsic to VSELECT_VL.

Reviewed By: rogfer01

Differential Revision: https://reviews.llvm.org/D114629
2021-12-03 11:02:20 +00:00
Kirill Stoimenov
021ecbbb44 [ASan] Changed intrisic implemenation to use PLT safe registers.
Changed registers to R10 and R11 because PLT resolution clobbers them. Also changed the implementation to use R11 instead of RCX, which saves a push/pop.

Reviewed By: vitalybuka

Differential Revision: https://reviews.llvm.org/D115002
2021-12-03 04:06:30 +00:00
Matt Arsenault
0eebe2e36c AMDGPU: Sanitized functions require implicit arguments
Do not infer no-amdgpu-implicitarg-ptr for sanitized functions. If a
function is explicitly marked amdgpu-no-implicitarg-ptr and
sanitize_address, infer that it is required.
2021-12-02 17:55:43 -05:00
Amy Kwan
c27734c183 [PowerPC] Fix load/store selection infrastructure when load/store intrinsics are used on P10.
The load/store infrastructure previously made an incorrect assumption that
whenever it is used with a load/store intrinsic on Power10 - those intrinsics
would automatically be the lxvp/stxvp intrinsics introduced in Power10.

However, this is obviously not the case as there are multiple instances of
pre-P10 intrinsics that use the refactored load/store implementation.
This patch corrects this assumption, and produces the expected intrinsic on pre-P10.

Differential Revision: https://reviews.llvm.org/D114978
2021-12-02 15:59:29 -06:00
David Green
b8f1ccb0ac [ARM] Introduce i8neg and i8pos addressing modes
Some instructions with i8 immediate ranges can only hold negative values
(like t2LDRHi8), only hold positive values (like t2STRT) or hold +/-
depending on the U bit (like the pre/post inc instructions. e.g
t2LDRH_POST). This patch splits the AddrModeT2_i8 into AddrModeT2_i8,
AddrModeT2_i8pos and AddrModeT2_i8neg to make this clear.

This allows us to get the offset ranges of t2LDRHi8 correct in the
load/store optimizer, fixing issues where we could end up creating
instructions with positive offsets (which may then be encoded as ldrht).

Differential Revision: https://reviews.llvm.org/D114638
2021-12-02 17:10:26 +00:00
David Stuttard
0e8590f065 [AMDGPU] Add support for in-order bvh in waitcnt pass
bvh should be handled separately from vmem and vmem with sampler instructions
for waitcnt handling.

Differential Revision: https://reviews.llvm.org/D114794
2021-12-02 14:26:11 +00:00
David Stuttard
17a3385c35 [AMDGPU] Test for in-order waitcnt insertion for bvh instructions
In-order bvh instructions don't require a waitcnt as order is
guaranteed.

However, waitcnt IS required for other image instruction types vs
bvh.

Pre-commit test for new functionality in https://reviews.llvm.org/D114794

Differential Revision: https://reviews.llvm.org/D114792
2021-12-02 14:25:37 +00:00
Matt Devereau
4244f95cc6 [AArch64][SVE] Enable bf16 vector.insert
Allow passthrough bf16 registers for vector.insert

Differential revision: https://reviews.llvm.org/D114858
2021-12-02 12:59:19 +00:00
Simon Pilgrim
6803d08c38 [DAG][PowerPC] Enable initial ISD::BITCAST SimplifyDemandedBits/SimplifyMultipleUseDemandedBits big-endian handling
This patch begins extending handling for peeking through bitcast nodes to big-endian targets as well as the existing little-endian case.

Differential Revision: https://reviews.llvm.org/D114676
2021-12-02 11:47:53 +00:00
David Green
e629302558 [ARM] Correct range in isLegalAddressImm
The ranges in isLegalAddressImm were off by one, not allowing the
maximum values for unscaled offsets.

Differential Revision: https://reviews.llvm.org/D114636
2021-12-02 11:33:40 +00:00
David Green
73c50ccf7a [ARM] Add additional postinc distribute tests and regenerate tests. NFC 2021-12-02 10:40:10 +00:00
David Green
646c872f9d [ARM] Teach getIntImmCostInst about the cost of saturating fp converts
Given a min(max(fptosi, INT_MIN), INT_MAX) with the correct constants,
we can now generate a fptosi.sat. But in the arm backend, the constant
can be treated as high cost, pulling it out of the basic block in a way
that the DAG combine can no longer see it. This teaches it again that it
is a low cost constant, not worth hoisting out.

Recommitted from 0e98659ea1193c with a fix for APInt comparison.

Differential Revision: https://reviews.llvm.org/D114380
2021-12-02 07:56:27 +00:00
Austin Kerbow
da067ed569 [AMDGPU] Set most sched model resource's BufferSize to one
Using a BufferSize of one for memory ProcResources will result in better
ILP since it more accurately models the dependencies between memory ops
and their consumers on an in-order processor. After this change, the
scheduler will treat the data edges from loads as blocking so that
stalls are guaranteed when waiting for data to be retreaved from memory.
Since we don't actually track waitcnt here, this should do a better job
at modeling their behavior.

Practically, this means that the scheduler will trigger the 'STALL'
heuristic more often.

This type of change needs to be evaluated experimentally. Preliminary
results are positive.

Fixes: SWDEV-282962

Reviewed By: rampitec

Differential Revision: https://reviews.llvm.org/D114777
2021-12-01 22:31:28 -08:00
Phoebe Wang
f13b43d570 [X86][FP16] Only generate approximate rsqrt when Reciprocal is true for half type
We have reasonable fast sqrt and accurate rsqrt for half type due to the
limited fractions. So neither do we need multi steps refinement for
rsqrt nor replace sqrt by rsqrt.

Reviewed By: RKSimon

Differential Revision: https://reviews.llvm.org/D114844
2021-12-02 13:52:45 +08:00
Phoebe Wang
4756a2f157 [X86] Insert FMUL for estimated non reciprocal SQRT when RefinementSteps = 0
Reviewed By: spatel

Differential Revision: https://reviews.llvm.org/D114843
2021-12-02 13:52:45 +08:00
Petar Avramovic
641906da8d AMDGPU/GlobalISel: Fix constant bus restriction errors for med3
Detected on targets older then gfx10 (e.g. gfx9) for constants that are
too large to be inlined (constant are sgpr by default).
In med3 combine it is expected that regbankselect maps all operands of
min/max we try to match to vgpr. However constants are mapped to sgpr
and there will be a sgpr-to-vgpr copy. Matchers look through sgpr-to-vgpr
copies and return sgpr and these break constant bus restriction.
Build med3 with all vgpr operands. Use existing sgpr-to-vgpr copies for
matched sgprs. If there is no such copy (not expected) build one.

Differential Revision: https://reviews.llvm.org/D114700
2021-12-01 21:36:37 +01:00
Craig Topper
2f6beb7b0e [RISCV] Add inline expansion for vector ftrunc/fceil/ffloor.
This prevents scalarization of fixed vector operations or crashes
on scalable vectors.

We don't have direct support for these operations. To emulate
ftrunc we can convert to the same sized integer and back to fp using
round to zero. We don't need to do a convert if the value is large
enough to have no fractional bits or is a nan.

The ceil and floor lowering would be better if we changed FRM, but
we don't model FRM correctly yet. So I've used the trunc lowering
with a conditional add or subtract with 1.0 if the truncate rounded
in the wrong direction.

There are also missed opportunities to use masked instructions.

Reviewed By: frasercrmck

Differential Revision: https://reviews.llvm.org/D113543
2021-12-01 11:25:28 -08:00
Omer Aviram
617ad14060 [SelectionDAG] Add pattern to haveNoCommonBitsSet
Correctly identify the following pattern, which has no common bits: (X & ~M) op (Y & M).

Differential Revision: https://reviews.llvm.org/D113970
2021-12-01 12:04:04 -05:00
Simon Pilgrim
19d34f6e95 [X86] combinePMULH - recognise 'cheap' trunctions via PACKS/PACKUS as well as SEXT/ZEXT
combinePMULH currently only truncates vXi32/vXi64 multiplies to PMULHW/PMULUW if the source operands are SEXT/ZEXT instructions for a 'free' truncation.

But we can generalize this to any source operand with sufficient leading sign/zero bits that would allow PACKS/PACKUS to be used as a 'cheap' truncation.

This helps us avoid the wider multiplies, in exchange for truncation on both source operands instead of the result.

Differential Revision: https://reviews.llvm.org/D113371
2021-12-01 16:37:49 +00:00
Simon Moll
444013d324 [VE][NFC] Use POSIX-compatible stream redirection
Drop Bash-style stream redirect in favor of POSIX stream redirection to
fix spurious test failures on Windows.

Failure:
https://lab.llvm.org/buildbot/#/builders/123/builds/7509/steps/8/logs/stdio
2021-12-01 17:28:57 +01:00
Yousuf Ali
415e821a50 [PowerPC][AIX] Add toc-data support for 64-bit AIX small code model.
The patch expands the existing 32-bit toc-data attribute support to 64-bit.
In both 32-bit and 64-bit it is supported for small code model only.

Differential Revision: https://reviews.llvm.org/D114654
2021-12-01 10:56:21 -05:00
Bradley Smith
fd9069ffce [AArch64][SVE] Duplicate FP_EXTEND/FP_TRUNC -> LOAD/STORE dag combines
By duplicating these dag combines we can bypass the legality checks that
they do, this allows us to perform these combines on larger than legal
fixed types, which in turn allows us to bring the same benefits D114580
brought but to larger than legal fixed types.

Depends on D114580

Differential Revision: https://reviews.llvm.org/D114628
2021-12-01 15:33:53 +00:00
David Green
13e66c070b Revert "[ARM] Teach getIntImmCostInst about the cost of saturating fp converts"
This reverts commit 6d41de380f223c8da02fd4d6a7f7dd1e7a404a24 as the
windows bots are not happy, in a way I do not understand. Revert whilst
we figure out what is wrong.
2021-12-01 15:25:19 +00:00
Ties Stuij
f5f28d5b0c [ARM] Implement BTI placement pass for PACBTI-M
This patch implements a new MachineFunction in the ARM backend for
placing BTI instructions. It is similar to the existing AArch64
aarch64-branch-targets pass.

BTI instructions are inserted into basic blocks that:
- Have their address taken
- Are the entry block of a function, if the function has external
  linkage or has its address taken
- Are mentioned in jump tables
- Are exception/cleanup landing pads

Each BTI instructions is placed in the beginning of a BB after the
so-called meta instructions (e.g. exception handler labels).

Each outlining candidate and the outlined function need to be in agreement about
whether BTI placement is enabled or not. If branch target enforcement is
disabled for a function, the outliner should not covertly enable it by emitting
a call to an outlined function, which begins with BTI.

The cost mode of the outliner is adjusted to account for the extra BTI
instructions in the outlined function.

The ARM Constant Islands pass will maintain the count of the jump tables, which
reference a block. A `BTI` instruction is removed from a block only if the
reference count reaches zero.

PAC instructions in entry blocks are replaced with PACBTI instructions (tests
for this case will be added in a later patch because the compiler currently does
not generate PAC instructions).

The ARM Constant Island pass is adjusted to handle BTI
instructions correctly.

Functions with static linkage that don't have their address taken can
still be called indirectly by linker-generated veneers and thus their
entry points need be marked with BTI or PACBTI.

The changes are tested using "LLVM IR -> assembly" tests, jump tables
also have a MIR test. Unfortunately it is not possible add MIR tests
for exception handling and computed gotos because of MIR parser
limitations.

This patch is part of a series that adds support for the PACBTI-M extension of
the Armv8.1-M architecture, as detailed here:

https://community.arm.com/arm-community-blogs/b/architectures-and-processors-blog/posts/armv8-1-m-pointer-authentication-and-branch-target-identification-extension

The PACBTI-M specification can be found in the Armv8-M Architecture Reference
Manual:

https://developer.arm.com/documentation/ddi0553/latest

The following people contributed to this patch:

- Mikhail Maltsev
- Momchil Velikov
- Ties Stuij

Reviewed By: ostannard

Differential Revision: https://reviews.llvm.org/D112426
2021-12-01 12:54:05 +00:00
Simon Pilgrim
4f7d397b6d [X86] Add some basic fptosi/fptoui saturate vector tests 2021-12-01 12:03:41 +00:00
Bradley Smith
0eb1efb92c [DAGCombiner] When combining REM ensure optimized div nodes are unique
The REM DAG combine uses the visitDivLike functions to try and get an
optimized DIV node to provide better codegen, however in some cases this
visitDivLike call ends up in the BuildSDIVPow2 target hook, which in
turn sometimes will return the same node passed in to indicate not to
change it. The REM DAG combine does not anticipate this and creates a
cycle in the DAG because of it.

Fix this by ensuring any such optimized div node returned is distinct
from the node being combined.

Differential Revision: https://reviews.llvm.org/D114716
2021-12-01 11:24:26 +00:00
David Green
0e98659ea1 [ARM] Strengthen fpclamptosat.ll triple to attempt to fix buildbot errors. NFC 2021-12-01 11:11:09 +00:00