1993 Commits

Author SHA1 Message Date
Roger Ferrer Ibáñez
05e6bb40eb
[SelectionDAG] Add an ISD::CLEAR_CACHE node to lower llvm.clear_cache (#93795)
The current way of lowering `llvm.clear_cache` is a bit unusual. As
suggested by Matt Arsenault we are better off using an ISD node.

This change introduces a new `ISD::CLEAR_CACHE`, registers a new libcall
by default named `__clear_cache` and the default legalisation is a
libcall.

This is preparatory work for a custom lowering of `ISD::CLEAR_CACHE`
needed by RISC-V on some platforms.
2024-05-30 14:55:32 +02:00
Graham Hunter
fbb37e9606
[AArch64] Add an all-in-one histogram intrinsic
Based on discussion from
https://discourse.llvm.org/t/rfc-vectorization-support-for-histogram-count-operations/74788

Current interface is:

llvm.experimental.histogram(<vecty> ptrs, <intty> inc_amount, <vecty> mask)

The integer type used by 'inc_amount' needs to match the type of the buckets in memory.

The intrinsic covers the following operations:
  * Gather load
  * histogram on the elements of 'ptrs'
  * multiply the histogram results by 'inc_amount'
  * add the result of the multiply to the values loaded by the gather
  * scatter store the results of the add

Supports lowering to histcnt instructions for AArch64 targets, and scalarization for all others at present.
2024-05-13 11:35:28 +01:00
Paul Walker
b277bf56d7
[LLVM][CodeGen][SVE] Clean up lowering of VECTOR_SPLICE operations. (#91330)
Remove DAG combine that is performing type legalisation and instead
add isel patterns for all legal types.
2024-05-10 10:53:57 +01:00
Simon Pilgrim
df21ee4c62 [DAG] Add clang-format off/on wrappers around compact switch handlers. NFC.
Avoids a problem identified in #90503
2024-05-09 17:02:17 +01:00
David Sherwood
b52fa9461a
[Analysis] Add cost model for experimental.cttz.elts intrinsic (#90720)
In PR #88385 I've added support for auto-vectorisation of some early
exit loops, which requires using the experimental.cttz.elts to calculate
final indices in the early exit block. We need a more accurate cost
model for this intrinsic to better reflect the cost of work required in
the early exit block. I've tried to accurately represent the expansion
code for the intrinsic when the target does not have efficient lowering
for it. It's quite tricky to model because you need to first figure out
what types will actually be used in the expansion. The type used can
have a significant effect on the cost if you end up using illegal vector
types.

Tests added here:

  Analysis/CostModel/AArch64/cttz_elts.ll
  Analysis/CostModel/RISCV/cttz_elts.ll
2024-05-09 09:40:33 +01:00
Aleksandr Popov
df311a2762
Add interface to check if a call has a deopt bundle (NFC) (#91348)
Encapsulate check that a call has a deopt bundle to make it easier to
change the deopt scheme.
2024-05-08 11:54:49 +02:00
Paul Walker
235cea720c
[NFC][LLVM] Refactor rounding mode detection of constrained fp intrinsic IDs (#90854)
I've refactored the code to genericise the implementation to better
allow for target specific constrained fp intrinsics.
2024-05-07 11:23:55 +01:00
Min-Yih Hsu
539f626ecd
[VP][RISCV] Add vp.cttz.elts intrinsic and its RISC-V codegen (#90502)
This intrinsic is the VP version of `experimental.cttz.elts`.
2024-04-30 09:27:10 -07:00
Maciej Gabka
bfc0317153
Move several vector intrinsics out of experimental namespace (#88748)
This patch is moving out following intrinsics:
* vector.interleave2/deinterleave2
* vector.reverse
* vector.splice

from the experimental namespace.

All these intrinsics exist in LLVM for more than a year now, and are
widely used, so should not be considered as experimental.
2024-04-29 10:16:45 +01:00
Pierre van Houtryve
cf328ff96d
[IR] Memory Model Relaxation Annotations (#78569)
Implements the core/target-agnostic components of Memory Model
Relaxation Annotations.

RFC:
https://discourse.llvm.org/t/rfc-mmras-memory-model-relaxation-annotations/76361/5
2024-04-24 08:52:25 +02:00
Björn Pettersson
d8b253be56
[SelectionDAG] Mark frame index as "aliased" at argument copy elison (#89712)
This is a fix for miscompiles reported in
  https://github.com/llvm/llvm-project/issues/89060

After argument copy elison the IR value for the eliminated alloca
is aliasing with the fixed stack object. This patch is making sure
that we mark the fixed stack object as being aliased with IR values
to avoid that for example schedulers are reordering accesses to
the fixed stack object. This could otherwise happen when there is a
mix of MemOperands refering the shared fixed stack slow via both
the IR value for the elided alloca, and via a fixed stack pseudo
source value (as would be the case when lowering the arguments).
2024-04-23 13:49:18 +02:00
Noah Goldstein
7013638978 [DAG] Add support for nneg flag with uitofp
Copy `nneg` flag when building `UINT_TO_FP` from `uitofp` and use
`nneg` flag in the one place we transform `UINT_TO_FP` -> `SINT_TO_FP`
if the operand is non-negative.
2024-04-09 23:06:55 -05:00
David Green
9fd2e2c2fd
[DAG][AArch64] Support masked loads/stores with nontemporal flags (#87608)
SVE has some non-temporal masked loads and stores. The metadata coming
from the nodes is not copied to the MMO at the moment though, meaning it
will generate a normal instruction. This patch ensures that the right
flags are set if the instruction has non-temporal metadata.
2024-04-08 08:53:27 +01:00
Sameer Sahasrabuddhe
421557974a
[AMDGPU] Use glue for convergence tokens at call-like operations (#86766)
The earlier implementation on AMDGPU used explicit token operands at
SI_CALL and SI_CALL_ISEL. This is now replaced with CONVERGENCECTRL_GLUE
operands, with the following effects:

- The treatment of tokens at call-like operations is now consistent with
the treatment at intrinsics.
- Support for tail calls using implicit tokens at SI_TCRETURN "just
works".
- The extra parameter at call-like instructions is eliminated, thus
restoring those instructions and their handling to the original state.

The new glue node is placed after the existing glue node for the
outgoing call parameters, which seems to not interfere with selection of
the call-like nodes.
2024-04-01 10:51:13 +05:30
Vitaly Buka
20f56e1f8e
[CodeGen] Add default lowering for llvm.allow.{runtime,ubsan}.check() (#86049)
RFC:
https://discourse.llvm.org/t/rfc-add-llvm-experimental-hot-intrinsic-or-llvm-hot/77641
2024-03-31 22:19:33 -07:00
Emil Pedersen
0e5c504d3d
[DebugInfo] [SelectionDAG] Fix handling of duplicate dbg values (#86598)
Before this fix, a duplicate llvm.dbg.value intrinsic referring to an
argument, after an alloca, would be generated with `$noreg`, losing
debug information. Instead, we silently drop the second debug info, so
it doesn't break the first one.

rdar://125375717
2024-03-26 12:09:22 -07:00
Il-Capitano
308ed0233a
[Intrinsics] Make patchpoint.i64 generic on its return type (#85911)
Currently patchpoints can only have two result types, `void` and `i64`.
This limits the result to general purpose registers.
This patch makes `patchpoint.i64` an overloadable intrinsic, allowing
result values that can fit in a single register (e.g. integers,
pointers, floats).
2024-03-26 19:08:52 +05:30
Harvin Iriawan
57146daeaa
[CodeGen] Update for scalable MemoryType in MMO (#70452)
Remove getSizeOrUnknown call when MachineMemOperand is created.  For Scalable
TypeSize, the MemoryType created becomes a scalable_vector.

2 MMOs that have scalable memory access can then use the updated BasicAA that
understands scalable LocationSize.

Original Patch by Harvin Iriawan
Co-authored-by: David Green <david.green@arm.com>
2024-03-23 12:56:25 +00:00
Craig Topper
c67ed2f1e1
[SelectionDAG][RISCV] Use TypeSize version of ComputeValueVTs in TargetLowering::LowerCallTo. (#86166)
This is needed to support non-intrinsic functions returning tuple types
which are represented as structs with scalable vector types in IR.

I suspect this may have been broken since
https://reviews.llvm.org/D158115
2024-03-21 20:35:08 -07:00
Stephen Tozer
bdc77d1ecc
[RemoveDIs][NFC] Rename DPLabel->DbgLabelRecord (#85918)
This patch renames DPLabel to DbgLabelRecord, in accordance with the
ongoing DbgRecord rename. This rename was fairly trivial, since DPLabel
isn't as widely used as DPValue and has no real conflicts in either its
full or abbreviated name. As usual, the entire replacement was done
automatically, with `s/DPLabel/DbgLabelRecord/` and `s/DPL/DLR/`.
2024-03-20 13:11:28 +00:00
Stephen Tozer
ffd08c7759
[RemoveDIs][NFC] Rename DPValue -> DbgVariableRecord (#85216)
This is the major rename patch that prior patches have built towards.
The DPValue class is being renamed to DbgVariableRecord, which reflects
the updated terminology for the "final" implementation of the RemoveDI
feature. This is a pure string substitution + clang-format patch. The
only manual component of this patch was determining where to perform
these string substitutions: `DPValue` and `DPV` are almost exclusively
used for DbgRecords, *except* for:

- llvm/lib/target, where 'DP' is used to mean double-precision, and so
appears as part of .td files and in variable names. NB: There is a
single existing use of `DPValue` here that refers to debug info, which
I've manually updated.
- llvm/tools/gold, where 'LDPV' is used as a prefix for symbol
visibility enums.

Outside of these places, I've applied several basic string
substitutions, with the intent that they only affect DbgRecord-related
identifiers; I've checked them as I went through to verify this, with
reasonable confidence that there are no unintended changes that slipped
through the cracks. The substitutions applied are all case-sensitive,
and are applied in the order shown:

```
  DPValue -> DbgVariableRecord
  DPVal -> DbgVarRec
  DPV -> DVR
```

Following the previous rename patches, it should be the case that there
are no instances of any of these strings that are meant to refer to the
general case of DbgRecords, or anything other than the DPValue class.
The idea behind this patch is therefore that pure string substitution is
correct in all cases as long as these assumptions hold.
2024-03-19 20:07:07 +00:00
David Green
18da51b2b2 [CodeGen] More uses of LocationSize::beforeOrAfterPointer().
As an extension to #84751, this adds some extra uses of beforeOrAfterPointer()
instead of UnknownSize.
2024-03-18 20:18:49 +00:00
David Green
601e102bdb
[CodeGen] Use LocationSize for MMO getSize (#84751)
This is part of #70452 that changes the type used for the external
interface of MMO to LocationSize as opposed to uint64_t. This means the
constructors take LocationSize, and convert ~UINT64_C(0) to
LocationSize::beforeOrAfter(). The getSize methods return a
LocationSize.

This allows us to be more precise with unknown sizes, not accidentally
treating them as unsigned values, and in the future should allow us to
add proper scalable vector support but none of that is included in this
patch. It should mostly be an NFC.

Global ISel is still expected to use the underlying LLT as it needs, and
are not expected to see unknown sizes for generic operations. Most of
the changes are hopefully fairly mechanical, adding a lot of getValue()
calls and protecting them with hasValue() where needed.
2024-03-17 18:15:56 +00:00
Stephen Tozer
15f3f446c5
[RemoveDIs][NFC] Rename common interface functions for DPValues->DbgRecords (#84793)
As part of the effort to rename the DbgRecord classes, this patch
renames the widely-used functions that operate on DbgRecords but refer
to DbgValues or DPValues in their names to refer to DbgRecords instead;
all such functions are defined in one of `BasicBlock.h`,
`Instruction.h`, and `DebugProgramInstruction.h`.

This patch explicitly does not change the names of any comments or
variables, except for where they use the exact name of one of the
renamed functions. The reason for this is reviewability; this patch can
be trivially examined to determine that the only changes are direct
string substitutions and any results from clang-format responding to the
changed line lengths. Future patches will cover renaming variables and
comments, and then renaming the classes themselves.
2024-03-12 14:53:13 +00:00
Sameer Sahasrabuddhe
60822637bf Restore "Implement convergence control in MIR using SelectionDAG (#71785)"
This restores commit c7fdd8c11e54585dc9d15d63de9742067e0506b9.
Previously reverted in f010b1bef4dda2c7082cbb41dbabf1f149cce306.

LLVM function calls carry convergence control tokens as operand bundles, where
the tokens themselves are produced by convergence control intrinsics. This patch
implements convergence control tokens in MIR as follows:

1. Introduce target-independent ISD opcodes and MIR opcodes for convergence
   control intrinsics.
2. Model token values as untyped virtual registers in MIR.

The change also introduces an additional ISD opcode CONVERGENCECTRL_GLUE and a
corresponding machine opcode with the same spelling. This glues the convergence
control token to SDNodes that represent calls to intrinsics. The glued token is
later translated to an implicit argument in the MIR.

The lowering of calls to user-defined functions is target-specific. On AMDGPU,
the convergence control operand bundle at a non-intrinsic call is translated to
an explicit argument to the SI_CALL_ISEL instruction. Post-selection adjustment
converts this explicit argument to an implicit argument on the SI_CALL
instruction.
2024-03-06 12:19:32 +05:30
Yeting Kuo
d95a0d7c0f
[DAG] Teach SelectionDAGBuilder to read parameter alignment of compressstore/expandload. (#83763)
Previously SelectionDAGBuilder used ABI alignment for
compressstore/expandload. This patch allows SelectionDAGBuilder to use
parameter alignment like vp intrinsics. This does not follow the
original code to default use vector type alignment, since it is possible
implemented to unaligned vector alignment.
2024-03-05 20:48:37 +08:00
Noah Goldstein
a4951eca40 Recommit "[X86] Don't always separate conditions in (br (and/or cond0, cond1)) into separate branches" (2nd Try)
Changes in Recommit:
    1) Fix non-determanism by using `SmallMapVector` instead of
       `SmallPtrSet`.
    2) Fix bug in dependency pruning where we discounted the actual
       `and/or` combining the two conditions. This lead to over pruning.

Closes #81689
2024-03-04 13:23:56 -06:00
Mitch Phillips
f010b1bef4 Revert "Restore "Implement convergence control in MIR using SelectionDAG (#71785)""
This reverts commit c7fdd8c11e54585dc9d15d63de9742067e0506b9.

Reason: Broke the sanitizer buildbots. See the comments at
https://github.com/llvm/llvm-project/pull/71785
for more information.
2024-03-04 17:05:34 +01:00
Sameer Sahasrabuddhe
c7fdd8c11e Restore "Implement convergence control in MIR using SelectionDAG (#71785)"
Original commit 79889734b940356ab3381423c93ae06f22e772c9.
Perviously reverted in commit a2afcd5721869d1d03c8146bae3885b3385ba15e.

LLVM function calls carry convergence control tokens as operand bundles, where
the tokens themselves are produced by convergence control intrinsics. This patch
implements convergence control tokens in MIR as follows:

1. Introduce target-independent ISD opcodes and MIR opcodes for convergence
   control intrinsics.
2. Model token values as untyped virtual registers in MIR.

The change also introduces an additional ISD opcode CONVERGENCECTRL_GLUE and a
corresponding machine opcode with the same spelling. This glues the convergence
control token to SDNodes that represent calls to intrinsics. The glued token is
later translated to an implicit argument in the MIR.

The lowering of calls to user-defined functions is target-specific. On AMDGPU,
the convergence control operand bundle at a non-intrinsic call is translated to
an explicit argument to the SI_CALL_ISEL instruction. Post-selection adjustment
converts this explicit argument to an implicit argument on the SI_CALL
instruction.
2024-03-04 13:28:04 +05:30
NAKAMURA Takumi
5b4759f9fd Revert "[X86] Don't always separate conditions in (br (and/or cond0, cond1)) into separate branches"
This has been buggy for a while.

Reverts #81689
This reverts commit ae76dfb74701e05e5ab4be194e20e49f10768e46.
2024-03-03 22:31:28 +09:00
Noah Goldstein
ae76dfb747 [X86] Don't always separate conditions in (br (and/or cond0, cond1)) into separate branches
It makes sense to split if the cost of computing `cond1` is high
(proportionally to how likely `cond0` is), but it doesn't really make
sense to introduce a second branch if its only a few instructions.

Splitting can also get in the way of potentially folding patterns.

This patch introduces some logic to try to check if the cost of
computing `cond1` is relatively low, and if so don't split the
branches.

Modest improvement on clang bootstrap build:
https://llvm-compile-time-tracker.com/compare.php?from=79ce933114e46c891a5632f7ad4a004b93a5b808&to=978278eabc0bafe2f390ca8fcdad24154f954020&stat=cycles
Average stage2-O3:   0.59% Improvement (cycles)
Average stage2-O0-g: 1.20% Improvement (cycles)

Likewise on llvm-test-suite on SKX saw a net 0.84% improvement  (cycles)

There is also a modest compile time improvement with this patch:
https://llvm-compile-time-tracker.com/compare.php?from=79ce933114e46c891a5632f7ad4a004b93a5b808&to=978278eabc0bafe2f390ca8fcdad24154f954020&stat=instructions%3Au

Note that the stage2 instruction count increases is expected, this
patch trades instructions for decreasing branch-misses (which is
proportionately lower):
https://llvm-compile-time-tracker.com/compare.php?from=79ce933114e46c891a5632f7ad4a004b93a5b808&to=978278eabc0bafe2f390ca8fcdad24154f954020&stat=branch-misses

NB: This will also likely help for APX targets with the new `CCMP` and
`CTEST` instructions.

Closes #81689
2024-03-01 15:35:34 -06:00
Craig Topper
62d0c01c2c
[SelectionDAG] Remove pointer from MMO for VP strided load/store. (#82667)
MachineIR alias analysis assumes that only bytes after the pointer will
be accessed. This is incorrect if the stride is negative.

This is causing miscompiles in our downstream after SLP started making
strided loads.

Fixes #82657
2024-02-26 16:15:34 -08:00
Orlando Cazalet-Hyams
8a16422020
[RemoveDIs] Add DPLabels support [3a/3] (#82633)
Patch 2 of 3 to add llvm.dbg.label support to the RemoveDIs project. The
patch stack adds the DPLabel class, which is the RemoveDIs llvm.dbg.label
equivalent.

   1. Add DbgRecord base class for DPValue and the not-yet-added
       DPLabel class.
   2. Add the DPLabel class.
-> 3. Add support to passes.

The next patch, #82639, will enable conversion between dbg.labels and DPLabels.

AssignemntTrackingAnalysis support could have gone two ways:

1. Have the analysis store a DPLabel representation in its results -
   SelectionDAGBuilder reads the analysis results and ignores all DbgRecord
   kinds.
2. Ignore DPLabels in the analysis - SelectionDAGBuilder reads the analysis
   results but still needs to iterate over DPLabels from the IR.

I went with option 2 because it's less work and is no less correct than 1. It's
worth noting that causes labels to sink to the bottom of packs of debug records.
e.g., [value, label, value] becomes [value, value, label]. This shouldn't be a
problem because labels and variable locations don't have an ordering requirement.
The ordering between variable locations is maintained and the label movement is
deterministic
2024-02-23 11:37:21 +00:00
Paul Walker
28fb2b33c2
[LLVM][SelectionDAG] Reduce number of ComputeValueVTs variants. (#75614)
This is another step in the direction of fixing the `Fixed(0) !=
Scalable(0)` bugbear, although whilst weird I don't believe it's causing
us any real issues.
2024-02-21 13:03:24 +00:00
Sameer Sahasrabuddhe
a2afcd5721 Revert "Implement convergence control in MIR using SelectionDAG (#71785)"
This reverts commit 79889734b940356ab3381423c93ae06f22e772c9.

Encountered multiple buildbot failures.
2024-02-21 11:07:02 +05:30
Sameer Sahasrabuddhe
79889734b9
Implement convergence control in MIR using SelectionDAG (#71785)
LLVM function calls carry convergence control tokens as operand bundles, where
the tokens themselves are produced by convergence control intrinsics. This patch
implements convergence control tokens in MIR as follows:

1. Introduce target-independent ISD opcodes and MIR opcodes for convergence
   control intrinsics.
2. Model token values as untyped virtual registers in MIR.

The change also introduces an additional ISD opcode CONVERGENCECTRL_GLUE and a
corresponding machine opcode with the same spelling. This glues the convergence
control token to SDNodes that represent calls to intrinsics. The glued token is
later translated to an implicit argument in the MIR.

The lowering of calls to user-defined functions is target-specific. On AMDGPU,
the convergence control operand bundle at a non-intrinsic call is translated to
an explicit argument to the SI_CALL_ISEL instruction. Post-selection adjustment
converts this explicit argument to an implicit argument on the SI_CALL
instruction.
2024-02-21 10:06:37 +05:30
Orlando Cazalet-Hyams
ababa96475
[RemoveDIs][NFC] Introduce DbgRecord base class [1/3] (#78252)
Patch 1 of 3 to add llvm.dbg.label support to the RemoveDIs project. The
patch stack adds a new base class

    -> 1. Add DbgRecord base class for DPValue and the not-yet-added
          DPLabel class.
       2. Add the DPLabel class.
       3. Enable dbg.label conversion and add support to passes.

Patches 1 and 2 are NFC.

In the near future we also will rename DPValue to DbgVariableRecord and
DPLabel to DbgLabelRecord, at which point we'll overhaul the function
names too. The name DPLabel keeps things consistent for now.
2024-02-20 16:00:55 +00:00
Tim Northover
0215d2c58b arm64_32: extend @llvm.stackguard call to in-DAG 64-bits before handing off
Pointers are 64-bits in the DAG, so we need to extend the result of loading the
cookie when building the DAG.
2024-02-19 10:32:29 +00:00
Joseph Huber
11fcae69db
[LLVM] Add __builtin_readsteadycounter intrinsic and builtin for realtime clocks (#81331)
Summary:
This patch adds a new intrinsic and builtin function mirroring the
existing `__builtin_readcyclecounter`. The difference is that this
implementation targets a separate counter that some targets have which
returns a fixed frequency clock that can be used to determine elapsed
time, this is different compared to the cycle counter which often has
variable frequency.

This patch only adds support for the NVPTX and AMDGPU targets.

This is done as a new and separate builtin rather than an argument to
`readcyclecounter` to avoid needing to change existing code and to make
the separation more explicit.
2024-02-13 10:06:25 -06:00
Stephen Tozer
30845e8ab4
[RemoveDIs][DebugInfo] Handle DPVAssigns in Assignment Tracking excluding lowering (#78982)
This patch adds support for DPVAssigns across all of
AssignmentTrackingAnalysis except for AssignmentTrackingLowering, which
is implemented in a separate patch. This patch includes handling
DPValues in MemLocFragFill, the removal of redundant DPValues as part of
AssignmentTrackingAnalysis (which is different to the version in
`BasicBlockUtils.cpp`), and preventing the DPVAssigns from being
directly emitted in SelectionDAG (just as we don't emit llvm.dbg.assigns
directly, but receive a set of locations from
AssignmentTrackingAnalysis' output).
2024-01-23 14:27:01 +00:00
Jeremy Morse
8c1b7fba1f
[SelectionDAG][DebugInfo][RemoveDIs] Handle entry value variables in DPValues too (#78726)
This patch abstracts visitEntryValueDbgValue to deal with the substance
of variable locations (Value, Var, Expr, DebugLoc) rather than how
they're stored. That allows us to call it from handleDebugValue, which
is similarly abstracted. This allows the entry-value behaviour (see the
test) to be supported with non-instruction debug-info too!.
2024-01-22 15:39:35 +00:00
Matt Arsenault
11bf02e019
DAG: Fix ABI lowering with FP promote in strictfp functions (#74405)
This was emitting non-strict casts in ABI contexts for illegal
types.
2024-01-18 10:57:53 +07:00
Alex Bradbury
197214e39b
[RFC][SelectionDAG] Add and use SDNode::getAsZExtVal() helper (#76710)
This follows on from #76708, allowing
`cast<ConstantSDNode>(N)->getZExtValue()` to be replaced with just
`N->getAsZextVal();`
    
Introduced via `git grep -l "cast<ConstantSDNode>\(.*\).*getZExtValue" |
xargs sed -E -i
's/cast<ConstantSDNode>\((.*)\)->getZExtValue/\1->getAsZExtVal/'` and
then using `git clang-format` on the result.
2024-01-09 12:25:17 +00:00
Amara Emerson
535d8e8b92 NFC: Extract switch lowering binary tree splitting code from DAG into SwitchLoweringUtils.
This will help re-use this code with the upcoming GlobalISel implementation of
this optimization.
2024-01-07 07:42:27 -08:00
Jannik Silvanus
7954c57124
[IR] Fix GEP offset computations for vector GEPs (#75448)
Vectors are always bit-packed and don't respect the elements' alignment
requirements. This is different from arrays. This means offsets of
vector GEPs need to be computed differently than offsets of array GEPs.

This PR fixes many places that rely on an incorrect pattern
that always relies on `DL.getTypeAllocSize(GTI.getIndexedType())`.
We replace these by usages of  `GTI.getSequentialElementStride(DL)`, 
which is a new helper function added in this PR.

This changes behavior for GEPs into vectors with element types for which
the (bit) size and alloc size is different. This includes two cases:

* Types with a bit size that is not a multiple of a byte, e.g. i1.
GEPs into such vectors are questionable to begin with, as some elements
  are not even addressable.
* Overaligned types, e.g. i16 with 32-bit alignment.

Existing tests are unaffected, but a miscompilation of a new test is fixed.

---------

Co-authored-by: Nikita Popov <github@npopov.com>
2024-01-04 10:08:21 +01:00
Craig Topper
bbd57e1832
[SelectionDAG] Add initial plumbing for the disjoint flag. (#76751)
This copies the flag from IR to the SDNode in SelectionDAGBuilder, clears
the flag in SimplifyDemandedBits, and adds it to canCreateUndefOrPoison.

Uses of the flag will come in later patches.
2024-01-02 21:58:00 -08:00
Kazu Hirata
41cb686d0f [CodeGen] Use range-based for loops (NFC) 2023-12-24 22:45:50 -08:00
Orlando Cazalet-Hyams
5ee088134f
[DebugInfo][RemoveDIs] Handle dbg.declares in SelectionDAGISel (#73496)
This is a boring mechanical update to support DPValues that look like
dbg.declares in SelectionDAG.

The tests will become "live" once #74090 lands (see for more info).
2023-12-12 11:32:19 +00:00
Jay Foad
b3000ecb3c [SelectionDAG] Fix typo in comment 2023-12-09 10:12:32 +00:00
Philip Reames
943f3e52a0 [X86] Remove x86-experimental-unordered-atomic-isel option and associated code
This option enables an experimental lowering for unordered atomics I worked
on a few years back.  It never reached production quality, and hasn't been
worked on in years.  So let's rip it out.

This wasn't a crazy idea, but I hit some stumbling block which prevented me
from pushing it across the finish line.  From the look of 027aa27, that
change description is probably a good summary.  I don't remember the
details any longer.
2023-12-04 20:03:38 -08:00