Commit Graph

1065 Commits

Author SHA1 Message Date
Joe Ellis a7dde4c5f7 [AArch64][SVE] Lower fixed length INSERT_VECTOR_ELT
Differential Revision: https://reviews.llvm.org/D98496
2021-03-30 09:37:11 +00:00
Joe Ellis c4d39f64d0 [AArch64][SVE] Lower fixed length EXTRACT_VECTOR_ELT
Differential Revision: https://reviews.llvm.org/D98625
2021-03-30 09:35:44 +00:00
Florian Hahn 482283042f
[AArch64] Remove custom zext/sext legalization code.
Currently performExtendCombine assumes that the src-element bitwidth * 2
is a valid MVT. But this is not the case for i1 and it causes a crash on
the v64i1 test cases added in this patch.

It turns out that this code appears to not be needed; the same patterns are
handled by other code and we end up with the same results, even without the
custom lowering. I also added additional test cases in a50037aaa6.

Let's just remove the unneeded code.

Reviewed By: dmgreen

Differential Revision: https://reviews.llvm.org/D99437
2021-03-29 22:22:05 +01:00
Bradley Smith 9745dce8c3 [SelectionDAG][AArch64][SVE] Perform SETCC condition legalization in LegalizeVectorOps
This is currently performed in SelectionDAGLegalize, here we make it also
happen in LegalizeVectorOps, allowing a target to lower the SETCC condition
codes first in LegalizeVectorOps and then lower to a custom node afterwards,
without having to duplicate all of the SETCC condition legalization in the
target specific lowering.

As a result of this, fixed length floating point SETCC nodes can now be
properly lowered for SVE.

Differential Revision: https://reviews.llvm.org/D98939
2021-03-29 15:32:25 +01:00
Florian Hahn eb3d9f2eb6
[SelDag] Add isIntOrFPConstant helper function.
This patch adds a new isIntOrFPConstant  helper function to check if a
SDValue is a integer of FP constant. This pattern is used in various
places.

There also are places that incorrectly just check for integer constants,
e.g. D99384, so hopefully this helper will help people avoid that issue.

Reviewed By: RKSimon

Differential Revision: https://reviews.llvm.org/D99428
2021-03-28 12:48:58 +01:00
Nashe Mncube ac2a1e9596 [SVE] Suppress vselect warning from incorrect interface call
The VSelectCombine handler within AArch64ISelLowering,
uses an interface call which only expects fixed vectors.
This generates a warning when the call is made on a
scalable vector. This warning has been suppressed with this change,
by using the ElementCount interface, which supports both fixed and scalable vectors.
I have also added a regression test which recreates the warning.

Differential Revision: https://reviews.llvm.org/D98249
2021-03-24 14:34:34 +00:00
Benjamin Kramer 39e36fff3d [AArch64] Fix unused variable warning 2021-03-23 13:42:14 +01:00
David Sherwood 748ae5281d [IR][SVE] Add new llvm.experimental.stepvector intrinsic
This patch adds a new llvm.experimental.stepvector intrinsic,
which takes no arguments and returns a linear integer sequence of
values of the form <0, 1, ...>. It is primarily intended for
scalable vectors, although it will work for fixed width vectors
too. It is intended that later patches will make use of this
new intrinsic when vectorising induction variables, currently only
supported for fixed width. I've added a new CreateStepVector
method to the IRBuilder, which will generate a call to this
intrinsic for scalable vectors and fall back on creating a
ConstantVector for fixed width.

For scalable vectors this intrinsic is lowered to a new ISD node
called STEP_VECTOR, which takes a single constant integer argument
as the step. During lowering this argument is set to a value of 1.
The reason for this additional argument at the codegen level is
because in future patches we will introduce various generic DAG
combines such as

  mul step_vector(1), 2 -> step_vector(2)
  add step_vector(1), step_vector(1) -> step_vector(2)
  shl step_vector(1), 1 -> step_vector(2)
  etc.

that encourage a canonical format for all targets. This hopefully
means all other targets supporting scalable vectors can benefit
from this too.

I've added cost model tests for both fixed width and scalable
vectors:

  llvm/test/Analysis/CostModel/AArch64/neon-stepvector.ll
  llvm/test/Analysis/CostModel/AArch64/sve-stepvector.ll

as well as codegen lowering tests for fixed width and scalable
vectors:

  llvm/test/CodeGen/AArch64/neon-stepvector.ll
  llvm/test/CodeGen/AArch64/sve-stepvector.ll

See this thread for discussion of the intrinsic:
https://lists.llvm.org/pipermail/llvm-dev/2021-January/147943.html
2021-03-23 10:43:35 +00:00
Craig Topper 1066dcb550 [AArch64] Fix LowerMGATHER to return the chain result for floating point gathers.
Found by adding asserts to LegalizeDAG to make sure custom legalized
results had the right types.

Reviewed By: kmclaughlin

Differential Revision: https://reviews.llvm.org/D98968
2021-03-19 11:53:46 -07:00
Peter Waller 0d6482a76a [llvm][AArch64][SVE] Lower fixed length vector fabs
Seemingly striaghtforward.

Differential Revision: https://reviews.llvm.org/D98434
2021-03-18 17:20:08 +00:00
Sjoerd Meijer 90ecb862a0 [AArch64] Rewrite (add, csel) to cinc
Don't rewrite an add instruction with 2 SET_CC operands into a csel
instruction. The total instruction sequence uses an extra instruction and
register. Preventing this allows us to match a `(add, csel)` pattern and
rewrite this into a `cinc`.

Differential Revision: https://reviews.llvm.org/D98704
2021-03-18 08:49:27 +00:00
Bradley Smith cf0da91ba5 [AArch64][SVE/NEON] Add support for FROUNDEVEN for both NEON and fixed length SVE
Previously NEON used a target specific intrinsic for frintn, given that
the FROUNDEVEN ISD node now exists, move over to that instead and add
codegen support for that node for both NEON and fixed length SVE.

Differential Revision: https://reviews.llvm.org/D98487
2021-03-17 11:41:22 +00:00
Joe Ellis ff2dd8a212 [AArch64][SVE] Fold vector ZExt/SExt into gather loads where possible
This commit folds sxtw'd or uxtw'd offsets into gather loads where
possible with a DAGCombine optimization.

As an example, the following code:

     1	#include <arm_sve.h>
     2
     3	svuint64_t func(svbool_t pred, const int32_t *base, svint64_t offsets) {
     4	  return svld1sw_gather_s64offset_u64(
     5	    pred, base, svextw_s64_x(pred, offsets)
     6	  );
     7	}

would previously lower to the following assembly:

    sxtw	z0.d, p0/m, z0.d
    ld1sw	{ z0.d }, p0/z, [x0, z0.d]
    ret

but now lowers to:

    ld1sw   { z0.d }, p0/z, [x0, z0.d, sxtw]
    ret

Differential Revision: https://reviews.llvm.org/D97858
2021-03-16 15:09:46 +00:00
Stelios Ioannou ab86edbc88 [AArch64] Implement __rndr, __rndrrs intrinsics
This patch implements the __rndr and __rndrrs intrinsics to provide access to the random
number instructions introduced in Armv8.5-A. They are only defined for the AArch64
execution state and are available when __ARM_FEATURE_RNG is defined.

These intrinsics store the random number in their pointer argument and return a status
code if the generation succeeded. The difference between __rndr __rndrrs, is that the latter
intrinsic reseeds the random number generator.

The instructions write the NZCV flags indicating the success of the operation that we can
then read with a CSET.

[1] https://developer.arm.com/docs/101028/latest/data-processing-intrinsics
[2] https://bugs.llvm.org/show_bug.cgi?id=47838

Differential Revision: https://reviews.llvm.org/D98264

Change-Id: I8f92e7bf5b450e5da3e59943b53482edf0df6efc
2021-03-15 17:51:48 +00:00
Bradley Smith 860ae9d50c [AArch64][SVE] Add fixed/scalable lowering of FMAXIMUM/FMINIMUM ISD nodes
Differential Revision: https://reviews.llvm.org/D98348
2021-03-11 13:37:47 +00:00
David Green 1a808286ef [AArch64] Extend vecreduce -> udot handling to mla reductions
We previously have lowering for:
  vecreduce.add(zext(X)) to vecreduce.add(UDOT(zero, X, one))
This extends that to also handle:
  vecreduce.add(mul(zext(X), zext(Y)) to vecreduce.add(UDOT(zero, X, Y))
It extends the existing code to optionally handle a mul with equal
extends.

Differential Revision: https://reviews.llvm.org/D97280
2021-03-10 22:25:12 +00:00
David Green a02f506876 [AArch64] Extend vecreduce -> udot handling to v8i8
https://reviews.llvm.org/D88577 added v16i8 vecreduce to udot/sdot
lowering. This extends that to v8i8 too, generalizing the pattern to
handle the extra types.

Differential Revision: https://reviews.llvm.org/D97279
2021-03-10 21:03:15 +00:00
Cullen Rhodes 2750f3ed31 [IR] Introduce llvm.experimental.vector.splice intrinsic
This patch introduces a new intrinsic @llvm.experimental.vector.splice
that constructs a vector of the same type as the two input vectors,
based on a immediate where the sign of the immediate distinguishes two
variants. A positive immediate specifies an index into the first vector
and a negative immediate specifies the number of trailing elements to
extract from the first vector.

For example:

  @llvm.experimental.vector.splice(<A,B,C,D>, <E,F,G,H>, 1) ==> <B, C, D, E>  ; index
  @llvm.experimental.vector.splice(<A,B,C,D>, <E,F,G,H>, -3) ==> <B, C, D, E> ; trailing element count

These intrinsics support both fixed and scalable vectors, where the
former is lowered to a shufflevector to maintain existing behaviour,
although while marked as experimental the recommended way to express
this operation for fixed-width vectors is to use shufflevector. For
scalable vectors where it is not possible to express a shufflevector
mask for this operation, a new ISD node has been implemented.

This is one of the named shufflevector intrinsics proposed on the
mailing-list in the RFC at [1].

Patch by Paul Walker and Cullen Rhodes.

[1] https://lists.llvm.org/pipermail/llvm-dev/2020-November/146864.html

Reviewed By: sdesmalen

Differential Revision: https://reviews.llvm.org/D94708
2021-03-09 10:44:22 +00:00
Akira Hatanaka dca5737945 Move ObjCARCUtil.h back to llvm/Analysis
Instead of adding the header to llvm/IR, just duplicate the marker
string in the auto upgrader.
2021-03-08 16:35:24 -08:00
LemonBoy 8725b24c6d [AArch64] Legalize horizontal fmax/fmin reductions on f16 vectors
Expand the horizontal reduction during the instruction selection phase, but only if the target doesn't support the full fp16 instruction set.

Fixes https://bugs.llvm.org/show_bug.cgi?id=49401

Reviewed By: aemerson

Differential Revision: https://reviews.llvm.org/D97840
2021-03-05 16:09:37 +01:00
David Blaikie a2a55def35 Move llvm/Analysis/ObjCARCUtil.h to IR to fix layering.
This is included from IR files, and IR doesn't/can't depend on Analysis
(because Analysis depends on IR).

Also fix the implementation - don't use non-member static in headers, as
it leads to ODR violations, inaccurate "unused function" warnings, etc.
And fix the header protection macro name (we don't generally include
"LIB" in the names, so far as I can tell).
2021-03-04 16:14:53 -08:00
Akira Hatanaka 1900503595 [ObjC][ARC] Use operand bundle 'clang.arc.attachedcall' instead of
explicitly emitting retainRV or claimRV calls in the IR

This reapplies ed4718eccb, which was reverted
because it was causing a miscompile. The bug that was causing the miscompile
has been fixed in 75805dce5f.

Original commit message:

Background:

This fixes a longstanding problem where llvm breaks ARC's autorelease
optimization (see the link below) by separating calls from the marker
instructions or retainRV/claimRV calls. The backend changes are in
https://reviews.llvm.org/D92569.

https://clang.llvm.org/docs/AutomaticReferenceCounting.html#arc-runtime-objc-autoreleasereturnvalue

What this patch does to fix the problem:

- The front-end adds operand bundle "clang.arc.attachedcall" to calls,
  which indicates the call is implicitly followed by a marker
  instruction and an implicit retainRV/claimRV call that consumes the
  call result. In addition, it emits a call to
  @llvm.objc.clang.arc.noop.use, which consumes the call result, to
  prevent the middle-end passes from changing the return type of the
  called function. This is currently done only when the target is arm64
  and the optimization level is higher than -O0.

- ARC optimizer temporarily emits retainRV/claimRV calls after the calls
  with the operand bundle in the IR and removes the inserted calls after
  processing the function.

- ARC contract pass emits retainRV/claimRV calls after the call with the
  operand bundle. It doesn't remove the operand bundle on the call since
  the backend needs it to emit the marker instruction. The retainRV and
  claimRV calls are emitted late in the pipeline to prevent optimization
  passes from transforming the IR in a way that makes it harder for the
  ARC middle-end passes to figure out the def-use relationship between
  the call and the retainRV/claimRV calls (which is the cause of
  PR31925).

- The function inliner removes an autoreleaseRV call in the callee if
  nothing in the callee prevents it from being paired up with the
  retainRV/claimRV call in the caller. It then inserts a release call if
  claimRV is attached to the call since autoreleaseRV+claimRV is
  equivalent to a release. If it cannot find an autoreleaseRV call, it
  tries to transfer the operand bundle to a function call in the callee.
  This is important since the ARC optimizer can remove the autoreleaseRV
  returning the callee result, which makes it impossible to pair it up
  with the retainRV/claimRV call in the caller. If that fails, it simply
  emits a retain call in the IR if retainRV is attached to the call and
  does nothing if claimRV is attached to it.

- SCCP refrains from replacing the return value of a call with a
  constant value if the call has the operand bundle. This ensures the
  call always has at least one user (the call to
  @llvm.objc.clang.arc.noop.use).

- This patch also fixes a bug in replaceUsesOfNonProtoConstant where
  multiple operand bundles of the same kind were being added to a call.

Future work:

- Use the operand bundle on x86-64.

- Fix the auto upgrader to convert call+retainRV/claimRV pairs into
  calls with the operand bundles.

rdar://71443534

Differential Revision: https://reviews.llvm.org/D92808
2021-03-04 11:22:30 -08:00
Hans Wennborg 0a5dd06718 Revert "[ObjC][ARC] Use operand bundle 'clang.arc.attachedcall' instead of explicitly emitting retainRV or claimRV calls in the IR"
This caused miscompiles of Chromium tests for iOS due clobbering of live
registers. See discussion on the code review for details.

> Background:
>
> This fixes a longstanding problem where llvm breaks ARC's autorelease
> optimization (see the link below) by separating calls from the marker
> instructions or retainRV/claimRV calls. The backend changes are in
> https://reviews.llvm.org/D92569.
>
> https://clang.llvm.org/docs/AutomaticReferenceCounting.html#arc-runtime-objc-autoreleasereturnvalue
>
> What this patch does to fix the problem:
>
> - The front-end adds operand bundle "clang.arc.attachedcall" to calls,
>   which indicates the call is implicitly followed by a marker
>   instruction and an implicit retainRV/claimRV call that consumes the
>   call result. In addition, it emits a call to
>   @llvm.objc.clang.arc.noop.use, which consumes the call result, to
>   prevent the middle-end passes from changing the return type of the
>   called function. This is currently done only when the target is arm64
>   and the optimization level is higher than -O0.
>
> - ARC optimizer temporarily emits retainRV/claimRV calls after the calls
>   with the operand bundle in the IR and removes the inserted calls after
>   processing the function.
>
> - ARC contract pass emits retainRV/claimRV calls after the call with the
>   operand bundle. It doesn't remove the operand bundle on the call since
>   the backend needs it to emit the marker instruction. The retainRV and
>   claimRV calls are emitted late in the pipeline to prevent optimization
>   passes from transforming the IR in a way that makes it harder for the
>   ARC middle-end passes to figure out the def-use relationship between
>   the call and the retainRV/claimRV calls (which is the cause of
>   PR31925).
>
> - The function inliner removes an autoreleaseRV call in the callee if
>   nothing in the callee prevents it from being paired up with the
>   retainRV/claimRV call in the caller. It then inserts a release call if
>   claimRV is attached to the call since autoreleaseRV+claimRV is
>   equivalent to a release. If it cannot find an autoreleaseRV call, it
>   tries to transfer the operand bundle to a function call in the callee.
>   This is important since the ARC optimizer can remove the autoreleaseRV
>   returning the callee result, which makes it impossible to pair it up
>   with the retainRV/claimRV call in the caller. If that fails, it simply
>   emits a retain call in the IR if retainRV is attached to the call and
>   does nothing if claimRV is attached to it.
>
> - SCCP refrains from replacing the return value of a call with a
>   constant value if the call has the operand bundle. This ensures the
>   call always has at least one user (the call to
>   @llvm.objc.clang.arc.noop.use).
>
> - This patch also fixes a bug in replaceUsesOfNonProtoConstant where
>   multiple operand bundles of the same kind were being added to a call.
>
> Future work:
>
> - Use the operand bundle on x86-64.
>
> - Fix the auto upgrader to convert call+retainRV/claimRV pairs into
>   calls with the operand bundles.
>
> rdar://71443534
>
> Differential Revision: https://reviews.llvm.org/D92808

This reverts commit ed4718eccb.
2021-03-03 15:51:40 +01:00
David Green 7abf7dd5ef [AArch64] Add combine for add(udot(0, x, y), z) -> udot(z, x, y).
Given a zero input for a udot, an add can be folded in to take the place
of the input, using thte addition that the instruction naturally
performs.

Differential Revision: https://reviews.llvm.org/D97188
2021-03-01 12:53:34 +00:00
Fraser Cormack 6718fda6ad [CodeGen] Fix issues with subvector intrinsic index types
This patch addresses issues arising from the fact that the index type
used for subvector insertion/extraction is inconsistent between the
intrinsics and SDNodes. The intrinsic forms require i64 whereas the
SDNodes use the type returned by SelectionDAG::getVectorIdxTy.

Rather than update the intrinsic definitions to use an overloaded index
type, this patch fixes the issue by transforming the index to the
correct type as required. Any loss of index bits going from i64 to a
smaller type is unexpected, and will be caught by an assertion in
SelectionDAG::getVectorIdxConstant.

The patch also updates the documentation for INSERT_SUBVECTOR and adds
an assertion to its creation to bring it in line with EXTRACT_SUBVECTOR.
This necessitated changes to AArch64 which was using i64 for
EXTRACT_SUBVECTOR but i32 for INSERT_SUBVECTOR. Only one test changed
its codegen after updating the backend accordingly.

Reviewed By: sdesmalen

Differential Revision: https://reviews.llvm.org/D97459
2021-03-01 10:28:21 +00:00
David Green f51b3de4e8 [AArch64] Introduce UDOT/SDOT DAG nodes
This is used to lower UDOT/SDOT instructions, as opposed to relying on
the intrinsic. Subsequent optimizations will be able to optimize them
more cleanly based on these nodes.
2021-02-23 20:31:01 +00:00
Serge Pavlov 2c4f60e45b [FPEnv][AArch64] Implement lowering of llvm.set.rounding
Differential Revision: https://reviews.llvm.org/D96836
2021-02-19 13:16:51 +07:00
Bradley Smith 8bad8a43c3 [AArch64][SVE] Add patterns to generate FMLA/FMLS/FNMLA/FNMLS/FMAD
Adjust generateFMAsInMachineCombiner to return false if SVE is present
in order to combine fmul+fadd into fma. Also add new pseudo instructions
so as to select the most appropriate of FMLA/FMAD depending on register
allocation.

Depends on D96599

Differential Revision: https://reviews.llvm.org/D96424
2021-02-18 16:55:16 +00:00
Bradley Smith 5b094bfeb3 [AArch64] Allow folding FMUL/FADD into FMA for FP16 types
isFMAFasterThanFMulAndFAdd should return true for FP16 types when
HasFullFP16 is present, since we have the instructions to handle it for
both SVE and NEON. (SVE patterns and tests will follow).

Differential Revision: https://reviews.llvm.org/D96599
2021-02-18 16:51:22 +00:00
Fraser Cormack 0176fecfbc [SVE][CodeGen] Expand SVE MULH[SU] and [SU]MUL_LOHI nodes
This patch fixes a codegen crash introduced in fde2466171, where the
DAGCombiner started generating optimized MULH[SU] or [SU]MUL_LOHI nodes
unless the target opted out. The AArch64 backend cannot currently select
any of these nodes, so ensure that they are not generated in the first
place.

This issue was raised by @huihuiz in D94501.

Reviewed By: paulwalker-arm

Differential Revision: https://reviews.llvm.org/D96849
2021-02-18 10:06:24 +00:00
Florian Hahn 211147c5ba
[AArch64] Convert CMP/SELECT sign patterns to OR & ASR.
ICMP & SELECT patterns extracting the sign of a value can be simplified
to OR & ASR (see  https://alive2.llvm.org/ce/z/Xx4iZ0).

This does not save any instructions in IR, but it is profitable on
AArch64, because we need at least 2 extra instructions to materialize 1
and -1 for the SELECT.

The improvements result in ~5% speedups on loops of the form

    static int sign_of(int x) {
      if (x < 0) return -1;
      return 1;
    }

    void foo(const int *x, int *res, int cnt) {
      for (int i=0;i<cnt;i++)
        res[i] = sign_of(x[i]);
    }

Reviewed By: dmgreen

Differential Revision: https://reviews.llvm.org/D96596
2021-02-16 17:17:34 +00:00
Caroline Concatto 2d728bbff5 [CodeGen][SelectionDAG]Add new intrinsic experimental.vector.reverse
This patch adds  a new intrinsic experimental.vector.reduce that takes a single
vector and returns a vector of matching type but with the original lane order
 reversed. For example:

```
vector.reverse(<A,B,C,D>) ==> <D,C,B,A>
```

The new intrinsic supports fixed and scalable vectors types.
The fixed-width vector relies on shufflevector to maintain existing behaviour.
Scalable vector uses the new ISD node - VECTOR_REVERSE.

This new intrinsic is one of the named shufflevector intrinsics proposed on the
mailing-list in the RFC at [1].

Patch by Paul Walker (@paulwalker-arm).

[1] https://lists.llvm.org/pipermail/llvm-dev/2020-November/146864.html

Differential Revision: https://reviews.llvm.org/D94883
2021-02-15 13:39:43 +00:00
Akira Hatanaka ed4718eccb [ObjC][ARC] Use operand bundle 'clang.arc.attachedcall' instead of
explicitly emitting retainRV or claimRV calls in the IR

Background:

This fixes a longstanding problem where llvm breaks ARC's autorelease
optimization (see the link below) by separating calls from the marker
instructions or retainRV/claimRV calls. The backend changes are in
https://reviews.llvm.org/D92569.

https://clang.llvm.org/docs/AutomaticReferenceCounting.html#arc-runtime-objc-autoreleasereturnvalue

What this patch does to fix the problem:

- The front-end adds operand bundle "clang.arc.attachedcall" to calls,
  which indicates the call is implicitly followed by a marker
  instruction and an implicit retainRV/claimRV call that consumes the
  call result. In addition, it emits a call to
  @llvm.objc.clang.arc.noop.use, which consumes the call result, to
  prevent the middle-end passes from changing the return type of the
  called function. This is currently done only when the target is arm64
  and the optimization level is higher than -O0.

- ARC optimizer temporarily emits retainRV/claimRV calls after the calls
  with the operand bundle in the IR and removes the inserted calls after
  processing the function.

- ARC contract pass emits retainRV/claimRV calls after the call with the
  operand bundle. It doesn't remove the operand bundle on the call since
  the backend needs it to emit the marker instruction. The retainRV and
  claimRV calls are emitted late in the pipeline to prevent optimization
  passes from transforming the IR in a way that makes it harder for the
  ARC middle-end passes to figure out the def-use relationship between
  the call and the retainRV/claimRV calls (which is the cause of
  PR31925).

- The function inliner removes an autoreleaseRV call in the callee if
  nothing in the callee prevents it from being paired up with the
  retainRV/claimRV call in the caller. It then inserts a release call if
  claimRV is attached to the call since autoreleaseRV+claimRV is
  equivalent to a release. If it cannot find an autoreleaseRV call, it
  tries to transfer the operand bundle to a function call in the callee.
  This is important since the ARC optimizer can remove the autoreleaseRV
  returning the callee result, which makes it impossible to pair it up
  with the retainRV/claimRV call in the caller. If that fails, it simply
  emits a retain call in the IR if retainRV is attached to the call and
  does nothing if claimRV is attached to it.

- SCCP refrains from replacing the return value of a call with a
  constant value if the call has the operand bundle. This ensures the
  call always has at least one user (the call to
  @llvm.objc.clang.arc.noop.use).

- This patch also fixes a bug in replaceUsesOfNonProtoConstant where
  multiple operand bundles of the same kind were being added to a call.

Future work:

- Use the operand bundle on x86-64.

- Fix the auto upgrader to convert call+retainRV/claimRV pairs into
  calls with the operand bundles.

rdar://71443534

Differential Revision: https://reviews.llvm.org/D92808
2021-02-12 09:51:57 -08:00
Nico Weber de1966e542 Revert "[ObjC][ARC] Use operand bundle 'clang.arc.rv' instead of explicitly"
This reverts commit 4a64d8fe39.
Makes clang crash when buildling trivial iOS programs, see comment
after https://reviews.llvm.org/D92808#2551401
2021-02-09 11:06:32 -05:00
Akira Hatanaka 4a64d8fe39 [ObjC][ARC] Use operand bundle 'clang.arc.rv' instead of explicitly
emitting retainRV or claimRV calls in the IR

This reapplies 3fe3946d9a without the
changes made to lib/IR/AutoUpgrade.cpp, which was violating layering.

Original commit message:

Background:

This patch makes changes to the front-end and middle-end that are
needed to fix a longstanding problem where llvm breaks ARC's autorelease
optimization (see the link below) by separating calls from the marker
instructions or retainRV/claimRV calls. The backend changes are in
https://reviews.llvm.org/D92569.

https://clang.llvm.org/docs/AutomaticReferenceCounting.html#arc-runtime-objc-autoreleasereturnvalue

What this patch does to fix the problem:

- The front-end adds operand bundle "clang.arc.rv" to calls, which
  indicates the call is implicitly followed by a marker instruction and
  an implicit retainRV/claimRV call that consumes the call result. In
  addition, it emits a call to @llvm.objc.clang.arc.noop.use, which
  consumes the call result, to prevent the middle-end passes from changing
  the return type of the called function. This is currently done only when
  the target is arm64 and the optimization level is higher than -O0.

- ARC optimizer temporarily emits retainRV/claimRV calls after the calls
  with the operand bundle in the IR and removes the inserted calls after
  processing the function.

- ARC contract pass emits retainRV/claimRV calls after the call with the
  operand bundle. It doesn't remove the operand bundle on the call since
  the backend needs it to emit the marker instruction. The retainRV and
  claimRV calls are emitted late in the pipeline to prevent optimization
  passes from transforming the IR in a way that makes it harder for the
  ARC middle-end passes to figure out the def-use relationship between
  the call and the retainRV/claimRV calls (which is the cause of
  PR31925).

- The function inliner removes an autoreleaseRV call in the callee if
  nothing in the callee prevents it from being paired up with the
  retainRV/claimRV call in the caller. It then inserts a release call if
  the call is annotated with claimRV since autoreleaseRV+claimRV is
  equivalent to a release. If it cannot find an autoreleaseRV call, it
  tries to transfer the operand bundle to a function call in the callee.
  This is important since ARC optimizer can remove the autoreleaseRV
  returning the callee result, which makes it impossible to pair it up
  with the retainRV/claimRV call in the caller. If that fails, it simply
  emits a retain call in the IR if the implicit call is a call to
  retainRV and does nothing if it's a call to claimRV.

Future work:

- Use the operand bundle on x86-64.

- Fix the auto upgrader to convert call+retainRV/claimRV pairs into
  calls annotated with the operand bundles.

rdar://71443534

Differential Revision: https://reviews.llvm.org/D92808
2021-02-05 06:09:42 -08:00
Akira Hatanaka 2fbbb18c1d Revert "[ObjC][ARC] Use operand bundle 'clang.arc.rv' instead of explicitly"
This reverts commit 3fe3946d9a.

The commit violates layering by including a header from Analysis in
lib/IR/AutoUpgrade.cpp.
2021-02-05 06:00:05 -08:00
Akira Hatanaka 3fe3946d9a [ObjC][ARC] Use operand bundle 'clang.arc.rv' instead of explicitly
emitting retainRV or claimRV calls in the IR

Background:

This patch makes changes to the front-end and middle-end that are
needed to fix a longstanding problem where llvm breaks ARC's autorelease
optimization (see the link below) by separating calls from the marker
instructions or retainRV/claimRV calls. The backend changes are in
https://reviews.llvm.org/D92569.

https://clang.llvm.org/docs/AutomaticReferenceCounting.html#arc-runtime-objc-autoreleasereturnvalue

What this patch does to fix the problem:

- The front-end adds operand bundle "clang.arc.rv" to calls, which
  indicates the call is implicitly followed by a marker instruction and
  an implicit retainRV/claimRV call that consumes the call result. In
  addition, it emits a call to @llvm.objc.clang.arc.noop.use, which
  consumes the call result, to prevent the middle-end passes from changing
  the return type of the called function. This is currently done only when
  the target is arm64 and the optimization level is higher than -O0.

- ARC optimizer temporarily emits retainRV/claimRV calls after the calls
  with the operand bundle in the IR and removes the inserted calls after
  processing the function.

- ARC contract pass emits retainRV/claimRV calls after the call with the
  operand bundle. It doesn't remove the operand bundle on the call since
  the backend needs it to emit the marker instruction. The retainRV and
  claimRV calls are emitted late in the pipeline to prevent optimization
  passes from transforming the IR in a way that makes it harder for the
  ARC middle-end passes to figure out the def-use relationship between
  the call and the retainRV/claimRV calls (which is the cause of
  PR31925).

- The function inliner removes an autoreleaseRV call in the callee if
  nothing in the callee prevents it from being paired up with the
  retainRV/claimRV call in the caller. It then inserts a release call if
  the call is annotated with claimRV since autoreleaseRV+claimRV is
  equivalent to a release. If it cannot find an autoreleaseRV call, it
  tries to transfer the operand bundle to a function call in the callee.
  This is important since ARC optimizer can remove the autoreleaseRV
  returning the callee result, which makes it impossible to pair it up
  with the retainRV/claimRV call in the caller. If that fails, it simply
  emits a retain call in the IR if the implicit call is a call to
  retainRV and does nothing if it's a call to claimRV.

Future work:

- Use the operand bundle on x86-64.

- Fix the auto upgrader to convert call+retainRV/claimRV pairs into
  calls annotated with the operand bundles.

rdar://71443534

Differential Revision: https://reviews.llvm.org/D92808
2021-02-05 05:55:18 -08:00
Craig Topper 11ef356d9e [TargetLowering] Use Align in allowsMisalignedMemoryAccesses.
Reviewed By: arsenm

Differential Revision: https://reviews.llvm.org/D96097
2021-02-04 19:22:06 -08:00
Kerry McLaughlin 9b4fcfaa9e [SVE][CodeGen] Remove performMaskedGatherScatterCombine
The AArch64 DAG combine added by D90945 & D91433 extends the index
of a scalable masked gather or scatter to i32 if necessary.

This patch removes the combine and instead adds shouldExtendGSIndex, which
is used by visitMaskedGather/Scatter in SelectionDAGBuilder to query whether
the index should be extended before calling getMaskedGather/Scatter.

Reviewed By: david-arm

Differential Revision: https://reviews.llvm.org/D94525
2021-02-01 14:10:00 +00:00
Kazu Hirata 7925aa091d [llvm] Populate SmallVector at construction time (NFC) 2021-01-28 22:21:14 -08:00
Richard Smith 925ae8c790 Revert "[ObjC][ARC] Annotate calls with attributes instead of emitting retainRV"
This reverts commit 53176c1680, which
introduceed a layering violation. LLVM's IR library can't include
headers from Analysis.
2021-01-25 13:53:38 -08:00
Akira Hatanaka 53176c1680 [ObjC][ARC] Annotate calls with attributes instead of emitting retainRV
or claimRV calls in the IR

Background:

This patch makes changes to the front-end and middle-end that are
needed to fix a longstanding problem where llvm breaks ARC's autorelease
optimization (see the link below) by separating calls from the marker
instructions or retainRV/claimRV calls. The backend changes are in
https://reviews.llvm.org/D92569.

https://clang.llvm.org/docs/AutomaticReferenceCounting.html#arc-runtime-objc-autoreleasereturnvalue

What this patch does to fix the problem:

- The front-end annotates calls with attribute "clang.arc.rv"="retain"
  or "clang.arc.rv"="claim", which indicates the call is implicitly
  followed by a marker instruction and a retainRV/claimRV call that
  consumes the call result. This is currently done only when the target
  is arm64 and the optimization level is higher than -O0.

- ARC optimizer temporarily emits retainRV/claimRV calls after the
  annotated calls in the IR and removes the inserted calls after
  processing the function.

- ARC contract pass emits retainRV/claimRV calls after the annotated
  calls. It doesn't remove the attribute on the call since the backend
  needs it to emit the marker instruction. The retainRV/claimRV calls
  are emitted late in the pipeline to prevent optimization passes from
  transforming the IR in a way that makes it harder for the ARC
  middle-end passes to figure out the def-use relationship between the
  call and the retainRV/claimRV calls (which is the cause of PR31925).

- The function inliner removes the autoreleaseRV call in the callee that
  returns the result if nothing in the callee prevents it from being
  paired up with the calls annotated with "clang.arc.rv"="retain/claim"
  in the caller. If the call is annotated with "claim", a release call
  is inserted since autoreleaseRV+claimRV is equivalent to a release. If
  it cannot find an autoreleaseRV call, it tries to transfer the
  attributes to a function call in the callee. This is important since
  ARC optimizer can remove the autoreleaseRV call returning the callee
  result, which makes it impossible to pair it up with the retainRV or
  claimRV call in the caller. If that fails, it simply emits a retain
  call in the IR if the call is annotated with "retain" and does nothing
  if it's annotated with "claim".

- This patch teaches dead argument elimination pass not to change the
  return type of a function if any of the calls to the function are
  annotated with attribute "clang.arc.rv". This is necessary since the
  pass can incorrectly determine nothing in the IR uses the function
  return, which can happen since the front-end no longer explicitly
  emits retainRV/claimRV calls in the IR, and change its return type to
  'void'.

Future work:

- Use the attribute on x86-64.

- Fix the auto upgrader to convert call+retainRV/claimRV pairs into
  calls annotated with the attributes.

rdar://71443534

Differential Revision: https://reviews.llvm.org/D92808
2021-01-25 11:57:08 -08:00
QingShan Zhang ffc3e800c6 [NFC] [DAGCombine] Correct the result for sqrt even the iteration is zero
For now, we correct the result for sqrt if iteration > 0. This doesn't make
sense as they are not strict relative.

Reviewed By: dmgreen, spatel, RKSimon

Differential Revision: https://reviews.llvm.org/D94480
2021-01-25 04:02:44 +00:00
Kazu Hirata cfa241680f [llvm] Don't include StringSwitch.h where unnecessary (NFC) 2021-01-21 19:59:48 -08:00
Simon Pilgrim 69bc0990a9 [DAGCombiner] Enable SimplifyDemandedBits vector support for TRUNCATE (REAPPLIED).
Add DemandedElts support inside the TRUNCATE analysis.

REAPPLIED - this was reverted by @hans at rGa51226057fc3 due to an issue with vector shift amount types, which was fixed in rG935bacd3a724 and an additional test case added at rG0ca81b90d19d

Differential Revision: https://reviews.llvm.org/D56387
2021-01-21 13:01:34 +00:00
Hans Wennborg a51226057f Revert "[DAGCombiner] Enable SimplifyDemandedBits vector support for TRUNCATE"
It caused "Vector shift amounts must be in the same as their first arg"
asserts in Chromium builds. See the code review for repro instructions.

> Add DemandedElts support inside the TRUNCATE analysis.
>
> Differential Revision: https://reviews.llvm.org/D56387

This reverts commit cad4275d69.
2021-01-20 20:06:55 +01:00
Simon Pilgrim cad4275d69 [DAGCombiner] Enable SimplifyDemandedBits vector support for TRUNCATE
Add DemandedElts support inside the TRUNCATE analysis.

Differential Revision: https://reviews.llvm.org/D56387
2021-01-20 15:39:58 +00:00
Amanieu d'Antras 21bfd068b3 [AArch64] Add support for the GNU ILP32 ABI
Add the aarch64[_be]-*-gnu_ilp32 targets to support the GNU ILP32 ABI for AArch64.

The needed codegen changes were mostly already implemented in D61259, which added support for the watchOS ILP32 ABI. The main changes are:
- Wiring up the new target to enable ILP32 codegen and MC.
- ILP32 va_list support.
- ILP32 TLSDESC relocation support.

There was existing MC support for ELF ILP32 relocations from D25159 which could be enabled by passing "-target-abi ilp32" to llvm-mc. This was changed to check for "gnu_ilp32" in the target triple instead. This shouldn't cause any issues since the existing support was slightly broken: it was generating ELF64 objects instead of the ELF32 object files expected by the GNU ILP32 toolchain.

This target has been tested by running the full rustc testsuite on a big-endian ILP32 system based on the GCC ILP32 toolchain.

Reviewed By: kristof.beyls

Differential Revision: https://reviews.llvm.org/D94143
2021-01-20 13:34:47 +00:00
Nicholas Guy 16bf02c3a1 Reland "[AArch64] Attempt to sink mul operands""
This relands dda60035e9,
which was reverted by dbaa6a1858
2021-01-18 16:00:22 +00:00
Nicholas Guy f5fcbe4e3c [AArch64] Further restricts when a dup(*ext) can be rearranged
In most cases, the dup(*ext) pattern can be rearranged to perform
the extension on the vector side, allowing for further vector-specific
optimisations to be made. However the initial checks for this conversion
were insufficient, allowing invalid encodings to be attempted (causing
compilation to fail).

Differential Revision: https://reviews.llvm.org/D94778
2021-01-18 16:00:21 +00:00