Commit Graph

820 Commits

Author SHA1 Message Date
Dávid Bolvanský 324d641b75 [InstCombine] Enhance deduction of alignment for aligned_alloc
This patch improves https://reviews.llvm.org/D76971 (Deduce attributes for aligned_alloc in InstCombine) and implements "TODO" item mentioned in the review of that patch.

> The function aligned_alloc() is the same as memalign(), except for the added restriction that size should be a multiple of alignment.

Currently, we simply bail out if we see a non-constant size - change that.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D100785
2021-04-20 02:04:18 +02:00
Yuanfang Chen c5fda0e662 Reland "Revert "[InstCombine] when calling conventions are compatible, don't convert the call to undef idiom""
This reverts commit a3fabc79ae (relands
f4d682d6ce with fix for the compile-time
regression issue).
2021-04-12 14:50:54 -07:00
Nikita Popov a3fabc79ae Revert "[InstCombine] when calling conventions are compatible, don't convert the call to undef idiom"
This reverts commit f4d682d6ce.

This caused a significant compile-time regression:
https://llvm-compile-time-tracker.com/compare.php?from=4b7bad9eaea2233521a94f6b096aaa88dc584e23&to=f4d682d6ce6c5b3a41a0acf297507c82f5c21eef&stat=instructions

Possibly this is due to overeager parsing of target triples.
2021-04-12 22:55:59 +02:00
Yuanfang Chen f4d682d6ce [InstCombine] when calling conventions are compatible, don't convert the call to undef idiom
D24453 enabled libcalls simplication for ARM PCS. This may cause
caller/callee calling conventions mismatch in some situations such as
LTO. This patch makes instcombine aware that the compatible calling
conventions differences are benign (not emitting undef idom).

Differential Revision: https://reviews.llvm.org/D99773
2021-04-12 09:32:23 -07:00
Sanjay Patel 84cdccc9dc [InstCombine] try to eliminate an instruction in min/max -> abs fold
As suggested in the review thread for 5094e12 and seen in the
motivating example from https://llvm.org/PR49885, it's not
clear if we have a way to create the optimal code without
this heuristic.
2021-04-09 10:34:03 -04:00
Sanjay Patel 5094e1279e [InstCombine] fold min/max intrinsic with negated operand to abs
The smax case shows up in https://llvm.org/PR49885 .
The others seem unlikely, but we might as well try
for uniformity (although that could mean an extra
instruction to create "nabs").

smax -- https://alive2.llvm.org/ce/z/8yYaGy
smin -- https://alive2.llvm.org/ce/z/0_7zc_
umax -- https://alive2.llvm.org/ce/z/EcsZWs
umin -- https://alive2.llvm.org/ce/z/Xw6WvB
2021-04-08 14:37:39 -04:00
Philip Reames 9ef6aa020b Plumb AssumeInst through operand bundle apis [nfc]
Follow up to a6d2a8d6f5.  This covers all the public interfaces of the bundle related code.  I tried to cleanup the internals where the changes were obvious, but there's definitely more room for improvement.
2021-04-06 12:53:53 -07:00
Philip Reames a6d2a8d6f5 Add a subclass of IntrinsicInst for llvm.assume [nfc]
Add the subclass, update a few places which check for the intrinsic to use idiomatic dyn_cast, and update the public interface of AssumptionCache to use the new class.  A follow up change will do the same for the newer assumption query/bundle mechanisms.
2021-04-06 11:16:22 -07:00
Sanjay Patel c0645f1324 [InstCombine] fold popcount of exactly one bit to shift
This is discussed in https://llvm.org/PR48999 ,
but it does not solve that request.

The difference in the vector test shows that some
other logic transform is limited to scalar types.
2021-04-04 11:43:49 -04:00
Sanjay Patel 1462bdf1b9 [InstCombine] fold abs(srem X, 2)
This is a missing optimization based on an example in:
https://llvm.org/PR49763

As noted there and the test here, we could add a more
general fold if that is shown useful.

https://alive2.llvm.org/ce/z/xEHdTv
https://alive2.llvm.org/ce/z/97dcY5
2021-03-31 11:29:20 -04:00
Sanjay Patel 2986a9c7e2 [InstCombine] canonicalize 'not' op after min/max intrinsic
This is another step towards parity between existing select
transforms and min/max intrinsics (D98152)..

The existing 'not' folds around select are complicated, so
it's likely that we will need to enhance this, but this
should be a safe step.
2021-03-09 11:33:28 -05:00
Sanjay Patel 41b9209a12 [InstCombine] fold min/max intrinsics with not ops
This is a partial translation of the existing select-based
folds. We need to recreate several different transforms to
avoid regressions as noted in D98152.

https://alive2.llvm.org/ce/z/teuZ_J
2021-03-09 08:55:48 -05:00
Alexey Bataev 04ba80ca4d [Instcombiner]Improve emission of logical or/and reductions.
For logical or/and reductions we emit regular intrinsics @llvm.vector.reduce.or/and.vxi1 calls.
These intrinsics are not effective for the logical or/and reductions,
especially if the optimizer is able to emit short circuit versions of
the scalar or/and instructions and vector code gets less effective than
the scalar version.
Instead, or reduction for i1 can be represented as:
```
%val = bitcast <ReduxWidth x i1> to iReduxWidth
%res = cmp ne iReduxWidth %val, 0
```
and reduction for i1 can be represented as:
```
%val = bitcast <ReduxWidth x i1> to iReduxWidth
%res = cmp eq iReduxWidth %val, 11111
```
This improves perfromance of the vector code significantly and make it
to outperform short circuit scalar code.

Part of D57059.

Differential Revision: https://reviews.llvm.org/D97406
2021-03-04 08:01:02 -08:00
Serguei Katkov a0ff0f30df [InstCombine] Move statepoint intrinsic handling from visitCall to visitCallBase
statepoint intrinsic can be used in invoke context,
so it should be handled in visitCallBase to cover both call and invoke.

Reviewers: reames, dantrushin
Reviewed By: reames
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D97833
2021-03-04 11:00:22 +07:00
Philip Reames 99f5417346 Sink routine for replacing a operand bundle to CallBase [NFC]
We had equivalent code for both CallInst and InvokeInst, but never cared about the result type.
2021-03-03 12:07:55 -08:00
Nikita Popov 70e3c9a8b6 [BasicAA] Always strip single-argument phi nodes
We can always look through single-argument (LCSSA) phi nodes when
performing alias analysis. getUnderlyingObject() already does this,
but stripPointerCastsAndInvariantGroups() does not. We still look
through these phi nodes with the usual aliasPhi() logic, but
sometimes get sub-optimal results due to the restrictions on value
equivalence when looking through arbitrary phi nodes. I think it's
generally beneficial to keep the underlying object logic and the
pointer cast stripping logic in sync, insofar as it is possible.

With this patch we get marginally better results:

  aa.NumMayAlias | 5010069 | 5009861
  aa.NumMustAlias | 347518 | 347674
  aa.NumNoAlias | 27201336 | 27201528
  ...
  licm.NumPromoted | 1293 | 1296

I've renamed the relevant strip method to stripPointerCastsForAliasAnalysis(),
as we're past the point where we can explicitly spell out everything
that's getting stripped.

Differential Revision: https://reviews.llvm.org/D96668
2021-02-18 23:07:50 +01:00
Tyker 642e9225c6 reland [InstCombine] convert assumes to operand bundles
Instcombine will convert the nonnull and alignment assumption that use the boolean condtion
to an assumption that uses the operand bundles when knowledge retention is enabled.

Differential Revision: https://reviews.llvm.org/D82703
2021-02-13 13:03:11 +01:00
Tyker 5652e192fc Revert "[InstCombine] convert assumes to operand bundles"
This reverts commit 5eb2e994f9.
2021-02-10 01:32:00 +01:00
Tyker 5eb2e994f9 [InstCombine] convert assumes to operand bundles
Instcombine will convert the nonnull and alignment assumption that use the boolean condtion
to an assumption that uses the operand bundles when knowledge retention is enabled.

Differential Revision: https://reviews.llvm.org/D82703
2021-02-09 19:33:53 +01:00
Sanjay Patel 0ce2920f17 [InstCombine] try to narrow min/max intrinsics with constant operand
The constant trunc/ext may not be the optimal pre-condition,
but I think that handles the common cases.

Example of Alive2 proof:
https://alive2.llvm.org/ce/z/sREeLC

This is another step towards canonicalizing to the intrinsics.
Narrowing was identified as source of potential regression for
abs(), so we need to handle this for min/max - see:
https://llvm.org/PR48816

If this is not enough, we could process intrinsics in
the trunc-driven matching in canEvaluateTruncated().
2021-02-01 13:44:13 -05:00
Valery N Dmitriev 716b9dd0d8 [InstCombine] Preserve FMF for powi simplifications.
Differential Revision: https://reviews.llvm.org/D95455
2021-01-26 13:26:06 -08:00
Sanjay Patel 09a136bcc6 [InstCombine] narrow min/max intrinsics with extended inputs
We can sink extends after min/max if they match and would
not change the sign-interpreted compare. The only combo
that doesn't work is zext+smin/smax because the zexts
could change a negative number into positive:
https://alive2.llvm.org/ce/z/D6sz6J

Sext+umax/umin works:

  define i32 @src(i8 %x, i8 %y) {
  %0:
    %sx = sext i8 %x to i32
    %sy = sext i8 %y to i32
    %m = umax i32 %sx, %sy
    ret i32 %m
  }
  =>
  define i32 @tgt(i8 %x, i8 %y) {
  %0:
    %m = umax i8 %x, %y
    %r = sext i8 %m to i32
    ret i32 %r
  }
  Transformation seems to be correct!
2021-01-25 07:52:50 -05:00
Sanjay Patel 411c144e4c [InstCombine] narrow abs with sign-extended input
In the motivating cases from https://llvm.org/PR48816 ,
we have a trailing trunc. But that is not required to
reduce the abs width:
https://alive2.llvm.org/ce/z/ECaz-p
...as long as we clear the int-min-is-poison bit (nsw).

We have some existing tests that are affected, and I'm
not sure what the overall implications are, but in general
we favor narrowing operations over preserving nsw/nuw.

If that causes problems, we could restrict this transform
based on type (shouldChangeType() and/or vector vs. scalar).

Differential Revision: https://reviews.llvm.org/D95235
2021-01-22 13:36:04 -05:00
Nikita Popov 23390e7a13 [InstCombine] Handle logical and/or in assume optimization
assume(a && b) can be converted to assume(a); assume(b) even if
the condition is logical. Same for assume(!(a || b)).
2021-01-12 22:36:40 +01:00
Juneyoung Lee 9b29610228 Use unary CreateShuffleVector if possible
As mentioned in D93793, there are quite a few places where unary `IRBuilder::CreateShuffleVector(X, Mask)` can be used
instead of `IRBuilder::CreateShuffleVector(X, Undef, Mask)`.
Let's update them.

Actually, it would have been more natural if the patches were made in this order:
(1) let them use unary CreateShuffleVector first
(2) update IRBuilder::CreateShuffleVector to use poison as a placeholder value (D93793)

The order is swapped, but in terms of correctness it is still fine.

Reviewed By: spatel

Differential Revision: https://reviews.llvm.org/D93923
2020-12-30 22:36:08 +09:00
Roman Lebedev b3021a72a6
[IR][InstCombine] Add m_ImmConstant(), that matches on non-ConstantExpr constants, and use it
A pattern to ignore ConstantExpr's is quite common, since they frequently
lead into infinite combine loops, so let's make writing it easier.
2020-12-24 21:20:47 +03:00
Joe Ellis 80c33de2d3 [SelectionDAG] Add llvm.vector.{extract,insert} intrinsics
This commit adds two new intrinsics.

- llvm.experimental.vector.insert: used to insert a vector into another
  vector starting at a given index.

- llvm.experimental.vector.extract: used to extract a subvector from a
  larger vector starting from a given index.

The codegen work for these intrinsics has already been completed; this
commit is simply exposing the existing ISD nodes to LLVM IR.

Reviewed By: cameron.mcinally

Differential Revision: https://reviews.llvm.org/D91362
2020-12-09 11:08:41 +00:00
Florian Hahn 53f4c4b2cc [InstCombine] Do not introduce bitcasts for swifterror arguments.
The following constraints hold for swifterror values:

    A swifterror value (either the parameter or the alloca) can only
    be loaded and stored from, or used as a swifterror argument.

This patch updates instcombine to not try to convert a bitcast of a
function into a bitcast of a swifterror argument.

Reviewed By: rjmccall

Differential Revision: https://reviews.llvm.org/D90258
2020-10-28 21:52:12 +00:00
Simon Pilgrim 60ba9233d1 Revert rG25a97c3a43d7 - "[InstCombine] visitCallInst - retain undefs in vector funnel shift amounts"
This reverts commit 25a97c3a43.

We have other constant folds that fold undef funnel shift amounts to 0 - so we need to be consistent.

If we end up with regressions where we lose a splat shift amount pattern we'll have to investigate other canonicalizations, but matchFunnelShift currently protects us from that.
2020-10-14 18:14:37 +01:00
Simon Pilgrim 25a97c3a43 [InstCombine] visitCallInst - retain undefs in vector funnel shift amounts
By always performing a modulo on the shift amount constants this was causing undef amounts being replaced with zero, meaning we were losing funnel shift by splat (with undef) patterns.

Tweaked the shift amount bounds check to support (passthrough) undefs, and use Constant::mergeUndefsWith to preserve the undefs after folding.
2020-10-14 14:38:21 +01:00
Simon Pilgrim 323d08e50a [InstCombine] Fix bswap(trunc(bswap(x))) -> trunc(lshr(x, c)) vector support
Use getScalarSizeInBits not getPrimitiveSizeInBits to determine the shift value at the element level.
2020-09-30 16:01:08 +01:00
Sanjay Patel 0527c8749b [InstCombine] ease alignment restriction for converting masked load to normal load
I think we initially made this fold conservative to be safer, but we do not
need the alignment attribute/metadata limitation because the masked load
intrinsic itself specifies the alignment. A normal vector load is better for
IR transforms and should be no worse in codegen than the masked alternative.
If it is worse for some target, the backend can reverse this transform.

Differential Revision: https://reviews.llvm.org/D88505
2020-09-29 15:26:22 -04:00
Tyker 78de7297ab Reland [AssumeBundles] Use operand bundles to encode alignment assumptions
NOTE: There is a mailing list discussion on this: http://lists.llvm.org/pipermail/llvm-dev/2019-December/137632.html

Complemantary to the assumption outliner prototype in D71692, this patch
shows how we could simplify the code emitted for an alignemnt
assumption. The generated code is smaller, less fragile, and it makes it
easier to recognize the additional use as a "assumption use".

As mentioned in D71692 and on the mailing list, we could adopt this
scheme, and similar schemes for other patterns, without adopting the
assumption outlining.
2020-09-12 15:36:06 +02:00
Christopher Tetreault 7ddfd9b3eb [SVE] Bail from VectorUtils heuristics for scalable vectors
Bail from maskIsAllZeroOrUndef and maskIsAllOneOrUndef prior to iterating over the number of
elements for scalable vectors.

Assert that the mask type is not scalable in possiblyDemandedEltsInMask .

Assert that the types are correct in all three functions.

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D87424
2020-09-10 12:29:37 -07:00
Nikita Popov e97f3b1b43 [InstCombine] Fold abs of known negative operand
If we know that the abs operand is known negative, we can replace
it with a neg.

To avoid computing known bits twice, I've removed the fold for the
non-negative case from InstSimplify. Both the non-negative and the
negative case are handled by InstCombine now, with one known bits call.

Differential Revision: https://reviews.llvm.org/D87196
2020-09-08 20:14:35 +02:00
Nikita Popov 4892d3a198 [InstCombine] Fold abs with dominating condition
Similar to D87168, but for abs. If we have a dominating x >= 0
condition, then we know that abs(x) is x. This fold is in
InstCombine, because we need to create a sub instruction for
the x < 0 case.

Differential Revision: https://reviews.llvm.org/D87184
2020-09-05 16:18:35 +02:00
Nikita Popov 10cb23c6ca [InstCombine] Fold cttz of abs intrinsic
Same as the existing fold for SPF_ABS. We don't need to explicitly
handle the NABS variant, as we'll first fold away the neg in that
case.
2020-09-05 12:25:41 +02:00
Sanjay Patel 2391a34f9f [InstCombine] canonicalize all commutative intrinsics with constant arg 2020-09-03 12:42:04 -04:00
Christopher Tetreault 640f20b0c7 [SVE] Remove calls to VectorType::getNumElements from InstCombine
Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D82237
2020-08-31 12:59:10 -07:00
Roman Lebedev bd12113f57
[NFC][InstCombine] Fix some comments: the code already uses IC::replaceInstUsesWith() 2020-08-29 15:10:14 +03:00
Sanjay Patel 6a44edb8da [InstCombine] fold abs of select with negated op (PR39474)
Similar to the existing transform - peek through a select
to match a value and its negation.

https://alive2.llvm.org/ce/z/MXi5KG

  define i8 @src(i1 %b, i8 %x) {
  %0:
    %neg = sub i8 0, %x
    %sel = select i1 %b, i8 %x, i8 %neg
    %abs = abs i8 %sel, 1
    ret i8 %abs
  }
  =>
  define i8 @tgt(i1 %b, i8 %x) {
  %0:
    %abs = abs i8 %x, 1
    ret i8 %abs
  }
  Transformation seems to be correct!
2020-08-24 07:37:55 -04:00
Serguei Katkov 9e362bb0eb [InstCombine] Remove unused entries in gc-live bundle of statepoint
If some of gc live value are not used in gc.relocate we can remove them
from gc-live bundle of statepoint instruction.

Also the CL removes duplicated Values in gc-live bundle.

Reviewers: reames, dantrushin
Reviewed By: dantrushin
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D85959
2020-08-22 01:36:22 +07:00
Serguei Katkov 63d9d56a55 [InstCombine] Move handling of gc.relocate in a gc.statepoint
The only def for gc.relocate is a gc.statepoint. But real dependency is not
described by def-use chain. Instead this dependency is encoded by indecies
of operands in gc-live bundle of statepoint as integer constants in gc.relocate.

InstCombine operates by def-use chain. As a result when value in gc-live bundle
is simplified the gc.statepoint itself is not simplified but it might simplify dependent
gc.relocates. To trigger the optimization of gc.relocate we now unconditionally trigger
check of all dependent gc.relocates by adding them to worklist.

This CL handles of gc.relocates as process of gc.statepoint optimization considering
gc.statepoint and related gc.relocate as whole entity.

Reviewers: reames, dantrushin
Reviewed By: reames
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D85954
2020-08-21 23:44:23 +07:00
Sanjay Patel 139da9c4d7 [InstCombine] fold fabs of select with negated operand
This is the FP example shown in:
https://bugs.llvm.org/PR39474
2020-08-18 09:23:07 -04:00
Sanjay Patel 3ffb751f3d [InstCombine] fold copysign with fabs/fneg operand
We already get this in the backend, but we need to do
it in IR too to consistently get yet more copysign
transforms.
2020-08-16 08:53:47 -04:00
Sanjay Patel 3fed67b7e6 [InstCombine] reduce code duplication; NFC 2020-08-16 08:53:47 -04:00
Serguei Katkov 98ba0a5ffe [InstCombine] Handle gc.relocate(null) in one iteration
InstCombine adds users of transformed instruction to working list to
process on the same iteration. However gc.relocate may have a hidden
user (next gc.relocate) which is connected through gc.statepoint intrinsic and
there is no direct def-use chain between them.

In this case if the next gc.relocation is already processed it will not be added
to worklist and will not be able to be processed on the same iteration.
Let's we have the following case:
A = gc.relocate(null)
B = statepoint(A)
C = gc.relocate(B, hidden(A))
If C is already considered then after replacement of A with null, statepoint B
instruction will be added to the queue but not C.
C can be processed only on the next iteration.

If the chain of relocation is pretty long the many iteration may be required.
This change is to reduce the number of iteration to meet the latest changes
related to reducing infinite loop threshold.

This is a quick (not best) fix. In the follow up patches I plan to move gc relocation
handling into statepoint handler. This should also help to remove unused gc live
entries in statepoint bundle.

Reviewers: reames, dantrushin
Reviewed By: reames
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D75598
2020-08-13 23:16:27 +07:00
Craig Topper 4a19e6156e [InstCombine] Fold abs(-x) -> abs(x)
Negating the input doesn't matter. I left a FIXME to copy the nsw flag if its present on the neg but not on the abs.

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D85055
2020-08-01 13:25:00 -07:00
Sebastian Neubauer 2a6c871596 [InstCombine] Move target-specific inst combining
For a long time, the InstCombine pass handled target specific
intrinsics. Having target specific code in general passes was noted as
an area for improvement for a long time.

D81728 moves most target specific code out of the InstCombine pass.
Applying the target specific combinations in an extra pass would
probably result in inferior optimizations compared to the current
fixed-point iteration, therefore the InstCombine pass resorts to newly
introduced functions in the TargetTransformInfo when it encounters
unknown intrinsics.
The patch should not have any effect on generated code (under the
assumption that code never uses intrinsics from a foreign target).

This introduces three new functions:
TargetTransformInfo::instCombineIntrinsic
TargetTransformInfo::simplifyDemandedUseBitsIntrinsic
TargetTransformInfo::simplifyDemandedVectorEltsIntrinsic

A few target specific parts are left in the InstCombine folder, where
it makes sense to share code. The largest left-over part in
InstCombineCalls.cpp is the code shared between arm and aarch64.

This allows to move about 3000 lines out from InstCombine to the targets.

Differential Revision: https://reviews.llvm.org/D81728
2020-07-22 15:59:49 +02:00
Eric Christopher 7bfaa40086 Temporarily Revert "[AssumeBundles] Use operand bundles to encode alignment assumptions"
due to the performance bugs filed in https://bugs.llvm.org/show_bug.cgi?id=46753.

An SROA change soon may obviate some of these problems.

This reverts commit 8d09f20798.
2020-07-16 11:54:04 -07:00
Tyker 8d09f20798 [AssumeBundles] Use operand bundles to encode alignment assumptions
Summary:
NOTE: There is a mailing list discussion on this: http://lists.llvm.org/pipermail/llvm-dev/2019-December/137632.html

Complemantary to the assumption outliner prototype in D71692, this patch
shows how we could simplify the code emitted for an alignemnt
assumption. The generated code is smaller, less fragile, and it makes it
easier to recognize the additional use as a "assumption use".

As mentioned in D71692 and on the mailing list, we could adopt this
scheme, and similar schemes for other patterns, without adopting the
assumption outlining.

Reviewers: hfinkel, xbolva00, lebedev.ri, nikic, rjmccall, spatel, jdoerfert, sstefan1

Reviewed By: jdoerfert

Subscribers: thopre, yamauchi, kuter, fhahn, merge_guards_bot, hiraditya, bollu, rkruppe, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D71739
2020-07-14 01:05:58 +02:00
Guillaume Chatelet 04288e93be Fix 46594 - Alignment assertion failure in instcombine 2020-07-06 08:45:05 +00:00
Roman Lebedev 7ea46aee36
Revert "[AssumeBundles] Use operand bundles to encode alignment assumptions"
Assume bundle can have more than one entry with the same name,
but at least AlignmentFromAssumptionsPass::extractAlignmentInfo() uses
getOperandBundle("align"), which internally assumes that it isn't the
case, and happily crashes otherwise.

Minimal reduced reproducer: run `opt -alignment-from-assumptions` on

target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"

%0 = type { i64, %1*, i8*, i64, %2, i32, %3*, i8* }
%1 = type opaque
%2 = type { i8, i8, i16 }
%3 = type { i32, i32, i32, i32 }

; Function Attrs: nounwind
define i32 @f(%0* noalias nocapture readonly %arg, %0* noalias %arg1) local_unnamed_addr #0 {
bb:
  call void @llvm.assume(i1 true) [ "align"(%0* %arg, i64 8), "align"(%0* %arg1, i64 8) ]
  ret i32 0
}

; Function Attrs: nounwind willreturn
declare void @llvm.assume(i1) #1

attributes #0 = { nounwind "reciprocal-estimates"="none" }
attributes #1 = { nounwind willreturn }


This is what we'd have with -mllvm -enable-knowledge-retention

This reverts commit c95ffadb24.
2020-07-04 23:49:23 +03:00
Guillaume Chatelet 87e2751cf0 [Alignment][NFC] Use proper getter to retrieve alignment from ConstantInt and ConstantSDNode
This patch is part of a series to introduce an Alignment type.
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html
See this patch for the introduction of the type: https://reviews.llvm.org/D64790

Differential Revision: https://reviews.llvm.org/D83082
2020-07-03 08:06:43 +00:00
David Green 9e49d1d9b8 [InstCombine] fma x, y, 0 -> fmul x, y
If the addend of the fma is zero, common sense would suggest that we can
convert fma x, y, 0.0 to fmul x, y. This comes up with some user code
that was expecting the first fma in an unrolled loop to simplify to a
fmul.

Floating point often does not follow naive common sense though. Alive
suggests that this should be guarded by nsz (as fadd -0.0, 0.0 = 0.0).
fma x, y, -0.0 is always valid.

Differential Revision: https://reviews.llvm.org/D82778
2020-06-30 19:56:37 +01:00
Simon Pilgrim db69b17409 LoopAccessAnalysis.h - reduce AliasAnalysis.h include to forward declaration. NFC.
Fix implicit include dependencies in source files and replace legacy AliasAnalysis typedef with AAResults where necessary.
2020-06-25 16:00:42 +01:00
Tyker c95ffadb24 [AssumeBundles] Use operand bundles to encode alignment assumptions
Summary:
NOTE: There is a mailing list discussion on this: http://lists.llvm.org/pipermail/llvm-dev/2019-December/137632.html

Complemantary to the assumption outliner prototype in D71692, this patch
shows how we could simplify the code emitted for an alignemnt
assumption. The generated code is smaller, less fragile, and it makes it
easier to recognize the additional use as a "assumption use".

As mentioned in D71692 and on the mailing list, we could adopt this
scheme, and similar schemes for other patterns, without adopting the
assumption outlining.

Reviewers: hfinkel, xbolva00, lebedev.ri, nikic, rjmccall, spatel, jdoerfert, sstefan1

Reviewed By: jdoerfert

Subscribers: yamauchi, kuter, fhahn, merge_guards_bot, hiraditya, bollu, rkruppe, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D71739
2020-06-25 12:59:44 +02:00
Simon Pilgrim 8233439fdb [InstCombine] Ensure allocation alignment mask is within range before applying as an attribute
Fixes OSS-Fuzz #23214
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=23214
2020-06-09 17:31:55 +01:00
Yevgeny Rouban 417bcb8827 [Instruction] Remove setProfWeight()
Remove the function Instruction::setProfWeight() and make
use of Instruction::copyMetadata(.., {LLVMContext::MD_prof}).
This is correct for all use cases of setProfWeight() as it
is applied to CallBase instructions only.
This change results in prof metadata copied intact even if
the source has "VP". The old pair of calls
extractProfTotalWeight() + setProfWeight() resulted in
setting branch_weights if the source had "VP" data.

Reviewers: yamauchi, davidxl
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D80987
2020-06-04 15:10:55 +07:00
Christopher Tetreault 8f8029b458 [SVE] Eliminate calls to default-false VectorType::get() from InstCombine
Reviewers: efriedma, david-arm, fpetrogalli, spatel

Reviewed By: david-arm

Subscribers: tschuett, hiraditya, rkruppe, psnobl, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D80334
2020-05-29 15:31:31 -07:00
Philip Reames 87bea912c2 [Statepoint] Replace uses of isX functions with idiomatic isa<X>
Now that all of the statepoint related routines have classes with isa support, let's cleanup.

I'm leaving the (dead) utitilities in tree for a few days so that I can do the same cleanup downstream without breakage.
2020-05-27 18:32:28 -07:00
Serge Pavlov 4d20e31f73 [FPEnv] Intrinsic llvm.roundeven
This intrinsic implements IEEE-754 operation roundToIntegralTiesToEven,
and performs rounding to the nearest integer value, rounding halfway
cases to even. The intrinsic represents the missed case of IEEE-754
rounding operations and now llvm provides full support of the rounding
operations defined by the standard.

Differential Revision: https://reviews.llvm.org/D75670
2020-05-26 19:24:58 +07:00
Matt Arsenault 27fe841aa6 AMDGPU: Refine rcp/rsq intrinsic folding for modern FP rules
We have to assume undef could be an snan, which would need quieting so
returning qnan is safer than undef. Also consider strictfp, and don't
care if the result rounded.
2020-05-23 13:28:36 -04:00
Matt Arsenault 88c20fa3d2 InstCombine: Add constant folding/simplify for amdgcn.ldexp intrinsic
This really belongs in InstructionSimplify since it doesn't introduce
new instructions. Put it in instcombine to avoid increasing the number
of passes considering target intrinsics.

I also noticed that we seem to now be interpreting strictfp attributes
on call sites, so try to handle that.
2020-05-22 08:21:38 -04:00
Arthur Eubanks 8a88755610 Reland [X86] Codegen for preallocated
See https://reviews.llvm.org/D74651 for the preallocated IR constructs
and LangRef changes.

In X86TargetLowering::LowerCall(), if a call is preallocated, record
each argument's offset from the stack pointer and the total stack
adjustment. Associate the call Value with an integer index. Store the
info in X86MachineFunctionInfo with the integer index as the key.

This adds two new target independent ISDOpcodes and two new target
dependent Opcodes corresponding to @llvm.call.preallocated.{setup,arg}.

The setup ISelDAG node takes in a chain and outputs a chain and a
SrcValue of the preallocated call Value. It is lowered to a target
dependent node with the SrcValue replaced with the integer index key by
looking in X86MachineFunctionInfo. In
X86TargetLowering::EmitInstrWithCustomInserter() this is lowered to an
%esp adjustment, the exact amount determined by looking in
X86MachineFunctionInfo with the integer index key.

The arg ISelDAG node takes in a chain, a SrcValue of the preallocated
call Value, and the arg index int constant. It produces a chain and the
pointer fo the arg. It is lowered to a target dependent node with the
SrcValue replaced with the integer index key by looking in
X86MachineFunctionInfo. In
X86TargetLowering::EmitInstrWithCustomInserter() this is lowered to a
lea of the stack pointer plus an offset determined by looking in
X86MachineFunctionInfo with the integer index key.

Force any function containing a preallocated call to use the frame
pointer.

Does not yet handle a setup without a call, or a conditional call.
Does not yet handle musttail. That requires a LangRef change first.

Tried to look at all references to inalloca and see if they apply to
preallocated. I've made preallocated versions of tests testing inalloca
whenever possible and when they make sense (e.g. not alloca related,
inalloca edge cases).

Aside from the tests added here, I checked that this codegen produces
correct code for something like

```
struct A {
        A();
        A(A&&);
        ~A();
};

void bar() {
        foo(foo(foo(foo(foo(A(), 4), 5), 6), 7), 8);
}
```

by replacing the inalloca version of the .ll file with the appropriate
preallocated code. Running the executable produces the same results as
using the current inalloca implementation.

Reverted due to unexpectedly passing tests, added REQUIRES: asserts for reland.

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D77689
2020-05-20 11:25:44 -07:00
Arthur Eubanks b8cbff51d3 Revert "[X86] Codegen for preallocated"
This reverts commit 810567dc69.

Some tests are unexpectedly passing
2020-05-20 10:04:55 -07:00
Arthur Eubanks 810567dc69 [X86] Codegen for preallocated
See https://reviews.llvm.org/D74651 for the preallocated IR constructs
and LangRef changes.

In X86TargetLowering::LowerCall(), if a call is preallocated, record
each argument's offset from the stack pointer and the total stack
adjustment. Associate the call Value with an integer index. Store the
info in X86MachineFunctionInfo with the integer index as the key.

This adds two new target independent ISDOpcodes and two new target
dependent Opcodes corresponding to @llvm.call.preallocated.{setup,arg}.

The setup ISelDAG node takes in a chain and outputs a chain and a
SrcValue of the preallocated call Value. It is lowered to a target
dependent node with the SrcValue replaced with the integer index key by
looking in X86MachineFunctionInfo. In
X86TargetLowering::EmitInstrWithCustomInserter() this is lowered to an
%esp adjustment, the exact amount determined by looking in
X86MachineFunctionInfo with the integer index key.

The arg ISelDAG node takes in a chain, a SrcValue of the preallocated
call Value, and the arg index int constant. It produces a chain and the
pointer fo the arg. It is lowered to a target dependent node with the
SrcValue replaced with the integer index key by looking in
X86MachineFunctionInfo. In
X86TargetLowering::EmitInstrWithCustomInserter() this is lowered to a
lea of the stack pointer plus an offset determined by looking in
X86MachineFunctionInfo with the integer index key.

Force any function containing a preallocated call to use the frame
pointer.

Does not yet handle a setup without a call, or a conditional call.
Does not yet handle musttail. That requires a LangRef change first.

Tried to look at all references to inalloca and see if they apply to
preallocated. I've made preallocated versions of tests testing inalloca
whenever possible and when they make sense (e.g. not alloca related,
inalloca edge cases).

Aside from the tests added here, I checked that this codegen produces
correct code for something like

```
struct A {
        A();
        A(A&&);
        ~A();
};

void bar() {
        foo(foo(foo(foo(foo(A(), 4), 5), 6), 7), 8);
}
```

by replacing the inalloca version of the .ll file with the appropriate
preallocated code. Running the executable produces the same results as
using the current inalloca implementation.

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D77689
2020-05-20 09:20:38 -07:00
Eli Friedman 11aa3707e3 StoreInst should store Align, not MaybeAlign
This is D77454, except for stores.  All the infrastructure work was done
for loads, so the remaining changes necessary are relatively small.

Differential Revision: https://reviews.llvm.org/D79968
2020-05-15 12:26:58 -07:00
Eli Friedman accc6b5545 LoadInst should store Align, not MaybeAlign.
The fact that loads and stores can have the alignment missing is a
constant source of confusion: code that usually works can break down in
rare cases.  So fix the LoadInst API so the alignment is never missing.

To reduce the number of changes required to make this work, IRBuilder
and certain LoadInst constructors will grab the module's datalayout and
compute the alignment automatically.  This is the same alignment
instcombine would eventually apply anyway; we're just doing it earlier.
There's a minor risk that the way we're retrieving the datalayout
could break out-of-tree code, but I don't think that's likely.

This is the last in a series of patches, so most of the necessary
changes have already been merged.

Differential Revision: https://reviews.llvm.org/D77454
2020-05-14 13:19:21 -07:00
Christopher Tetreault b6c6bab9a5 [SVE] Fix incorrect usage of getNumElements() in InstCombineCalls
Summary:
Remove incorrect usage of getNumElements() from visitCallInst(). The
number of elements was being used to construct a DemandedElts bitfield.
This operation does not make sense for scalable vectors. Cast to
FixedVectorType

Identified by test case Clang :: CodeGen/aarch64-sve-intrinsics/acle_sve_mla.c

Reviewers: rengolin, efriedma, sdesmalen, c-rhodes, david-arm

Reviewed By: david-arm

Subscribers: tschuett, kristof.beyls, hiraditya, rkruppe, psnobl, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D79524
2020-05-07 08:46:51 -07:00
Arthur Eubanks a90948fd6e [NFC] Rename *ByValOrInalloca* to *PassPointeeByValue*
Summary: In preparation for preallocated.

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D79152
2020-04-30 09:42:13 -07:00
Craig Topper a58b62b4a2 [IR] Replace all uses of CallBase::getCalledValue() with getCalledOperand().
This method has been commented as deprecated for a while. Remove
it and replace all uses with the equivalent getCalledOperand().

I also made a few cleanups in here. For example, to removes use
of getElementType on a pointer when we could just use getFunctionType
from the call.

Differential Revision: https://reviews.llvm.org/D78882
2020-04-27 22:17:03 -07:00
Sanjay Patel e4175ff525 [InstCombine] intersect FMF when reassociating FP min/max intrinsics
As discussed in PR45478:
https://bugs.llvm.org/show_bug.cgi?id=45478
...propagating FMF from the outer (second) call is not correct,
so intersect them instead.
I suspect we could do better (see TODO comment), but mismatched
FMF is probably too rare to care about.

Differential Revision: https://reviews.llvm.org/D78631
2020-04-24 12:14:03 -04:00
Craig Topper 68b2e507e4 [Local] Update getOrEnforceKnownAlignment/getKnownAlignment to use Align/MaybeAlign.
Differential Revision: https://reviews.llvm.org/D78443
2020-04-20 21:31:44 -07:00
Craig Topper fcc9d70260 Revert "[Local] Update getOrEnforceKnownAlignment/getKnownAlignment to use Align/MaybeAlign."
This is breaking the clang build.

This reverts commit 897409fb56.
2020-04-20 13:25:06 -07:00
Craig Topper 897409fb56 [Local] Update getOrEnforceKnownAlignment/getKnownAlignment to use Align/MaybeAlign.
Differential Revision: https://reviews.llvm.org/D78443
2020-04-20 13:08:05 -07:00
Benjamin Kramer b639091c02 Change users of CreateShuffleVector to pass the masks as int instead of Constants
No functionality change intended.
2020-04-17 16:34:29 +02:00
Johannes Doerfert ea7f17ee38 [InstCombine] Simplify calls with casted `returned` attribute
The handling of the `returned` attribute in D75815 did miss the case
where the argument is (bit)casted to a different type. This is
explicitly allowed by the language reference and exposed by the
Attributor.

Reviewed By: lebedev.ri

Differential Revision: https://reviews.llvm.org/D77977
2020-04-16 00:56:00 -05:00
Benjamin Kramer 6f64daca8f Upgrade calls to CreateShuffleVector to use the preferred form of passing an array of ints
No functionality change intended.
2020-04-15 12:51:38 +02:00
Craig Topper f3d3cec648 [InstCombine] Avoid a call to deprecated version of CreateCall.
Passing a Value * to CreateCall has to call getPointerElementType
to find the type of the pointer.

In this case we can rely on the fact that Intrinsic::getDeclaration
returns a Function * and use that version of CreateCall.
2020-04-08 17:41:16 -07:00
Christopher Tetreault 155740cc33 Clean up usages of asserting vector getters in Type
Summary:
Remove usages of asserting vector getters in Type in preparation for the
VectorType refactor. The existence of these functions complicates the
refactor while adding little value.

Reviewers: sdesmalen, rriddle, efriedma

Reviewed By: sdesmalen

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D77263
2020-04-08 15:15:41 -07:00
Matt Arsenault 57a55313c3 InstCombine: Reduce minnum/maxnum if inputs are casted 2020-04-03 11:57:25 -04:00
Tyker c00cb76274 [NFC] Split Knowledge retention and place it more appropriatly
Summary:
Splitting Knowledge retention into Queries in Analysis and Builder into Transform/Utils
allows Queries and Transform/Utils to use Analysis.

Reviewers: jdoerfert, sstefan1

Reviewed By: jdoerfert

Subscribers: mgorny, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D77171
2020-04-02 15:01:41 +02:00
Uday Bondhugula dc817b2dea [InstCombine] Deduce attributes for aligned_alloc in InstCombine
Make InstCombine aware of the aligned_alloc library function.

Signed-off-by: Uday Bondhugula <uday@polymagelabs.com>

Depends on D76970.

Differential Revision: https://reviews.llvm.org/D76971
2020-03-31 23:17:28 +05:30
Sebastian Neubauer 5d3a69feca [AMDGPU] New llvm.amdgcn.ballot intrinsic
Add a new llvm.amdgcn.ballot intrinsic modeled on the ballot function
in GLSL and other shader languages. It returns a bitfield containing the
result of its boolean argument in all active lanes, and zero in all
inactive lanes.

This is intended to replace the existing llvm.amdgcn.icmp and
llvm.amdgcn.fcmp intrinsics after a suitable transition period.

Use the new intrinsic in the atomic optimizer pass.

Differential Revision: https://reviews.llvm.org/D65088
2020-03-31 10:35:39 +02:00
Nikita Popov 53d209076a [InstCombine] Use replaceOperand() in demanded elements simplification
To make sure that dead operands get DCEd. This fixes the largest
source of leftover dead operands we see in tests.

NFC apart from worklist changes.
2020-03-29 20:43:19 +02:00
Nikita Popov 28f67bd5c5 [InstCombine] Fix worklist management in varargs transform
Add a replaceUse() helper to mirror replaceOperand() for the
rare cases where we're working directly on uses.

NFC apart from worklist order changes.
2020-03-29 18:04:12 +02:00
Sanjay Patel a1fe6beb1e [InstCombine] remove one-use check for ctpop -> cttz
Two one-use checks were added with rGfdcb27105537,
but only the first one is necessary to limit an
increase in instruction count. The second transform
only creates one instruction, so it is always a
reasonable canonicalization/optimization.
2020-03-23 13:59:57 -04:00
Simon Pilgrim fdcb271055 [InstCombine] Limit CTPOP -> CTTZ simplifications to one use
Tweak D76568 so we only combine if it will remove the bit-twiddling.

Suggested by @spatel
2020-03-23 14:33:41 +00:00
Simon Pilgrim 72d1419bfb [InstCombine] Add CTPOP -> CTTZ simplifications (PR43513)
As detailed on PR43513, we can simplify:

ctpop(x | -x) -> bitwidth - cttz(x, false)
Alive2: http://volta.cs.utah.edu:8080/z/caw49X

ctpop(~x & (x - 1)) -> cttz(x, false)
Alive2: http://volta.cs.utah.edu:8080/z/5zfVrx

I've tweaked the initial test cases I added at rG2d712fb75584 to increase commutativity testing.

Differential Revision: https://reviews.llvm.org/D76568
2020-03-23 11:04:33 +00:00
Simon Pilgrim f00a4b531a [InstCombine][X86] simplifyX86immShift - remove ConstantAggregateZero handling. NFC.
The llvm::computeKnownBits path now handles this.
2020-03-21 11:30:44 +00:00
Simon Pilgrim 34659de5fd [InstCombine][X86] simplifyX86immShift - convert variable in-range vector shift by scalar amounts to generic shifts (PR40391)
The sll/srl/sra scalar vector shifts can be replaced with generic shifts if the shift amount is known to be in range.

This also required public DemandedElts variants of llvm::computeKnownBits to be exposed (PR36319).
2020-03-20 15:48:06 +00:00
Nikita Popov 0372768776 [InstCombine] Simplify calls with "returned" attribute
If a call argument has the "returned" attribute, we can simplify
the call to the value of that argument. This was already partially
handled by InstSimplify/InstCombine for the case where the argument
is an integer constant, and the result is thus known via known bits.
The non-constant (or non-int) argument cases weren't handled though.

This previously landed as an InstSimplify transform, but was reverted
due to assertion failures when compiling the Linux kernel. The reason
is that simplifying a call to another call breaks assumptions in
call graph updating during inlining. As the code is not easy to fix,
and there is no particularly strong motivation for having this in
InstSimplify, the transform is only performed in InstCombine instead.

Differential Revision: https://reviews.llvm.org/D75815
2020-03-20 10:23:39 +01:00
Simon Pilgrim a11e5b32df [InstCombine][X86] simplifyX86immShift - handle variable out-of-range vector shift by immediate amounts (PR40391)
If we know the SSE shift amount is out of range then we can simplify to zero value (logical) or a 'signsplat' bitwidth-1 shift (arithmetic). This allows us to remove the equivalent ConstantInt constant folding path from simplifyX86immShift.
2020-03-19 18:27:31 +00:00
Simon Pilgrim 433897da4a [InstCombine][X86] simplifyX86immShift - convert variable in-range vector shift by immediate amounts to generic shifts (PR40391)
The slli/srli/srai 'immediate' vector shifts (although its not immediate anymore to match gcc) can be replaced with generic shifts if the shift amount is known to be in range.
2020-03-19 15:44:24 +00:00
Simon Pilgrim f4e495a18e [InstCombine][X86] simplifyX86varShift - convert variable in-range per-element shift amounts to generic shifts (PR40391)
AVX2/AVX512 per-element shifts can be replaced with generic shifts if the shift amounts are guaranteed to be in-range (upper bits are known zero).
2020-03-18 11:26:54 +00:00
Tyker e8ac825f5b [AssumeBundles] Detection of Empty bundles
Summary: Prevent InstCombine from removing llvm.assume for which the arguement is true when they have operand bundles with usefull information.

Reviewers: jdoerfert, nikic, lebedev.ri

Reviewed By: jdoerfert

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D76147
2020-03-17 15:50:15 +01:00
Serguei Katkov 80c351cdb6 [InstCombine] Transform to undef incorrect atomic unordered mem intrinsics
According to LangRef:
If len is not a positive integer multiple of element_size, then the behaviour of the intrinsic is undefined.

Add InstCombine rule to transform intrinsic to undef operation.

This is a follow-up for D76116.

Reviewers: reames
Reviewed By: reames
Subscribers: hiraditya, jfb, dantrushin, llvm-commits
Differential Revision: https://reviews.llvm.org/D76215
2020-03-17 10:20:16 +07:00
Nikita Popov c3ca6876ed [InstCombine] Don't simplify calls without uses
When simplifying a call without uses, replaceInstUsesWith() is
going to do nothing, but we'll skip all following folds. We can
only run into this problem with calls that both simplify and are
not trivially dead if unused, which currently seems to happen only
with calls to undef, as the test diff shows. When extending
SimplifyCall() to handle "returned" attributes, this becomes a much
bigger problem, so I'm fixing this first.

Differential Revision: https://reviews.llvm.org/D75814
2020-03-09 18:47:46 +01:00
Simon Pilgrim 7e9747b50b [X86][F16C] Remove cvtph2ps intrinsics and use generic half2float conversion (PR37554)
This removes everything but int_x86_avx512_mask_vcvtph2ps_512 which provides the SAE variant, but even this can use the fpext generic if the rounding control is the default.

Differential Revision: https://reviews.llvm.org/D75162
2020-02-29 18:57:35 +00:00