Commit Graph

9942 Commits

Author SHA1 Message Date
Simon Pilgrim bfd00a6440 [SelectionDAG] computeKnownBits - remove some duplicate/shadow variables. NFCI.
llvm-svn: 359872
2019-05-03 11:11:03 +00:00
Craig Topper e8a1cde886 [SelectionDAG] Add asserts to verify the vectorness of input and output types of TRUNCATE/ZERO_EXTEND/ANY_EXTEND/SIGN_EXTEND agree
As a result of the underlying cause of PR41678 we created an ANY_EXTEND node with a scalar result type and v1i1 input type. Ideally we would have asserted for this instead of letting it go through to instruction selection and generate bad machine IR

Differential Revision: https://reviews.llvm.org/D61463

llvm-svn: 359836
2019-05-02 22:26:26 +00:00
Sanjay Patel 1972826178 [DAGCombiner] try repeated fdiv divisor transform before building estimate (2nd try)
The original patch was committed at rL359398 and reverted at rL359695 because of
infinite looping.

This includes a fix to check for a vector splat of "1.0" to avoid the infinite loop.

Original commit message:

This was originally part of D61028, but it's an independent diff.

If we try the repeated divisor reciprocal transform before producing an estimate sequence,
then we have an opportunity to use scalar fdiv. On x86, the trade-off is 1 divss vs. 5
vector FP ops in the default estimate sequence. On recent chips (Skylake, Ryzen), the
full-precision division is only 3 cycle throughput, so that's probably the better perf
default option and avoids problems from x86's inaccurate estimates.

The last 2 tests show that users still have the option to override the defaults by using
the function attributes for reciprocal estimates, but those patterns are potentially made
faster by converting the vector ops (including ymm ops) to scalar math.

Differential Revision: https://reviews.llvm.org/D61149

llvm-svn: 359793
2019-05-02 15:02:08 +00:00
Sanjay Patel 284472be6d [SelectionDAG] remove constant folding limitations based on FP exceptions
We don't have FP exception limits in the IR constant folder for the binops (apart from strict ops),
so it does not make sense to have them here in the DAG either. Nothing else in the backend tries
to preserve exceptions (again outside of strict ops), so I don't see how this could have ever
worked for real code that cares about FP exceptions.

There are still cases (examples: unary opcodes in SDAG, FMA in IR) where we are trying (at least
partially) to preserve exceptions without even asking if the target supports FP exceptions. Those
should be corrected in subsequent patches.

Real support for FP exceptions requires several changes to handle the constrained/strict FP ops.

Differential Revision: https://reviews.llvm.org/D61331

llvm-svn: 359791
2019-05-02 14:47:59 +00:00
Sanjay Patel 64d5751254 Revert "[DAGCombiner] try repeated fdiv divisor transform before building estimate"
This reverts commit fb9a5307a9 (rL359398)
because it can cause an infinite loop due to opposing combines.

llvm-svn: 359695
2019-05-01 16:06:21 +00:00
Tim Northover ee2474df9f DAG: allow DAG pointer size different from memory representation.
In preparation for supporting ILP32 on AArch64, this modifies the SelectionDAG
builder code so that pointers are allowed to have a larger type when "live" in
the DAG compared to memory.

Pointers get zero-extended whenever they are loaded, and truncated prior to
stores.  In addition, a few not quite so obvious locations need updating:

  * A GEP that has not been marked inbounds needs to enforce the IR-documented
    2s-complement wrapping at the memory pointer size. Inbounds GEPs are
    undefined if they overflow the address space, so no additional operations
    are needed.
  * Signed comparisons would give incorrect results if performed on the
    zero-extended values.

This shouldn't affect CodeGen for now, but will become active when the AArch64
ILP32 support is committed.

llvm-svn: 359676
2019-05-01 12:37:30 +00:00
Sanjay Patel 0387bf5269 [SelectionDAG] remove div-by-zero constant folding restriction
We don't have this restriction in IR, so it should not be here
either simply out of consistency. Code that wants to handle FP
exceptions is expected to use the 'strict' variants of these
nodes.

We don't get the frem case because frem by 0.0 produces NaN (invalid),
and that's the remaining check here (so the removed check for frem
was dead code AFAIK).

This is the only place in SDAG that uses "HasFPExceptions", so I
think we should remove that entirely as a follow-up patch.

llvm-svn: 359566
2019-04-30 14:37:15 +00:00
Sjoerd Meijer 0ed4619679 [TargetLowering] findOptimalMemOpLowering. NFCI.
This was a local static funtion in SelectionDAG, which I've promoted to
TargetLowering so that I can reuse it to estimate the cost of a memory
operation in D59787.

Differential Revision: https://reviews.llvm.org/D59766

llvm-svn: 359543
2019-04-30 10:09:15 +00:00
Sjoerd Meijer 180f1ae57c [TargetLowering] Change getOptimalMemOpType to take a function attribute list
The MachineFunction wasn't used in getOptimalMemOpType, but more importantly,
this allows reuse of findOptimalMemOpLowering that is calling getOptimalMemOpType.

This is the groundwork for the changes in D59766 and D59787, that allows
implementation of TTI::getMemcpyCost.

Differential Revision: https://reviews.llvm.org/D59785

llvm-svn: 359537
2019-04-30 08:38:12 +00:00
Zi Xuan Wu 49d60fdc2e [DAGCombiner] Do not generate ISD::ADDE node if adde is not legal for the target when combine ISD::TRUNC node
Do not combine (trunc adde(X, Y, Carry)) into (adde trunc(X), trunc(Y), Carry), 
if adde is not legal for the target. Even it's at type-legalize phase. 
Because adde is special and will not be legalized at operation-legalize phase later.

This fixes: PR40922
https://bugs.llvm.org/show_bug.cgi?id=40922

Differential Revision: https://reviews.llvm.org//D60854

llvm-svn: 359532
2019-04-30 03:01:14 +00:00
Bjorn Pettersson 820994572c [DAG] Refactor DAGCombiner::ReassociateOps
Summary:
Extract the logic for doing reassociations
from DAGCombiner::reassociateOps into a helper
function DAGCombiner::reassociateOpsCommutative,
and use that helper to trigger reassociation
on the original operand order, or the commuted
operand order.

Codegen is not identical since the operand order will
be different when doing the reassociations for the
commuted case. That causes some unfortunate churn in
some test cases. Apart from that this should be NFC.

Reviewers: spatel, craig.topper, tstellar

Reviewed By: spatel

Subscribers: dmgreen, dschuff, jvesely, nhaehnle, javed.absar, sbc100, jgravelle-google, hiraditya, aheejin, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D61199

llvm-svn: 359476
2019-04-29 17:50:10 +00:00
Sanjay Patel fb9a5307a9 [DAGCombiner] try repeated fdiv divisor transform before building estimate
This was originally part of D61028, but it's an independent diff.

If we try the repeated divisor reciprocal transform before producing an estimate sequence,
then we have an opportunity to use scalar fdiv. On x86, the trade-off is 1 divss vs. 5
vector FP ops in the default estimate sequence. On recent chips (Skylake, Ryzen), the
full-precision division is only 3 cycle throughput, so that's probably the better perf
default option and avoids problems from x86's inaccurate estimates.

The last 2 tests show that users still have the option to override the defaults by using
the function attributes for reciprocal estimates, but those patterns are potentially made
faster by converting the vector ops (including ymm ops) to scalar math.

Differential Revision: https://reviews.llvm.org/D61149

llvm-svn: 359398
2019-04-28 12:23:43 +00:00
Simon Pilgrim ef54b1dddf [DAGCombine] Cleanup visitEXTRACT_SUBVECTOR. NFCI.
Use ArrayRef::slice, reduce some rather awkward long lines for legibility and run clang-format.

llvm-svn: 359326
2019-04-26 17:49:02 +00:00
Simon Pilgrim 5d6ef94c36 [X86][SSE] Disable shouldFoldConstantShiftPairToMask for btver1/btver2 targets (PR40758)
As detailed on PR40758, Bobcat/Jaguar can perform vector immediate shifts on the same pipes as vector ANDs with the same latency - so it doesn't make sense to replace a shl+lshr with a shift+and pair as it requires an additional mask (with the extra constant pool, loading and register pressure costs).

Differential Revision: https://reviews.llvm.org/D61068

llvm-svn: 359293
2019-04-26 10:49:13 +00:00
Craig Topper f9c30eddd0 [SelectionDAG][X86] Use stack load/store in PromoteIntRes_BITCAST when the input needs to be be split and the output type is a vector.
We had special case handling here, but it uses a scalar any_extend for the
promotion then bitcasts to the final type. This won't split up the input data
into multiple promoted elements like we need.

This patch falls back to doing the conversion through memory.

Fixes PR41594 which I believe was reflected in the bitcast-vector-bool.ll
changes. The changes to vector-half-conversions.ll are fixing a previously
unknown miscompile from this issue.

Differential Revision: https://reviews.llvm.org/D61114

llvm-svn: 359219
2019-04-25 18:19:59 +00:00
Amy Huang 68c9199493 Recommitting r358783 and r358786 "[MS] Emit S_HEAPALLOCSITE debug info" with fixes for buildbot error (undefined assembler label).
Summary:
This emits labels around heapallocsite calls and S_HEAPALLOCSITE debug
info in codeview. Currently only changes FastISel, so emitting labels still
needs to be implemented in SelectionDAG.

Reviewers: rnk

Subscribers: aprantl, hiraditya, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D61083

llvm-svn: 359149
2019-04-24 23:02:48 +00:00
Sanjay Patel 6f41bf948b [DAGCombiner] scale repeated FP divisor by splat factor
If we have a vector FP division with a splatted divisor, use the existing transform
that converts 'x/y' into 'x * (1.0/y)' to allow more conversions. This can then
potentially be converted into a scalar FP division by existing combines (rL358984)
as seen in the tests here.

That can be a potentially big perf difference if scalar fdiv has better timing
(including avoiding possible frequency throttling for vector ops).

Differential Revision: https://reviews.llvm.org/D61028

llvm-svn: 359147
2019-04-24 22:28:58 +00:00
Bjorn Pettersson 71e8c6f20f Add "const" in GetUnderlyingObjects. NFC
Summary:
Both the input Value pointer and the returned Value
pointers in GetUnderlyingObjects are now declared as
const.

It turned out that all current (in-tree) uses of
GetUnderlyingObjects were trivial to update, being
satisfied with have those Value pointers declared
as const. Actually, in the past several of the users
had to use const_cast, just because of ValueTracking
not providing a version of GetUnderlyingObjects with
"const" Value pointers. With this patch we get rid
of those const casts.

Reviewers: hfinkel, materi, jkorous

Reviewed By: jkorous

Subscribers: dexonsmith, jkorous, jholewinski, sdardis, eraman, hiraditya, jrtc27, atanasyan, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D61038

llvm-svn: 359072
2019-04-24 06:55:50 +00:00
Amy Huang fc79ab9857 Revert "[MS] Emit S_HEAPALLOCSITE debug info" because of ToTWin64(db)
buildbot failure.

This reverts commit d07d6d6177 and
c774f687b6.

llvm-svn: 359034
2019-04-23 21:12:58 +00:00
Fangrui Song efd94c56ba Use llvm::stable_sort
While touching the code, simplify if feasible.

llvm-svn: 358996
2019-04-23 14:51:27 +00:00
Sanjay Patel 06ff5eae5b [DAGCombiner] generalize binop-of-splats scalarization
If we only match build vectors, we can miss some patterns
that use shuffles as seen in the affected tests.

Note that the underlying calls within getSplatSourceVector()
have the potential for compile-time explosion because of
exponential recursion looking through binop opcodes, but
currently the list of supported opcodes is very limited.
Both of those problems should be addressed in follow-up
patches.

llvm-svn: 358984
2019-04-23 13:16:41 +00:00
Bjorn Pettersson f97b29be88 [DAGCombiner] Combine OR as ADD when no common bits are set
Summary:
The DAGCombiner is rewriting (canonicalizing) an ISD::ADD
with no common bits set in the operands as an ISD::OR node.

This could sometimes result in "missing out" on some
combines that normally are performed for ADD. To be more
specific this could happen if we already have rewritten an
ADD into OR, and later (after legalizations or combines)
we expose patterns that could have been optimized if we
had seen the OR as an ADD (e.g. reassociations based on ADD).

To make the DAG combiner less sensitive to if ADD or OR is
used for these "no common bits set" ADD/OR operations we
now apply most of the ADD combines also to an OR operation,
when value tracking indicates that the operands have no
common bits set.

Reviewers: spatel, RKSimon, craig.topper, kparzysz

Reviewed By: spatel

Subscribers: arsenm, rampitec, lebedev.ri, jvesely, nhaehnle, hiraditya, javed.absar, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D59758

llvm-svn: 358965
2019-04-23 10:01:08 +00:00
Sanjay Patel bf8aacb715 [SelectionDAG] move splat util functions up from x86 lowering
This was supposed to be NFC, but the change in SDLoc
definitions causes instruction scheduling changes.

There's nothing x86-specific in this code, and it can
likely be used from DAGCombiner's simplifyVBinOp().

llvm-svn: 358930
2019-04-22 22:43:36 +00:00
Simon Pilgrim 6276ce0142 [TargetLowering][AMDGPU][X86] Improve SimplifyDemandedBits bitcast handling
This patch adds support for BigBitWidth -> SmallBitWidth bitcasts, splitting the DemandedBits/Elts accordingly.

The AMDGPU backend needed an extra  (srl (and x, c1 << c2), c2) -> (and (srl(x, c2), c1) combine to encourage BFE creation, I investigated putting this in DAGCombine but it caused a lot of noise on other targets - some improvements, some regressions.

The X86 changes are all definite wins.

Differential Revision: https://reviews.llvm.org/D60462

llvm-svn: 358887
2019-04-22 14:04:35 +00:00
Sanjay Patel 9bc6c77220 [DAGCombiner] make variable name less ambiguous; NFC
llvm-svn: 358886
2019-04-22 13:42:50 +00:00
Sanjay Patel d6989daae9 [DAGCombiner] prepare shuffle-of-splat to handle more patterns; NFC
llvm-svn: 358884
2019-04-22 13:36:07 +00:00
Amy Huang c774f687b6 [MS] Emit S_HEAPALLOCSITE debug info
Summary:
This emits labels around heapallocsite calls and S_HEAPALLOCSITE debug
info in codeview. Currently only changes FastISel, so emitting labels still
needs to be implemented in SelectionDAG.

Reviewers: hans, rnk

Subscribers: aprantl, hiraditya, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D60800

llvm-svn: 358783
2019-04-19 21:09:11 +00:00
Sanjay Patel e197c617a6 [SelectionDAG] soften splat mask assert/unreachable (PR41535)
These are general queries, so they should not die when given
a degenerate input like an all undef mask. Callers should be
able to deal with an op that will eventually be simplified away.

llvm-svn: 358761
2019-04-19 15:31:11 +00:00
Simon Pilgrim e7fe6dd5ed [DAGCombine] Add SimplifyDemandedBits helper that handles demanded elts mask as well
The other SimplifyDemandedBits helpers become wrappers to this new demanded elts variant.

llvm-svn: 358585
2019-04-17 15:45:44 +00:00
Florian Hahn 258a425c69 [ScheduleDAGRRList] Recompute topological ordering on demand.
Currently there is a single point in ScheduleDAGRRList, where we
actually query the topological order (besides init code). Currently we
are recomputing the order after adding a node (which does not have
predecessors) and then we add predecessors edge-by-edge.

We can avoid adding edges one-by-one after we added a new node. In that case, we can
just rebuild the order from scratch after adding the edges to the DAG
and avoid all the updates to the ordering.

Also, we can delay updating the DAG until we query the DAG, if we keep a
list of added edges. Depending on the number of updates, we can either
apply them when needed or recompute the order from scratch.

This brings down the geomean compile time for of CTMark with -O1 down 0.3% on X86,
with no regressions.

Reviewers: MatzeB, atrick, efriedma, niravd, paquette

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D60125

llvm-svn: 358583
2019-04-17 15:05:29 +00:00
Simon Pilgrim e5573f4f4e [TargetLowering] Rename preferShiftsToClearExtremeBits and shouldFoldShiftPairToMask (PR41359)
As discussed on PR41359, this patch renames the pair of shift-mask target feature functions to make their purposes more obvious.

shouldFoldShiftPairToMask -> shouldFoldConstantShiftPairToMask

preferShiftsToClearExtremeBits -> shouldFoldMaskToVariableShiftPair

llvm-svn: 358526
2019-04-16 20:57:28 +00:00
Luis Marques eda370d4c8 [DAGCombiner] Add missing flag to addressing mode check
The checks in `canFoldInAddressingMode` tested for addressing modes that have a
base register but didn't set the `HasBaseReg` flag to true (it's false by
default). This patch fixes that. Although the omission of the flag was
technically incorrect it had no known observable impact, so no tests were
changed by this patch.

Differential Revision:  https://reviews.llvm.org/D60314

llvm-svn: 358502
2019-04-16 15:09:18 +00:00
Tim Northover 2be3f868f9 DAG: propagate ConsecutiveRegs flags to returns too.
Arguments already have a flag to inform backends when they have been split up.
The AArch64 arm64_32 ABI makes use of these on return types too, so that code
emitted for armv7k can be ABI-compliant.

There should be no CodeGen changes yet, just making more information available.

llvm-svn: 358399
2019-04-15 12:04:10 +00:00
Tim Northover 9db00f7e5b DAG: propagate whether an arg is a pointer for CallingConv decisions.
The arm64_32 ABI specifies that pointers (despite being 32-bits) should be
zero-extended to 64-bits when passed in registers for efficiency reasons. This
means that the SelectionDAG needs to be able to tell the backend that an
argument was originally a pointer, which is implmented here.

Additionally, some memory intrinsics need to be declared as taking an i8*
instead of an iPTR.

There should be no CodeGen change yet, but it will be triggered when AArch64
backend support for ILP32 is added.

llvm-svn: 358398
2019-04-15 12:03:54 +00:00
Bjorn Pettersson 60569363a5 [SelectionDAG] Use KnownBits::computeForAddSub/computeForAddCarry
Summary:
Use KnownBits::computeForAddSub/computeForAddCarry
in SelectionDAG::computeKnownBits when doing value
tracking for addition/subtraction.

This should improve the precision of the known bits,
as we only used to make a simple estimate of known
zeroes. The KnownBits support functions are also
able to deduce bits that are known to be one in the
result.

Reviewers: spatel, RKSimon, nikic, lebedev.ri

Reviewed By: nikic

Subscribers: nikic, javed.absar, lebedev.ri, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D60460

llvm-svn: 358372
2019-04-15 07:19:11 +00:00
Sanjay Patel 5e4ad39af7 [DAGCombiner] narrow shuffle of concatenated vectors
// shuffle (concat X, undef), (concat Y, undef), Mask -->
// concat (shuffle X, Y, Mask0), (shuffle X, Y, Mask1)

The ARM changes with 'vtrn' and narrowed 'vuzp' are improvements.

The x86 changes look neutral or better. There's one test with an
extra instruction, but that could be reversed for a subtarget with
the right attributes. But by default, we want to avoid the 256-bit
op when possible (in my motivating benchmark, a handful of ymm ops
sprinkled into a sequence of xmm ops are triggering frequency
throttling on Haswell resulting in significantly worse perf).

Differential Revision: https://reviews.llvm.org/D60545

llvm-svn: 358291
2019-04-12 16:31:56 +00:00
Craig Topper 3b1239d2a8 [TargetLowering][X86] Teach SimplifyDemandedBits to use ShrinkDemandedOp on ISD::SHL nodes.
If the upper bits of the SHL result aren't used, we might be able to use a narrower shift. For example, on X86 this can turn a 64-bit into 32-bit enabling a smaller encoding.

Differential Revision: https://reviews.llvm.org/D60358

llvm-svn: 358257
2019-04-12 06:49:28 +00:00
Sanjay Patel fd314eca8f [DAGCombiner] refactor narrowing of extracted vector binop; NFC
There's a TODO comment about handling patterns with insert_subvector,
and we do want to match that.

llvm-svn: 358187
2019-04-11 15:59:47 +00:00
Sanjay Patel c0f4a35e68 [DAGCombiner][x86] scalarize inserted vector FP ops
// bo (build_vec ...undef, x, undef...), (build_vec ...undef, y, undef...) -->
// build_vec ...undef, (bo x, y), undef...

The lifetime of the nodes in these examples is different for variables versus constants,
but they are all build vectors briefly, so I'm proposing to catch them in this form to
handle all of the leading examples in the motivating test file.

Before we have build vectors, we might have insert_vector_element. After that, we might
have scalar_to_vector and constant pool loads.

It's going to take more work to ensure that FP vector operands are getting simplified
with undef elements, so this transform can apply more widely. In a non-loose FP environment,
we are likely simplifying FP elements to NaN values rather than undefs.

We also need to allow more opcodes down this path. Eg, we don't handle FP min/max flavors
yet.

Differential Revision: https://reviews.llvm.org/D60514

llvm-svn: 358172
2019-04-11 14:21:57 +00:00
David Green 0861c87b06 Revert rL357745: [SelectionDAG] Compute known bits of CopyFromReg
Certain optimisations from ConstantHoisting and CGP rely on Selection DAG not
seeing through to the constant in other blocks. Revert this patch while we come
up with a better way to handle that.

I will try to follow this up with some better tests.

llvm-svn: 358113
2019-04-10 18:00:41 +00:00
Craig Topper 61e77b11d1 [DAGCombiner][X86][SystemZ] Canonicalize SSUBO with immediate RHS to SADDO by negating the immediate.
This lines up with what we do for regular subtract and it matches up better with X86 assumptions in isel patterns that add with immediate is more canonical than sub with immediate.

Differential Revision: https://reviews.llvm.org/D60020

llvm-svn: 358027
2019-04-09 18:33:56 +00:00
Simon Pilgrim d7cc0ec581 [TargetLowering] SimplifyDemandedBits - add ISD::INSERT_SUBVECTOR support
llvm-svn: 358019
2019-04-09 16:52:21 +00:00
Simon Pilgrim 55f79ef9fe [TargetLowering] SimplifyDemandedBits - Remove GetDemandedSrcMask lambda. NFCI.
An older version of this could return false but now that this always succeeds we can just inline and simplify it.

llvm-svn: 357999
2019-04-09 12:29:26 +00:00
Simon Pilgrim 345eacd555 [TargetLowering] SimplifyDemandedBits - call SimplifyDemandedBits in bitcast handling
When bitcasting from a source op to a larger bitwidth op, split the demanded bits and OR them on top of one another and demand those merged bits in the SimplifyDemandedBits call on the source op.

llvm-svn: 357992
2019-04-09 10:27:59 +00:00
Simon Pilgrim 9f74df7d5b [TargetLowering] SimplifyDemandedBits - use DemandedElts in bitcast handling
Be more selective in the SimplifyDemandedBits -> SimplifyDemandedVectorElts bitcast call based on the demanded elts.

llvm-svn: 357942
2019-04-08 20:59:38 +00:00
Simon Pilgrim 561ba38623 [DAG] Pull out ComputeNumSignBits call to make debugging easier. NFCI.
llvm-svn: 357861
2019-04-07 11:49:33 +00:00
Simon Pilgrim 17586cda4a [SelectionDAG] Add fcmp UNDEF handling to SelectionDAG::FoldSetCC
Second half of PR40800, this patch adds DAG undef handling to fcmp instructions to match the behavior in llvm::ConstantFoldCompareInstruction, this permits constant folding of vector comparisons where some elements had been reduced to UNDEF (by SimplifyDemandedVectorElts etc.).

This involves a lot of tweaking to reduced tests as bugpoint loves to reduce fcmp arguments to undef........

Differential Revision: https://reviews.llvm.org/D60006

llvm-svn: 357765
2019-04-05 14:56:21 +00:00
Sanjay Patel 50a8652785 [DAGCombiner][x86] scalarize splatted vector FP ops
There are a variety of vector patterns that may be profitably reduced to a
scalar op when scalar ops are performed using a subset (typically, the
first lane) of the vector register file.

For x86, this is true for float/double ops and element 0 because
insert/extract is just a sub-register rename.

Other targets should likely enable the hook in a similar way.

Differential Revision: https://reviews.llvm.org/D60150

llvm-svn: 357760
2019-04-05 13:32:17 +00:00
Piotr Sobczak 0376ac1d94 [SelectionDAG] Compute known bits of CopyFromReg
Summary:
Teach SelectionDAG how to compute known bits of ISD::CopyFromReg if
the virtual reg used has one def only.

This can be particularly useful when calling isBaseWithConstantOffset()
with the ISD::CopyFromReg argument, as more optimizations may get enabled
in the result.

Also add a missing truncation on X86, found by testing of this patch.

Change-Id: Id1c9fceec862d118c54a5b53adf72ada5d6daefa

Reviewers: bogner, craig.topper, RKSimon

Reviewed By: RKSimon

Subscribers: lebedev.ri, nemanjai, jvesely, nhaehnle, javed.absar, jsji, jdoerfert, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D59535

llvm-svn: 357745
2019-04-05 07:44:09 +00:00
Serguei Katkov c39636cc2c [FastISel] Fix crash for gc.relocate lowring
Lowering safepoint checks that all gc.relocaes observed in safepoint
must be lowered. However Fast-Isel is able to skip dead gc.relocate.

To resolve this issue we just ignore dead gc.relocate in the check.

Reviewers: reames
Reviewed By: reames
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D60184

llvm-svn: 357742
2019-04-05 05:41:08 +00:00
Evandro Menezes 85bd3978ae [IR] Refactor attribute methods in Function class (NFC)
Rename the functions that query the optimization kind attributes.

Differential revision: https://reviews.llvm.org/D60287

llvm-svn: 357731
2019-04-04 22:40:06 +00:00
Serguei Katkov fb44846e37 [FastISel] Fix the crash in gc.result lowering
The Fast ISel has a fallback to SelectionDAGISel in case it cannot handle the instruction.
This works as follows:
Using reverse order, try to select instruction using Fast ISel, if it cannot handle instruction it fallbacks to SelectionDAGISel
for these instructions if it is a call and continue fast instruction selections.

However if unhandled instruction is not a call or statepoint related instruction it fallbacks to SelectionDAGISel for all remaining
instructions in basic block.

However gc.result instruction is missed and as a result it is possible that gc.result is processed earlier than statepoint
causing breakage invariant the gc.results should be handled after statepoint.

Test is updated because in the current form fast-isel cannot handle ret instruction (due to i1 ret type without explicit ext)
and as a result test does not check fast-isel at all.

Reviewers: reames
Reviewed By: reames
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D60182

llvm-svn: 357672
2019-04-04 04:19:56 +00:00
Simon Pilgrim 8d248dbd77 [DAGCombiner] Rename variables Demanded -> DemandedBits/DemandedElts. NFCI.
Use consistent variable names down the SimplifyDemanded* call stack so debugging isn't such a annoyance.

llvm-svn: 357602
2019-04-03 16:00:59 +00:00
Sanjay Patel 00dae6b22d [DAGCombiner] loosen restrictions for moving shuffles after vector binop
There are 3 changes to make this correspond to the same transform in instcombine:
1. Remove the legality check - we can't create anything less legal than we started with.
2. Ease the use restriction, so we only bail out if both operands have >1 use.
3. Ease the use restriction for binops with a repeated operand (eg, mul x, x).

As discussed in D60150, there's a scalarization opportunity that will be made
easier by allowing this transform more generally.

llvm-svn: 357580
2019-04-03 13:42:06 +00:00
Simon Pilgrim 02599de2e1 [DAGCombine] Don't use getZExtValue() until we know the constant is in range.
Noticed during prep for a patch for PR40758.

llvm-svn: 357571
2019-04-03 11:00:55 +00:00
Hans Wennborg 94b867dc7c Revert r357256 "[DAGCombine] Improve Lifetime node chains."
As it caused a pathological compile-time regressionin V8, see PR41352.

> Improve both start and end lifetime nodes chain dependencies.
>
> Reviewers: courbet
>
> Reviewed By: courbet
>
> Subscribers: hiraditya, llvm-commits
>
> Tags: #llvm
>
> Differential Revision: https://reviews.llvm.org/D59795

This also reverts the follow-up r357309:

> [DAGCombiner] Rewrite ImproveLifetimeNodeChain to avoid DAG loop.
>
> Avoid EXPENSIVE_CHECK failure. NFCI.

llvm-svn: 357563
2019-04-03 07:41:58 +00:00
Sanjay Patel 7cb7daabbb [DAGCombiner] reduce code duplication; NFC
llvm-svn: 357498
2019-04-02 17:20:54 +00:00
Nirav Dave 54f7118de5 [DAGCombiner] Rewrite ImproveLifetimeNodeChain to avoid DAG loop.
Avoid EXPENSIVE_CHECK failure. NFCI.

llvm-svn: 357309
2019-03-29 20:26:23 +00:00
Nirav Dave 7e84cacdbd [DAG] Avoid redundancy in StoreMerge TokenFactor generation.
Avoid generating redundant TokenFactor when all merged stores have
the same chain.

llvm-svn: 357299
2019-03-29 18:50:22 +00:00
Nirav Dave fe59e14031 [DAGCombine] Prune unnused nodes.
Summary:
Nodes that have no uses are eventually pruned when they are selected
from the worklist. Record nodes newly added to the worklist or DAG and
perform pruning after every combine attempt.

Reviewers: efriedma, RKSimon, craig.topper, spatel, jyknight

Reviewed By: jyknight

Subscribers: jdoerfert, jyknight, nemanjai, jvesely, nhaehnle, javed.absar, hiraditya, jsji, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D58070

llvm-svn: 357283
2019-03-29 17:35:56 +00:00
Nirav Dave 610036c506 [DAG] Set up infrastructure to avoid smart constructor-based dangling nodes
Summary:
Various SelectionDAG non-combine operations (e.g. the getNode smart
constructor and legalization) may leave dangling nodes by applying
optimizations without fully pruning unused result values. This results
in nodes that are never added to the worklist and therefore can not be
pruned.

Add a node inserter for the combiner to make sure such nodes have the
chance of being pruned. This allows a number of additional peephole
optimizations.

Reviewers: efriedma, RKSimon, craig.topper, jyknight

Reviewed By: jyknight

Subscribers: msearles, jyknight, sdardis, nemanjai, javed.absar, hiraditya, jrtc27, atanasyan, jsji, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D58068

llvm-svn: 357279
2019-03-29 17:26:40 +00:00
Sanjay Patel 12685d0f7c [DAGCombiner] simplify shuffle of shuffle
After investigating the examples from D59777 targeting an SSE4.1 machine,
it looks like a very different problem due to how we map illegal types (256-bit in these cases).

We're missing a shuffle simplification that maps elements of a vector back to a shuffled operand.
We have a more general version of this transform in DAGCombiner::visitVECTOR_SHUFFLE(), but that
generality means it is limited to patterns with a one-use constraint, and the examples here have
2 uses. We don't need any uses or legality limitations for a simplification (no new value is
created).

It looks like we miss this pattern in IR too.

In one of the zext examples here, we have shuffle masks like this:

Shuf0 = vector_shuffle<0,u,3,7,0,u,3,7>
Shuf = vector_shuffle<4,u,6,7,u,u,u,u>

...so that's moving the high half of the 1st vector into the low half. But the high half of the
1st vector is already identical to the low half.

Differential Revision: https://reviews.llvm.org/D59961

llvm-svn: 357258
2019-03-29 14:20:38 +00:00
Nirav Dave 9259de217e [DAGCombine] Improve Lifetime node chains.
Improve both start and end lifetime nodes chain dependencies.

Reviewers: courbet

Reviewed By: courbet

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D59795

llvm-svn: 357256
2019-03-29 14:09:47 +00:00
Sanjay Patel 665a385035 [DAGCombiner] fold sext into decrement
This is a sibling to rL357178 that I noticed we'd hit if we chose
an alternate transform in D59818.

  %z = zext i8 %x to i32
  %dec = add i32 %z, -1
  %r = sext i32 %dec to i64
  =>
  %z2 = zext i8 %x to i64
  %r = add i64 %z2, -1

https://rise4fun.com/Alive/kPP

The x86 vector diffs show a slight regression, so there's a chance
that we should limit this and the previous transform to scalars.

But given that we allowed vectors before, I'm matching that behavior
here. We should change both transforms together if that's the right
thing to do.

llvm-svn: 357254
2019-03-29 13:49:08 +00:00
Hans Wennborg 800b12f90a Switch lowering: exploit unreachable fall-through when lowering case range cluster
In the example below, we would previously emit two range checks, one for cases
1--3 and one for 4--6. This patch makes us exploit the fact that the
fall-through is unreachable and only one range check is necessary.

  switch i32 %i, label %default [
    i32 1,  label %bb1
    i32 2,  label %bb1
    i32 3,  label %bb1
    i32 4,  label %bb2
    i32 5,  label %bb2
    i32 6,  label %bb2
  ]
  default: unreachable

llvm-svn: 357252
2019-03-29 13:40:05 +00:00
Craig Topper ea626d8bdb [SelectionDAGBuilder] Fix 80 column violation. NFC
llvm-svn: 357213
2019-03-28 20:52:22 +00:00
Nirav Dave 8b9c9822a1 [DAG] Fix Lifetime Node ID hashing.
llvm-svn: 357179
2019-03-28 15:53:01 +00:00
Sanjay Patel ffa8d3def7 [DAGCombiner] fold sext into negation
As noted in D59818:
  %z = zext i8 %x to i32
  %neg = sub i32 0, %z
  %r = sext i32 %neg to i64
  =>
  %z2 = zext i8 %x to i64
  %r = sub i64 0, %z2

https://rise4fun.com/Alive/KzSR

llvm-svn: 357178
2019-03-28 15:46:02 +00:00
Simon Pilgrim 38a0616c1d [DAGCombiner] Fold truncate(build_vector(x,y)) -> build_vector(truncate(x),truncate(y))
If scalar truncates are free, attempt to pre-truncate build_vectors source operands.

Only attempt to do this before legalization as we often end up with truncations/extensions during build_vector lowering.

Differential Revision: https://reviews.llvm.org/D59654

llvm-svn: 357161
2019-03-28 11:34:21 +00:00
Nirav Dave 6b741a8038 [DAGCombiner] Teach TokenFactor pruning to peek through lifetime nodes
Summary: Lifetime nodes were inhibiting TokenFactor simplification inhibiting chain-based optimizations.

Reviewers: courbet, jyknight

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D59897

llvm-svn: 357121
2019-03-27 20:37:08 +00:00
Justin Bogner b1650f0da9 [LegalizeVectorTypes] Allow single loads and stores for more short vectors
When lowering a load or store for TypeWidenVector, the type legalizer
would use a single load or store if the associated integer type was legal
or promoted. E.g. it loads a v4i8 as an i32 if i32 is legal/promotable.
(See https://reviews.llvm.org/rL236528 for reference.)

This applies that behaviour to vector types. If the vector type is
TypePromoteInteger, the element type is going to be TypePromoteInteger
as well, which will lead to have a single promoting load rather than N
individual promoting loads. For instance, if we have a v3i1, we would
now have a load of v4i1 instead of 3 loads of i1.

Patch by Guillaume Marques. Thanks!

Differential Revision: https://reviews.llvm.org/D56201

llvm-svn: 357120
2019-03-27 20:35:56 +00:00
Nirav Dave c6dfaa0e83 Revert r356996 "[DAG] Avoid smart constructor-based dangling nodes."
This patch appears to trigger very large compile time increases in
halide builds.

llvm-svn: 357116
2019-03-27 19:54:41 +00:00
Nikita Popov 6d855ea024 [ConstantRange] Rename isWrappedSet() to isUpperWrapped()
Split out from D59749. The current implementation of isWrappedSet()
doesn't do what it says on the tin, and treats ranges like
[X, Max] as wrapping, because they are represented as [X, 0) when
using half-inclusive ranges. This also makes it inconsistent with
the semantics of isSignWrappedSet().

This patch renames isWrappedSet() to isUpperWrapped(), in preparation
for the introduction of a new isWrappedSet() method with corrected
behavior.

llvm-svn: 357107
2019-03-27 18:19:33 +00:00
Nirav Dave b5630a2ab1 [DAGCombiner] Unify Lifetime and memory Op aliasing.
Rework BaseIndexOffset and isAlias to fully work with lifetime nodes
and fold in lifetime alias analysis.

This is mostly NFC.

Reviewers: courbet

Reviewed By: courbet

Subscribers: hiraditya, jdoerfert, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D59794

llvm-svn: 357070
2019-03-27 14:14:46 +00:00
Nirav Dave 96a264e053 [DAGCombine] Refactor GatherAllAliases. NFCI.
llvm-svn: 357069
2019-03-27 14:14:35 +00:00
Hans Wennborg 5c0d7a24e8 Re-commit r355490 "[CodeGen] Omit range checks from jump tables when lowering switches with unreachable default"
Original commit by Ayonam Ray.

This commit adds a regression test for the issue discovered in the
previous commit: that the range check for the jump table can only be
omitted if the fall-through destination of the jump table is
unreachable, which isn't necessarily true just because the default of
the switch is unreachable.

This addresses the missing optimization in PR41242.

> During the lowering of a switch that would result in the generation of a
> jump table, a range check is performed before indexing into the jump
> table, for the switch value being outside the jump table range and a
> conditional branch is inserted to jump to the default block. In case the
> default block is unreachable, this conditional jump can be omitted. This
> patch implements omitting this conditional branch for unreachable
> defaults.
>
> Differential Revision: https://reviews.llvm.org/D52002
> Reviewers: Hans Wennborg, Eli Freidman, Roman Lebedev

llvm-svn: 357067
2019-03-27 14:10:11 +00:00
Jonas Paulsson 38342a5185 [DAGCombiner] Don't allow addcarry if the carry producer is illegal.
getAsCarry() checks that the input argument is a carry-producing node before
allowing a transformation to addcarry. This patch adds a check to make sure
that the carry-producing node is legal. If it is not, it may not remain in a
form that is manageable by the target backend. The test case caused a
compilation failure during instruction selection for this reason on SystemZ.

Patch by Ulrich Weigand.

Review: Sanjay Patel
https://reviews.llvm.org/D59822

llvm-svn: 357052
2019-03-27 08:41:46 +00:00
Sanjay Patel bb5cba3cca [SDAG] add simplifications for FP at node creation time
We have the folds for fadd/fsub/fmul already in DAGCombiner,
so it may be possible to remove that code if we can guarantee that
these ops are zapped before they can exist.

llvm-svn: 357029
2019-03-26 20:54:15 +00:00
Nirav Dave a28c514581 [DAG] Avoid smart constructor-based dangling nodes.
Various SelectionDAG non-combine operations (e.g. the getNode smart
constructor and legalization) may leave dangling nodes by applying
optimizations or not fully pruning unused result values. This can
result in nodes that are never added to the worklist and therefore can
not be pruned.

Add a node inserter as the current node deleter to make sure such
nodes have the chance of being pruned.

Many minor changes, mostly positive.

llvm-svn: 356996
2019-03-26 15:08:14 +00:00
Simon Pilgrim e24441aab0 [TargetLowering] Add SimplifyDemandedBits support for ISD::INSERT_VECTOR_ELT
This helps us relax the extension of a lot of scalar elements before they are inserted into a vector.

Its exposes an issue in DAGCombiner::convertBuildVecZextToZext as some/all the zero-extensions may be relaxed to ANY_EXTEND, so we need to handle that case to avoid a couple of AVX2 VPMOVZX test regressions.

Once this is in it should be easier to fix a number of remaining failures to fold loads into VBROADCAST nodes.

Differential Revision: https://reviews.llvm.org/D59484

llvm-svn: 356989
2019-03-26 12:32:01 +00:00
Yi Kong 74b874ac4c Fix nondeterminism introduced in r353954
DenseMap iteration order is not guaranteed, use MapVector instead.

Fix provided by srhines.

Differential Revision: https://reviews.llvm.org/D59807

llvm-svn: 356988
2019-03-26 12:18:08 +00:00
Simon Pilgrim 167af1bafb [SelectionDAG] Add icmp UNDEF handling to SelectionDAG::FoldSetCC
First half of PR40800, this patch adds DAG undef handling to icmp instructions to match the behaviour in llvm::ConstantFoldCompareInstruction and SimplifyICmpInst, this permits constant folding of vector comparisons where some elements had been reduced to UNDEF (by SimplifyDemandedVectorElts etc.).

This involved a lot of tweaking to reduced tests as bugpoint loves to reduce icmp arguments to undef........

Differential Revision: https://reviews.llvm.org/D59363

llvm-svn: 356938
2019-03-25 18:51:57 +00:00
Craig Topper 07e3071854 [LegalizeDAG] Expand i16 bswap directly to a rotate by 8 instead of relying on DAG combine.
An i16 bswap can be implemented with an i16 rotate by 8. We previously emitted
a shift and OR sequence that DAG combine should be able to turn back into
rotate. But we might as well go there directly. If rotate isn't legal,
LegalizeDAG should further legalize it to either the opposite rotate, or the
shift and OR pattern.

I don't know of any way to get the existing DAG combine reliance to fail. So
I don't know any way to add new tests for this that wouldn't have worked
previously.

llvm-svn: 356860
2019-03-24 17:02:14 +00:00
Simon Pilgrim 94e8f152c1 [TargetLowering] SimplifyDemandedBits trunc(srl(x, C1)) - early out for out of range C1. NFCI.
llvm-svn: 356810
2019-03-22 20:53:49 +00:00
Florian Hahn 71033f2987 [DAGCombiner] Use getTokenFactor in a few more cases.
SDNodes can only have 64k operands and for some inputs (e.g. large
number of stores), we can reach this limit when creating TokenFactor
nodes. This patch is a follow up to D56740 and updates a few more places
that potentially can create TokenFactors with too many operands.

Reviewers: efriedma, craig.topper, aemerson, RKSimon

Reviewed By: RKSimon

Differential Revision: https://reviews.llvm.org/D59156

llvm-svn: 356668
2019-03-21 14:32:09 +00:00
Simon Pilgrim da4992bf8d [DAGCombine] SimplifySelectCC - call FoldSetCC with the setcc result type
We were calling FoldSetCC with the compare operand type instead of the result type.

Found by OSS-Fuzz #13838 (https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=13838)

llvm-svn: 356667
2019-03-21 14:07:18 +00:00
Simon Pilgrim 54ed653870 [SelectionDAG] Add scalarization of ABS node (PR41149)
Patch by: @ikulagin (Ivan Kulagin)

Differential Revision: https://reviews.llvm.org/D59577

llvm-svn: 356656
2019-03-21 11:18:54 +00:00
Simon Pilgrim 51f65171e9 Remove out of date comment. NFCI.
DAGCombiner::convertBuildVecZextToZext just requires the extractions to be sequential, they don't have to start from 0'th index.

llvm-svn: 356552
2019-03-20 12:24:15 +00:00
Simon Pilgrim 77482120da Fix for ABS legalization on PPC buildbot.
llvm-svn: 356498
2019-03-19 18:55:46 +00:00
Philip Reames db65a5b776 Allow unordered loads to be considered invariant in CodeGen
The actual code change is fairly straight forward, but exercising it isn't. First, it turned out we weren't adding the appropriate flags in SelectionDAG. Second, it turned out that we've got some optimization gaps, so obvious test cases don't work.

My first attempt (in atomic-unordered.ll) points out a deficiency in our peephole-opt folding logic which I plan to fix separately. Instead, I'm exercising this through MachineLICM.

Differential Revision: https://reviews.llvm.org/D59375

llvm-svn: 356494
2019-03-19 18:27:18 +00:00
Justin Bogner b353d6887e [DAGCombine] Fix a miscompile when reducing BUILD_VECTORs to a shuffle
In r311255 we added a case where we split vectors whose elements are
all derived from the same input vector so that we could shuffle it
more efficiently. In doing so, createBuildVecShuffle was taught to
adjust for the fact that all indices would be based off of the first
vector when this happens, but it's possible for the code that checked
that to fire incorrectly if we happen to have a BUILD_VECTOR of
extracts from subvectors and don't hit this new optimization.

Instead of trying to detect if we've split the vector by checking if
we have extracts from the same base vector, we can just pass that
information into createBuildVecShuffle, avoiding the miscompile.

Differential Revision: https://reviews.llvm.org/D59507

llvm-svn: 356476
2019-03-19 16:52:00 +00:00
Simon Pilgrim a56f2822d0 [SelectionDAG] Handle unary SelectPatternFlavor for ABS case in SelectionDAGBuilder::visitSelect
These changes are related to PR37743 and include:

    SelectionDAGBuilder::visitSelect handles the unary SelectPatternFlavor::SPF_ABS case to build ABS node.

    Delete the redundant recognizer of the integer ABS pattern from the DAGCombiner.

    Add promoting the integer ABS node in the LegalizeIntegerType.

    Expand-based legalization of integer result for the ABS nodes.

    Expand-based legalization of ABS vector operations.

    Add some integer abs testcases for different typesizes for Thumb arch

    Add the custom ABS expanding and change the SAD pattern recognizer for X86 arch: The i64 result of the ABS is expanded to:
        tmp = (SRA, Hi, 31)
        Lo = (UADDO tmp, Lo)
        Hi = (XOR tmp, (ADDCARRY tmp, hi, Lo:1))
        Lo = (XOR tmp, Lo)

    The "detectZextAbsDiff" function is changed for the recognition of pattern with the ABS node. Given a ABS node, detect the following pattern:
        (ABS (SUB (ZERO_EXTEND a), (ZERO_EXTEND b))).

    Change integer abs testcases for codegen with the ABS node support for AArch64.
        Indicate that the ABS is legal for the i64 type when the NEON is supported.
        Change the integer abs testcases to show changing of codegen.

    Add combine and legalization of ABS nodes for Thumb arch.

    Extend 'matchSelectPattern' to recognize the ABS patterns with ICMP_SGE condition.

For discussion, see https://bugs.llvm.org/show_bug.cgi?id=37743

Patch by: @ikulagin (Ivan Kulagin)

Differential Revision: https://reviews.llvm.org/D49837

llvm-svn: 356468
2019-03-19 16:24:55 +00:00
Adhemerval Zanella 664c1ef528 [TargetLowering] Add code size information on isFPImmLegal. NFC
This allows better code size for aarch64 floating point materialization
in a future patch.

Reviewers: evandro

Differential Revision: https://reviews.llvm.org/D58690

llvm-svn: 356389
2019-03-18 18:40:07 +00:00
Nirav Dave 55c921f4bf [DAG] Cleanup unused node in SimplifySelectCC.
Delete temporarily constructed node uses for analysis after it's use,
holding onto original input nodes. Ideally this would be rewritten
without making nodes, but this appears relatively complex.

Reviewers: spatel, RKSimon, craig.topper

Subscribers: jdoerfert, hiraditya, deadalnix, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D57921

llvm-svn: 356382
2019-03-18 17:02:38 +00:00
David Stenberg 8a2e4af7e7 [DebugInfo] Ignore bitcasts when lowering stack arg dbg.values
Summary:
Look past bitcasts when looking for parameter debug values that are
described by frame-index loads in `EmitFuncArgumentDbgValue()`.

In the attached test case we would be left with an undef `DBG_VALUE`
for the parameter without this patch.

A similar fix was done for parameters passed in registers in D13005.

This fixes PR40777.

Reviewers: aprantl, vsk, jmorse

Reviewed By: aprantl

Subscribers: bjope, javed.absar, jdoerfert, llvm-commits

Tags: #debug-info, #llvm

Differential Revision: https://reviews.llvm.org/D58831

llvm-svn: 356363
2019-03-18 11:27:32 +00:00
Tim Renouf c302b9b5fe [CodeGen] Prepare for introduction of v3 and v5 MVTs
AMDGPU would like to have MVTs for v3i32, v3f32, v5i32, v5f32. This
commit does not add them, but makes preparatory changes:

* Exclude non-legal non-power-of-2 vector types from ComputeRegisterProp
  mechanism in TargetLoweringBase::getTypeConversion.

* Cope with SETCC and VSELECT for odd-width i1 vector when the other
  vectors are legal type.

Some of this patch is from Matt Arsenault, also of AMD.

Differential Revision: https://reviews.llvm.org/D58899

Change-Id: Ib5f23377dbef511be3a936211a0b9f94e46331f8
llvm-svn: 356350
2019-03-17 21:43:12 +00:00
Nikita Popov 9a4453592b [DAGCombine] Fold (x & ~y) | y patterns
Fold (x & ~y) | y and it's four commuted variants to x | y. This pattern
can in particular appear when a vselect c, x, -1 is expanded to
(x & ~c) | (-1 & c) and combined to (x & ~c) | c.

This change has some overlap with D59066, which avoids creating a
vselect of this form in the first place during uaddsat expansion.

Differential Revision: https://reviews.llvm.org/D59174

llvm-svn: 356333
2019-03-17 15:45:38 +00:00
Sanjay Patel 6a6e808b69 [TargetLowering] improve the default expansion of uaddsat/usubsat
This is a subset of what was proposed in:
D59006
...and may overlap with test changes from:
D59174
...but it seems like a good general optimization to turn selects
into bitwise-logic when possible because we never know exactly
what can happen at this stage of DAG combining depending on how
the target has defined things.

Differential Revision: https://reviews.llvm.org/D59066

llvm-svn: 356332
2019-03-17 14:57:40 +00:00
Simon Pilgrim 3b0a6c69ee [DAGCombine] combineShuffleOfScalars - handle non-zero SCALAR_TO_VECTOR indices (PR41097)
rL356292 reduces the size of scalar_to_vector if we know the upper bits are undef - which means that shuffles may find they are suddenly referencing scalar_to_vector elements other than zero - so make sure we handle this as undef.

llvm-svn: 356327
2019-03-16 17:36:26 +00:00
Heejin Ahn 66ce419468 [WebAssembly] Make rethrow take an except_ref type argument
Summary:
In the new wasm EH proposal, `rethrow` takes an `except_ref` argument.
This change was missing in r352598.

This patch adds `llvm.wasm.rethrow.in.catch` intrinsic. This is an
intrinsic that's gonna eventually be lowered to wasm `rethrow`
instruction, but this intrinsic can appear only within a catchpad or a
cleanuppad scope. Also this intrinsic needs to be invokable - otherwise
EH pad successor for it will not be correctly generated in clang.

This also adds lowering logic for this intrinsic in
`SelectionDAGBuilder::visitInvoke`. This routine is basically a
specialized and simplified version of
`SelectionDAGBuilder::visitTargetIntrinsic`, but we can't use it
because if is only for `CallInst`s.

This deletes the previous `llvm.wasm.rethrow` intrinsic and related
tests, which was meant to be used within a `__cxa_rethrow` library
function. Turned out this needs some more logic, so the intrinsic for
this purpose will be added later.

LateEHPrepare takes a result value of `catch` and inserts it into
matching `rethrow` as an argument.

`RETHROW_IN_CATCH` is a pseudo instruction that serves as a link between
`llvm.wasm.rethrow.in.catch` and the real wasm `rethrow` instruction. To
generate a `rethrow` instruction, we need an `except_ref` argument,
which is generated from `catch` instruction. But `catch` instrutions are
added in LateEHPrepare pass, so we use `RETHROW_IN_CATCH`, which takes
no argument, until we are able to correctly lower it to `rethrow` in
LateEHPrepare.

Reviewers: dschuff

Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D59352

llvm-svn: 356316
2019-03-16 05:38:57 +00:00
Simon Pilgrim 8fbe439345 [SelectionDAG] Add SimplifyDemandedBits handling for ISD::SCALAR_TO_VECTOR
Fixes a lot of constant folding mismatches between i686 and x86_64

llvm-svn: 356273
2019-03-15 17:00:55 +00:00
Nirav Dave ee5183c796 [DAGCombiner] Fix Comment. NFC.
llvm-svn: 356069
2019-03-13 17:44:40 +00:00
Nirav Dave d6351340bb [DAGCombiner] If a TokenFactor would be merged into its user, consider the user later.
Summary:
A number of optimizations are inhibited by single-use TokenFactors not
being merged into the TokenFactor using it. This makes we consider if
we can do the merge immediately.

Most tests changes here are due to the change in visitation causing
minor reorderings and associated reassociation of paired memory
operations.

CodeGen tests with non-reordering changes:

  X86/aligned-variadic.ll -- memory-based add folded into stored leaq
  value.

  X86/constant-combiners.ll -- Optimizes out overlap between stores.

  X86/pr40631_deadstore_elision -- folds constant byte store into
  preceding quad word constant store.

Reviewers: RKSimon, craig.topper, spatel, efriedma, courbet

Reviewed By: courbet

Subscribers: dylanmckay, sdardis, nemanjai, jvesely, nhaehnle, javed.absar, eraman, hiraditya, kbarton, jrtc27, atanasyan, jsji, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D59260

llvm-svn: 356068
2019-03-13 17:07:09 +00:00
Clement Courbet 3bb5d0bb9b Re-land r354244 "[DAGCombiner] Eliminate dead stores to stack."
Always check candidates for hasOtherUses(), not only stores.

llvm-svn: 356050
2019-03-13 13:56:23 +00:00
Simon Pilgrim 360ce82db2 [DAG] Move integer setcc %x, %x folding into FoldSetCC
First step towards PR40800 - I intend to move the float case in a separate future patch.

I had to tweak the (overly reduced) thumb2 test and the x86 widening test change is annoying (no longer rematerializable) but we should address this separately.

Differential Revision: https://reviews.llvm.org/D59244

llvm-svn: 356040
2019-03-13 11:08:57 +00:00
Philip Reames 18408d5e79 [CodeGen] Add MMOs to statepoint nodes during SelectionDAG
The existing statepoint lowering code does something odd; it adds machine memory operands post instruction selection. This was copied from the stackmap/patchpoint implementation, but appears to be non-idiomatic.

This change is largely NFC. It moves the MMO creation logic into SelectionDAG building. It ends up not quite being NFC because the size of the stack slot is reflected in the MMO. The old code blindly used pointer size for the MMO size, which appears to have always been incorrect for larger values. It just happened nothing actually relied on the MMOs, so it worked out okay.

For context, I'm planning on removing the MOVolatile flag from these in a future commit, and then removing the MOStore flag from deopt spill slots in a separate one. Doing so is motivated by a small test case where we should be able to better schedule spill slots, but don't do so due to a memory use/def implied by the statepoint.

Differential Revision: https://reviews.llvm.org/D59106

llvm-svn: 355953
2019-03-12 19:12:33 +00:00
Nikita Popov 149bc099f6 [SDAG] Expand pow2 mulo using shifts
Expand MULO with constant power of two operand into a shift. The
overflow is checked with (x << shift) >> shift == x, where the right
shift will be logical for umulo and arithmetic for smulo (with
exception for multiplications by signed_min).

Differential Revision: https://reviews.llvm.org/D59041

llvm-svn: 355937
2019-03-12 16:57:25 +00:00
Simon Pilgrim 9f0a5ca843 [DAGCombine] Pull out repeated demanded bitmask generation. NFCI.
llvm-svn: 355932
2019-03-12 15:58:28 +00:00
Nikita Popov aa7cfa75f9 [SDAG][AArch64] Legalize VECREDUCE
Fixes https://bugs.llvm.org/show_bug.cgi?id=36796.

Implement basic legalizations (PromoteIntRes, PromoteIntOp,
ExpandIntRes, ScalarizeVecOp, WidenVecOp) for VECREDUCE opcodes.
There are more legalizations missing (esp float legalizations),
but there's no way to test them right now, so I'm not adding them.

This also includes a few more changes to make this work somewhat
reasonably:

 * Add support for expanding VECREDUCE in SDAG. Usually
   experimental.vector.reduce is expanded prior to codegen, but if the
   target does have native vector reduce, it may of course still be
   necessary to expand due to legalization issues. This uses a shuffle
   reduction if possible, followed by a naive scalar reduction.
 * Allow the result type of integer VECREDUCE to be larger than the
   vector element type. For example we need to be able to reduce a v8i8
   into an (nominally) i32 result type on AArch64.
 * Use the vector operand type rather than the scalar result type to
   determine the action, so we can control exactly which vector types are
   supported. Also change the legalize vector op code to handle
   operations that only have vector operands, but no vector results, as
   is the case for VECREDUCE.
 * Default VECREDUCE to Expand. On AArch64 (only target using VECREDUCE),
   explicitly specify for which vector types the reductions are supported.

This does not handle anything related to VECREDUCE_STRICT_*.

Differential Revision: https://reviews.llvm.org/D58015

llvm-svn: 355860
2019-03-11 20:22:13 +00:00
Simon Pilgrim f3be93a2ff [DAG] FoldSetCC - reuse valuetype + ensure its simple.
llvm-svn: 355847
2019-03-11 17:56:18 +00:00
Simon Pilgrim 1bb5b56485 [DAG] Move SetCC NaN handling into FoldSetCC
llvm-svn: 355845
2019-03-11 17:43:10 +00:00
Simon Pilgrim 53518b45a5 [DAG] TargetLowering::SimplifySetCC - call FoldSetCC early to handle constant/commute folds.
Noticed while looking at PR40800 (and also D57921)

llvm-svn: 355828
2019-03-11 15:01:31 +00:00
Amaury Sechet a135fd5562 Remove redundant extractBooleanFlip argument. NFC
llvm-svn: 355794
2019-03-11 00:37:01 +00:00
Craig Topper 1a872f2b15 Recommit r355224 "[TableGen][SelectionDAG][X86] Add specific isel matchers for immAllZerosV/immAllOnesV. Remove bitcasts from X86 patterns that are no longer necessary."
Includes a fix to emit a CheckOpcode for build_vector when immAllZerosV/immAllOnesV is used as a pattern root. This means it can't be used to look through bitcasts when used as a root, but that's probably ok. This extra CheckOpcode will ensure that the first match in the isel table will be a SwitchOpcode which is needed by the caching optimization in the ISel Matcher.

Original commit message:

Previously we had build_vector PatFrags that called ISD::isBuildVectorAllZeros/Ones. Internally the ISD::isBuildVectorAllZeros/Ones look through bitcasts, but we aren't able to take advantage of that in isel. Instead of we have to canonicalize the types of the all zeros/ones build_vectors and insert bitcasts. Then we have to pattern match those exact bitcasts.

By emitting specific matchers for these 2 nodes, we can make isel look through any bitcasts without needing to explicitly match them. We should also be able to remove the canonicalization to vXi32 from lowering, but I've left that for a follow up.

This removes something like 40,000 bytes from the X86 isel table.

Differential Revision: https://reviews.llvm.org/D58595

llvm-svn: 355784
2019-03-10 05:21:52 +00:00
Amaury Sechet b62642a115 Refactor isBooleanFlip into extractBooleanFlip so that users do not depend on the patern matched. NFC
llvm-svn: 355769
2019-03-09 02:51:52 +00:00
Matt Arsenault 26e76ef0e2 DAG: Don't try to cluster loads with tied inputs
This avoids breaking possible value dependencies when sorting loads by
offset.

AMDGPU has some load instructions that write into the high or low bits
of the destination register, and have a tied input for the other input
bits. These can easily have the same base pointer, but be a swizzle so
the high address load needs to come first. This was inserting glue
forcing the opposite ordering, producing a cycle the InstrEmitter
would assert on. It may be potentially expensive to look for the
dependency between the other loads, so just skip any where this could
happen.

Fixes bug 40936 by reverting r351379, which added a hacky attempt to
fix this by adding chains in this case, which I think was just working
around broken glue before the InstrEmitter. The core of the patch is
re-implementing the fix for that problem.

llvm-svn: 355728
2019-03-08 20:46:15 +00:00
Amaury Sechet 782ac933b5 [DAGCombiner] fold (add (add (xor a, -1), b), 1) -> (sub b, a)
Summary: This pattern is sometime created after legalization.

Reviewers: efriedma, spatel, RKSimon, zvi, bkramer

Subscribers: llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D58874

llvm-svn: 355716
2019-03-08 19:39:32 +00:00
Simon Pilgrim 04e8439f72 [DAGCombine] Merge visitSMULO+visitUMULO into visitMULO. NFCI.
llvm-svn: 355690
2019-03-08 11:41:18 +00:00
Simon Pilgrim c71d6d157f [DAGCombine] Merge visitSADDO+visitUADDO into visitADDO. NFCI.
llvm-svn: 355689
2019-03-08 11:30:33 +00:00
Simon Pilgrim 2c2e76a9e2 [DAGCombine] Merge visitSSUBO+visitUSUBO into visitSUBO. NFCI.
llvm-svn: 355688
2019-03-08 11:16:55 +00:00
Paul Robinson 05efe0fdc4 [PS4] Emit a trap after a stack-protector fail call.
llvm-svn: 355542
2019-03-06 19:57:43 +00:00
Simon Pilgrim 9d6347cfc1 [DAGCombine] Improve select (not Cond), N1, N2 -> select Cond, N2, N1 fold
Move the x86 combine from D58974 into the DAGCombine VSELECT code and update the SELECT version to use the isBooleanFlip helper as well.

Requested by @spatel on D59006

llvm-svn: 355533
2019-03-06 18:52:52 +00:00
Simon Pilgrim cdf95f8f07 [DAGCombiner] Enable UADDO/USUBO vector combine support
Differential Revision: https://reviews.llvm.org/D58965

llvm-svn: 355517
2019-03-06 16:11:03 +00:00
Sanjay Patel 1fefc30b08 [TargetLowering] simplify code for uaddsat/usubsat expansion; NFC
We had 2 local variable names for the same type.

llvm-svn: 355516
2019-03-06 16:06:27 +00:00
Alexander Kornienko 3d467a890e Revert "[CodeGen] Omit range checks from jump tables when lowering switches with unreachable default"
This reverts commit 2a0f2c5ef3 (r355490).

The commit causes an assertion failure when compiling LLVM code:
$ cat repro.cpp
class QQQ {
public:
  bool x() const;
  bool y() const;
  unsigned getSizeInBits() const {
    if (y() || x())
      return getScalarSizeInBits();
    return getScalarSizeInBits() * 2;
  }
  unsigned getScalarSizeInBits() const;
};
int f(const QQQ &Ty) {
  switch (Ty.getSizeInBits()) {
    case 1:
    case 8:
      return 0;
    case 16:
      return 1;
    case 32:
      return 2;
    case 64:
      return 3;
    default:
      __builtin_unreachable();
  }
}
$ clang -O2 -o repro.o repro.cpp
assert.h assertion failed at llvm/include/llvm/ADT/ilist_iterator.h:139 in llvm::ilist_iterator::reference llvm::ilist_iterator<llvm::ilist_detail::node_options<llvm::MachineInstr, true, true, void>, true, false>::operator*() const [OptionsT = llvm::ilist_detail::node_options<llvm::MachineInstr, true, true, void>, IsReverse = true, IsConst = false]: !NodePtr->isKnownSentinel()
*** Check failure stack trace: ***
    @     0x558aab4afc10  __assert_fail
    @     0x558aa885479b  llvm::ilist_iterator<>::operator*()
    @     0x558aa8854715  llvm::MachineInstrBundleIterator<>::operator*()
    @     0x558aa92c33c3  llvm::X86InstrInfo::optimizeCompareInstr()
    @     0x558aa9a9c251  (anonymous namespace)::PeepholeOptimizer::optimizeCmpInstr()
    @     0x558aa9a9b371  (anonymous namespace)::PeepholeOptimizer::runOnMachineFunction()
    @     0x558aa99a4fc8  llvm::MachineFunctionPass::runOnFunction()
    @     0x558aab019fc4  llvm::FPPassManager::runOnFunction()
    @     0x558aab01a3a5  llvm::FPPassManager::runOnModule()
    @     0x558aab01aa9b  (anonymous namespace)::MPPassManager::runOnModule()
    @     0x558aab01a635  llvm::legacy::PassManagerImpl::run()
    @     0x558aab01afe1  llvm::legacy::PassManager::run()
    @     0x558aa5914769  (anonymous namespace)::EmitAssemblyHelper::EmitAssembly()
    @     0x558aa5910f44  clang::EmitBackendOutput()
    @     0x558aa5906135  clang::BackendConsumer::HandleTranslationUnit()
    @     0x558aa6d165ad  clang::ParseAST()
    @     0x558aa6a94e22  clang::ASTFrontendAction::ExecuteAction()
    @     0x558aa590255d  clang::CodeGenAction::ExecuteAction()
    @     0x558aa6a94840  clang::FrontendAction::Execute()
    @     0x558aa6a38cca  clang::CompilerInstance::ExecuteAction()
    @     0x558aa4e2294b  clang::ExecuteCompilerInvocation()
    @     0x558aa4df6200  cc1_main()
    @     0x558aa4e1b37f  ExecuteCC1Tool()
    @     0x558aa4e1a725  main
    @     0x7ff20d56abbd  __libc_start_main
    @     0x558aa4df51c9  _start

llvm-svn: 355515
2019-03-06 15:23:50 +00:00
Sanjay Patel 89e534746f [TargetLowering] simplify code for uaddsat/usubsat expansion; NFC
llvm-svn: 355508
2019-03-06 14:34:59 +00:00
Simon Pilgrim 1bdc2d1874 [DAGCombiner] Add SADDO/SSUBO combine support
Basic constant handling folds, for both scalars and vectors

Differential Revision: https://reviews.llvm.org/D58967

llvm-svn: 355506
2019-03-06 14:22:21 +00:00
Simon Pilgrim 642f53d292 [DAGCombiner] Enable SMULO/UMULO vector combine support (PR40442)
Differential Revision: https://reviews.llvm.org/D58968

llvm-svn: 355495
2019-03-06 11:04:21 +00:00
Ayonam Ray 2a0f2c5ef3 [CodeGen] Omit range checks from jump tables when lowering switches with unreachable default
During the lowering of a switch that would result in the generation of a
jump table, a range check is performed before indexing into the jump
table, for the switch value being outside the jump table range and a
conditional branch is inserted to jump to the default block. In case the
default block is unreachable, this conditional jump can be omitted. This
patch implements omitting this conditional branch for unreachable
defaults.

Differential Revision: https://reviews.llvm.org/D52002
Reviewers: Hans Wennborg, Eli Freidman, Roman Lebedev

llvm-svn: 355490
2019-03-06 10:01:02 +00:00
Ayonam Ray af92b7a3b8 Reversing the commit of revision 355483 since it is giving a regression on a newly added test.
llvm-svn: 355487
2019-03-06 07:51:28 +00:00
Ayonam Ray 6025fa8e30 [CodeGen] Omit range checks from jump tables when lowering switches with unreachable default
During the lowering of a switch that would result in the generation of a
jump table, a range check is performed before indexing into the jump
table, for the switch value being outside the jump table range and a
conditional branch is inserted to jump to the default block. In case the
default block is unreachable, this conditional jump can be omitted. This
patch implements omitting this conditional branch for unreachable
defaults.

Differential Revision: https://reviews.llvm.org/D52002
Reviewers: Hans Wennborg, Eli Freidman, Roman Lebedev

llvm-svn: 355483
2019-03-06 07:27:45 +00:00
Craig Topper 57fd733140 Revert r355224 "[TableGen][SelectionDAG][X86] Add specific isel matchers for immAllZerosV/immAllOnesV. Remove bitcasts from X86 patterns that are no longer necessary."
This caused the first matcher in the isel table for many targets to Opc_Scope instead of Opc_SwitchOpcode. This leads to a significant increase in isel match failures.

llvm-svn: 355433
2019-03-05 19:18:16 +00:00
Sanjay Patel 8b72080d4d [SDAG] move FP constant folding to helper function; NFC
llvm-svn: 355411
2019-03-05 16:42:33 +00:00
Craig Topper 509a8a3cf1 [DAGCombiner][X86][SystemZ][AArch64] Combine some cases of (bitcast (build_vector constants)) between legalize types and legalize dag.
This patch enables combining integer bitcasts of integer build vectors when the new scalar type is legal. I've avoided floating point because the implementation bitcasts float to int along the way and we would need to check the intermediate types for legality

Differential Revision: https://reviews.llvm.org/D58884

llvm-svn: 355324
2019-03-04 19:12:16 +00:00
Heejin Ahn 195a62e9ae [WebAssembly] Delete ThrowUnwindDest map from WasmEHFuncInfo
Summary:
Before when we implemented the first EH proposal, 'catch <tag>'
instruction may not catch an exception so there were multiple EH pads an
exception can unwind to. That means a BB could have multiple EH pad
successors.

Now after we switched to the new proposal, every 'catch' instruction
catches an exception, and there is only one catchpad per catchswitch, so
we at most have one EH pad successor, making `ThrowUnwindDest` map in
`WasmEHInfo` unnecessary.

Keeping `ThrowUnwindDest` map in `WasmEHInfo` has its own problems,
because other optimization passes can split a BB that contains possibly
throwing calls (previously invokes), and we have to update the map every
time that happens, which is not easy for common CodeGen passes.

This also correctly updates successor info in LateEHPrepare when we add
a rethrow instruction.

Reviewers: dschuff

Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D58486

llvm-svn: 355296
2019-03-03 22:35:56 +00:00
Simon Pilgrim 37a63a748e Use SDValue::getConstantOperandAPInt helper where possible. NFCI.
llvm-svn: 355267
2019-03-02 11:11:22 +00:00
Craig Topper 4cfc39179e [TableGen][SelectionDAG][X86] Add specific isel matchers for immAllZerosV/immAllOnesV. Remove bitcasts from X86 patterns that are no longer necessary.
Previously we had build_vector PatFrags that called ISD::isBuildVectorAllZeros/Ones. Internally the ISD::isBuildVectorAllZeros/Ones look through bitcasts, but we aren't able to take advantage of that in isel. Instead of we have to canonicalize the types of the all zeros/ones build_vectors and insert bitcasts. Then we have to pattern match those exact bitcasts.

By emitting specific matchers for these 2 nodes, we can make isel look through any bitcasts without needing to explicitly match them. We should also be able to remove the canonicalization to vXi32 from lowering, but I've left that for a follow up.

This removes something like 40,000 bytes from the X86 isel table.

Differential Revision: https://reviews.llvm.org/D58595

llvm-svn: 355224
2019-03-01 20:18:38 +00:00
Bjorn Pettersson d30f308a9f Add support for computing "zext of value" in KnownBits. NFCI
Summary:
The description of KnownBits::zext() and
KnownBits::zextOrTrunc() has confusingly been telling
that the operation is equivalent to zero extending the
value we're tracking. That has not been true, instead
the user has been forced to explicitly set the extended
bits as known zero afterwards.

This patch adds a second argument to KnownBits::zext()
and KnownBits::zextOrTrunc() to control if the extended
bits should be considered as known zero or as unknown.

Reviewers: craig.topper, RKSimon

Reviewed By: RKSimon

Subscribers: javed.absar, hiraditya, jdoerfert, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D58650

llvm-svn: 355099
2019-02-28 15:45:29 +00:00
Philip Reames 288a95fc8c Seperate volatility and atomicity/ordering in SelectionDAG
At the moment, we mark every atomic memory access as being also volatile. This is unnecessarily conservative and prohibits many legal transforms (DCE, folding, etc..).

This patch removes MOVolatile from the MachineMemOperands of atomic, but not volatile, instructions. This should be strictly NFC after a series of previous patches which have gone in to ensure backend code is conservative about handling of isAtomic MMOs. Once it's in and baked for a bit, we'll start working through removing unnecessary bailouts one by one. We applied this same strategy to the middle end a few years ago, with good success.

To make sure this patch itself is NFC, it is build on top of a series of other patches which adjust code to (for the moment) be as conservative for an atomic access as for a volatile access and build up a test corpus (mostly in test/CodeGen/X86/atomics-unordered.ll)..

Previously landed

    D57593 Fix a bug in the definition of isUnordered on MachineMemOperand
    D57596 [CodeGen] Be conservative about atomic accesses as for volatile
    D57802 Be conservative about unordered accesses for the moment
    rL353959: [Tests] First batch of cornercase tests for unordered atomics.
    rL353966: [Tests] RMW folding tests w/unordered atomic operations.
    rL353972: [Tests] More unordered atomic lowering tests.
    rL353989: [SelectionDAG] Inline a single use helper function, and remove last non-MMO interface
    rL354740: [Hexagon, SystemZ] Be super conservative about atomics
    rL354800: [Lanai] Be super conservative about atomics
    rL354845: [ARM] Be super conservative about atomics

Attention Out of Tree Backend Owners: This patch may break you. If it does, you can use the TLI getMMOFlags hook to restore the MOVolatile to any instruction you need to. (See llvm-dev thread titled "PSA: Changes to how atomics are handled in backends" started Feb 27, 2019.)

Differential Revision: https://reviews.llvm.org/D57601

llvm-svn: 355025
2019-02-27 20:20:08 +00:00
Nirav Dave 582d46328c [DAG] Fix constant store folding to handle non-byte sizes.
Avoid crashes from zero-byte values due to sub-byte store sizes.

Reviewers: uabelho, courbet, rnk

Reviewed By: courbet

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D58626

llvm-svn: 354884
2019-02-26 15:02:32 +00:00
Simon Pilgrim 566177c3d5 [LegalizeDAG] Use APInt::getSplat helper to create bitreverse masks. NFCI.
llvm-svn: 354867
2019-02-26 11:44:23 +00:00
Simon Pilgrim 810fa04ac7 [LegalizeDAG] Expand SADDO/SSUBO using SADDSAT/SSUBSAT (PR37763)
If SADDSAT/SSUBSAT are legal, then we can expand SADDO/SSUBO by performing a ADD/SUB and a SADDO/SSUBO and then compare the results.

I looked at doing this for UADDO/USUBO as well but as we don't have to do as many range comparisons I didn't see any/much benefit.

Differential Revision: https://reviews.llvm.org/D58637

llvm-svn: 354866
2019-02-26 11:27:53 +00:00
Andrea Di Biagio 4a1e59a6e0 Fix a sign compare warning breaking the -Werror build.
The warning was introduced at r354793.

llvm-svn: 354810
2019-02-25 19:33:58 +00:00
Simon Pilgrim 80d0e9c563 [SelectionDAG] Add demanded elts variants to isConstOrConstSplat helpers. NFCI.
These helpers extend the existing isConstOrConstSplat helper checks to support DemandedElts masks as well.

We already had a local version of this in SelectionDAG that computeKnownBits/ComputeNumSignBits made use of, but this adds the functionality directly to the BuildVectorSDNode node and extends isConstOrConstSplat etc. to use that.

This will allow us to reuse the functionality in SimplifyDemandedVectorElts/SimplifyDemandedBits.

Differential Revision: https://reviews.llvm.org/D58503

llvm-svn: 354797
2019-02-25 16:31:58 +00:00
Simon Pilgrim 28441ac75f [DAGCombine] Add undef shuffle elt support to partitionShuffleOfConcats
Support undef shuffle mask indices in the shuffle(concat_vectors, concat_vectors) -> concat_vectors fold

Differential Revision: https://reviews.llvm.org/D58585

llvm-svn: 354793
2019-02-25 16:02:01 +00:00
Craig Topper 8c9724ea4f [SelectionDAG] Add a OPC_CheckChild2CondCode to SelectionDAGISel to remove a MoveChild and MoveParent pair.
OPC_CheckCondCode is always used as operand 2 of a setcc. And its always surrounded by a MoveChild2 and a MoveParent. By having a dedicated opcode for this case we can reduce the number of bytes needed for this pattern from 4 bytes to 2.

This saves ~3000 bytes in the X86 table.

llvm-svn: 354763
2019-02-25 03:11:44 +00:00
Craig Topper be3348573e [LegalizeTypes][AArch64][X86] Make type legalization of vector (S/U)ADD/SUB/MULO follow getSetCCResultType for the overflow bits. Make UnrollVectorOverflowOp properly convert from scalar boolean contents to vector boolean contents
Summary:
When promoting the over flow vector for these ops we should use the target's desired setcc result type. This way a v8i32 result type will use a v8i32 overflow vector instead of a v8i16 overflow vector. A v8i16 overflow vector will cause LegalizeDAG/LegalizeVectorOps to have to use v8i32 and truncate to v8i16 in its expansion. By doing this in type legalization instead, we get the truncate into the DAG earlier and give DAG combine more of a chance to optimize it.

We also have to fix unrolling to use the scalar setcc result type for the scalarized operation, and convert it to the required vector element type after the scalar operation. We have to observe the vector boolean contents when doing this conversion. The previous code was just taking the scalar result and putting it in the vector. But for X86 and AArch64 that would have only put a the boolean value in bit 0 of the element and left all other bits in the element 0. We need to ensure all bits in the element are the same. I'm using a select with constants here because that's what setcc unrolling in LegalizeVectorOps used.

Reviewers: spatel, RKSimon, nikic

Reviewed By: nikic

Subscribers: javed.absar, kristof.beyls, dmgreen, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D58567

llvm-svn: 354753
2019-02-24 19:23:36 +00:00
Craig Topper ccc860cb81 Recommit r354647 and r354648 "[LegalizeTypes] When promoting the result of EXTRACT_SUBVECTOR, also check if the input needs to be promoted. Use that to determine the element type to extract"
r354648 was a follow up to fix a regression "[X86] Add a DAG combine for (aext_vector_inreg (aext_vector_inreg X)) -> (aext_vector_inreg X) to fix a regression from my previous commit."

These were reverted in r354713 as their context depended on other patches that were reverted for a bug.

llvm-svn: 354734
2019-02-23 19:51:32 +00:00
Jordan Rupprecht 6387fa2715 [NFC] Fix typos: preceeding -> preceding
llvm-svn: 354715
2019-02-23 01:28:32 +00:00
Reid Kleckner e3876637cf Revert r354363 & co "[X86][SSE] Generalize X86ISD::BLENDI support to more value types"
r354363 caused https://crbug.com/934963#c1, which has a plain C reduced
test case.

I also had to revert some dependent changes:
- r354648
- r354647
- r354640
- r354511

llvm-svn: 354713
2019-02-23 01:19:42 +00:00
Craig Topper 62619d064d [LegalizeTypes] Use PromoteTargetBoolean in PromoteIntOp_ADDSUBCARRY instead of reimplementing it. NFCI
llvm-svn: 354710
2019-02-23 00:38:19 +00:00
Nirav Dave 46f939c118 Disable big-endian constant store merges from rL354676.
llvm-svn: 354677
2019-02-22 16:20:34 +00:00
Nirav Dave 44037d7a63 [DAGCombine] Fold overlapping constant stores
Fold a smaller constant store into larger constant stores immediately
preceeding it.

Reviewers: rnk, courbet

Subscribers: javed.absar, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D58468

llvm-svn: 354676
2019-02-22 16:00:19 +00:00
Craig Topper fa6187d230 [LegalizeVectorOps] Improve the placement of ANDs in the ExpandLoad path for non-byte-sized loads.
When we need to merge two adjacent loads the AND mask for the low piece was still sized for the full src element size. But we didn't have that many bits. The upper bits are already zero due to the SRL. So we can skip the AND if we're going to combine with the high bits.

We do need an AND to clear out any bits from the high part. We were anding the high part before combining with the low part, but it looks like ANDing after the OR gets better results.

So we can just emit the final AND after the optional concatentation is done. That will handling skipping before the OR and get rid of extra high bits after the OR.

llvm-svn: 354655
2019-02-22 07:03:25 +00:00
Craig Topper 069cf05e87 [LegalizeVectorOps] Simplify the non-byte sized load handling VectorLegalizer::ExpandLoad. NFCI
Remove an if that should always be true. Merge the body of another into the only block that could make the if true.

llvm-svn: 354654
2019-02-22 06:18:33 +00:00
Matt Arsenault 0280a5e143 DAG: Add helper for creating shifts with correct type
llvm-svn: 354649
2019-02-22 03:38:47 +00:00
Craig Topper be22f329a9 [LegalizeTypes] When promoting the result of EXTRACT_SUBVECTOR, also check if the input needs to be promoted. Use that to determine the element type to extract.
Otherwise we end up creating extract_vector_elts that then each need to have their input promoted. This can lead to truncates needing to be emitted for each of those.

But we already emitted any_extends when we legalized the extract_subvector. So now we have pairs of any_extend+trunc that partially cancel. But depending on how DAGCombiner visits them we can get weird results.

By promoting the input at the same time we can create only a single any_extend or truncate.

There's one regression in the vector-narrow-binop.ll case, but that looks easy to fix with a follow up patch.

llvm-svn: 354647
2019-02-22 01:49:50 +00:00
Sanjay Patel ba5ee817e9 [DAGCombiner] prevent infinite looping by truncating 'and' (PR40793)
This fold can occur during legalization, so it can fight with promotion
to the larger type. It apparently takes a special sequence and subtarget
to avoid more basic simplifications that would hide the problem.

But there's a bigger question raised here: why does distributeTruncateThroughAnd()
even exist? It duplicates functionality from a more minimal pattern that we
already have. But getting rid of this function requires some preliminary steps.

https://bugs.llvm.org/show_bug.cgi?id=40793

llvm-svn: 354594
2019-02-21 16:01:48 +00:00
Clement Courbet a0321c23e8 Re-land part of r354244 "[DAGCombiner] Eliminate dead stores to stack."
This part introduces the lifetime node.

llvm-svn: 354578
2019-02-21 12:59:36 +00:00
Nirav Dave 48cf37b55c [DAGCombine] Generalize Dead Store to overlapping stores.
Summary:
Remove stores that are immediately overwritten by larger
stores.

Reviewers: courbet, rnk

Reviewed By: rnk

Subscribers: javed.absar, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D58467

llvm-svn: 354518
2019-02-20 21:07:50 +00:00
Craig Topper 8d9c224a8c [SelectionDAG] Teach GetDemandedBits to look at the known zeros of the LHS when handling ISD::AND
If the LHS has known zeros, then the RHS immediate mask might have been simplified to remove those bits.

This patch adds a call to computeKnownBits to get the known zeroes to handle that possibility. I left an early out to skip the call if all of the demanded bits are set in the mask.

Differential Revision: https://reviews.llvm.org/D58464

llvm-svn: 354514
2019-02-20 20:52:26 +00:00
Nikita Popov c3b496de7a [SDAG] Support vector UMULO/SMULO
Second part of https://bugs.llvm.org/show_bug.cgi?id=40442.

This adds an extra UnrollVectorOverflowOp() method to SDAG, because
the general UnrollOverflowOp() method can't deal with multiple results.

Additionally we need to expand UMULO/SMULO during vector op
legalization, as it may result in unrolling, which may need additional
type legalization.

Differential Revision: https://reviews.llvm.org/D57997

llvm-svn: 354513
2019-02-20 20:41:44 +00:00
Craig Topper f4923db5a3 Revert r354498 "[X86] Add test case to show missed opportunity to remove an explicit AND on the bit position from BT when it has known zeros."
I accidentally committed more than just the test.

llvm-svn: 354499
2019-02-20 18:47:26 +00:00
Craig Topper f8498a615b [X86] Add test case to show missed opportunity to remove an explicit AND on the bit position from BT when it has known zeros.
If the bit position has known zeros in it, then the AND immediate will likely be optimized to remove bits.

This can prevent GetDemandedBits from recognizing that the AND is unnecessary.

llvm-svn: 354498
2019-02-20 18:45:38 +00:00
Clement Courbet 62b3b91ab2 Re-land the refactoring part of r354244 "[DAGCombiner] Eliminate dead stores to stack."
This is an NFC.

llvm-svn: 354476
2019-02-20 15:45:58 +00:00
Chen Zheng b934fce613 [NFC] add/modify wrapper function for findRegisterDefOperand().
llvm-svn: 354438
2019-02-20 07:01:04 +00:00
Nikita Popov 04e45e9311 [SDAG] Use shift amount type in MULO promotion; NFC
Directly use the correct shift amount type if it is possible, and
future-proof the code against vectors. The added test makes sure that
bitwidths that do not fit into the shift amount type do not assert.

Split out from D57997.

llvm-svn: 354359
2019-02-19 17:37:55 +00:00
Clement Courbet 292291fb90 Revert r354244 "[DAGCombiner] Eliminate dead stores to stack."
Breaks some bots.

llvm-svn: 354245
2019-02-18 08:24:29 +00:00
Clement Courbet 57f34dbd3e [DAGCombiner] Eliminate dead stores to stack.
Summary:
A store to an object whose lifetime is about to end can be removed.

See PR40550 for motivation.

Reviewers: niravd

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D57541

llvm-svn: 354244
2019-02-18 07:59:01 +00:00
Nikita Popov f62aeda58d [SelectionDAG] Extract [US]MULO expansion into TL method; NFC
In preparation for supporting vector expansion.

Add an isPostTypeLegalization flag to makeLibCall(), because this
expansion relies on the legalized form using MERGE_VALUES. Drop
the corresponding variant of ExpandLibCall, which is no longer used.

Differential Revision: https://reviews.llvm.org/D58006

llvm-svn: 354226
2019-02-17 17:40:47 +00:00
Nirav Dave 7875841121 [X86] Fix LowerAsmOutputForConstraint.
Summary:
Update Flag when generating cc output.

Fixes PR40737.

Reviewers: rnk, nickdesaulniers, craig.topper, spatel

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D58283

llvm-svn: 354163
2019-02-15 20:01:55 +00:00
Simon Pilgrim a22814a399 Fix 80-column limit in SimplifyDemandedBits/SimplifyDemandedVectorElts. NFCI.
llvm-svn: 354152
2019-02-15 18:15:58 +00:00
Jeremy Morse 897a9f8d00 Fix an accidentally flipped pair of arguments, NFCI
While rebasing a refactor in r353950 I accidentally swapped two function
arguments; one is SelectionDAGBuilders "current" DebugLoc, the other is the one
from the "current" debug intrinsic. They're probably always identical, but I
haven't proved that yet.

llvm-svn: 354019
2019-02-14 11:09:24 +00:00
Philip Reames e4cfb7dae8 [SelectionDAG] Inline a single use helper function, and remove last non-MMO interface [NFC]
For D57601, we need to know whether the instruction is volatile.  We'd either have to pass yet another parameter, or just standardize on the MMO interface.  I chose the second.

llvm-svn: 353989
2019-02-13 23:01:11 +00:00
Philip Reames 41f400c948 [SelectionDAG] Kill last uses of getAtomic w/o a MMO operand [NFC]
The helper function was used by only two callers, and largely ended up providing distinct functionality based on optional arguments and opcode.  Inline and simply to make the functionality much more clear.

llvm-svn: 353977
2019-02-13 20:42:59 +00:00
Jeremy Morse 291713a596 [DebugInfo][DAG] Either salvage dangling debug info or emit Undef DBG_VALUEs
In this patch SelectionDAG tries to salvage any dbg.values that are going to be
dropped, in case they can be recovered from Values in the current BB. It also
strengthens SelectionDAGs handling of dangling debug data, so that dbg.values
are *always* emitted (as Undef or otherwise) instead of dangling forever.

The motivation behind this patch exists in the new test case: a memory address
(here a bitcast and GEP) exist in one basic block, and a dbg.value referring to
the address is left in the 'next' block. The base pointer is live across all
basic blocks. In current llvm trunk the dbg.value cannot be encoded, and it
isn't even emitted as an Undef DBG_VALUE.

The change is simply: if we're definitely going to drop a dbg.value, repeatedly
apply salvageDebugInfo to its operand until either we find something that can
be encoded, or we can't salvage any further in which case we produce an Undef
DBG_VALUE. To know when we're "definitely going to drop a dbg.value",
SelectionDAG signals SelectionDAGBuilder when all IR instructions have been
encoded to force salvaging. This ensures that any dbg.value that's dangling
after DAG creation will have a corresponding DBG_VALUE encoded. 

Differential Revision: https://reviews.llvm.org/D57694

llvm-svn: 353954
2019-02-13 16:33:05 +00:00
Jeremy Morse 6d3cd3b4ec [DebugInfo][DAG] Refactor dbg.value lowering into its own method
This is a pure copy-and-paste job, moving the logic for lowering dbg.value
intrinsics to SDDbgValues into its own function. This is ahead of adding some
more users of this logic.

Differential Revision: https://reviews.llvm.org/D57697

llvm-svn: 353950
2019-02-13 15:53:10 +00:00
Jeremy Morse a9a11aac0f [DebugInfo][DAG] Limit special-casing of dbg.values for Arguments
SelectionDAGBuilder has special handling for dbg.value intrinsics that are
understood to define the location of function parameters on entry to the
function. To enable this, we avoid recording a dbg.value as a virtual register
reference if it might be such a parameter, so that it later hits
EmitFuncArgumentDbgValue.

This patch reduces the set of circumstances where we avoid recording a
dbg.value as a virtual register reference, to allow more "normal" variables
to be recorded that way. We now only bypass for potential parameters if:
 * The dbg.value operand is an Argument,
 * The Variable is a parameter, and
 * The Variable is not inlined.
meaning it's very likely that the dbg.value is a function-entry parameter
location.

Differential Revision: https://reviews.llvm.org/D57584

llvm-svn: 353948
2019-02-13 13:37:33 +00:00
Bjorn Pettersson ecd0960718 [SelectionDAG] Clean up comments in SelectionDAGBuilder.h. NFC
Remove redundant function/variable names from doxygen
comments (as suggested in https://reviews.llvm.org/D57697).

llvm-svn: 353886
2019-02-12 22:11:20 +00:00
Sanjay Patel 86fac11d5a [DAGCombiner] convert logic-of-setcc into bit magic (PR40611)
If we're comparing some value for equality against 2 constants
and those constants have an absolute difference of just 1 bit,
then we can offset and mask off that 1 bit and reduce to a single
compare against zero:
         and/or (setcc X, C0, ne), (setcc X, C1, ne/eq) -->
         setcc ((add X, -C1), ~(C0 - C1)), 0, ne/eq

https://rise4fun.com/Alive/XslKj

This transform is disabled by default using a TLI hook
("convertSetCCLogicToBitwiseLogic()").

That should be overridden for AArch64, MIPS, Sparc and possibly
others based on the asm shown in:
https://bugs.llvm.org/show_bug.cgi?id=40611

llvm-svn: 353859
2019-02-12 17:07:47 +00:00
whitequark 77ccc2eba4 [SelectionDAG] Fix return calling convention in expansion of ?MULO
Summary:
The SMULO/UMULO DAG nodes, when not directly supported by the target,
expand to a multiplication twice as wide. In case that the resulting
type is not legal, the legalizer cannot directly call the intrinsic
with the wide arguments; instead, it "pre-lowers" them by splitting
them in halves.

rL283203 made sure that on big endian targets, the legalizer passes
the argument halves in the correct order. It did not do the same
for the return value halves because the existing code used a hack;
it put an illegal type into DAG and hoped that nothing would break
and it would be correctly lowered elsewhere.

rL307207 fixed this, handling return value halves similar to how
argument handles are handled, but did not take big-endian targets
into account.

This commit fixes the expansion on big-endian targets, such as
the out-of-tree OR1K target.

Reviewers: eli.friedman, vadimcn

Subscribers: george-hopkins, efriedma, llvm-commits

Differential Revision: https://reviews.llvm.org/D45355

llvm-svn: 353854
2019-02-12 16:41:50 +00:00
Philip Reames b6dc6eb8bb [Statepoint Lowering] Update misleading comments about chains
llvm-svn: 353800
2019-02-12 06:25:58 +00:00
Ana Pazos 9a3dc3e60b [LegalizeTypes] Expand FNEG to bitwise op for IEEE FP types
Summary:
Except for custom floating point types x86_fp80 and ppc_fp128,
expand Y = FNEG(X) to Y = X ^ sign mask to avoid library call.
 Using bitwise operation can improve code size and performance.

Reviewers: efriedma

Reviewed By: efriedma

Subscribers: efriedma, kpn, arsenm, eli.friedman, javed.absar, rbar, johnrusso, simoncook, sabuasal, niosHD, zzheng, edward-jones, rogfer01, MartinMosbeck, brucehoult, the_o, PkmX, jocewei, asb, llvm-commits

Differential Revision: https://reviews.llvm.org/D57875

llvm-svn: 353757
2019-02-11 22:10:08 +00:00
Bjorn Pettersson 4892f06e06 [SelectionDAGBuilder] Add restrictions to EmitFuncArgumentDbgValue
Summary:
This patch fixes PR40587.

When a dbg.value instrinsic is emitted to the DAG
by using EmitFuncArgumentDbgValue the resulting
DBG_VALUE is hoisted to the beginning of the entry
block. I think the idea is to be able to locate
a formal argument already from the start of the
function.
However, EmitFuncArgumentDbgValue only checked that
the value that was used to describe a variable was
originating from a function parameter, not that the
variable itself actually was an argument to the
function. So when for example assigning a local
variable "local" the value from an argument "a",
the assocated DBG_VALUE instruction would be hoisted
to the beginning of the function, even if the scope
for "local" started somewhere else (or if "local"
was mapped to other values earlier in the function).

This patch adds some logic to EmitFuncArgumentDbgValue
to check that the variable being described actually
is an argument to the function. And that the dbg.value
being lowered already is in the entry block. Otherwise
we bail out, and the dbg.value will be handled as an
ordinary dbg.value (not as a "FuncArgumentDbgValue").

A tricky situation is when both the variable and
the value is related to function arguments, but not
neccessarily the same argument. We make sure that we
do not describe the same argument more than once as
a "FuncArgumentDbgValue". This solution works as long
as opt has injected a "first" dbg.value that corresponds
to the formal argument at the function entry.

Reviewers: jmorse, aprantl

Subscribers: jyknight, hiraditya, fedor.sergeev, dstenb, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D57702

llvm-svn: 353735
2019-02-11 19:23:30 +00:00
Benjamin Kramer 711950c116 Move some classes into anonymous namespaces. NFC.
llvm-svn: 353710
2019-02-11 15:16:21 +00:00
Chandler Carruth 3160734af1 [CallSite removal] Migrate the statepoint GC infrastructure to use the
`CallBase` class rather than `CallSite` wrappers.

I pushed this change down through most of the statepoint infrastructure,
completely removing the use of CallSite where I could reasonably do so.
I ended up making a couple of cut-points: generic call handling
(instcombine, TLI, SDAG). As soon as it hit truly generic handling with
users outside the immediate code, I simply transitioned into or out of
a `CallSite` to make this a reasonable sized chunk.

Differential Revision: https://reviews.llvm.org/D56122

llvm-svn: 353660
2019-02-11 07:42:30 +00:00
Nikita Popov a0e96bd56d [CodeGen][X86] Don't scalarize vector saturating add/sub
Now that we have vector support for [US](ADD|SUB)O we no longer
need to scalarize when expanding [US](ADD|SUB)SAT.

This matches what the cost model already does.

Differential Revision: https://reviews.llvm.org/D57348

llvm-svn: 353651
2019-02-10 19:06:38 +00:00
Simon Pilgrim c5744d4d69 [DAG] Add optional AllowUndefs to isNullOrNullSplat
No change in default behaviour (AllowUndefs = false)

llvm-svn: 353646
2019-02-10 17:42:15 +00:00
Simon Pilgrim 5a82a788a2 [DAGCombine] Simplify funnel shifts with undef/zero args to bitshifts
Now that we have SimplifyDemandedBits support for funnel shifts (rL353539), we need to simplify funnel shifts back to bitshifts in cases where either argument has been folded to undef/zero.

Differential Revision: https://reviews.llvm.org/D58009

llvm-svn: 353645
2019-02-10 17:04:00 +00:00
Sanjay Patel 2f319420f9 [TargetLowering] refactor setcc folds to fix another miscompile (PR40657)
SimplifySetCC still has much room for improvement, but this should
fix the remaining problem examples from:
https://bugs.llvm.org/show_bug.cgi?id=40657

The initial fix for this problem was rL353615.

llvm-svn: 353639
2019-02-10 14:29:57 +00:00
Sanjay Patel 7467510453 [TargetLowering] add tests to show effect of setcc sub->shift; NFC
There's effectively no difference for the cases with variables.
We just trade a sub for an add on those. But the case with a
subtract from constant would require an extra move instruction
on x86, so this looks like a reasonable generic combine.

llvm-svn: 353619
2019-02-09 17:03:59 +00:00
Sanjay Patel 887ac1b38c [TargetLowering] avoid miscompile in setcc transform (PR40657)
llvm-svn: 353615
2019-02-09 15:59:02 +00:00
Nikita Popov 37bce93e36 Revert "[SelectionDAG] Extract [US]MULO expansion into TL method; NFC"
This reverts commit r353611.

Triggers an assertion during the libcall expansion on ARM.

llvm-svn: 353612
2019-02-09 13:54:02 +00:00
Nikita Popov 7de44ed945 [SelectionDAG] Extract [US]MULO expansion into TL method; NFC
In preparation for supporting vector expansion.

Also drop a variant of ExpandLibCall, of which the MULO expansions
were the only user.

llvm-svn: 353611
2019-02-09 13:29:22 +00:00
Craig Topper 784929d045 Implementation of asm-goto support in LLVM
This patch accompanies the RFC posted here:
http://lists.llvm.org/pipermail/llvm-dev/2018-October/127239.html

This patch adds a new CallBr IR instruction to support asm-goto
inline assembly like gcc as used by the linux kernel. This
instruction is both a call instruction and a terminator
instruction with multiple successors. Only inline assembly
usage is supported today.

This also adds a new INLINEASM_BR opcode to SelectionDAG and
MachineIR to represent an INLINEASM block that is also
considered a terminator instruction.

There will likely be more bug fixes and optimizations to follow
this, but we felt it had reached a point where we would like to
switch to an incremental development model.

Patch by Craig Topper, Alexander Ivchenko, Mikhail Dvoretckii

Differential Revision: https://reviews.llvm.org/D53765

llvm-svn: 353563
2019-02-08 20:48:56 +00:00
Nemanja Ivanovic 92a8c36735 [DAGCombine] Optimize pow(X, 0.75) to sqrt(X) * sqrt(sqrt(X))
The sqrt case is faster and we already do this for the case where
the exponent is 0.25. This adds the 0.75 case which is also not
sensitive to signed zeros.

Patch by Whitney Tsang (Whitney)

Differential revision: https://reviews.llvm.org/D57434

llvm-svn: 353557
2019-02-08 19:50:58 +00:00
Simon Pilgrim eb6a47a462 [TargetLowering] Use ISD::FSHR in expandFixedPointMul
Replace OR(SHL,SRL) pattern with ISD::FSHR (legalization expands this later if necessary) - this helps with the scale == 0 'undefined' drop-through case that was discussed on D55720.

llvm-svn: 353546
2019-02-08 18:57:38 +00:00
Simon Pilgrim 478bb90779 [TargetLowering] Add SimplifyDemandedBits funnel shift support
llvm-svn: 353539
2019-02-08 17:19:01 +00:00
Nirav Dave 97011ccce0 Revert r353416 "[DAG] Cleanup unused nodes on failed store-to-load forward combine."
This cleanup causes out-of-tree crashes.

llvm-svn: 353527
2019-02-08 15:21:13 +00:00
Nikita Popov 9d7e86a978 [CodeGen] Handle vector UADDO, SADDO, USUBO, SSUBO
This is part of https://bugs.llvm.org/show_bug.cgi?id=40442.

Vector legalization is implemented for the add/sub overflow opcodes.
UMULO/SMULO are also handled as far as legalization is concerned, but
they don't support vector expansion yet (so no tests for them).

The vector result widening implementation is suboptimal, because it
could result in a legalization loop.

Differential Revision: https://reviews.llvm.org/D57639

llvm-svn: 353464
2019-02-07 21:02:22 +00:00
Simon Pilgrim fe3ac70b18 [DAGCombiner] (add (umax X, C), -C) --> (usubsat X, C) (PR40111)
Move the (add (umax X, C), -C) --> (usubsat X, C) X86 combine into generic DAGCombiner

First of a number of saturated arithmetic folds that can be moved out of X86-specific code for PR40111.

Differential Revision: https://reviews.llvm.org/D57754

llvm-svn: 353457
2019-02-07 20:14:43 +00:00
Nirav Dave 9332fc2e19 Revert "[DAG] Cleanup of unused node in SimplifySelectCC."
Causes ASAN use-after-poison errors.

llvm-svn: 353442
2019-02-07 18:31:05 +00:00
Sanjay Patel 2d4b186844 [DAGCombiner] fold add/sub with bool operand based on target's boolean contents
I noticed that we are missing this canonicalization in IR:
rL352515
...and then realized that we don't get this right in SDAG either,
so this has to be fixed first regardless of what we choose to do in IR.

The existing fold was limited to scalars and using the wrong predicate
to guard the transform. We have a boolean contents TLI query that can
be used to decide which direction to fold.

This may eventually lead back to the problems/question in:
https://bugs.llvm.org/show_bug.cgi?id=40486
...but it makes no difference to that yet.

Differential Revision: https://reviews.llvm.org/D57401

llvm-svn: 353433
2019-02-07 17:43:34 +00:00
Nirav Dave 24e60819f6 [DAG] Cleanup of unused node in SimplifySelectCC.
llvm-svn: 353428
2019-02-07 17:13:55 +00:00
Nirav Dave 4b12236f7d [DAG] Cleanup unused node on failed SELECT Combine.
llvm-svn: 353426
2019-02-07 16:57:50 +00:00
Nirav Dave 724b81087d [DAG] Cleanup unused nodes on failed store-to-load forward combine.
llvm-svn: 353416
2019-02-07 15:38:14 +00:00
Nirav Dave b3506bf985 [DAG] Immediately cleanup unused nodes from extend-based combines.
llvm-svn: 353338
2019-02-06 20:12:03 +00:00
Bjorn Pettersson 350352c8a5 [SelectionDAG] Cleanup some code comments. NFC
Don't repeat the function name in some doxygen
comments.

(Just a minor cleanup, while testing to push
from the git monorepo setup.)

llvm-svn: 353317
2019-02-06 17:36:18 +00:00
Nirav Dave e5c37958f9 [InlineAsm][X86] Add backend support for X86 flag output parameters.
Allow custom handling of inline assembly output parameters and add X86
flag parameter support.

llvm-svn: 353307
2019-02-06 15:26:29 +00:00
Nirav Dave 54511076d4 [SelectionDAGBuilder] Refactor Inline Asm output check. NFCI.
llvm-svn: 353305
2019-02-06 15:12:46 +00:00
Clement Courbet 5a6712b633 [DAGCombine][NFC] GatherAllAliases should take a LSBaseSDNode.
GatherAllAliases only makes sense for LSBaseSDNode. Enforce it with
static typing instead of runtime cast.

llvm-svn: 353291
2019-02-06 12:36:17 +00:00
Clement Courbet 17b51b655e [DAG] BaseIndexOffset: FrameIndexSDNodes with the same FrameIndex compare equal.
Reviewers: niravd

Subscribers: arphaman, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D57692

llvm-svn: 353143
2019-02-05 07:36:20 +00:00
Craig Topper d4e37afe45 [DAGCombiner] Discard pointer info when combining extract_vector_elt of a vector load when the index isn't constant
Summary:
If the index isn't constant, this transform inserts a multiply and an add on the index to calculating the base pointer for a scalar load. But we still create a memory operand with an offset of 0 and the size of the scalar access. But the access is really to an unknown offset within the original access size.

This can cause the machine scheduler to incorrectly calculate dependencies between this load and other accesses. In the case we saw, there was a 32 byte vector store that was split into two 16 byte stores, one with offset 0 and one with offset 16. The size of the memory operand for both was 16. The scheduler correctly detected the alias with the offset 0 store, but not the offset 16 store.

This patch discards the pointer info so we don't incorrectly detect aliasing. I wasn't sure if we could keep using the original offset and size without risking some other transform on the load changing the size.

I tried to reduce a test case, but there's still a lot of memory operations needed to get the scheduler to do the bad reordering. So it looked pretty fragile to maintain.

Reviewers: efriedma

Reviewed By: efriedma

Subscribers: arphaman, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D57616

llvm-svn: 353124
2019-02-05 00:22:23 +00:00
Leonard Chan 68d428e578 [Intrinsic] Unsigned Fixed Point Multiplication Intrinsic
Add an intrinsic that takes 2 unsigned integers with the scale of them
provided as the third argument and performs fixed point multiplication on
them.

This is a part of implementing fixed point arithmetic in clang where some of
the more complex operations will be implemented as intrinsics.

Differential Revision: https://reviews.llvm.org/D55625

llvm-svn: 353059
2019-02-04 17:18:11 +00:00
Simon Pilgrim a536b89fe0 [DAGCombine] Add ADD(SUB,SUB) combines
Noticed while investigating PR40483, and fixes the basic test case from the bug - but not a more general case.

We're pretty weak at dealing with ADD/SUB combines compared to the SimplifyAssociativeOrCommutative/SimplifyUsingDistributiveLaws abilities that InstCombine can manage.

llvm-svn: 353044
2019-02-04 13:44:49 +00:00
Clement Courbet 1bb0e5ccfb [SelectionDAG] Add a BaseIndexOffset::print() method for debugging.
llvm-svn: 353028
2019-02-04 09:30:43 +00:00
Simon Pilgrim bd42f97946 [SDAG] Add SDNode/SDValue getConstantOperandAPInt helper. NFCI.
We already have the getConstantOperandVal helper which returns a uint64_t, but along comes the fuzzer and inserts a i128 -1 constant or something and the whole thing asserts.......

I've updated a few obvious cases, and tried to make use of the const reference where possible, but there's more to do. A number of existing oss-fuzz tickets should be fixed if we start using APInt and perform value clamping where necessary.

llvm-svn: 352961
2019-02-02 17:35:06 +00:00
Mandeep Singh Grang 70d484d94e [COFF, ARM64] Fix localaddress to handle stack realignment and variable size objects
Summary: This fixes using the correct stack registers for SEH when stack realignment is needed or when variable size objects are present.

Reviewers: rnk, efriedma, ssijaric, TomTan

Reviewed By: rnk, efriedma

Subscribers: javed.absar, kristof.beyls, llvm-commits

Differential Revision: https://reviews.llvm.org/D57183

llvm-svn: 352923
2019-02-01 21:41:33 +00:00
James Y Knight 7976eb5838 [opaque pointer types] Pass function types to CallInst creation.
This cleans up all CallInst creation in LLVM to explicitly pass a
function type rather than deriving it from the pointer's element-type.

Differential Revision: https://reviews.llvm.org/D57170

llvm-svn: 352909
2019-02-01 20:43:25 +00:00
Sanjay Patel 6502b1444d [SDAG] improve variable names; NFC
The version of FoldConstantArithmetic() that takes arbitrary nodes
was confusingly naming those nodes as constants when they might
not be; also "Cst" reads like "Cast".

llvm-svn: 352884
2019-02-01 16:06:53 +00:00
Sanjay Patel 0279b5b0b8 [TargetLowering] try harder to determine undef elements of vector binops
This might be the start of tracking all vector element constants generally if we take it to its 
logical conclusion, but let's stop here and make sure this is correct/beneficial so far.

The affected tests require a convoluted path before they get simplified currently because we 
don't call SimplifyDemandedVectorElts() from binops directly and don't modify the binop operands 
directly in SimplifyDemandedVectorElts().

That's why the tests all have a trailing shuffle to induce a chain reaction of transforms. So 
something like this is happening:

1. Improve the knowledge of undefs in the binop via a SimplifyDemandedVectorElts() call that 
   originates from a shuffle.
2. Transfer that undef knowledge back to the shuffle mask user as more undef lanes.
3. Combine the modified shuffle by calling SimplifyDemandedVectorElts() again.
4. Translate the improved shuffle mask as undemanded lanes of build vector constants causing 
   those to become full undef constants.
5. Simplify the binop now that it has a full undef operand.

As we can see from the unchanged 'and' and 'or' tests, tracking undefs alone isn't a full solution. 
We would need to track zero and all-ones constants to improve those opcodes. We'd probably need to 
track NaN for FP ops too (assuming we don't have fast-math-flags set).

Differential Revision: https://reviews.llvm.org/D57066

llvm-svn: 352880
2019-02-01 15:35:12 +00:00
Alex Bradbury 32b77383ec [SelectionDAG] Support promotion of the FPOWI integer operand
For targets where i32 is not a legal type (e.g. 64-bit RISC-V),
LegalizeIntegerTypes must promote the integer operand of ISD::FPOWI. As this
is a signed value, this should be sign-extended.

This patch enables all tests in test/CodeGen/RISCVfloat-intrinsics.ll for
RV64, as prior to this patch that file couldn't be compiled for RV64 due to an
assertion when performing codegen for fpowi.

Differential Revision: https://reviews.llvm.org/D54574

llvm-svn: 352832
2019-02-01 03:46:28 +00:00
Guozhi Wei 0bed9e0453 [DAGCombine] Avoid CombineZExtLogicopShiftLoad if there is free ZEXT
This patch fixes pr39098.

For the attached test case, CombineZExtLogicopShiftLoad can optimize it to

t25: i64 = Constant<1099511627775>
t35: i64 = Constant<0>
  t0: ch = EntryToken
t57: i64,ch = load<(load 4 from `i40* undef`, align 8), zext from i32> t0, undef:i64, undef:i64
    t58: i64 = srl t57, Constant:i8<1>
  t60: i64 = and t58, Constant:i64<524287>
t29: ch = store<(store 5 into `i40* undef`, align 8), trunc to i40> t57:1, t60, undef:i64, undef:i64

But later visitANDLike transforms it to

t25: i64 = Constant<1099511627775>
t35: i64 = Constant<0>
  t0: ch = EntryToken
t57: i64,ch = load<(load 4 from `i40* undef`, align 8), zext from i32> t0, undef:i64, undef:i64
      t61: i32 = truncate t57
    t63: i32 = srl t61, Constant:i8<1>
  t64: i32 = and t63, Constant:i32<524287>
t65: i64 = zero_extend t64
    t58: i64 = srl t57, Constant:i8<1>
  t60: i64 = and t58, Constant:i64<524287>
t29: ch = store<(store 5 into `i40* undef`, align 8), trunc to i40> t57:1, t60, undef:i64, undef:i64

And it triggers CombineZExtLogicopShiftLoad again, causes a dead loop.

Both forms should generate same instructions, CombineZExtLogicopShiftLoad generated IR looks cleaner. But it looks more difficult to prevent visitANDLike to do the transform, so I prevent CombineZExtLogicopShiftLoad to do the transform if the ZExt is free.

Differential Revision: https://reviews.llvm.org/D57491

llvm-svn: 352792
2019-01-31 20:46:42 +00:00
Nirav Dave 4061b44057 [DAG] Aggressively cleanup dangling node in CombineZExtLogicopShiftLoad.
While dangling nodes will eventually be pruned when they are
considered, leaving them disables combines requiring single-use.

Reviewers: Carrot, spatel, craig.topper, RKSimon, efriedma

Subscribers: hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D57520

llvm-svn: 352784
2019-01-31 19:35:14 +00:00
Leonard Chan ae527ac603 [Intrinsic] Expand SMULFIX to MUL, MULH[US], or [US]MUL_LOHI on vector arguments
r zero scale SMULFIX, expand into MUL which produces better code for X86.

For vector arguments, expand into MUL if SMULFIX is provided with a zero scale.
Otherwise, expand into MULH[US] or [US]MUL_LOHI.

Differential Revision: https://reviews.llvm.org/D56987

llvm-svn: 352783
2019-01-31 19:15:37 +00:00
Sjoerd Meijer f7cc34cae8 [SelectionDAG] Codesize: don't expand SHIFT to SHIFT_PARTS
And instead just generate a libcall. My motivating example on ARM was a simple:
  
  shl i64 %A, %B

for which the code bloat is quite significant. For other targets that also
accept __int128/i128 such as AArch64 and X86, it is also beneficial for these
cases to generate a libcall when optimising for minsize. On these 64-bit targets,
the 64-bits shifts are of course unaffected because the SHIFT/SHIFT_PARTS
lowering operation action is not set to custom/expand.

Differential Revision: https://reviews.llvm.org/D57386

llvm-svn: 352736
2019-01-31 08:07:30 +00:00
Thomas Lively 9510adafe6 [LegalizeVectorTypes] Allow illegal indices when splitting extract_vector_elt
Summary:
Fixes PR40267, in which the removed assertion was triggering on
perfectly valid IR. As far as I can tell, constant out of bounds
indices should be allowed when splitting extract_vector_elt, since
they will simply be propagated as out of bounds indices in the
resulting split vector and handled appropriately elsewhere.

Reviewers: aheejin

Subscribers: dschuff, sbc100, jgravelle-google, hiraditya

Differential Revision: https://reviews.llvm.org/D57471

llvm-svn: 352702
2019-01-31 00:35:37 +00:00
Craig Topper 49c4c68919 [LegalizeTypes] Use report_fatal_error instead of llvm_unreachable in the default case of some type legalization handlers that can be reached with intrinsics with result or operands that aren't legal types.
These can be triggered by mistakenly using a 64-bit mode only intrinsics with a -mtriple=i686. Using report_fatal_error gives a better experience for this mistake in release builds instead of probably crashing.

We already do this for some of the vector type legalization handles.

llvm-svn: 352699
2019-01-31 00:04:48 +00:00
Sanjay Patel 9ab23101a8 [DAGCombiner] sub X, 0/1 --> add X, 0/-1
This extends the existing transform for:
add X, 0/1 --> sub X, 0/-1
...to allow the sibling subtraction fold.

This pattern could regress with the proposed change in D57401.

llvm-svn: 352680
2019-01-30 22:41:35 +00:00
Heejin Ahn d6f487863d [WebAssembly] Exception handling: Switch to the new proposal
Summary:
This switches the EH implementation to the new proposal:
https://github.com/WebAssembly/exception-handling/blob/master/proposals/Exceptions.md
(The previous proposal was
 https://github.com/WebAssembly/exception-handling/blob/master/proposals/old/Exceptions.md)

- Instruction changes
  - Now we have one single `catch` instruction that returns a except_ref
    value
  - `throw` now can take variable number of operations
  - `rethrow` does not have 'depth' argument anymore
  - `br_on_exn` queries an except_ref to see if it matches the tag and
    branches to the given label if true.
  - `extract_exception` is a pseudo instruction that simulates popping
    values from wasm stack. This is to make `br_on_exn`, a very special
    instruction, work: `br_on_exn` puts values onto the stack only if it
    is taken, and the # of values can vay depending on the tag.

- Now there's only one `catch` per `try`, this patch removes all special
  handling for terminate pad with a call to `__clang_call_terminate`.
  Before it was the only case there are two catch clauses (a normal
  `catch` and `catch_all` per `try`).

- Make `rethrow` act as a terminator like `throw`. This splits BB after
  `rethrow` in WasmEHPrepare, and deletes an unnecessary `unreachable`
  after `rethrow` in LateEHPrepare.

- Now we stop at all catchpads (because we add wasm `catch` instruction
  that catches all exceptions), this creates new
  `findWasmUnwindDestinations` function in SelectionDAGBuilder.

- Now we use `br_on_exn` instrution to figure out if an except_ref
  matches the current tag or not, LateEHPrepare generates this sequence
  for catch pads:
```
  catch
  block i32
  br_on_exn $__cpp_exception
  end_block
  extract_exception
```

- Branch analysis for `br_on_exn` in WebAssemblyInstrInfo

- Other various misc. changes to switch to the new proposal.

Reviewers: dschuff

Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D57134

llvm-svn: 352598
2019-01-30 03:21:57 +00:00
Sanjay Patel a61d586f74 [DAGCombiner] fold extract_subvector of extract_subvector
This is the sibling fold for insert-of-insert that was added with D56604.

Now that we have x86 shuffle narrowing (D57156), this change shows improvements for 
lots of AVX512 reduction code (not sure that we would ever expect extract-of-extract otherwise).

There's a small regression in some of the partial-permute tests (extracting followed by splat).
That is tracked by PR40500:
https://bugs.llvm.org/show_bug.cgi?id=40500

Differential Revision: https://reviews.llvm.org/D57336

llvm-svn: 352528
2019-01-29 19:13:39 +00:00
James Y Knight 5d71fc5d7b Adjust documentation for git migration.
This fixes most references to the paths:
 llvm.org/svn/
 llvm.org/git/
 llvm.org/viewvc/
 github.com/llvm-mirror/
 github.com/llvm-project/
 reviews.llvm.org/diffusion/

to instead point to https://github.com/llvm/llvm-project.

This is *not* a trivial substitution, because additionally, all the
checkout instructions had to be migrated to instruct users on how to
use the monorepo layout, setting LLVM_ENABLE_PROJECTS instead of
checking out various projects into various subdirectories.

I've attempted to not change any scripts here, only documentation. The
scripts will have to be addressed separately.

Additionally, I've deleted one document which appeared to be outdated
and unneeded:
  lldb/docs/building-with-debug-llvm.txt

Differential Revision: https://reviews.llvm.org/D57330

llvm-svn: 352514
2019-01-29 16:37:27 +00:00
Nirav Dave 1527c0e727 [SelectionDAGBuilder] Remove redundant variable. NFCI.
llvm-svn: 352506
2019-01-29 15:14:07 +00:00
Ayonam Ray a1f6973ade Reversing the checkin for version 352484 as tests are failing.
llvm-svn: 352504
2019-01-29 15:00:50 +00:00
Ayonam Ray 4272af9b3e [CodeGen] Omit range checks from jump tables when lowering switches with unreachable default
During the lowering of a switch that would result in the generation of a 
jump table, a range check is performed before indexing into the jump 
table, for the switch value being outside the jump table range and a 
conditional branch is inserted to jump to the default block. In case the 
default block is unreachable, this conditional jump can be omitted. This 
patch implements omitting this conditional branch for unreachable 
defaults.

Review ID: D52002
Reviewers: Hans Wennborg, Eli Freidman, Roman Lebedev

llvm-svn: 352484
2019-01-29 12:01:32 +00:00
Jeremy Morse 66ac86b58d [DebugInfo][DAG] Process FrameIndex dbg.values unconditionally
A FrameIndex should be valid throughout a block regardless of what instructions
get selected in that block -- therefore we shouldn't harness dbg.values that
refer to FrameIndexes to an SDNode. There are numerous codegen reasons why
an SDNode never appears or doesn't become a location that a DBG_VALUE can
refer to. None of them actually affect the variable location.

Therefore, before any other tests to encode dbg_values in a SelectionDAG,
identify FrameIndex operands and encode them unattached to any SDNode.

Differential Revision: https://reviews.llvm.org/D57328

llvm-svn: 352467
2019-01-29 09:40:05 +00:00
Craig Topper 390ac61b93 Recommit r352255 "[SelectionDAG][X86] Don't use SEXTLOAD for promoting masked loads in the type legalizer"
This did not cause the buildbot failure it was previously reverted for.

Original commit message:

I'm not sure why we were using SEXTLOAD. EXTLOAD seems more appropriate since we don't care about the upper bits.

This patch changes this and then modifies the X86 post legalization combine to emit a extending shuffle instead of a sign_extend_vector_inreg. Could maybe use an any_extend_vector_inre

On AVX512 targets I think we might be able to use a masked vpmovzx and not have to expand this at all.

llvm-svn: 352433
2019-01-28 21:38:47 +00:00
Nikita Popov 8e1a464e6a [CodeGen][X86] Expand UADDSAT to NOT+UMIN+ADD
Followup to D56636, this time handling the UADDSAT case by expanding
uadd.sat(a, b) to umin(a, ~b) + b.

Differential Revision: https://reviews.llvm.org/D56869

llvm-svn: 352409
2019-01-28 19:19:09 +00:00
Michael Berg 685d5f675e [NFC] TLI query with default(on) behavior wrt DAG combines for fmin/fmax target control
llvm-svn: 352396
2019-01-28 18:03:08 +00:00
Jeremy Morse 8ebffb4b82 [DebugInfo][DAG] Avoid re-ordering of DBG_VALUEs
This patch improves the placement of DBG_VALUEs when by SelectionDAG, which
as documented in PR40427 can go very wrong. At the core of this is
ProcessSourceNode, which assumes the last instruction in a BB is the start
of the last processed IR instruction, which isn't always true.

Instead, use a helper function to call InstrEmitter::EmitNode, that records
before-and-after iterators and determines the first of any new instruction
created during emission. This is passed to ProcessSourceNode, which can
then make more elightened decisions about ordering for DBG_VALUE placement.

Differential revision: https://reviews.llvm.org/D57163

llvm-svn: 352350
2019-01-28 12:08:31 +00:00
Craig Topper 58e6b37e62 Revert r352255 "[SelectionDAG][X86] Don't use SEXTLOAD for promoting masked loads in the type legalizer"
This might be breaking an lldb windows buildbot.

llvm-svn: 352268
2019-01-26 02:44:58 +00:00
Craig Topper b1d3457c03 [SelectionDAG][X86] Don't use SEXTLOAD for promoting masked loads in the type legalizer
Summary:
I'm not sure why we were using SEXTLOAD. EXTLOAD seems more appropriate since we don't care about the upper bits.

This patch changes this and then modifies the X86 post legalization combine to emit a extending shuffle instead of a sign_extend_vector_inreg. Could maybe use an any_extend_vector_inreg, but I just did what we already do in LowerLoad. I think we can actually get rid of this code entirely if we switch to -x86-experimental-vector-widening-legalization.

On AVX512 targets I think we might be able to use a masked vpmovzx and not have to expand this at all.

Reviewers: RKSimon, spatel

Reviewed By: RKSimon

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D57186

llvm-svn: 352255
2019-01-26 00:26:37 +00:00
James Y Knight 2c36240a82 Fix emission of _fltused for MSVC.
It should be emitted when any floating-point operations (including
calls) are present in the object, not just when calls to printf/scanf
with floating point args are made.

The difference caused by this is very subtle: in static (/MT) builds,
on x86-32, in a program that uses floating point but doesn't print it,
the default x87 rounding mode may not be set properly upon
initialization.

This commit also removes the walk of the types pointed to by pointer
arguments in calls. (To assist in opaque pointer types migration --
eventually the pointee type won't be available.)

That latter implies that it will no longer consider a call like
`scanf("%f", &floatvar)` as sufficient to emit _fltused on its
own. And without _fltused, `scanf("%f")` will abort with error R6002. This
new behavior is unlikely to bite anyone in practice (you'd have to
read a float, and do nothing with it!), and also, is consistent with
MSVC.

Differential Revision: https://reviews.llvm.org/D56548

llvm-svn: 352076
2019-01-24 18:34:00 +00:00
Nirav Dave 58e9833e98 [SelectionDAGBuilder] Simplify HasSideEffect calculation. NFC.
llvm-svn: 352067
2019-01-24 17:56:03 +00:00
Nirav Dave b41a198472 [InlineAsm] Don't calculate registers for inline asm memory operands. NFCI.
llvm-svn: 352066
2019-01-24 17:47:18 +00:00
Simon Pilgrim 2f018de6a3 [TargetLowering] Rename getExpandedFixedPointMultiplication to expandFixedPointMul. NFCI.
Match the (much shorter) name used in various legalization methods.

llvm-svn: 352056
2019-01-24 15:46:54 +00:00
Nirav Dave bd069f424f [SelectionDAGBuilder] Fuse inline asm input operand loops passes. NFCI.
llvm-svn: 352053
2019-01-24 15:15:32 +00:00
Craig Topper 1e718429c1 [X86] Update SelectionDAGDumper to print the extension type and expanding flag for masked loads. Add truncating and compressing for masked stores.
llvm-svn: 352029
2019-01-24 07:51:34 +00:00
Sam Parker 9a2a89d58f [DAGCombine] Enable more pre-indexed stores
The current check in CombineToPreIndexedLoadStore is too
conversative, preventing a pre-indexed store when the base pointer
is a predecessor of the value being stored. Instead, we should check
the pointer operand of the store.

Differential Revision: https://reviews.llvm.org/D56719

llvm-svn: 351933
2019-01-23 09:11:49 +00:00
Craig Topper f0eac9f247 [LegalizeTypes] Add debug prints to the top of PromoteFloatOperand and PromoteFloatResult.
Also add debug prints in the default case of the switches in these routines.

Most if not all of the type legalization handlers already do this so this makes promoting floats consistent

llvm-svn: 351890
2019-01-22 22:33:55 +00:00