32115 Commits

Author SHA1 Message Date
Nikita Popov
8e69c3cde8 [DAGCombiner] Fold fmin/fmax with INF / FLT_MAX
Similar to D87415, this folds the various float min/max opcodes
with a constant INF or -INF operand, or FLT_MAX / -FLT_MAX operand
if the ninf flag is set. Some of the folds are only possible under
nnan.

The fminnum(X, INF) with nnan and fmaxnum(X, -INF) with nnan cases
are needed to improve the VECREDUCE_FMIN/FMAX lowerings on X86,
the rest is here for the sake of completeness.

Differential Revision: https://reviews.llvm.org/D87571
2020-09-14 19:59:33 +02:00
Rahman Lavaee
7841e21c98 Let -basic-block-sections=labels emit basicblock metadata in a new .bb_addr_map section, instead of emitting special unary-encoded symbols.
This patch introduces the new .bb_addr_map section feature which allows us to emit the bits needed for mapping binary profiles to basic blocks into a separate section.
The format of the emitted data is represented as follows. It includes a header for every function:

|  Address of the function                      |  -> 8 bytes (pointer size)
|  Number of basic blocks in this function (>0) |  -> ULEB128

The header is followed by a BB record for every basic block. These records are ordered in the same order as MachineBasicBlocks are placed in the function. Each BB Info is structured as follows:

|  Offset of the basic block relative to function begin |  -> ULEB128
|  Binary size of the basic block                       |  -> ULEB128
|  BB metadata                                          |  -> ULEB128  [ MBB.isReturn() OR MBB.hasTailCall() << 1  OR  MBB.isEHPad() << 2 ]

The new feature will replace the existing "BB labels" functionality with -basic-block-sections=labels.
The .bb_addr_map section scrubs the specially-encoded BB symbols from the binary and makes it friendly to profilers and debuggers.
Furthermore, the new feature reduces the binary size overhead from 70% bloat to only 12%.

For more information and results please refer to the RFC: https://lists.llvm.org/pipermail/llvm-dev/2020-July/143512.html

Reviewed By: MaskRay, snehasish

Differential Revision: https://reviews.llvm.org/D85408
2020-09-14 10:16:44 -07:00
David Green
06fb4e9064 [CGP] Limit converting phi types to simple loads and stores
Instcombine limits converting phi types to simple loads and stores. This
does the same in codegenprepare, not processing phis that are not
simple.

Note that volatile loads/store ISel will happily convert between float
and int. Atomics are more likely to always be integer. This just keeps
things simple and doesn't process either.

Differential Revision: https://reviews.llvm.org/D83770
2020-09-14 12:08:34 +01:00
Petar Avramovic
6e2a86ed5a AMDGPU/GlobalISel Check for NoNaNsFPMath in isKnownNeverSNaN
Check for NoNaNsFPMath function attribute in isKnownNeverSNaN.
Function attributes are in held in 'TargetMachine.Options'.
Among other things, this allows selection of some patterns imported
in D87351 since G_FCANONICALIZE is not generated when isKnownNeverSNaN
returns true in lowerFMinNumMaxNum.

However we notice some incorrect results since function attributes are
not correctly written in TargetMachine.Options when next function is
processed. Take a look at @v_test_no_global_nnans_med3_f32_pat0_srcmod0,
it has "no-nans-fp-math"="false" but TargetMachine.Options still has it
set to true since first function in test file had this attribute set to
true. This will be fixed in D87511.

Differential Revision: https://reviews.llvm.org/D87456
2020-09-14 12:11:00 +02:00
Simon Pilgrim
00e5676cf6 [LegalizeDAG] Fix MSVC "result of 32-bit shift implicitly converted to 64 bits" warning. NFCI. 2020-09-14 11:09:43 +01:00
Jeremy Morse
d3af441dfe [DebugInstrRef][1/9] Add fields for instr-ref variable locations
Add a DBG_INSTR_REF instruction and a "debug instruction number" field to
MachineInstr. The two allow variable values to be specified by
identifying where the value is computed, rather than the register it lies
in, like so:

  %0 = fooinst, debug-instr-number 1
  [...]
  DBG_INSTR_REF 1, 0

See the original RFC for motivation:
http://lists.llvm.org/pipermail/llvm-dev/2020-February/139440.html

This patch is NFCI; it only adds fields and other boiler plate.

Differential Revision: https://reviews.llvm.org/D85741
2020-09-14 10:06:52 +01:00
David Sherwood
15bff4dec4 [CodeGen] Fix bug in IncrementPointer
In an earlier patch I meant to add the correct flags to the ADD
node when incrementing the pointer, but forgot to pass them to
SelectionDAG::getNode.

Differential Revision: https://reviews.llvm.org/D87496
2020-09-14 08:03:55 +01:00
Yevgeny Rouban
88690a9658 [CodeGenPrepare] Fix zapping dead operands of assume
This patch fixes a problem of the commit 52cc97a0.
A test case is created to demonstrate the crash caused by
the instruction iterator invalidated by the recursive
removal of dead operands of assume. The solution restarts
from the blocks's first instruction in case CurInstIterator
is invalidated by RecursivelyDeleteTriviallyDeadInstructions().

Reviewed By: bkramer

Differential Revision: https://reviews.llvm.org/D87434
2020-09-14 11:46:34 +07:00
Craig Topper
56b33391d3 [SelectionDAG] Move ISD:PARITY formation from DAGCombine to SimplifyDemandedBits.
Previously, we formed ISD::PARITY by looking for (and (ctpop X), 1)
but the AND might be separated from the ctpop. For example if the
parity result is multiplied by 2, we'll pull the AND through the
shift.

So to handle more cases, move to SimplifyDemandedBits where we
can handle more cases that result in only the LSB of the CTPOP
being used.
2020-09-13 21:04:13 -07:00
Qiu Chaofan
a4c5351986 [DAGCombiner] Propagate FMF flags in FMA folding
DAG combiner folds (fma a 1.0 b) into (fadd a b) but the flag isn't
propagated into new fadd. This patch fixes that.

Some code in visitFMA is redundant and such support for vector constants
is missing. Need follow-up patch to clean.

Reviewed By: spatel

Differential Revision: https://reviews.llvm.org/D87037
2020-09-14 00:19:06 +08:00
David Green
9237fde481 [CGP] Prevent optimizePhiType from iterating forever
The recently added optimizePhiType algorithm had no checks to make sure
it didn't continually iterate backward and forth between float and int
types. This means that given an input like store(phi(bitcast(load))), we
could convert that back and forth to store(bitcast(phi(load))). This
particular case would usually have been simplified to a different load
type (folding the bitcast into the load) before CGP, but other cases can
occur. The one that came up was phi(bitcast(phi)), where the two phi's
of different types were bitcast between. That was not helped by a dead
bitcast being kept around which could make conversion look profitable.

This adds an extra check of the bitcast Uses or Defs, to make sure that
at least one is grounded and will not end up being converted back. It
also makes sure that dead bitcasts are removed, and there is a minor
change to include newly created Phi nodes in the Visited set so that
they do not need to be revisited.

Differential Revision: https://reviews.llvm.org/D82676
2020-09-13 16:11:01 +01:00
Craig Topper
61d29e0dff [LegalizeTypes] Remove a few cases from SplitVectorOperand that should never happen. NFC
CTTZ, CTLZ, CTPOP, and FCANONICALIZE all have the same input and
output types so the operand should have already been legalized when the
result type was legalized.
2020-09-12 20:59:14 -07:00
Craig Topper
ad3d6f993d [SelectionDAG][X86][ARM][AArch64] Add ISD opcode for __builtin_parity. Expand it to shifts and xors.
Clang emits (and (ctpop X), 1) for __builtin_parity. If ctpop
isn't natively supported by the target, this leads to poor codegen
due to the expansion of ctpop being more complex than what is needed
for parity.

This adds a DAG combine to convert the pattern to ISD::PARITY
before operation legalization. Type legalization is updated
to handled Expanding and Promoting this operation. If after type
legalization, CTPOP is supported for this type, LegalizeDAG will
turn it back into CTPOP+AND. Otherwise LegalizeDAG will emit a
series of shifts and xors followed by an AND with 1.

I've avoided vectors in this patch to avoid more legalization
complexity for this patch.

X86 previously had a custom DAG combiner for this. This is now
moved to Custom lowering for the new opcode. There is a minor
regression in vector-reduce-xor-bool.ll, but a follow up patch
can easily fix that.

Fixes PR47433

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D87209
2020-09-12 11:42:18 -07:00
Sanjay Patel
3a8ea8609b [Intrinsics] define semantics for experimental fmax/fmin vector reductions
As discussed on llvm-dev:
http://lists.llvm.org/pipermail/llvm-dev/2020-April/140729.html

This is hopefully the final remaining showstopper before we can remove
the 'experimental' from the reduction intrinsics.

No behavior was specified for the FP min/max reductions, so we have a
mess of different interpretations.

There are a few potential options for the semantics of these max/min ops.
I think this is the simplest based on current behavior/implementation:
make the reductions inherit from the existing llvm.maxnum/minnum intrinsics.
These correspond to libm fmax/fmin, and those are similar to the (now
deprecated?) IEEE-754 maxNum/minNum functions (NaNs are treated as missing
data). So the default expansion creates calls to libm functions.

Another option would be to inherit from llvm.maximum/minimum (NaNs propagate),
but most targets just crash in codegen when given those nodes because no
default expansion was ever implemented AFAICT.

We could also just assume 'nnan' semantics by default (we are already
assuming 'nsz' semantics in the maxnum/minnum intrinsics), but some targets
(AArch64, PowerPC) support the more defined behavior, so it doesn't make much
sense to not allow a tighter spec. Fast-math-flags (nnan) can be used to
loosen the semantics.

(Note that D67507 was proposed to update the LangRef to acknowledge the more
recent IEEE-754 2019 standard, but that patch seems to have stalled. If we do
update based on the new standard, the reduction instructions can seamlessly
inherit from whatever updates are made to the max/min intrinsics.)

x86 sees a regression here on 'nnan' tests because we have underlying,
longstanding bugs in FMF creation/propagation. Those need to be fixed apart
from this change (for example: https://llvm.org/PR35538). The expansion
sequence before this patch may not have been correct.

Differential Revision: https://reviews.llvm.org/D87391
2020-09-12 09:10:28 -04:00
Yuanfang Chen
ad99e34c59 Revert "[NewPM][CodeGen] Introduce CodeGenPassBuilder to help build codegen pipeline"
This reverts commit 31ecf8d29d81d196374a562c6d2bd2c25a62861e.
This reverts commit 3fdaa8602a086a3fca5f0fc8527536ac659079d0.

There is laying violation for Target->CodeGen.
2020-09-11 18:52:32 -07:00
Yuanfang Chen
31ecf8d29d [NewPM][CodeGen] Introduce CodeGenPassBuilder to help build codegen pipeline
Following up on D67687.
Please refer to the RFC here http://lists.llvm.org/pipermail/llvm-dev/2020-July/143309.html

`CodeGenPassBuilder` is the NPM counterpart of `TargetPassConfig` with below differences.
- Debugging features (MIR print/verify, disable pass, start/stop-before/after, etc.) living in `TargetPassConfig` are moved to use PassInstrument as much as possible. (Implementation also lives in `TargetPassConfig.cpp`)
- `TargetPassConfig` is a polymorphic base (virtual inheritance) to build the target-dependent pipeline whereas `CodeGenPassBuilder` is the CRTP base/helper to implement the target-dependent pipeline. The motivation is flexibility for targets to customize the pipeline, inlining opportunity, and fits the overall NPM value semantics design.
- `TargetPassConfig` is a legacy immutable pass to declare hooks for targets to customize some target-independent codegen layer behavior. This is partially ported to TargetMachine::options. The rest, such as `createMachineScheduler/createPostMachineScheduler`, are left out for now. They should be implemented in LLVMTargetMachine in the future.

Reviewed By: arsenm

Differential Revision: https://reviews.llvm.org/D83608
2020-09-11 16:41:17 -07:00
Matt Arsenault
382b2b1b51 RegAllocFast: Fix typo in comment 2020-09-11 18:06:14 -04:00
Matt Arsenault
e21bb31eb6 CodeGen: Require SSA to run PeepholeOptimizer 2020-09-11 18:03:04 -04:00
Jeremy Morse
0caeaff123 [LiveDebugValues][NFC] Re-land 60db26a66d, add instr-ref tests
This was landed but reverted in 5b9c2b1bea7 due to asan picking up a memory
leak. This is fixed in the change to InstrRefBasedImpl.cpp. Original
commit message follows:

[LiveDebugValues][NFC] Add instr-ref tests, adapt old tests

This patch adds a few tests in DebugInfo/MIR/InstrRef/ of interesting
behaviour that the instruction referencing implementation of
LiveDebugValues has. Mostly, these tests exist to ensure that if you
give the "-experimental-debug-variable-locations" command line switch,
the right implementation runs; and to ensure it behaves the same way as
the VarLoc LiveDebugValues implementation.

I've also touched roughly 30 other tests, purely to make the tests less
rigid about what output to accept. DBG_VALUE instructions are usually
printed with a trailing !debug-location indicating its scope:

  !debug-location !1234

However InstrRefBasedLDV produces new DebugLoc instances on the fly,
meaning there sometimes isn't a numbered node when they're printed,
making the output:

  !debug-location !DILocation(line: 0, blah blah)

Which causes a ton of these tests to fail. This patch removes checks for
that final part of each DBG_VALUE instruction. None of them appear to
be actually checking the scope is correct, just that it's present, so
I don't believe there's any loss in coverage here.

Differential Revision: https://reviews.llvm.org/D83054
2020-09-11 12:14:44 +01:00
Benjamin Kramer
5405ee553a [CodeGenPrepare] Simplify code. NFCI. 2020-09-11 11:24:08 +02:00
Martin Storsjö
46416f0803 [CodeGen] [WinException] Remove a redundant explicit section switch for aarch64
The following EmitWinEHHandlerData() implicitly switches to .xdata, just
like on x86_64.

This became orphaned from the original code requiring it in
0b61d220c9b1f0 / https://reviews.llvm.org/D61095.

Differential Revision: https://reviews.llvm.org/D87447
2020-09-11 10:31:04 +03:00
Alok Kumar Sharma
e45b0708ae [DebugInfo] Fixing CodeView assert related to lowerBound field of DISubrange.
This is to fix CodeView build failure https://bugs.llvm.org/show_bug.cgi?id=47287
    after DIsSubrange upgrade D80197

    Assert condition is now removed and Count is calculated in case LowerBound
    is absent or zero and Count or UpperBound is constant. If Count is unknown
    it is later handled as VLA (currently Count is set to zero).

Reviewed By: rnk

Differential Revision: https://reviews.llvm.org/D87406
2020-09-11 11:12:49 +05:30
Reid Kleckner
2c73bef7fa Fix wrong comment about enabling optimizations to work around a bug 2020-09-10 16:45:20 -07:00
Reid Kleckner
4e3edef4b8 Use pragmas to work around MSVC x86_32 debug miscompile bug
Halide users reported this here: https://llvm.org/pr46176
I reported the issue to MSVC here:
https://developercommunity.visualstudio.com/content/problem/1179643/msvc-copies-overaligned-non-trivially-copyable-par.html

This codepath is apparently not covered by LLVM's unit tests, so I added
coverage in a unit test.

If we want to support this configuration going forward, it means that is
in general not safe to pass a SmallVector<T, N> by value if alignof(T)
is greater than 4. This doesn't appear to come up often because passing
a SmallVector by value is inefficient and not idiomatic: it copies the
inline storage. In this case, the SmallVector<LLT,4> is captured by
value by a lambda, and the lambda is passed by value into std::function,
and that's how we hit the bug.

Differential Revision: https://reviews.llvm.org/D87475
2020-09-10 14:50:01 -07:00
Volkan Keles
d4bf90271f GlobalISel: Combine fneg(fneg x) to x
https://reviews.llvm.org/D87473
2020-09-10 12:57:38 -07:00
Anna Thomas
b1b9806370 [ImplicitNullChecks] NFC: Remove unused PointerReg arg in dep analysis
The PointerReg arg was passed into the dependence function for an
assertion which no longer exists. So, this patch updates the dependence
functions to avoid the PointerReg in the signature.

Tests-Run: make check
2020-09-10 15:31:57 -04:00
Anna Thomas
46329f6079 [ImplicitNullCheck] Handle instructions that preserve zero value
This is the first in a series of patches to make implicit null checks
more general. This patch identifies instructions that preserves zero
value of a register and considers that as a valid instruction to hoist
along with the faulting load. See added testcases.

Reviewed-By: reames, dantrushin

Differential Revision: https://reviews.llvm.org/D87108
2020-09-10 13:39:50 -04:00
Simon Pilgrim
f42f733af9 SwitchLoweringUtils.h - reduce TargetLowering.h include. NFCI.
Only include the headers we actually need, and move the remaining includes down to implicit dependent files.
2020-09-10 17:42:18 +01:00
Jay Foad
517202c720 [TargetLowering] Fix comments describing XOR -> OR/AND transformations 2020-09-10 13:56:34 +01:00
Kerry McLaughlin
cd89f5c91b [SVE][CodeGen] Legalisation of truncate for scalable vectors
Truncating from an illegal SVE type to a legal type, e.g.
`trunc <vscale x 4 x i64> %in to <vscale x 4 x i32>`
fails after PromoteIntOp_CONCAT_VECTORS attempts to
create a BUILD_VECTOR.

This patch changes the promote function to create a sequence of
INSERT_SUBVECTORs if the return type is scalable, and replaces
these with UNPK+UZP1 for AArch64.

Reviewed By: paulwalker-arm

Differential Revision: https://reviews.llvm.org/D86548
2020-09-10 11:35:33 +01:00
Nikita Popov
0a5dc7effb [DAGCombiner] Fold fmin/fmax of NaN
fminnum(X, NaN) is X, fminimum(X, NaN) is NaN. This mirrors the
behavior of existing InstSimplify folds.

This is expected to improve the reduction lowerings in D87391,
which use NaN as a neutral element.

Differential Revision: https://reviews.llvm.org/D87415
2020-09-09 23:53:32 +02:00
Amara Emerson
e5784ef8f6 [GlobalISel] Enable usage of BranchProbabilityInfo in IRTranslator.
We weren't using this before, so none of the MachineFunction CFG edges had the
branch probability information added. As a result, block placement later in the
pipeline was flying blind.

This is enabled only with optimizations enabled like SelectionDAG.

Differential Revision: https://reviews.llvm.org/D86824
2020-09-09 14:31:12 -07:00
Amara Emerson
467a071285 [GlobalISel][IRTranslator] Generate better conditional branch lowering.
This is a port of the functionality from SelectionDAG, which tries to find
a tree of conditions from compares that are then combined using OR or AND,
before using that result as the input to a branch. Instead of naively
lowering the code as is, this change converts that into a sequence of
conditional branches on the sub-expressions of the tree.

Like SelectionDAG, we re-use the case block codegen functionality from
the switch lowering utils, which causes us to generate some different code.
The result of which I've tried to mitigate in earlier combine patches.

Differential Revision: https://reviews.llvm.org/D86665
2020-09-09 13:16:11 -07:00
Amara Emerson
cc76da7ada [GlobalISel] Rewrite the elide-br-by-swapping-icmp-ops combine to do less.
This combine previously tried to take sequences like:
  %cond = G_ICMP pred, a, b
  G_BRCOND %cond, %truebb
  G_BR %falsebb
%truebb:
  ...
%falsebb:
  ...

and by inverting the compare predicate and swapping branch targets, delete the
G_BR and instead have a single conditional branch to the falsebb. Since in an
earlier patch we have a combine to fold not(icmp) into just an inverted icmp,
we don't need this combine to do as much. This patch instead generalizes the
combine by just looking for:
  G_BRCOND %cond, %truebb
  G_BR %falsebb
%truebb:
  ...
%falsebb:
  ...

and then inverting the condition using a not (xor). The xor can be folded away
in a separate combine. This change also lets us avoid some optimization code
in the IRTranslator.

I also think that deleting G_BRs in the combiner is unnecessary. That's
something that targets can decide to do at selection time and could simplify
generic code in future.

Differential Revision: https://reviews.llvm.org/D86664
2020-09-09 13:08:16 -07:00
Ulrich Weigand
1a25133bcd [DAGCombine] Skip re-visiting EntryToken to avoid compile time explosion
During the main DAGCombine loop, whenever a node gets replaced, the new
node and all its users are pushed onto the worklist.  Omit this if the
new node is the EntryToken (e.g. if a store managed to get optimized
out), because re-visiting the EntryToken and its users will not uncover
any additional opportunities, but there may be a large number of such
users, potentially causing compile time explosion.

This compile time explosion showed up in particular when building the
SingleSource/UnitTests/matrix-types-spec.cpp test-suite case on any
platform without SIMD vector support.

Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D86963
2020-09-09 19:13:46 +02:00
Alon Kom
818cf30b83 [MachinePipeliner] Fix II_setByPragma initialization
II_setByPragma was not reset between 2 calls of the MachinePipleiner pass

Reviewed By: bcahoon

Differential Revision: https://reviews.llvm.org/D87088
2020-09-09 13:38:35 +00:00
Denis Antrushin
4358fa782e [Statepoints] Update DAG root after emitting statepoint.
Since we always generate CopyToRegs for statepoint results,
we must update DAG root after emitting statepoint, so that
these copies are scheduled before any possible local uses.
Note: getControlRoot() flushes all PendingExports, not only
those we generates for relocates. If that'll become a problem,
we can change it to flushing relocate exports only.

Reviewed By: reames

Differential Revision: https://reviews.llvm.org/D87251
2020-09-09 20:22:10 +07:00
Simon Pilgrim
d816499f95 [KnownBits] Move SelectionDAG::computeKnownBits ISD::ABS handling to KnownBits::abs
Move the ISD::ABS handling to a KnownBits::abs handler, to simplify future implementations in ValueTracking/GlobalISel.
2020-09-09 13:22:58 +01:00
Denis Antrushin
2a52c3301a [Statepoints] Properly handle const base pointer.
Current code in InstEmitter assumes all GC pointers are either
VRegs or stack slots - hence, taking only one operand.
But it is possible to have constant base, in which case it
occupies two machine operands.

Add a convinience function to StackMaps to get index of next
meta argument and use it in InsrEmitter to properly advance to
the next statepoint meta operand.

Reviewed By: reames

Differential Revision: https://reviews.llvm.org/D87252
2020-09-09 14:07:00 +07:00
Craig Topper
844e94a502 [SelectionDAGBuilder] Remove Unnecessary FastMathFlags temporary. Use SDNodeFlags instead. NFCI
This was a missed simplication in D87200
2020-09-08 15:50:12 -07:00
Craig Topper
b1e68f885b [SelectionDAGBuilder] Pass fast math flags to getNode calls rather than trying to set them after the fact.:
This removes the after the fact FMF handling from D46854 in favor of passing fast math flags to getNode. This should be a superset of D87130.

This required adding a SDNodeFlags to SelectionDAG::getSetCC.

Now we manage to contant fold some stuff undefs during the
initial getNode that we don't do in later DAG combines.

Differential Revision: https://reviews.llvm.org/D87200
2020-09-08 15:27:21 -07:00
Volkan Keles
1242dd330d GlobalISel: Combine op undef, x to 0
https://reviews.llvm.org/D86611
2020-09-08 09:46:38 -07:00
Simon Pilgrim
3c83b967cf LiveRegUnits.h - reduce MachineRegisterInfo.h include. NFC.
We only need to include MachineInstrBundle.h, but exposes an implicit dependency in MachineOutliner.h.

Also, remove duplicate includes from LiveRegUnits.cpp + MachineOutliner.cpp.
2020-09-08 17:27:00 +01:00
Jonas Paulsson
6dc3e22b57 [DAGTypeLegalizer] Handle ZERO_EXTEND of promoted type in WidenVecRes_Convert.
On SystemZ, a ZERO_EXTEND of an i1 vector handled by WidenVecRes_Convert()
always ended up being scalarized, because the type action of the input is
promotion which was previously an unhandled case in this method.

This fixes https://bugs.llvm.org/show_bug.cgi?id=47132.

Differential Revision: https://reviews.llvm.org/D86268

Patch by Eli Friedman.
Review: Ulrich Weigand
2020-09-08 16:49:51 +02:00
Craig Topper
da79b1eecc [SelectionDAG][X86][ARM] Teach ExpandIntRes_ABS to use sra+add+xor expansion when ADDCARRY is supported.
Rather than using SELECT instructions, use SRA, UADDO/ADDCARRY and
XORs to expand ABS. This is the multi-part version of the sequence
we use in LegalizeDAG.

It's also the same as the Custom sequence uses for i64 on 32-bit
and i128 on 64-bit. So we can remove the X86 customization.

Reviewed By: RKSimon

Differential Revision: https://reviews.llvm.org/D87215
2020-09-07 13:15:26 -07:00
Sanjay Patel
7a06b166b1 [DAGCombiner] allow more store merging for non-i8 truncated ops
This is a follow-up suggested in D86420 - if we have a pair of stores
in inverted order for the target endian, we can rotate the source
bits into place.
The "be_i64_to_i16_order" test shows a limitation of the current
function (which might be avoided if we integrate this function with
the other cases in mergeConsecutiveStores). In the earlier
"be_i64_to_i16" test, we skip the first 2 stores because we do not
match the full set as consecutive or rotate-able, but then we reach
the last 2 stores and see that they are an inverted pair of 16-bit
stores. The "be_i64_to_i16_order" test alters the program order of
the stores, so we miss matching the sub-pattern.

Differential Revision: https://reviews.llvm.org/D87112
2020-09-07 14:12:36 -04:00
Momchil Velikov
eb482afaf5 Reduce the number of memory allocations when displaying
a warning about clobbering reserved registers (NFC).

Also address some minor inefficiencies and style issues.

Differential Revision: https://reviews.llvm.org/D86088
2020-09-07 17:04:00 +01:00
Simon Pilgrim
6670f5d1e6 MachineStableHash.h - remove MachineInstr.h include. NFC.
Use forward declarations and move the include to MachineStableHash.cpp
2020-09-07 13:33:48 +01:00
Simon Wallis
79ea83e104 [SelectionDAG] memcpy expansion of const volatile struct ignores const zero
In getMemcpyLoadsAndStores(), a memcpy where the source is a zero constant is expanded to a MemOp::Set instead of a MemOp::Copy, even when the memcpy is volatile.
This is incorrect.

The fix is to add a check for volatile, and expand to MemOp::Copy in the volatile case.

Reviewed By: chill

Differential Revision: https://reviews.llvm.org/D87134
2020-09-07 13:22:09 +01:00
Simon Pilgrim
e57cbcbdc1 LegalizeTypes.h - remove orphan SplitVSETCC declaration. NFCI.
The implementation no longer exists
2020-09-07 13:11:49 +01:00