Commit Graph

9917 Commits

Author SHA1 Message Date
Simon Pilgrim 0da13ed1f6 [DAGCombine] narrowExtractedVectorBinOp - pull out repeated getOpcode(). NFCI.
llvm-svn: 364076
2019-06-21 16:44:51 +00:00
Simon Pilgrim ca9933c22d [DAGCombine] narrowInsertExtractVectorBinOp - reuse "extract from insert" detection code.
Move the "extract from insert detection code" into a lambda helper function.

llvm-svn: 364059
2019-06-21 14:46:21 +00:00
Simon Pilgrim 801c0f12b0 [DAGCombiner] Use getAPIntValue() instead of getZExtValue() where possible.
Better handling of out-of-i64-range values due to large integer types or from fuzz tests.

llvm-svn: 363955
2019-06-20 17:36:23 +00:00
Jordan Rupprecht 02508decf4 [DAGCombiner][NFC] Remove unused var
llvm-svn: 363954
2019-06-20 17:30:01 +00:00
Simon Pilgrim 1d8093249f [DAGCombiner] Support (shl (zext (srl x, C)), C) -> (zext (shl (srl x, C), C)) non-uniform folds.
Use matchBinaryPredicate instead of isConstOrConstSplat to let us handle non-uniform shift cases. 

llvm-svn: 363929
2019-06-20 14:42:27 +00:00
Simon Pilgrim 98a0ac5c0f [DAGCombine] Add TODOs for some combines that should support non-uniform vectors
We tend to only test for scalar/scalar consts when really we could support non-uniform vectors using ISD::matchUnaryPredicate/matchBinaryPredicate etc.

llvm-svn: 363924
2019-06-20 12:48:49 +00:00
Simon Pilgrim a487628270 [DAGCombine] Reduce scope of ShAmtVal variable. NFCI.
Fixes cppcheck warning.

Use the more capable getAPIntVal() instead of getZExtValue() as well since I'm here.

llvm-svn: 363921
2019-06-20 10:56:37 +00:00
Simon Pilgrim 046d49a8dc [DAGCombine] Use ConstantSDNode::getAPIntValue() instead of getZExtValue().
Use getAPIntValue() in a few more places. Most of the time getZExtValue() is fine, but occasionally there's fuzzed code or someone decides to create i65536 or something.....

llvm-svn: 363887
2019-06-19 22:14:24 +00:00
Simon Pilgrim f05369768c [TargetLowering] SimplifyDemandedBits - add ANY_EXTEND_VECTOR_INREG support
Move 'lowest' demanded elt -> bitcast fold out of ZERO_EXTEND_VECTOR_INREG into ANY_EXTEND_VECTOR_INREG case.

llvm-svn: 363856
2019-06-19 18:34:58 +00:00
Simon Pilgrim 6016fb726c [TargetLowering] SimplifyDemandedBits ZERO_EXTEND_VECTOR_INREG -> ANY_EXTEND_VECTOR_INREG
Simplify ZERO_EXTEND_VECTOR_INREG if the extended bits are not required.

Matches what we already do for ZERO_EXTEND.

llvm-svn: 363850
2019-06-19 18:00:24 +00:00
Simon Pilgrim c3994f77cb [TargetLowering] SimplifyDemandedBits SIGN_EXTEND_VECTOR_INREG -> ANY/ZERO_EXTEND_VECTOR_INREG
Simplify SIGN_EXTEND_VECTOR_INREG if the extended bits are not required/known zero.

Matches what we already do for SIGN_EXTEND.

llvm-svn: 363802
2019-06-19 13:58:02 +00:00
Simon Pilgrim 9eed5d2f78 [DAGCombiner] Support (shl (ext (shl x, c1)), c2) -> (shl (ext x), (add c1, c2)) non-uniform folds.
Use matchBinaryPredicate instead of isConstOrConstSplat to let us handle non-uniform shift cases. 

llvm-svn: 363793
2019-06-19 12:41:37 +00:00
Simon Pilgrim 8c49366c9b [DAGCombiner] Support (shl (ext (shl x, c1)), c2) -> 0 non-uniform folds.
Use matchBinaryPredicate instead of isConstOrConstSplat to let us handle non-uniform shift cases. 

This requires us to tweak matchBinaryPredicate to allow it to (optionally) handle constants with different type widths.

llvm-svn: 363792
2019-06-19 12:25:29 +00:00
Simon Pilgrim bb6b856183 [DAGCombiner] visitSHL - pull out repeated shift amount VT. NFCI.
llvm-svn: 363789
2019-06-19 11:31:26 +00:00
Simon Pilgrim d954a53633 [DAGCombine] Fix (shl (ext (shl x, c1)), c2) -> (shl (ext x), (add c1, c2)) comment. NFCI.
We pre-extend, not post.

llvm-svn: 363787
2019-06-19 11:17:48 +00:00
Matt Arsenault 9cac4e6d14 Rename ExpandISelPseudo->FinalizeISel, delay register reservation
This allows targets to make more decisions about reserved registers
after isel. For example, now it should be certain there are calls or
stack objects in the frame or not, which could have been introduced by
legalization.

Patch by Matthias Braun

llvm-svn: 363757
2019-06-19 00:25:39 +00:00
Simon Pilgrim 5bef886cd8 [TargetLowering] SimplifyDemandedBits - Cleanup ANY_EXTEND handling
Match SIGN_EXTEND + ZERO_EXTEND handling - will be adding ANY_EXTEND_VECTOR_INREG support in a future patch.

llvm-svn: 363716
2019-06-18 18:22:30 +00:00
Simon Pilgrim 032b54f8e8 [TargetLowering] SimplifyDemandedBits - Merge ZERO_EXTEND+ZERO_EXTEND_VECTOR_INREG handling
Other than adding consistent demanded elts handling which was a trivial addition, the other differences in functionality will be added in later patches.

llvm-svn: 363713
2019-06-18 18:08:30 +00:00
Simon Pilgrim b6e7108dcd [TargetLowering] SimplifyDemandedBits - Merge SIGN_EXTEND+SIGN_EXTEND_VECTOR_INREG handling
Other than adding consistent demanded elts handling which was a trivial addition, the other differences in functionality will be added in later patches.

llvm-svn: 363710
2019-06-18 17:57:53 +00:00
Simon Pilgrim 9aa25be149 [TargetLowering] SimplifyDemandedVectorElts - support MUL and ANY_EXTEND_VECTOR_INREG
Also fold ANY_EXTEND_VECTOR_INREG -> BITCAST if we only need the bottom element.

Fixes temporary regression introduced in rL363693.

llvm-svn: 363694
2019-06-18 15:49:35 +00:00
Simon Pilgrim 83bacd8d72 [SelectionDAG] Legalize vaargs that require vector splitting
This adds vector splitting for vaarg instructions during type legalization

Committed on behalf of @luke (Luke Lau)

Differential Revision: https://reviews.llvm.org/D60762

llvm-svn: 363671
2019-06-18 12:24:02 +00:00
Luis Marques 2e46312ffd [DAGCombiner] [CodeGenPrepare] More comprehensive GEP splitting
Some GEPs were not being split, presumably because that split would just be 
undone by the DAGCombiner. Not performing those splits can prevent important 
optimizations, such as preventing the element indices / member offsets from 
being (partially) folded into load/store instruction immediates. This patch:

- Makes the splits also occur in the cases where the base address and the GEP 
  are in the same BB.
- Ensures that the DAGCombiner doesn't reassociate them back again.

Differential Revision: https://reviews.llvm.org/D60294

llvm-svn: 363544
2019-06-17 10:54:12 +00:00
Simon Pilgrim ef78e55205 [SelectionDAG] Fold insert_subvector(undef, extract_subvector(v, c), c) -> v in getNode
This is already done in DAGCombiner::visitINSERT_SUBVECTOR, but this helps a number of shuffles across different vector widths recognise when they come from the same source.

llvm-svn: 363542
2019-06-17 10:14:52 +00:00
Michael Berg ad6bb86b2d adding more fmf propagation for selects plus updated tests
llvm-svn: 363484
2019-06-15 04:53:51 +00:00
Fangrui Song 968b5f84af Revert "adding more fmf propagation for selects plus tests"
This reverts rL363474. -debug-only=isel was added to some tests that
don't specify `REQUIRES: asserts`. This causes failures on
-DLLVM_ENABLE_ASSERTIONS=off builds.

I chose to revert instead of fixing the tests because I'm not sure
whether we should add `REQUIRES: asserts` to more tests.

llvm-svn: 363482
2019-06-15 03:51:08 +00:00
Michael Berg 69394bedc5 adding more fmf propagation for selects plus tests
llvm-svn: 363474
2019-06-14 23:30:52 +00:00
Simon Pilgrim 4e0648a541 [TargetLowering] Add MachineMemOperand::Flags to allowsMemoryAccess tests (PR42123)
As discussed on D62910, we need to check whether particular types of memory access are allowed, not just their alignment/address-space.

This NFC patch adds a MachineMemOperand::Flags argument to allowsMemoryAccess and allowsMisalignedMemoryAccesses, and wires up calls to pass the relevant flags to them.

If people are happy with this approach I can then update X86TargetLowering::allowsMisalignedMemoryAccesses to handle misaligned NT load/stores.

Differential Revision: https://reviews.llvm.org/D63075

llvm-svn: 363179
2019-06-12 17:14:03 +00:00
Simon Pilgrim 266f43964e [TargetLowering] Add allowsMemoryAccess(MachineMemOperand) helper wrapper. NFCI.
As suggested by @arsenm on D63075 - this adds a TargetLowering::allowsMemoryAccess wrapper that takes a Load/Store node's MachineMemOperand to handle the AddressSpace/Alignment arguments and will also implicitly handle the MachineMemOperand::Flags change in D63075.

llvm-svn: 363048
2019-06-11 11:00:23 +00:00
Simon Pilgrim 287e78c82b [DAGCombine] GetNegatedExpression - constant float vector support (PR42105)
Add support for negation of constant build vectors.

Differential Revision: https://reviews.llvm.org/D62963

llvm-svn: 363040
2019-06-11 09:44:33 +00:00
Sander de Smalen cbeb563cfb Change semantics of fadd/fmul vector reductions.
This patch changes how LLVM handles the accumulator/start value
in the reduction, by never ignoring it regardless of the presence of
fast-math flags on callsites. This change introduces the following
new intrinsics to replace the existing ones:

  llvm.experimental.vector.reduce.fadd -> llvm.experimental.vector.reduce.v2.fadd
  llvm.experimental.vector.reduce.fmul -> llvm.experimental.vector.reduce.v2.fmul

and adds functionality to auto-upgrade existing LLVM IR and bitcode.

Reviewers: RKSimon, greened, dmgreen, nikic, simoll, aemerson

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D60261

llvm-svn: 363035
2019-06-11 08:22:10 +00:00
Francis Visoiu Mistrih a438432acc [FastISel] Skip creating unnecessary vregs for arguments
This behavior was added in r130928 for both FastISel and SD, and then
disabled in r131156 for FastISel.

This re-enables it for FastISel with the corresponding fix.

This is triggered only when FastISel can't lower the arguments and falls
back to SelectionDAG for it.

FastISel contains a map of "register fixups" where at the end of the
selection phase it replaces all uses of a register with another
register that FastISel sometimes pre-assigned. Code at the end of
SelectionDAGISel::runOnMachineFunction is doing the replacement at the
very end of the function, while other pieces that come in before that
look through the MachineFunction and assume everything is done. In this
case, the real issue is that the code emitting COPY instructions for the
liveins (physreg to vreg) (EmitLiveInCopies) is checking if the vreg
assigned to the physreg is used, and if it's not, it will skip the COPY.
If a register wasn't replaced with its assigned fixup yet, the copy will
be skipped and we'll end up with uses of undefined registers.

This fix moves the replacement of registers before the emission of
copies for the live-ins.

The initial motivation for this fix is to enable tail calls for
swiftself functions, which were blocked because we couldn't prove that
the swiftself argument (which is callee-save) comes from a function
argument (live-in), because there was an extra copy (vreg to vreg).

A few tests are affected by this:

* llvm/test/CodeGen/AArch64/swifterror.ll: we used to spill x21
(callee-save) but never reload it because it's attached to the return.
We now don't even spill it anymore.
* llvm/test/CodeGen/*/swiftself.ll: we tail-call now.
* llvm/test/CodeGen/AMDGPU/mubuf-legalize-operands.ll: I believe this
test was not really testing the right thing, but it worked because the
same registers were re-used.
* llvm/test/CodeGen/ARM/cmpxchg-O0.ll: regalloc changes
* llvm/test/CodeGen/ARM/swifterror.ll: get rid of a copy
* llvm/test/CodeGen/Mips/*: get rid of spills and copies
* llvm/test/CodeGen/SystemZ/swift-return.ll: smaller stack
* llvm/test/CodeGen/X86/atomic-unordered.ll: smaller stack
* llvm/test/CodeGen/X86/swifterror.ll: same as AArch64
* llvm/test/DebugInfo/X86/dbg-declare-arg.ll: stack size changed

Differential Revision: https://reviews.llvm.org/D62361

llvm-svn: 362963
2019-06-10 16:53:37 +00:00
QingShan Zhang ab846da7e8 [DAGCombine] Match a pattern where a wide type scalar value is stored by several narrow stores
This opportunity is found from spec 2017 557.xz_r. And it is used by the sha encrypt/decrypt. See sha-2/sha512.c

static void store64(u64 x, unsigned char* y)
{
    for(int i = 0; i != 8; ++i)
        y[i] = (x >> ((7-i) * 8)) & 255;
}

static u64 load64(const unsigned char* y)
{
    u64 res = 0;
    for(int i = 0; i != 8; ++i)
        res |= (u64)(y[i]) << ((7-i) * 8);
    return res;
}
The load64 has been implemented by https://reviews.llvm.org/D26149
This patch is trying to implement the store pattern.

Match a pattern where a wide type scalar value is stored by several narrow
stores. Fold it into a single store or a BSWAP and a store if the targets
supports it.

Assuming little endian target:
i8 *p = ...
i32 val = ...
p[0] = (val >> 0) & 0xFF;
p[1] = (val >> 8) & 0xFF;
p[2] = (val >> 16) & 0xFF;
p[3] = (val >> 24) & 0xFF;

>
*((i32)p) = val;

i8 *p = ...
i32 val = ...
p[0] = (val >> 24) & 0xFF;
p[1] = (val >> 16) & 0xFF;
p[2] = (val >> 8) & 0xFF;
p[3] = (val >> 0) & 0xFF;

>
*((i32)p) = BSWAP(val);

Differential Revision: https://reviews.llvm.org/D62897

llvm-svn: 362921
2019-06-10 05:40:21 +00:00
David Bolvansky dcf5e6abdf [TargetLowering] Simplify (ctpop x) == 1
Reviewers: craig.topper, spatel, RKSimon, bkramer

Reviewed By: spatel

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

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D63004

llvm-svn: 362912
2019-06-09 18:18:57 +00:00
Simon Pilgrim 5f337149fa Use for-range loop. NFCI.
llvm-svn: 362897
2019-06-09 09:07:30 +00:00
Simon Pilgrim 6bae6d5a5d [DAGCombine] visitAND - merge (zext_inreg ((s)extload x)) -> (zextload x) combines. NFCI.
Same codegen, only differ by the oneuse limit for the sextload case.

llvm-svn: 362880
2019-06-08 17:02:00 +00:00
Amara Emerson 829037a914 Factor out SelectionDAG's switch analysis and lowering into a separate component.
In order for GlobalISel to re-use the significant amount of analysis and
optimization code in SDAG's switch lowering, we first have to extract it and
create an interface to be used by both frameworks.

No test changes as it's NFC.

Differential Revision: https://reviews.llvm.org/D62745

llvm-svn: 362857
2019-06-08 00:05:17 +00:00
Simon Pilgrim f0240ee76d [DAGCombine] visitAND - fix local shadow variable warnings. NFCI.
llvm-svn: 362825
2019-06-07 18:36:43 +00:00
Simon Pilgrim 4c9db2045a [DAGCombine] Use APInt::extractBits in "sub-splat" constant mask detection. NFCI.
llvm-svn: 362820
2019-06-07 18:07:06 +00:00
Jason Liu 60ec248148 [AIX] Implement function descriptor on SDAG
Summary:
(1) Function descriptor on AIX
On AIX, a called routine may have 2 distinct symbols associated with it:
 * A function descriptor (Name)
 * A function entry point (.Name)

The descriptor structure on AIX is the same as those in the ELF V1 ABI:
 * The address of the entry point of the function.
 * The TOC base address for the function.
 * The environment pointer.

The descriptor symbol uses the same name as the source level function in C.
The function entry point is analogous to the symbol we would generate for a
 function in a non-descriptor-based ABI, except that it is renamed by
prepending a ".".

Which symbol gets referenced depends on the context:
 * Taking the address of the function references the descriptor symbol.
 * Calling the function references the entry point symbol.

(2) Speaking of implementation on AIX, for direct function call target, we
 create proper MCSymbol SDNode(e.g . ".foo") while constructing SDAG to
 replace original TargetGlobalAddress SDNode. Then down the path, we can
 take advantage of this MCSymbol.

Patch by: Xiangling_L

Reviewed by: sfertile, hubert.reinterpretcast, jasonliu, syzaara

Differential Revision: https://reviews.llvm.org/D62532

llvm-svn: 362735
2019-06-06 19:13:36 +00:00
Simon Pilgrim 842c7792aa [DAGCombine] MergeConsecutiveStores - improve non-temporal load\store handling (PR42123)
This patch is the first step towards ensuring MergeConsecutiveStores correctly handles non-temporal loads\stores:

1 - When merging load\stores we must ensure that they all have the same non-temporal flag. This is unlikely to occur, but can in strange cases where we're storing at the end of one page and the beginning of another.

2 - The merged load\store node must retain the non-temporal flag.

Differential Revision: https://reviews.llvm.org/D62910

llvm-svn: 362723
2019-06-06 17:04:13 +00:00
Simon Pilgrim da993d08c8 [DAGCombine] Cleanup isNegatibleForFree/GetNegatedExpression. NFCI.
Prep work for PR42105 - clang-format, use auto for cast and merge nested if()s

llvm-svn: 362695
2019-06-06 10:21:18 +00:00
Ulrich Weigand 6c5d5ce551 Allow target to handle STRICT floating-point nodes
The ISD::STRICT_ nodes used to implement the constrained floating-point
intrinsics are currently never passed to the target back-end, which makes
it impossible to handle them correctly (e.g. mark instructions are depending
on a floating-point status and control register, or mark instructions as
possibly trapping).

This patch allows the target to use setOperationAction to switch the action
on ISD::STRICT_ nodes to Legal. If this is done, the SelectionDAG common code
will stop converting the STRICT nodes to regular floating-point nodes, but
instead pass the STRICT nodes to the target using normal SelectionDAG
matching rules.

To avoid having the back-end duplicate all the floating-point instruction
patterns to handle both strict and non-strict variants, we make the MI
codegen explicitly aware of the floating-point exceptions by introducing
two new concepts:

- A new MCID flag "mayRaiseFPException" that the target should set on any
  instruction that possibly can raise FP exception according to the
  architecture definition.
- A new MI flag FPExcept that CodeGen/SelectionDAG will set on any MI
  instruction resulting from expansion of any constrained FP intrinsic.

Any MI instruction that is *both* marked as mayRaiseFPException *and*
FPExcept then needs to be considered as raising exceptions by MI-level
codegen (e.g. scheduling).

Setting those two new flags is straightforward. The mayRaiseFPException
flag is simply set via TableGen by marking all relevant instruction
patterns in the .td files.

The FPExcept flag is set in SDNodeFlags when creating the STRICT_ nodes
in the SelectionDAG, and gets inherited in the MachineSDNode nodes created
from it during instruction selection. The flag is then transfered to an
MIFlag when creating the MI from the MachineSDNode. This is handled just
like fast-math flags like no-nans are handled today.

This patch includes both common code changes required to implement the
new features, and the SystemZ implementation.

Reviewed By: andrew.w.kaylor

Differential Revision: https://reviews.llvm.org/D55506

llvm-svn: 362663
2019-06-05 22:33:10 +00:00
Tim Northover 607c8a9d14 IR: make getParamByValType Just Work. NFC.
Most parts of LLVM don't care whether the byval type is derived from an
explicit Attribute or from the parameter's pointee type, so it makes
sense for the main access function to just return the right value.

The very few users who do care (only BitcodeReader so far) can find out
how it's specified by accessing the Attribute directly.

llvm-svn: 362642
2019-06-05 20:37:47 +00:00
Simon Pilgrim 77d6adc491 Fix shadow local variable warning. NFCI.
llvm-svn: 362622
2019-06-05 17:26:29 +00:00
Simon Pilgrim 5a81af547c [TargetLowering] SimplifyDemandedBits - pull out shift value type. NFCI.
Will be used more in an upcoming patch.

llvm-svn: 362595
2019-06-05 10:59:04 +00:00
Johannes Doerfert 6b432dca5d [SelectionDAG][FIX] Allow "returned" arguments to be bit-casted
Summary:
An argument that is return by a function but bit-casted before can still
be annotated as "returned". Make sure we do not crash for this case.

Reviewers: sunfish, stephenwlin, niravd, arsenm

Subscribers: wdng, hiraditya, bollu, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D59917

llvm-svn: 362546
2019-06-04 20:34:43 +00:00
Nemanja Ivanovic aed7227b71 Revert r362472 as it is breaking PPC build bots
The patch https://reviews.llvm.org/rL362472 broke PPC LNT buildbots.
Reverting it to bring the bots back to green.

llvm-svn: 362539
2019-06-04 18:48:43 +00:00
Craig Topper 09a4415803 [DAGCombiner][X86] Fold (not (neg X)) -> (add X, -1)
This is a special case of a more general transform (not (sub Y, X)) -> (add X, ~Y). InstCombine knows the general form. I've restricted to the special case to fix the motivating case PR42118. I tried handling any case where Y was constant, but got some changes on some Mips tests that I couldn't quickly prove where beneficial.

Fixes PR42118

Differential Revision: https://reviews.llvm.org/D62828

llvm-svn: 362533
2019-06-04 17:44:18 +00:00
Sanjay Patel 1e63dd0b44 [SelectionDAG][x86] limit post-legalization store merging by type
The proposal in D62498 showed that x86 would benefit from vector
store splitting, but that may conflict with the generic DAG
combiner's store merging transforms.

Add memory type to the existing TLI hook that enables the merging
transforms, so we can limit those changes to scalars only for x86.

llvm-svn: 362507
2019-06-04 15:15:59 +00:00
Roman Lebedev 3dce0326fe [DAGCombine][X86][AArch64][MIPS][LANAI] (C - x) - y -> C - (x + y) fold (PR41952)
Summary:
This *might* be the last fold for `sink-addsub-of-const.ll`, but i'm not sure yet.

As far as i can tell, there are no regressions here (ignoring x86-32),
all changes are either good or neutral.

This, almost surprisingly to me, fixes the motivational tests (in `shift-amount-mod.ll`)
`@reg32_lshr_by_sub_from_negated` from [[ https://bugs.llvm.org/show_bug.cgi?id=41952 | PR41952 ]].

https://rise4fun.com/Alive/vMd3

Reviewers: RKSimon, t.p.northover, craig.topper, spatel, efriedma

Reviewed By: RKSimon

Subscribers: sdardis, javed.absar, arichardson, kristof.beyls, jrtc27, atanasyan, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D62774

llvm-svn: 362488
2019-06-04 11:06:21 +00:00