1345 Commits

Author SHA1 Message Date
Craig Topper
a37df84f99 [SelectionDAG][RISCV] Remove code for handling too small shift type from SimplifyDemandedBits.
This code detected that the type returned from getShiftAmountTy was
too small to hold the constant shift amount. But it used the full
type size instead of scalar type size leading it to crash for
scalable vectors.

This code was necessary when getShiftAmountTy would always
return the target preferred shift amount type for scalars even when
the type was an illegal type larger than the target supported. For
vectors, getShiftAmountTy has always returned the vector type.

Fortunately, getShiftAmountTy was fixed a while ago to detect that
the target's preferred size for scalars is not large enough for the
type. So we can delete this code.

Switched to use getShiftAmountConstant to further simplify the code.

Fixs PR61561.
2023-03-21 11:08:19 -07:00
Matt Arsenault
9356ec1516 CodeGen: Reorder case handling for is.fpclass legalization
Subnormal and zero checks can be combined into one, so move
the code closer to reduce the diff in a future change.
2023-03-17 11:29:50 -04:00
Simon Pilgrim
6bc0e362d7 [DAG] TargetLowering::ShrinkDemandedOp - move SmallVTBits iterator inside for loop. NFC 2023-03-16 12:12:33 +00:00
Simon Pilgrim
7aa7393aab [DAG] TargetLowering::ShrinkDemandedOp - pull out repeated getValueType calls. NFC 2023-03-16 12:12:33 +00:00
Simon Pilgrim
dc20ce7e54 [DAG] TargetLowering::ShrinkDemandedOp - rename Demanded arg to DemandedBits. NFC
Make it clear this is referring to DemandedBits not DemandedElts.
2023-03-15 13:22:21 +00:00
Jay Foad
0265dd9925 Fix "compatiable" typos 2023-03-07 12:57:39 +00:00
Simon Pilgrim
73cdccad55 [DAG] expandIntMINMAX - attempt to match existing SETCC node
As noticed on D144789, when we have pairs of min/max nodes we often end up with multiple comparisons which we could reuse with commuted select ops, so check to see if a suitable SETCC already exists. This also allowed us to remove a similar X86 peephole.

There are other getSETCC cases where we could safely reuse other CondCodes as well - I've been trying to think of how we could reuse this logic in SelectionDAG but haven't found anything that always works well.

An alternative would be to have a TLI callback that returns a preferred CondCode from a list of options, I've noticed this helped fpclamptosat tests on some other targets (MVE + WebAssembly), but other tests suffered.

Differential Revision: https://reviews.llvm.org/D145065
2023-03-01 19:04:03 +00:00
David Green
06daa515b2 [AArch64] Don't remove free sext_inreg(vector_extract(x)) if it leads to multiple extracts
If we have sext_inreg(vector_extract(x)) but the top bits are not used, DAG
will try to remove the sext_inreg, using vector_extract(x) directly. This can
lead to multiple uses of both sext_inreg(vector_extract(x)) and
vector_extract(x), leading to the generation of both umov and smov extracts.
This adds a target hook to prevent that under AArch64 where the sext_inreg can
be considered free if there are multiple uses of the sext and no uses of the
vector_extract. This helps fix a small regression from D144550.

Differential Revision: https://reviews.llvm.org/D144850
2023-02-27 19:20:10 +00:00
Serge Pavlov
7f81dd4dd6 [NFC] Make FPClassTest a bitmask enumeration
This is recommit of 2e416cdd52, fixed to be accepatble by GCC.
The original commit message is below.

With this change bitwise operations are allowed for FPClassTest
enumeration, it must simplify using this type. Also some functions
changed to get argument of type FPClassTest instead of unsigned.

Differential Revision: https://reviews.llvm.org/D144241
2023-02-24 15:12:16 +07:00
Serge Pavlov
08a09235b6 Revert "[NFC] Make FPClassTest a bitmask enumeration"
This reverts commit e7613c1d9b259bdf2b0b06b4169d9a10dd553406.

GCC issues an error:

In file included from /home/buildbot/as-builder-4/lld-x86_64-ubuntu-fast/llvm-project/llvm/unittests/ADT/BitmaskEnumTest.cpp:9:
/home/buildbot/as-builder-4/lld-x86_64-ubuntu-fast/llvm-project/llvm/include/llvm/ADT/BitmaskEnum.h:66:22: error: explicit specialization of template<class E, class Enable> struct llvm::is_bitmask_enum outside its namespace must use a nested-name-specifier [-fpermissive]
   66 |   template <> struct is_bitmask_enum<Enum> : std::true_type {};                \
      |                      ^~~~~~~~~~~~~~~~~~~~~
/home/buildbot/as-builder-4/lld-x86_64-ubuntu-fast/llvm-project/llvm/unittests/ADT/BitmaskEnumTest.cpp:30:1: note: in expansion of macro LLVM_DECLARE_ENUM_AS_BITMASK
   30 | LLVM_DECLARE_ENUM_AS_BITMASK(Flags2, V4);
      | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
2023-02-23 12:55:58 +07:00
Serge Pavlov
e7613c1d9b [NFC] Make FPClassTest a bitmask enumeration
This is recommit of 2e416cdd52, reverted in 8555ab2fcd, because GCC
complains on extra qualification. The macro LLVM_DECLARE_ENUM_AS_BITMASK
does not specify llvm:: anymore, so the macro must occur in the namespace
llvm. Documentation updated accordingly. The original commit message is below.

With this change bitwise operations are allowed for FPClassTest
enumeration, it must simplify using this type. Also some functions
changed to get argument of type FPClassTest instead of unsigned.

Differential Revision: https://reviews.llvm.org/D144241
2023-02-23 12:38:57 +07:00
Nikita Popov
8555ab2fcd Revert "[NFC] Make FPClassTest a bitmask enumeration"
This reverts commit 2e416cdd52c1079b8c7cb1f7d7e557c889a4fb56.

Breaks the GCC build:

In file included from /home/npopov/repos/llvm-project/llvm/include/llvm/ADT/FloatingPointMode.h:18,
                 from /home/npopov/repos/llvm-project/llvm/include/llvm/ADT/APFloat.h:20,
                 from /home/npopov/repos/llvm-project/llvm/lib/Support/APFloat.cpp:14:
/home/npopov/repos/llvm-project/llvm/include/llvm/ADT/BitmaskEnum.h:66:22: error: extra qualification not allowed [-fpermissive]
   66 |   template <> struct llvm::is_bitmask_enum<Enum> : std::true_type {};          \
      |                      ^~~~
/home/npopov/repos/llvm-project/llvm/include/llvm/ADT/FloatingPointMode.h:223:1: note: in expansion of macro ‘LLVM_DECLARE_ENUM_AS_BITMASK’
  223 | LLVM_DECLARE_ENUM_AS_BITMASK(FPClassTest, /* LargestValue */ fcPosInf);
      | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/home/npopov/repos/llvm-project/llvm/include/llvm/ADT/BitmaskEnum.h:67:22: error: extra qualification not allowed [-fpermissive]
   67 |   template <> struct llvm::largest_bitmask_enum_bit<Enum> {                    \
      |                      ^~~~
/home/npopov/repos/llvm-project/llvm/include/llvm/ADT/FloatingPointMode.h:223:1: note: in expansion of macro ‘LLVM_DECLARE_ENUM_AS_BITMASK’
  223 | LLVM_DECLARE_ENUM_AS_BITMASK(FPClassTest, /* LargestValue */ fcPosInf);
      | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
[43/4396] Building CXX object lib/Supp...iles/LLVMSupport.dir/CommandLine.cpp.o
2023-02-22 08:56:19 +01:00
Serge Pavlov
2e416cdd52 [NFC] Make FPClassTest a bitmask enumeration
With this change bitwise operations are allowed for FPClassTest
enumeration, it must simplify using this type. Also some functions
changed to get argument of type FPClassTest instead of unsigned.

Differential Revision: https://reviews.llvm.org/D144241
2023-02-22 14:20:04 +07:00
Kazu Hirata
a28b252d85 Use APInt::getSignificantBits instead of APInt::getMinSignedBits (NFC)
Note that getMinSignedBits has been soft-deprecated in favor of
getSignificantBits.
2023-02-19 23:56:52 -08:00
Kazu Hirata
397265d88f [llvm] Use APInt::isAllOnes instead of isAllOnesValue (NFC)
Note that isAllOnesValue has been soft-deprecated in favor of
isAllOnes.
2023-02-19 23:35:39 -08:00
Kazu Hirata
9e5d2495ac Use APInt::isOne instead of APInt::isOneValue (NFC)
Note that isOneValue has been soft-deprecated in favor of isOne.
2023-02-19 23:06:36 -08:00
Kazu Hirata
b7ffd9686d Use APInt::getAllOnes instead of APInt::getAllOnesValue (NFC)
Note that getAllOnesValue has been soft-deprecated in favor of
getAllOnes.
2023-02-19 22:54:23 -08:00
Kazu Hirata
f8f3db2756 Use APInt::count{l,r}_{zero,one} (NFC) 2023-02-19 22:04:47 -08:00
Kazu Hirata
7e6e636fb6 Use llvm::has_single_bit<uint32_t> (NFC)
This patch replaces isPowerOf2_32 with llvm::has_single_bit<uint32_t>
where the argument is wider than uint32_t.
2023-02-15 22:17:27 -08:00
Kazu Hirata
64dad4ba9a Use llvm::bit_cast (NFC) 2023-02-14 01:22:12 -08:00
Samuel Parker
7bff37783f [SDAG] Check fminnum/fmaxnum for non-zero operand.
Currently, in TargetLowering, if the target does not support fminnum, we lower
to fminimum if neither operand could be a NaN. But this isn't quite correct
because fminnum and fminimum treat +/-0 differently; so, we need to prove that
one of the operands isn't a zero, or we don't have signed zeros.

Differential Revision: https://reviews.llvm.org/D143256
2023-02-07 10:54:23 +00:00
David Green
fd67e9545d [DAG] Remove non-canonical AVG case.
This removes a condition in the detection of AVG nodes, where we needn't be
checking the LHS of an add node as any const will be canonicalized to the RHS.
2023-02-06 17:24:25 +00:00
David Green
b76f40c12f [DAG][AArch64][ARM] Recognize avg (hadd) from wrapping flags
This slightly extends the creation of hadd nodes to allow them to be generated
with the original type size if wrapping flags allow.
https://alive2.llvm.org/ce/z/bPjakD
https://alive2.llvm.org/ce/z/fa_gzb

Differential Revision: https://reviews.llvm.org/D143371
2023-02-06 17:24:01 +00:00
Simon Pilgrim
f7b10467b6 [TLI] SimplifyMultipleUseDemandedBits - remove insert_subvector(undef, x, 0) fold
SimplifyMultipleUseDemandedBits shouldn't be creating general nodes on the fly, it should mainly just peek through them (although we do currently allow creation of new bitcasts and constant folding).

This is mostly a win - by avoiding new nodes we avoid a lot of hasOneUse limitations inside x86 shuffle combining - the main regressions I've noticed are where we've ended up with multiple insert_subvector(undef, x, 0) nodes, widening x to different vector widths - that should hopefully be improved when we remove the last of the vector widening from combineX86ShufflesRecursively for Issue #45319
2023-02-06 09:55:11 +00:00
Matt Arsenault
db0e659161 DAG: Fix broken lowering of is.fplcass fcZero with DAZ
is.fpclass x, fcZero is not equivalent to fcmp with 0 if
denormals are treated as 0. It would be equivalent to fcZero|fcSubnormal
which can be done separately; this is the minimal correctness fix.

The same optimization was not ported to the GlobalISel version.
2023-02-05 09:14:16 -04:00
Kazu Hirata
526966d07d Use llvm::bit_ceil (NFC)
Note that:

  std::has_single_bit(X) ? X : llvm::NextPowerOf2(X);

is equivalent to:

  std::bit_ceil(X)

even for input 0.
2023-01-28 16:13:09 -08:00
Kazu Hirata
22cdc6a126 [llvm] Use llvm::bit_ceil instead of PowerOf2Ceil (NFC)
The arguments to PowerOf2Ceil in this patch are all known to be
nonzero, so we can safely use llvm::bit_ceil here.
2023-01-25 00:05:33 -08:00
Roman Lebedev
edf004e691
[NFC][TargetLowering] isSplatValueForTargetNode(): add DAG operand
Without it we can't recurse further.
2023-01-16 00:02:20 +03:00
Guillaume Chatelet
48f5d77eee [NFC] Use TypeSize::getKnownMinValue() instead of TypeSize::getKnownMinSize()
This change is one of a series to implement the discussion from
https://reviews.llvm.org/D141134.
2023-01-11 16:36:39 +00:00
Sanjay Patel
bf82070ea4 [SDAG] try to avoid multiply for X*Y==0
Forking this off from D140850 -
https://alive2.llvm.org/ce/z/TgBeK_
https://alive2.llvm.org/ce/z/STVD7d

We could almost justify doing this in IR, but consideration for
"minsize" requires that we only try it in codegen -- the
transform is not reversible.

In all other cases, avoiding multiply should be a win because a
mul is more expensive than simple/parallelizable compares. AArch
even has a trick to keep instruction count even for some types.

Differential Revision: https://reviews.llvm.org/D141086
2023-01-06 09:06:11 -05:00
Craig Topper
11e92bd61f [SelectionDAG] Improve codegen for udiv by constant if any divisors are 1.
If the divisor is 1, the magic algorithm does not return a correct
result and we end up using a select to pick the numerator for those
elements at the end.

Therefore we can use undef for that element of the earlier operations
when the divisor is 1. We sometimes get this through SimplifyDemandedVectorElts,
but not always. Definitely seems like we don't if the NPQ fixup is used.

Unfortunately, DAGCombiner is unable to fold srl X, <0, undef> to X so
I had to add flags to avoid emitting the srl unless one of the shift
amounts is non-zero.

Reviewed By: lebedev.ri

Differential Revision: https://reviews.llvm.org/D141022
2023-01-05 08:41:44 -08:00
Craig Topper
f8751b8ee6 [TargetLowering] Remove stale FIXME. NFC
This was implemented for scalars in D140750.
2023-01-04 18:40:42 -08:00
Craig Topper
3f749a5d9d [Support][SelectionDAG][GlobalISel] Hoist PostShift adjustment for IsAdd into UnsignedDivideUsingMagic.
Instead of doing the adjustment in 3 different places in the code
base, do it inside UnsignedDivideUsingMagic::get.

Differential Revision: https://reviews.llvm.org/D141014
2023-01-04 15:18:12 -08:00
Craig Topper
8bca60fb0a [SelectionDAG][GlobalISel] Don't use UnsignedDivisionByConstantInfo for divisor of 1.
The magic algorithm sets IsAdd indication for division by 1 that
the caller had to ignore.

I considered folding the ignore into UnsignedDivisionByConstantInfo,
but we only allow 1 for vectors of mixed visiors. And really what we
want to end up with is undef. Currently, we get to undef via
DemandedElts optimizations using the select instruction. We could
directly emit undef.

Differential Revision: https://reviews.llvm.org/D140940
2023-01-04 10:01:15 -08:00
Yeting Kuo
1e9e1b9cf8 [VP][RISCV] Add vp.ctlz/cttz and RISC-V support.
The patch also adds expandVPCTLZ and expandVPCTTZ to expand vp.ctlz/cttz nodes
and the cost model of vp.ctlz/cttz.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D140370
2023-01-04 15:15:01 +08:00
Craig Topper
84daed7fd4 [SelectionDAG][GlobalISel] Move even divisor optimization for division by constant into UnsignedDivideUsingMagic implementation. NFC
I've added a bool to UnsignedDivideUsingMagic so we can continue
testing it in the unit test with and without this optimization in
the unit test.

This is a step towards supporting "uncooperative" odd divisors.
See https://ridiculousfish.com/blog/posts/labor-of-division-episode-iii.html

Reviewed By: lebedev.ri

Differential Revision: https://reviews.llvm.org/D140924
2023-01-03 16:34:13 -08:00
Craig Topper
8abd70081f [TargetLowering] Teach BuildUDIV to take advantage of leading zeros in the dividend.
If the dividend has leading zeros, we can use them to reduce the
size of the multiplier and avoid the fixup cases.

This patch is for scalars only, but we might be able to do this
for vectors in a follow up.

Differential Revision: https://reviews.llvm.org/D140750
2022-12-29 13:58:46 -08:00
Philip Reames
f1dcb9c36f [SDAG] neg x with only low bit demanded is x
We have a version of this transform in InstCombine, but surprisingly not in SDAG.  Even more surprisingly, this benefits RISCV, but no other target. This was surprising enough I double checked my build configuration to make sure all targets were enabled; they appear to be.

Differential Revision: https://reviews.llvm.org/D140324
2022-12-19 15:25:43 -08:00
Saleem Abdulrasool
9b92f70d47 Revert "Reland "[TargetLowering] Teach DemandedBits about VSCALE""
This reverts commit 3010f60381bcd828d1b409cfaa576328bcd05bbc.

This change introduced undefined behaviour (reported at
https://reviews.llvm.org/D138508#inline-1352840).  Additionally, it
appears to be responsible for a mis-compilation on RISCV64 with the
vector extension (https://github.com/llvm/llvm-project/issues/59594).
The commit message indicates that this is meant to be ARM64 specific
though is a generic selection change.
2022-12-19 18:52:29 +00:00
Simon Pilgrim
6161a8dd5c DAG: Pull fneg out of select feeding fadd into fsub
Enables folding fadd x, (select c, (fneg a), (fneg b))
-> fsub (select a, b), c

Avoids some regressions in a future AMDGPU change.
2022-12-19 11:38:30 -05:00
Fangrui Song
036e092282 [CodeGen] std::optional::value => operator*/operator->
value() has undesired exception checking semantics and calls
__throw_bad_optional_access in libc++. Moreover, the API is unavailable without
_LIBCPP_NO_EXCEPTIONS on older Mach-O platforms (see
_LIBCPP_AVAILABILITY_BAD_OPTIONAL_ACCESS).

This fixes LLVMMIRParser, LLVMGlobalISel, LLVMAsmPrinter, LLVMSelectionDAG.
2022-12-16 23:41:36 +00:00
Fangrui Song
b1df3a2c0b [Support] llvm::Optional => std::optional
https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
2022-12-16 08:49:10 +00:00
Benjamin Maxwell
3010f60381 Reland "[TargetLowering] Teach DemandedBits about VSCALE"
Reland with a fixup to avoid converting APInts to int64_t which allowed for
overflows (UB) with sufficiently high/low multiplier values.

This allows DemandedBits to see the result of VSCALE will be at most
VScaleMax * some compile-time constant. This relies on the vscale_range()
attribute being present on the function, with a max set. (This is done by
default when clang is targeting AArch64+SVE).

Using this various redundant operations (zexts, sexts, ands, ors, etc)
can be eliminated.

Differential Revision: https://reviews.llvm.org/D138508
2022-12-15 13:50:02 +00:00
Benjamin Maxwell
20b29a59c5 Revert "[TargetLowering] Teach DemandedBits about VSCALE"
This reverts commit c165b0553a96394b9bbf3984782703cdae99821d.
2022-12-15 11:29:34 +00:00
Benjamin Maxwell
c165b0553a [TargetLowering] Teach DemandedBits about VSCALE
This allows DemandedBits to see the result of VSCALE will be at most
VScaleMax * some compile-time constant. This relies on the vscale_range()
attribute being present on the function, with a max set. (This is done by
default when clang is targeting AArch64+SVE).

Using this various redundant operations (zexts, sexts, ands, ors, etc)
can be eliminated.

Differential Revision: https://reviews.llvm.org/D138508
2022-12-14 15:49:08 +00:00
Yeting Kuo
ad68586a37 [VP][RISCV] Add vp.ctpop and RISC-V support.
The patch also adds expandVPCTPOP in TargetLowering to expand VP_CTPOP nodes.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D139920
2022-12-14 09:47:44 +08:00
Yeting Kuo
47b9da72e0 [VP][RISCV] Add vp.bitreverse and RISC-V support.
The patch also added function expandVPBITREVERSE to expand ISD::VP_BITREVERSE nodes.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D139697
2022-12-12 10:58:44 +08:00
Yeting Kuo
0f8c761c48 [VP][RISCV] Recommit "Add vp.fshl/fshr and RISC-V support."
This reverts commit 7883e5b061bdbbe8bee5f479ebe911db5045b7e9.

The original commit was reverted that it didn't update test files after D136263
landed. The recommit fixed those.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D139509
2022-12-07 15:58:12 +08:00
Kazu Hirata
7883e5b061 Revert "[VP][RISCV] Add vp.fshl/fshr and RISC-V support."
This reverts commit 70de0e014013b4d97febe6704881a9a8c893d078.

I'm seeing:

Failed Tests (2):
  LLVM :: CodeGen/RISCV/rvv/fixed-vectors-fshr-fshl-vp.ll
  LLVM :: CodeGen/RISCV/rvv/fshr-fshl-vp.ll

Also reported at:

https://lab.llvm.org/buildbot/#/builders/123/builds/14531
2022-12-06 22:27:43 -08:00
Yeting Kuo
70de0e0140 [VP][RISCV] Add vp.fshl/fshr and RISC-V support.
The patch made VectorLegalizer expand ISD::VP_FSHL and ISD::VP_FSHR to
achieve the codegen.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D138379
2022-12-07 12:16:36 +08:00