SelectionDAGBuilder::visitShift will always zero-extend a shift amount when it
is promoted to the ShiftAmountTy. This results in zero-extension (masking)
which is unnecessary for RISC-V as the shift operations only read the lower 5
or 6 bits (RV32 or RV64).
I initially proposed adding a getExtendForShiftAmount hook so the shift amount
can be any-extended (D52975). @efriedma explained this was unsafe, so I have
instead eliminate the unnecessary and operations at instruction selection time
in a manner similar to X86InstrCompiler.td.
Differential Revision: https://reviews.llvm.org/D53224
llvm-svn: 344432
This is more consistent with what we usually do and matches some code X86 custom emits in some cases that I think I can cleanup.
The MIPS test change just looks to be an instruction ordering change.
llvm-svn: 344422
This saves a conversion to extracts and build_vector. We already do this when both the result and the input need to be widened to the same type.
This changed the sse-intrinsics-fast-isel test because we don't lower (insert_vector_elt (scalar_to_vector X), Y, 1) well. We turn it into (vector_shuffle (scalar_to_vector X), (scalar_to_vector Y), <0, 4, 2, 3>) losing track of the fact that the upper elts could be undef.
We should probably find a way to prevent the scalarization of the <2 x f32> load on these tests.
llvm-svn: 344404
This is the planned follow-up to D52997. Here we are reducing horizontal vector math codegen
by default. AMD Jaguar (btver2) should have no difference with this patch because it has
fast-hops. (If we want to set that bit for other CPUs, let me know.)
The code changes are small, but there are many test diffs. For files that are specifically
testing for hops, I added RUNs to distinguish fast/slow, so we can see the consequences
side-by-side. For files that are primarily concerned with codegen other than hops, I just
updated the CHECK lines to reflect the new default codegen.
To recap the recent horizontal op story:
1. Before rL343727, we were producing hops for all subtargets for a variety of patterns.
Hops were likely not optimal for all targets though.
2. The IR improvement in r343727 exposed a hole in the backend hop pattern matching, so
we reduced hop codegen for all subtargets. That was bad for Jaguar (PR39195).
3. We restored the hop codegen for all targets with rL344141. Good for Jaguar, but
probably bad for other CPUs.
4. This patch allows us to distinguish when we want to produce hops, so everyone can be
happy. I'm not sure if we have the best predicate here, but the intent is to undo the
extra hop-iness that was enabled by r344141.
Differential Revision: https://reviews.llvm.org/D53095
llvm-svn: 344361
Summary:
Reland of
- r344197 "[MC][ELF] compute entity size for explicit sections"
- r344206 "[MC][ELF] Fix section_mergeable_size.ll"
after being reverted in r344278 due to build breakages from not
specifying a target triple.
Move test from test/CodeGen/Generic/ to test/MC/ELF/.
Add explicit target triple so we don't try to run
this test on non ELF targets.
Reported: https://reviews.llvm.org/D53056#1261707
Reviewers: fhahn, rnk, espindola, NoQ
Reviewed By: fhahn, rnk
Subscribers: NoQ, MaskRay, rengolin, emaste, arichardson, llvm-commits, pirama, srhines
Differential Revision: https://reviews.llvm.org/D53146
llvm-svn: 344360
If you have the string /usr/bin, prior to this patch it would not
be quoted by our YAML serializer. But a string like C:\src would
be, due to the presence of a backslash. This makes the quoting
rules of basically every single file path different depending on
the path syntax (posix vs. Windows).
While technically not required by the YAML specification to quote
forward slashes, when the behavior of paths is inconsistent it
makes it difficult to portably write FileCheck lines that will
work with either kind of path.
Differential Revision: https://reviews.llvm.org/D53169
llvm-svn: 344359
This reverts commit b86c16ad8c97dadc1f529da72a5bb74e9eaed344.
This is being reverted because I forgot to write a useful
commit message, so I'm going to resubmit it with an actual
commit message.
llvm-svn: 344358
Generalize SelectionDAGLegalize's CTLZ expansion to handle vectors - lets VectorLegalizer::ExpandCTLZ to just pass the expansion on instead of repeating the same codegen.
llvm-svn: 344349
Pull out repeated byte sum stage for popcount of vector elements > 8bits.
This allows us to simplify the LUT/BITMATH popcnt code to always assume vXi8 vectors, and also improves avx512bitalg codegen which only has access to vpopcntb/vpopcntw.
llvm-svn: 344348
The current BitPermutationSelector generates a code to build a value by tracking two types of bits: ConstZero and Variable.
ConstZero means a bit we need to mask off and Variable is a bit we copy from an input value.
This patch add third type of bits VariableKnownToBeZero caused by AssertZext node or zero-extending load node.
VariableKnownToBeZero means a bit comes from an input value, but it is known to be already zero. So we do not need to mask them.
VariableKnownToBeZero enhances flexibility to group bits, since we can avoid redundant masking for these bits.
This patch also renames "HasZero" to "NeedMask" since now we may skip masking even when we have zeros (of type VariableKnownToBeZero).
Differential Revision: https://reviews.llvm.org/D48025
llvm-svn: 344347
Fixes PR32160 by reducing the size of PSHUFB if we only use one of the lanes.
This approach can probably be generalized to handle any target shuffle (and any subvector index) but we have no test coverage at the moment.
llvm-svn: 344336
Failure was discovered upon running
projects/compiler-rt/test/builtins/Unit/divtc3_test.c
in a stage2 compiler build.
When compiling projects/compiler-rt/lib/builtins/divtc3.c,
a call to fmaxl within the divtc3 implementation had its
return values read from registers $2 and $3 instead of $f0 and $f2.
Include fmaxl in the list of long double emulation routines
to have its return value correctly interpreted as f128.
Almost exact issue here: https://reviews.llvm.org/D17760
Differential Revision: https://reviews.llvm.org/D52649
llvm-svn: 344326
I want to add another pattern here that includes scalar_to_vector,
so this makes that patch smaller. I was hoping to remove the
hasOneUse() check because it shouldn't be necessary for common
codegen, but an AMDGPU test has a comment suggesting that the
extra check makes things better on one of those targets.
llvm-svn: 344320
On 64-bit targets the generic legalize will use an i64 load and a scalar_to_vector for us. But on 32-bit targets i64 isn't legal and the generic legalizer will end up emitting two 32-bit loads. We have DAG combines that try to put those two loads back together with pretty good success.
This patch instead uses f64 to avoid the splitting entirely. I've made it do the same for 64-bit mode for consistency and to keep the load in the fp domain.
There are a few things in here that look like regressions in 32-bit mode, but I believe they bring us closer to the 64-bit mode codegen. And that the 64-bit mode code could be better. I think those issues should be looked at separately.
Differential Revision: https://reviews.llvm.org/D52528
llvm-svn: 344291
Having a constant value operand in the compound instruction
is not always profitable. This patch improves coremark by ~4% on
Hexagon.
Differential Revision: https://reviews.llvm.org/D53152
llvm-svn: 344284
Revert r344206 "[MC][ELF] Fix section_mergeable_size.ll"
They were causing failures on too many important buildbots for too long.
Please revert eagerly if your fix takes more than a couple of hours to land!
llvm-svn: 344278
This is an alternative to D53080 since I think using a BEXTR for a shifted mask is definitely an improvement when the shl can be absorbed into addressing mode. The other cases I'm less sure about.
We already have several tricks for handling an and of a shift in address matching. This adds a new case for BEXTR.
I've moved the BEXTR matching code back to X86ISelDAGToDAG to allow it to match. I suppose alternatively we could directly emit a X86ISD::BEXTR node that isel could pattern match. But I'm trying to view BEXTR matching as an isel concern so DAG combine can see 'and' and 'shift' operations that are well understood. We did lose a couple cases from tbm_patterns.ll, but I think there are ways to recover that.
I've also put back the manual load folding code in matchBEXTRFromAnd that I removed a few months ago in r324939. This gives us some more freedom to make decisions based on the ability to fold a load. I haven't done anything with that yet.
Differential Revision: https://reviews.llvm.org/D53126
llvm-svn: 344270
Summary:
As discussed in D48491, we can't really do this in the TableGen,
since we need to produce *two* instructions. This only implements
one single pattern. The other 3 patterns will be in follow-ups.
I'm not sure yet if we want to also fuse shift into here
(i.e `(x >> start) & ...`)
Reviewers: RKSimon, craig.topper, spatel
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D52304
llvm-svn: 344224
Summary:
Although the saturating float to int instructions are already
emitted from normal IR, the fpto{s,u}i instructions produce poison
values if the argument cannot fit in the result type. These intrinsics
are therefore necessary to get guaranteed defined saturating behavior.
Reviewers: aheejin, dschuff
Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits
Differential Revision: https://reviews.llvm.org/D53004
llvm-svn: 344204
Summary:
Global variables might declare themselves to be in explicit sections.
Calculate the entity size always to prevent assembler warnings
"entity size for SHF_MERGE not specified" when sections are to be
marked merge-able.
Fixes PR31828.
Reviewers: rnk, echristo
Reviewed By: rnk
Subscribers: llvm-commits, pirama, srhines
Differential Revision: https://reviews.llvm.org/D53056
llvm-svn: 344197
Summary:
As discussed in [[ https://bugs.llvm.org/show_bug.cgi?id=38938 | PR38938 ]],
we fail to emit `BEXTR` if the mask is shifted.
We can't deal with that in `X86DAGToDAGISel` `before the address mode for the inc is selected`,
and we can't really do it in the normal DAGCombine, because we don't have generic `ISD::BitFieldExtract` node,
and if we simply turn the shifted mask into a normal mask + shift-left, it will be folded back.
So it would seem X86ISelLowering is the place to handle this.
This patch only moves the matchBEXTRFromAnd()
from X86DAGToDAGISel to X86ISelLowering.
It does not add support for the 'shifted mask' pattern.
Reviewers: RKSimon, craig.topper, spatel
Reviewed By: RKSimon
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D52426
llvm-svn: 344179
Summary:
GlobalISel generates incorrect code because the legalizer artifact
combiner assumes `G_[SZ]EXT (G_IMPLICIT_DEF)` is equivalent to
`G_IMPLICIT_DEF `.
Replace `G_[SZ]EXT (G_IMPLICIT_DEF)` with 0 because the top bits
will be 0 for G_ZEXT and 0/1 for the G_SEXT.
Reviewers: aditya_nandakumar, dsanders, aemerson, javed.absar
Reviewed By: aditya_nandakumar
Subscribers: rovka, kristof.beyls, llvm-commits
Differential Revision: https://reviews.llvm.org/D52996
llvm-svn: 344163
Summary:
Extend analysis forwarding loads from preceeding stores to work with
extended loads and truncated stores to the same address so long as the
load is fully subsumed by the store.
Hexagon's swp-epilog-phis.ll and swp-memrefs-epilog1.ll test are
deleted as they've no longer seem to be relevant.
Reviewers: RKSimon, rnk, kparzysz, javed.absar
Subscribers: sdardis, nemanjai, hiraditya, atanasyan, llvm-commits
Differential Revision: https://reviews.llvm.org/D49200
llvm-svn: 344142
This is intended to restore horizontal codegen to what it looked like before IR demanded elements improved in:
rL343727
As noted in PR39195:
https://bugs.llvm.org/show_bug.cgi?id=39195
...horizontal ops can be worse for performance than a shuffle+regular binop, so I've added a TODO. Ideally, we'd
solve that in a machine instruction pass, but a quicker solution will be adding a 'HasFastHorizontalOp' feature
bit to deal with it here in the DAG.
Differential Revision: https://reviews.llvm.org/D52997
llvm-svn: 344141
When SimplifyCFG changes the PHI node into a select instruction, the debug line records becomes ambiguous. It causes the debugger to display unreachable source lines.
Differential Revision: https://reviews.llvm.org/D52887
llvm-svn: 344120
An upcoming patch will change the codegen for these patterns. This test case is
added now so that the patch can show the differences in codegen.
llvm-svn: 344112
Commit r343851 changed the format of the generated instructions.
An unnecessary load has been removed. Previously, a value would be moved
from r24 into a temporary register just to be copied into r30 before the
indirect call. Now, codegen immediately loads r24 into r30, saving a
MOVW instruction.
llvm-svn: 344111
For ISD::SIGN_EXTEND_INREG operation of v2i16 and v2i8 types will cause assert because they are registered as custom operation.
So that the type legalization phase will enter the custom hook, which do not handle ISD::SIGN_EXTEND_INREG operation and fall throw into unreachable assert.
Patch By: wuzish (Zixuan Wu)
Differential Revision: https://reviews.llvm.org/D52449
llvm-svn: 344109
Summary:
Subtraction from zero and floating point negation do not have the same
semantics, so fix lowering.
Reviewers: aheejin, dschuff
Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits
Differential Revision: https://reviews.llvm.org/D52948
llvm-svn: 344107
Summary:
Also add tests to catch crashes in passes that are not normally run in
tests.
Reviewers: aheejin, dschuff
Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits
Differential Revision: https://reviews.llvm.org/D52959
llvm-svn: 344094
We already do the following combines:
(bitcast int (and (bitcast fp X to int), 0x7fff...) to fp) -> fabs X
(bitcast int (xor (bitcast fp X to int), 0x8000...) to fp) -> fneg X
When the target has "bit preserving fp logic". This patch just extends it
to also combine:
(bitcast int (or (bitcast fp X to int), 0x8000...) to fp) -> fneg (fabs X)
As some targets have fnabs and even those that don't can efficiently lower
both the fabs and the fneg.
Differential revision: https://reviews.llvm.org/D44548
llvm-svn: 344093
Alex Bradbury