It's better to do the ands, shifts, ors in the vector domain than
to scalarize it and do those operations on each element.
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D112248
This renames the primary methods for creating a zero value to `getZero`
instead of `getNullValue` and renames predicates like `isAllOnesValue`
to simply `isAllOnes`. This achieves two things:
1) This starts standardizing predicates across the LLVM codebase,
following (in this case) ConstantInt. The word "Value" doesn't
convey anything of merit, and is missing in some of the other things.
2) Calling an integer "null" doesn't make any sense. The original sin
here is mine and I've regretted it for years. This moves us to calling
it "zero" instead, which is correct!
APInt is widely used and I don't think anyone is keen to take massive source
breakage on anything so core, at least not all in one go. As such, this
doesn't actually delete any entrypoints, it "soft deprecates" them with a
comment.
Included in this patch are changes to a bunch of the codebase, but there are
more. We should normalize SelectionDAG and other APIs as well, which would
make the API change more mechanical.
Differential Revision: https://reviews.llvm.org/D109483
Since gather lowering can now lower to nodes that may need expansion via
the vector legalizer, do MGATHER lowering via vector legalizer.
Additionally, as part of adding passthru support for fixed typed
gathers, fix passthru support for scalable types.
Depends on D104910
Differential Revision: https://reviews.llvm.org/D104217
This patch extends the cases in which the legalizer is able to express
VSELECT in terms of XOR/AND/OR. When dealing with a VSELECT between
boolean vector types, the mask itself is an all-ones or all-ones value
of the operand type, so a 0/1 boolean type behaves identically to a 0/-1
type.
This greatly helps RISC-V which relies on expansion for these nodes. It
also allows scalable-vector bool VSELECTs to use the default expansion,
where before it would crash in SelectionDAG::UnrollVectorOp.
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D103147
This patch extends VectorLegalizer::ExpandSELECT to permit expansion
also for scalable vector types. The only real change is conditionally
checking for BUILD_VECTOR or SPLAT_VECTOR legality depending on the
vector type.
We can use this to fix "cannot select" errors for scalable vector
selects on the RISCV target. Note that in future patches RISCV will
possibly custom-lower vector SELECTs to VSELECTs for branchless codegen.
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D102063
This is currently performed in SelectionDAGLegalize, here we make it also
happen in LegalizeVectorOps, allowing a target to lower the SETCC condition
codes first in LegalizeVectorOps and then lower to a custom node afterwards,
without having to duplicate all of the SETCC condition legalization in the
target specific lowering.
As a result of this, fixed length floating point SETCC nodes can now be
properly lowered for SVE.
Differential Revision: https://reviews.llvm.org/D98939
This patch adds support for the fptoui.sat and fptosi.sat intrinsics,
which provide basically the same functionality as the existing fptoui
and fptosi instructions, but will saturate (or return 0 for NaN) on
values unrepresentable in the target type, instead of returning
poison. Related mailing list discussion can be found at:
https://groups.google.com/d/msg/llvm-dev/cgDFaBmCnDQ/CZAIMj4IBAAJ
The intrinsics have overloaded source and result type and support
vector operands:
i32 @llvm.fptoui.sat.i32.f32(float %f)
i100 @llvm.fptoui.sat.i100.f64(double %f)
<4 x i32> @llvm.fptoui.sat.v4i32.v4f16(half %f)
// etc
On the SelectionDAG layer two new ISD opcodes are added,
FP_TO_UINT_SAT and FP_TO_SINT_SAT. These opcodes have two operands
and one result. The second operand is an integer constant specifying
the scalar saturation width. The idea here is that initially the
second operand and the scalar width of the result type are the same,
but they may change during type legalization. For example:
i19 @llvm.fptsi.sat.i19.f32(float %f)
// builds
i19 fp_to_sint_sat f, 19
// type legalizes (through integer result promotion)
i32 fp_to_sint_sat f, 19
I went for this approach, because saturated conversion does not
compose well. There is no good way of "adjusting" a saturating
conversion to i32 into one to i19 short of saturating twice.
Specifying the saturation width separately allows directly saturating
to the correct width.
There are two baseline expansions for the fp_to_xint_sat opcodes. If
the integer bounds can be exactly represented in the float type and
fminnum/fmaxnum are legal, we can expand to something like:
f = fmaxnum f, FP(MIN)
f = fminnum f, FP(MAX)
i = fptoxi f
i = select f uo f, 0, i # unnecessary if unsigned as 0 = MIN
If the bounds cannot be exactly represented, we expand to something
like this instead:
i = fptoxi f
i = select f ult FP(MIN), MIN, i
i = select f ogt FP(MAX), MAX, i
i = select f uo f, 0, i # unnecessary if unsigned as 0 = MIN
It should be noted that this expansion assumes a non-trapping fptoxi.
Initial tests are for AArch64, x86_64 and ARM. This exercises all of
the scalar and vector legalization. ARM is included to test float
softening.
Original patch by @nikic and @ebevhan (based on D54696).
Differential Revision: https://reviews.llvm.org/D54749
This is part of the discussion on D91876 about trying to reduce custom lowering of MIN/MAX ops on older SSE targets - if we can improve generic vector expansion we should be able to relax the limitations in SelectionDAGBuilder when it will let MIN/MAX ops be generated, and avoid having to flag so many ops as 'custom'.
ExpandStrictFPOp started taking two parameters instead of one on Jan
10, 2020 in commit f678fc7660b36ce0ad6ce4f05eaa28f3e9fdedb5, but the
declaration for the single-perameter version has remained since.
Hook up legalizations for VECREDUCE_SEQ_FMUL. This is following up on the VECREDUCE_SEQ_FADD work from D90247.
Differential Revision: https://reviews.llvm.org/D90644
Add Legalization support for VECREDUCE_SEQ_FADD, so that we don't need to depend on ExpandReductionsPass.
Differential Revision: https://reviews.llvm.org/D90247
Implement them on top of sdiv/udiv, similar to what we do for integer
types.
Potential future work: implementing i8/i16 srem/urem, optimizations for
constant divisors, optimizing the mul+sub to mls.
Differential Revision: https://reviews.llvm.org/D81511
This intrinsic implements IEEE-754 operation roundToIntegralTiesToEven,
and performs rounding to the nearest integer value, rounding halfway
cases to even. The intrinsic represents the missed case of IEEE-754
rounding operations and now llvm provides full support of the rounding
operations defined by the standard.
Differential Revision: https://reviews.llvm.org/D75670
The two code paths have the same goal, legalizing a load of a non-byte-sized vector by loading the "flattened" representation in memory, slicing off each single element and then building a vector out of those pieces.
The technique employed by `ExpandLoad` is slightly more convoluted and produces slightly better codegen on ARM, AMDGPU and x86 but suffers from some bugs (D78480) and is wrong for BE machines.
Differential Revision: https://reviews.llvm.org/D79096
The "Align" passed into getMachineMemOperand etc. is the alignment of
the MachinePointerInfo, not the alignment of the memory operation.
(getAlign() on a MachineMemOperand automatically reduces the alignment
to account for this.)
We were passing on wrong (overconservative) alignment in a bunch of
places. Fix a bunch of these, mostly in legalization. And while I'm
here, switch to the new Align APIs.
The test changes are all scheduling changes: the biggest effect of
preserving large alignments is that it improves alias analysis, so the
scheduler has more freedom.
(I was originally just trying to do a minor cleanup in
SelectionDAGBuilder, but I accidentally went deeper down the rabbit
hole.)
Differential Revision: https://reviews.llvm.org/D77687
Summary:
This patch adds intrinsics and ISelDAG nodes for signed
and unsigned fixed-point division:
```
llvm.sdiv.fix.sat.*
llvm.udiv.fix.sat.*
```
These intrinsics perform scaled, saturating division
on two integers or vectors of integers. They are
required for the implementation of the Embedded-C
fixed-point arithmetic in Clang.
Reviewers: bjope, leonardchan, craig.topper
Subscribers: hiraditya, jdoerfert, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D71550
and macro FUNCTION likewise. NFCI.
Some functions like fmuladd don't really have a node, we should divide
the declaration form those have node to avoid introducing fake nodes.
Differential Revision: https://reviews.llvm.org/D72871
Custom legalization can produce MERGE_VALUES to return multiple
results. We can expand them immediately instead of leaving them
around for DAG combine to clean up.
Some of the simplest handlers just call TLI and if that fails,
they fall back to unrolling. For those just inline the TLI call
and share the unrolling call with the default case of Expand.
For ExpandFSUB and ExpandBITREVERSE so that its obvious they
don't return results sometimes and want to defer to LegalizeDAG.
This system wasn't very well designed for multi-result nodes. As
a consequence they weren't consistently registered in the
LegalizedNodes map leading to nodes being revisited for different
results.
I've removed the "Result" variable from the main LegalizeOp method
and used a SDNode* instead. The result number from the incoming
Op SDValue is only used for deciding which result to return to the
caller. When LegalizeOp is called it should always register a
legalized result for all of its results. Future calls for any other
result should be pulled for the LegalizedNodes map.
Legal nodes will now register all of their results in the map
instead of just the one we were called for.
The Expand and Promote handling to use a vector of results similar
to LegalizeDAG. Each of the new results is then re-legalized and
logged in the LegalizedNodes map for all of the Results for the
node being legalized. None of the handles register their own
results now. And none call ReplaceAllUsesOfValueWith now.
Custom handling now always passes result number 0 to LowerOperation.
This matches what LegalizeDAG does. Since the introduction of
STRICT nodes, I've encountered several issues with X86's custom
handling being called with an SDValue pointing at the chain and
our custom handlers using that to get a VT instead of result 0.
This should prevent us from having any more of those issues. On
return we will update the LegalizedNodes map for all results so
we shouldn't call the custom handler again for each result number.
I want to push SDNode* further into the Expand and Promote
handlers, but I've left that for a follow to keep this patch size
down. I've created a dummy SDValue(Node, 0) to keep the handlers
working.
Differential Revision: https://reviews.llvm.org/D72224
Summary:
This patch adds intrinsics and ISelDAG nodes for
signed and unsigned fixed-point division:
llvm.sdiv.fix.*
llvm.udiv.fix.*
These intrinsics perform scaled division on two
integers or vectors of integers. They are required
for the implementation of the Embedded-C fixed-point
arithmetic in Clang.
Patch by: ebevhan
Reviewers: bjope, leonardchan, efriedma, craig.topper
Reviewed By: craig.topper
Subscribers: Ka-Ka, ilya, hiraditya, jdoerfert, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D70007
The code here isn't great in all caess. Particularly v4f64->v4i32
on 64-bit AVX targets. But there is some improvement in some
configurations.
There's definitely some issues with computeNumSignBits with
X86ISD::STRICT_FCMP. As well as not being able to propagate sign
bits through merge_values nodes that get created during custom
legalization.
ExpandStrictFPOp calls ExpandUINT_TO_FLOAT. Previously, ExpandUINT_TO_FLOAT
returned SDValue() if it wasn't able to handle and needed to unroll.
Then ExpandStrictFPOp would detect his SDValue() and do the unroll.
After this change, ExpandUINT_TO_FLOAT will directly call
UnrollStrictFPOp and return the unrolled result.
UpdateNodeOperands might CSE to another existing node. So we should make sure we're legalizing that node otherwise we might fail to hook up the operands properly. I've moved the result registration up to the caller to avoid having to pass both Result and Op into the functions where it might be confusing which is which.
This address 2 other issues pointed out in D71861.
Differential Revision: https://reviews.llvm.org/D72021
These operations are needed as building blocks for promoting so they
can't be promoted themselves.
This appeared to work because the fp_extend query type for operation
actions is the result type, not the input type so it never triggered
in the legalizer.
For fp_round, the vector op legalizer just ended up creating a
nop fp_extend that was elided by getNode, followed by a nop
fp_round that was also elided by getNode. This was followed by
a final fp_round from v4f32 back to vf416 which was CSEd to the
original node. Then legalize vector ops just believed that node
legalized to itself. LegalizeDAG took another crack at promoting
it, but didn't have a handler so just skipped it with a debug
message saying it wasn't promoted.
This patch just removes the operation actions to avoid this
non-sense. Found while trying to refactor LegalizeVectorOps to
handle multiple result nodes better.
This allows us to clean up some places that were peeking through
the MERGE_VALUES node after the call. By returning the SDValues
directly, we can clean that up.
Unfortunately, there are several call sites in AMDGPU that wanted
the MERGE_VALUES and now need to create their own.
of integers to floating point.
This includes some of Craig Topper's changes for promotion support from
D71130.
Differential Revision: https://reviews.llvm.org/D69275
This adds support for constrained floating-point comparison intrinsics.
Specifically, we add:
declare <ty2>
@llvm.experimental.constrained.fcmp(<type> <op1>, <type> <op2>,
metadata <condition code>,
metadata <exception behavior>)
declare <ty2>
@llvm.experimental.constrained.fcmps(<type> <op1>, <type> <op2>,
metadata <condition code>,
metadata <exception behavior>)
The first variant implements an IEEE "quiet" comparison (i.e. we only
get an invalid FP exception if either argument is a SNaN), while the
second variant implements an IEEE "signaling" comparison (i.e. we get
an invalid FP exception if either argument is any NaN).
The condition code is implemented as a metadata string. The same set
of predicates as for the fcmp instruction is supported (except for the
"true" and "false" predicates).
These new intrinsics are mapped by SelectionDAG codegen onto two new
ISD opcodes, ISD::STRICT_FSETCC and ISD::STRICT_FSETCCS, again
representing quiet vs. signaling comparison operations. Otherwise
those nodes look like SETCC nodes, with an additional chain argument
and result as usual for strict FP nodes. The patch includes support
for the common legalization operations for those nodes.
The patch also includes full SystemZ back-end support for the new
ISD nodes, mapping them to all available SystemZ instruction to
fully implement strict semantics (scalar and vector).
Differential Revision: https://reviews.llvm.org/D69281
float node
This patch add an option 'disable-strictnode-mutation' to prevent strict
node mutating to an normal node.
So we can make sure that the patch which sets strict-node as legal works
correctly.
Patch by Chen Liu(LiuChen3)
Differential Revision: https://reviews.llvm.org/D70226
Summary
In several places we need to enumerate all constrained intrinsics or IR
nodes that should be represented by them. It is easy to miss some of
the cases. To make working with these intrinsics more convenient and
robust, this change introduces file containing definitions of all
constrained intrinsics and some of their properties. This file can be
included to generate constrained intrinsics processing code.
Reviewers: kpn, andrew.w.kaylor, cameron.mcinally, uweigand
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D69887
Summary:
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. The
result is saturated and clamped between the largest and
smallest representable values of the first 2 operands.
This is a part of implementing fixed point arithmetic
in clang where some of the more complex operations
will be implemented as intrinsics.
Patch by: leonardchan, bjope
Reviewers: RKSimon, craig.topper, bevinh, leonardchan, lebedev.ri, spatel
Reviewed By: leonardchan
Subscribers: ychen, wuzish, nemanjai, MaskRay, jsji, jdoerfert, Ka-Ka, hiraditya, rjmccall, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D57836
llvm-svn: 371308
This implements constrained floating point intrinsics for FP to signed and
unsigned integers.
Quoting from D32319:
The purpose of the constrained intrinsics is to force the optimizer to
respect the restrictions that will be necessary to support things like the
STDC FENV_ACCESS ON pragma without interfering with optimizations when
these restrictions are not needed.
Reviewed by: Andrew Kaylor, Craig Topper, Hal Finkel, Cameron McInally, Roman Lebedev, Kit Barton
Approved by: Craig Topper
Differential Revision: http://reviews.llvm.org/D63782
llvm-svn: 370228
Summary:
After the commits that changed x86 backend to widen vectors
instead of using promotion some of our downstream tests
started to fail. It was noticed that WidenVectorResult has
been missing support for SMULFIX/UMULFIX/SMULFIXSAT. This
patch adds the missing functionality.
Reviewers: craig.topper, RKSimon
Reviewed By: craig.topper
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66051
llvm-svn: 368540
This patch changes the DAG legalizer to respect the operation actions
set by the target for strict floating-point operations. (Currently, the
legalizer will usually fall back to mutate to the non-strict action
(which is assumed to be legal), and only skip mutation if the strict
operation is marked legal.)
With this patch, if whenever a strict operation is marked as Legal or
Custom, it is passed to the target as usual. Only if it is marked as
Expand will the legalizer attempt to mutate to the non-strict operation.
Note that this will now fail if the non-strict operation is itself
marked as Custom -- the target will have to provide a Custom definition
for the strict operation then as well.
Reviewed By: hfinkel
Differential Revision: https://reviews.llvm.org/D65226
llvm-svn: 368012
The *_EXTEND_VECTOR_INREG opcodes were relaxed back around rL346784 to support source vector widths that are smaller than the output - it looks like the legalizers were never updated to account for this.
This patch inserts the smaller source vector into an undef vector of the same width of the result before performing the shuffle+bitcast to correctly handle this.
Part of the yak shaving to solve the crashes from rL364264 and rL364272
llvm-svn: 364295
