In most of cases, it has a single space after comma in assembly operands.
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D103790
In 0.9 these were defined to leave elements other than 0 in the
destination unmodified. They were changed to use the tail policy
in 0.10. I missed that update.
I assume no one has noticed because in order cores treat tail
agnostic the same as tail undisturbed. I believe Spike and QEMU do
the same.
Reviewed By: arcbbb, frasercrmck
Differential Revision: https://reviews.llvm.org/D103736
This can help avoid needing a virtual register for the vsetvl output
when the AVL is X0. For other register AVLs it can shorter the live
range of the AVL register if it isn't needed later.
There's probably no advantage when AVL is a 5 bit immediate that
can use vsetivli. But do it anyway for consistency.
Reviewed By: rogfer01
Differential Revision: https://reviews.llvm.org/D103215
We aren't going to connect the result to anything so we might
as well avoid allocating a register.
Reviewed By: frasercrmck, HsiangKai
Differential Revision: https://reviews.llvm.org/D102031
This adds a special operand type that is allowed to be either
an immediate or register. By giving it a unique operand type the
machine verifier will ignore it.
This perturbs a lot of tests but mostly it is just slightly different
instruction orders. Something bad did happen to some min/max reduction
tests. We're spilling vector registers when we weren't before.
Reviewed By: khchen
Differential Revision: https://reviews.llvm.org/D101246
This modifies my previous patch to push the strided load formation
to isel. This gives us opportunity to fold the splat into a .vx
operation first. Using a scalar register and a .vx operation reduces
vector register pressure which can be important for larger LMULs.
If we can't fold the splat into a .vx operation, then it can make
sense to use a strided load to free up the vector arithmetic
ALU to do actual arithmetic rather than tying it up with vmv.v.x.
Reviewed By: khchen
Differential Revision: https://reviews.llvm.org/D101138
I'm not sure how I failed to notice this before, but when optimizing
dominant-element BUILD_VECTORs we would lower via the scalable container type,
which lost us the information about the fixed length of the vector types. By
lowering via the fixed-length type we can preserve that information and
eliminate redundant vsetvli instructions.
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D98938
Returning the scalable-vector container type would present problems when
the fixed-length INSERT_VECTOR_ELT was used by later operations.
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D98776
This patch adds an optimization path for BUILD_VECTOR nodes where the
majority of the elements are identical. These can be splatted, with the
remaining elements patched up with INSERT_VECTOR_ELTs. The threshold can
be tweaked as required - it is currently conservative. Undef elements
are disregarded when judging the dominance of a particular element. This
allows them to be covered by the splat value.
In addition, vectors of 2 elements are always optimized to a splat (for
the upper element) and an insert at element zero.
This optimization is disabled when optimizing for size.
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D98700
This patch optimizes the codegen for INSERT_VECTOR_ELT in various ways.
Primarily, it removes the use of vslidedown during lowering, and the
vector element is inserted entirely using vslideup with a custom VL and
slide index.
Additionally, lowering of i64-element vectors on RV32 has been optimized
in several ways. When the 64-bit value to insert is the same as the
sign-extension of the lower 32-bits, the codegen can follow the regular
path. When this is not possible, a new sequence of two i32 vslide1up
instructions is used to get the vector element into a vector. This
sequence was suggested by @craig.topper. From there, the value is slid
into the final position for more consistent lowering across RV32 and
RV64.
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D98250
This patch fixes up one case where the fixed-length-vector VL was
dropped (falling back to VLMAX) when inserting vector elements, as the
code would lower via ISD::INSERT_VECTOR_ELT (at index 0) which loses the
fixed-length vector information.
To this end, a custom node, VMV_S_XF_VL, was introduced to carry the VL
operand through to the final instruction. This node wraps the RVV
vmv.s.x and vmv.s.f instructions, which were being selected by
insert_vector_elt anyway.
There should be no observable difference in scalable-vector codegen.
There is still one outstanding drop from fixed-length VL to VLMAX, when
an i64 element is inserted into a vector on RV32; the splat (which is
custom legalized) has no notion of the original fixed-length vector
type.
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D97842
This patch enables support for lowering INSERT_VECTOR_ELT on
fixed-length vector types. The strategy follows that for scalable vector
types.
This patch also includes a quick fix to prevent the compiler infinitely
looping between lowering BUILD_VECTOR as VECTOR_SHUFFLE and back again.
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D97698
We always create the VL operand using a register, but if we can
determine that it came from an ADDI X0, imm with a sufficiently
small immediate, we can use VSETIVLI.
Reviewed By: frasercrmck
Differential Revision: https://reviews.llvm.org/D97332
I've changed to use VL=1 for slidedown and shifts to avoid extra
element processing that we don't need.
The i64 fixed vector handling on i32 isn't great if the vector type
isn't legal due to an ordering issue in type legalization. If the
vector type isn't legal, we fall back to default legalization
which will bitcast the vector to vXi32 and use two independent extracts.
Doing better will require handling several different cases by
manually inserting insert_subvector/extract_subvector to adjust the type
to a legal vector before emitting custom nodes.
Reviewed By: frasercrmck
Differential Revision: https://reviews.llvm.org/D97319
The type legalizer can call this code based on the scalar type so
we need to verify the vector type is a scalable vector.
I think due to how type legalization visits nodes, the vector type
will have already been legalized so we don't have an issue with
using MVT here like we did for EXTRACT_VECTOR_ELT.
I've added a test just in case.
Jim Lin