Commit Graph

13 Commits

Author SHA1 Message Date
Simon Pilgrim d6fe8d37c6 [DAG] Fold concat_vectors(concat_vectors(x,y),concat_vectors(a,b)) -> concat_vectors(x,y,a,b)
Follow-up to D107068, attempt to fold nested concat_vectors/undefs, as long as both the vector and inner subvector types are legal.

This exposed the same issue in ARM's MVE LowerCONCAT_VECTORS_i1 (raised as PR51365) and AArch64's performConcatVectorsCombine which both assumed concat_vectors only took 2 subvector operands.

Differential Revision: https://reviews.llvm.org/D107597
2021-08-16 16:06:54 +01:00
Craig Topper 79fbddbea0 [RISCV] Teach vsetvli insertion pass that it doesn't need to insert vsetvli for unit-stride or strided loads/stores in some cases.
For unit-stride and strided load/stores we set the SEW operand of
the pseudo instruction equal the EEW in the opcode. The LMUL
of the pseudo instruction is the LMUL we want.

These instructions calculate EMUL=(EEW/SEW) * LMUL. We can use
this to avoid changing vtype if the SEW/LMUL of the previous
vtype matches the EEW/EMUL ratio we need for the instruction.

Due to how the global analysis works, we can only do this
optimization when the previous vsetvli was produced in the block
containing the store. We need to know in the first phase if the
vsetvli will be inserted so we can propagate information to
the successors in the second phase correctly. This means we can't
depend on predecessors.

Reviewed By: rogfer01

Differential Revision: https://reviews.llvm.org/D106601
2021-08-12 10:05:27 -07:00
Jim Lin 242ddd5089 [RISCV][NFC] Add a single space after comma for VType
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
2021-06-09 11:18:22 +08:00
Craig Topper 896f9bc350 [RISCV] Remove earlyclobber from vnsrl/vnsra/vnclip(u) when the source and dest are a single vector register.
This guarantees they meet this overlap exception:

"The destination EEW is smaller than the source EEW and the overlap
is in the lowest-numbered part of the source register group"

Being a single register guarantees the overlap is always in the
lowerst-number part of the group.

Reviewed By: frasercrmck, khchen

Differential Revision: https://reviews.llvm.org/D103351
2021-06-01 09:17:52 -07:00
Fraser Cormack eb23936591 [RISCV] Support vector conversions between fp and i1
This patch custom lowers FP_TO_[US]INT and [US]INT_TO_FP conversions
between floating-point and boolean vectors. As the default action is
scalarization, this patch both supports scalable-vector conversions and
improves the code generation for fixed-length vectors.

The lowering for these conversions can piggy-back on the existing
lowering, which lowers the operations to a supported narrowing/widening
conversion and then either an extension or truncation.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D103312
2021-05-31 09:55:39 +01:00
Fraser Cormack f3afd0d193 [RISCV] Add tests for fixed vector conversions between fp to/from i1
These fixed-length versions don't crash unlike the corresponding
scalable ones, but the code generation is scalarized. An imminent patch
will support scalable-vector conversions and improve the codegen for
these fixed-length conversions.
2021-05-28 12:31:47 +01:00
Craig Topper 527cd01314 [RISCV] Teach vsetvli insertion to use vsetvl x0, x0 form when we can tell that VLMAX and AVL haven't changed.
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
2021-05-27 10:11:38 -07:00
Craig Topper fdf10e6197 [RISCV] Use X0 as destination of inserted vsetvli when possible.
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
2021-05-26 13:08:51 -07:00
Fraser Cormack 797e580db9 [RISCV][NFC] Simplify test run lines
Several tests had -verify-machineinstrs twice, and several tests were
explicitly specifying the default FileCheck prefix of CHECK.
2021-05-13 12:41:00 +01:00
Craig Topper ce6e4f27dd [RISCV] Use fractional LMULs for fixed length types smaller than riscv-v-vector-bits-min.
My thought process is that if v2i64 is an LMUL=1 type then v2i32
should be an LMUL=1/2 type. We limit the fractional LMUL so that
SEW=64 clips to LMUL=1, SEW=32 clips to LMUL=1/2, etc. This
ensures there's always a fractional LMUL available to truncate a type.
This does reduce the number of vsetvlis in some cases.

Some tests increase vsetvlis because the best container type for a
mask type is dependent on the LMUL+SEW that the mask was produced
from, but you can't tell that from the type. I think this is
something we need to solve this in the machine IR when optimizing
vsetvlis.

Reviewed By: frasercrmck

Differential Revision: https://reviews.llvm.org/D101215
2021-05-11 09:42:48 -07:00
Craig Topper ce09dd54e6 [RISCV] Select 5 bit immediate for VSETIVLI during isel rather than peepholing in the custom inserter.
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
2021-04-27 14:38:16 -07:00
Fraser Cormack de2b70010a [RISCV] Lower CONCAT_VECTORS to INSERT_SUBVECTOR nodes
The default expansion of CONCAT_VECTORS goes through the stack. This
patch avoids that penalty by custom-lowering CONCAT_VECTORS to a series
of INSERT_SUBVECTOR nodes. Futher optimizations are possible, but this
is a good start.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D97692
2021-03-02 11:13:59 +00:00
Fraser Cormack 02f435db0b [RISCV] Support fixed-length vector i2fp/fp2i conversions
This patch extends the support for scalable-vector int->fp and fp->int
conversions by additionally handling fixed-length vectors.

The existing scalable-vector lowering re-expresses widening/narrowing by
x4+ conversions as standard nodes. The fixed-length vector support slots
in at "the end" of this process by lowering the now equally-sized and
widening/narrowing by x2 nodes to our custom VL versions.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D97374
2021-02-25 13:47:58 +00:00