Commit Graph

11 Commits

Author SHA1 Message Date
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 c653711fd3 [RISCV] Teach vsetvli insertion pass that operations on masks don't care about SEW/LMUL.
All that really matters is that the VLMAX of the preceding
instructions is the same as the VLMAX required by the mask
operation.

Also update the vmsge(u) handling to use the SEW/LMUL we use for
other mask register operations. We were matching it to the compare
before. Some cases will be improve if we fix masked compares to
use tail agnostic policy. I think they ignore the tail policy
anyway.

Reviewed By: frasercrmck

Differential Revision: https://reviews.llvm.org/D103299
2021-06-04 09:17:46 -07:00
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
Fraser Cormack 772b58a641 [SelectionDAG][RISCV] Don't unroll 0/1-type bool VSELECTs
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
2021-05-27 10:08:57 +01:00
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
Craig Topper 1b47a3de48 [RISCV] Enable cross basic block aware vsetvli insertion
This patch extends D102737 to allow VL/VTYPE changes to be taken
into account before adding an explicit vsetvli.

We do this by using a data flow analysis to propagate VL/VTYPE
information from predecessors until we've determined a value for
every value in the function.

We use this information to determine if a vsetvli needs to be
inserted before the first vector instruction the block.

Differential Revision: https://reviews.llvm.org/D102739
2021-05-26 09:25:42 -07:00
Fraser Cormack 7e27e4273d [RISCV] Pre-commit fixed-length mask vselect tests
These are default-expanded but later unrolled due to RISC-V's vector
boolean content policy. A patch to improve this codegen will follow
shortly.
2021-05-26 10:44:45 +01:00
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 efcdd598b7 [RISCV] Teach VSETVLI inserter to use VSETIVLI when possible.
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
2021-02-24 16:07:33 -08:00
Fraser Cormack d81161646a [RISCV] Add support for fixed vector vselect
This patch adds support for fixed-length vector vselect. It does so by
lowering them to a custom unmasked VSELECT_VL node with a vector length
operand.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D96768
2021-02-17 10:59:00 +00:00