Commit Graph

9 Commits

Author SHA1 Message Date
Craig Topper 5edccc4581 [RISCV] Avoid using x0,x0 vsetvli for vmv.x.s and vfmv.f.s unless we know the sew/lmul ratio is constant.
Since we're changing VTYPE, we may change VLMAX which could
invalidate the previous VL. If we can't tell if it is safe we
should use an AVL of 1 instead of keeping the old VL.

This is a quick fix. We may want to thread VL to the pseudo
instruction instead of making up a value. That will require ISD
opcode changes and changes to the C intrinsic interface.

This fixes the issue raised in D106286.

Reviewed By: frasercrmck

Differential Revision: https://reviews.llvm.org/D106403
2021-07-23 09:12:05 -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 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 95c6824995 [RISCV] Teach CleanupVSETVLI to remove 'vsetvli zero, zero, vtype' when the vtype matches the previous vsetvli or vsetivli
Reviewed By: frasercrmck, arcbbb

Differential Revision: https://reviews.llvm.org/D97408
2021-02-25 07:51:19 -08:00
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
Craig Topper 086670d367 [RISCV] Support fixed vector extract element. Use VL=1 for scalable vector extract element.
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
2021-02-24 10:17:00 -08:00
Fraser Cormack c3eb2da6c4 [RISCV] Optimize sign-extended EXTRACT_VECTOR_ELT nodes
This patch custom-legalizes all integer EXTRACT_VECTOR_ELT nodes where
SEW < XLEN to VMV_S_X nodes to help the compiler infer sign bits from
the result. This allows us to eliminate redundant sign extensions.

For parity, all integer EXTRACT_VECTOR_ELT nodes are legalized this way
so that we don't need TableGen patterns for some and not others.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D95741
2021-02-05 10:05:22 +00:00
Fraser Cormack c87dd614fd [RISCV] Update extractelt tests to sign-extend results (NFC)
This demonstrates a missed optimization: the `vmv.x.s` instruction is
used to extract the element from the vector, and this instruction
already sign-extends the value to XLEN.
2021-01-30 15:50:07 +00:00
Fraser Cormack 15141cd115 [RISCV] Add RVV insertelt/extractelt scalable-vector patterns
Original patch by @rogfer01.

This patch adds support for insertelt and extractelt operations on
scalable vectors.

Special care must be taken on RV32 when dealing with i64 vectors as
there are no straightforward ways to insert a 64-bit element without a
register of that size. To that end, both are custom-lowered to different
sequences.

Authored-by: Roger Ferrer Ibanez <rofirrim@gmail.com>
Co-Authored-by: Fraser Cormack <fraser@codeplay.com>

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D94615
2021-01-25 22:03:52 +00:00