Commit Graph

9 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 ae3ab4f0ec [RISCV] Masked compares should use a tail agnostic policy.
Writes of a mask result are always tail agnostic.

Unfortunately, this seems to have made codegen worse. I can only
think this must be because the vsetvli was acting as some sort
of barrier that prevented some code movement in the scheduler.

Reviewed By: arcbbb

Differential Revision: https://reviews.llvm.org/D103331
2021-06-07 21:43:44 -07:00
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 5a5219a0f9 [RISCV] Remove earlyclobber from compares with LMUL<=1.
Compares are considered a narrowing operation for register overlap.
I believe for LMUL<=1 they meet this exception to allow overlap

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

Both the result and the sources will occupy a single register for
LMUL<=1 so the overlap would always be in the "lowest-numbered part".

Reviewed By: frasercrmck, HsiangKai

Differential Revision: https://reviews.llvm.org/D103336
2021-06-01 09:08:11 -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
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
Jessica Clarke d63d662d3c [RISCV] Remove --riscv-no-aliases from RVV tests
This serves no useful purpose other than to clutter things up. Diff
summary as the real diff is extremely unwieldy:

   24844 -; CHECK-NEXT:    jalr zero, 0(ra)
   24844 +; CHECK-NEXT:    ret
       8 -; CHECK-NEXT:    vl4re8.v v28, (a0)
       8 +; CHECK-NEXT:    vl4r.v v28, (a0)
      64 -; CHECK-NEXT:    vl8re8.v v24, (a0)
      64 +; CHECK-NEXT:    vl8r.v v24, (a0)
     392 -; RUN:   --riscv-no-aliases < %s | FileCheck %s
     392 +; RUN:   < %s | FileCheck %s
       1 -; RUN:   -verify-machineinstrs --riscv-no-aliases < %s \
       1 +; RUN:   -verify-machineinstrs < %s \

As discussed in D103004.
2021-05-26 17:59:38 +01:00
Craig Topper 3064a63b2b [RISCV] Remove GetVRegNoV0 from the output register class of masked compare pseudo instructions.
Theses instructions are allowed to write v0 when they are masked.
We'll still never use v0 because of the earlyclobber constraint so
this doesn't really help anything. It just makes the definitions
correct.

While I was there remove an unused multiclass I noticed.

Reviewed By: HsiangKai

Differential Revision: https://reviews.llvm.org/D101118
2021-04-23 09:33:29 -07:00
Craig Topper e01c419ecd [RISCV] Add IR intrinsics for vmsge(u).vv/vx/vi.
These instructions don't really exist, but we have ways we can
emulate them.

.vv will swap operands and use vmsle().vv. .vi will adjust the
immediate and use .vmsgt(u).vi when possible. For .vx we need to
use some of the multiple instruction sequences from the V extension
spec.

For unmasked vmsge(u).vx we use:
  vmslt{u}.vx vd, va, x; vmnand.mm vd, vd, vd

For cases where mask and maskedoff are the same value then we have
vmsge{u}.vx v0, va, x, v0.t which is the vd==v0 case that
requires a temporary so we use:
  vmslt{u}.vx vt, va, x; vmandnot.mm vd, vd, vt

For other masked cases we use this sequence:
  vmslt{u}.vx vd, va, x, v0.t; vmxor.mm vd, vd, v0
We trust that register allocation will prevent vd in vmslt{u}.vx
from being v0 since v0 is still needed by the vmxor.

Differential Revision: https://reviews.llvm.org/D100925
2021-04-22 10:44:38 -07:00