Commit Graph

63 Commits

Author SHA1 Message Date
Evandro Menezes 7470017f24 [RISCV] Define the vfclass RVV intrinsics
Define the `vfclass` IR intrinsics for the respective V instructions.

Authored-by: Roger Ferrer Ibanez <rofirrim@gmail.com>
Co-Authored-by: Evandro Menezes <evandro.menezes@sifive.com>

Differential Revision: https://reviews.llvm.org/D94356
2021-01-11 17:40:09 -06:00
Craig Topper 278a3ea1b2 [RISCV] Use vmv.v.i vd, 0 instead of vmv.v.x vd, x0 for llvm.riscv.vfmv.v.f with 0.0
This matches what we use for integer 0. It's also consistent with
the scalar 'mv' pseudo that uses addi rather than add with x0.
2021-01-11 15:08:05 -08:00
Craig Topper 5cf73dca77 [RISCV] Convert most of the information about RVV Pseudos into bits in TSFlags.
This patch moves all but the BaseInstr to bits in TSFlags.

For the index fields, we can just use a bit to indicate their presence.
The locations of the operands are well defined.

This reduces the llc binary by about 32K on my build. It also
removes the binary search of the table from the custom inserter.
Instead we just check that the SEW op is present.

Reviewed By: rogfer01

Differential Revision: https://reviews.llvm.org/D94375
2021-01-10 19:15:45 -08:00
Craig Topper 0875a9da2a [RISCV] Cleanup a few section comments in RISCVInstrInfoVPseudos.td. NFC 2021-01-08 11:36:31 -08:00
Evandro Menezes 946bc50e4c [RISCV] Define the vfsqrt RVV intrinsics
Define the `vfsqrt` IR intrinsics for the respective V instructions.

Authored-by: Roger Ferrer Ibanez <rofirrim@gmail.com>
Co-Authored-by: Evandro Menezes <evandro.menezes@sifive.com>

Differential Revision: https://reviews.llvm.org/D93745
2021-01-07 17:29:29 -06:00
Craig Topper 7a8ced43d7 [RISCV] Fix a few section number comments in RISCVInstrInfoVPseudos.td to match the V extension 1.0 draft spec. NFC
The majority of the comments use the 1.0 draft spec section numbers.
2021-01-06 16:38:30 -08:00
Craig Topper c707716c04 [RISCV] Match vmslt(u).vx intrinsics with a small immediate to vmsle(u).vx.
There are vmsle(u).vx and vmsle(u).vi instructions, but there is
only vmslt(u).vx and no vmslt(u).vi. vmslt(u).vi can be emulated
for some immediates by decrementing the immediate and using vmsle(u).vi.

To avoid the user needing to know about this, this patch does this
conversion.

The assembler does the same thing for vmslt(u).vi and vmsge(u).vi
pseudoinstructions. There is no vmsge(u).vx intrinsic or
instruction so this patch is limited to vmslt(u).

Reviewed By: frasercrmck

Differential Revision: https://reviews.llvm.org/D94070
2021-01-05 10:20:21 -08:00
Monk Chiang 1d04cbeb43 [RISCV] Define vector single-width type-convert intrinsic.
Define intrinsics:
  1. vfcvt.xu.f.v/vfcvt.x.f.v
  2. vfcvt.rtz.xu.f.v/vfcvt.rtz.x.f.v
  3. vfcvt.f.xu.v/vfcvt.f.x.v

We work with @rogfer01 from BSC to come out this patch.

Authored-by: Roger Ferrer Ibanez <rofirrim@gmail.com>
Co-Authored-by: Monk Chiang <monk.chiang@sifive.com>

Differential Revision: https://reviews.llvm.org/D93933
2020-12-31 11:49:30 +08:00
Monk Chiang 2aed9bc98a [RISCV] Define vector narrowing type-convert intrinsic.
Define intrinsics:
  1. vfncvt.xu.f.w/vfncvt.x.f.w
  2. vfncvt.rtz.xu.f.w/vfncvt.rtz.x.f.w
  3. vfncvt.f.xu.w/vfncvt.f.x.w
  4. vfncvt.f.f.w/vfncvt.rod.f.f.w

We work with @rogfer01 from BSC to come out this patch.

Authored-by: Roger Ferrer Ibanez <rofirrim@gmail.com>
Co-Authored-by: Monk Chiang <monk.chiang@sifive.com>

Differential Revision: https://reviews.llvm.org/D93932
2020-12-31 11:48:28 +08:00
Monk Chiang fdd30faae5 [RISCV] Define vector widening type-convert intrinsic.
Define intrinsics:
  1. vfwcvt.xu.f.v/vfwcvt.x.f.v
  2. vfwcvt.rtz.xu.f.v/vfwcvt.rtz.x.f.v
  3. vfwcvt.f.xu.v/vfwcvt.f.x.v
  4. vfwcvt.f.f.v

We work with @rogfer01 from BSC to come out this patch.

Authored-by: Roger Ferrer Ibanez <rofirrim@gmail.com>
Co-Authored-by: Monk Chiang <monk.chiang@sifive.com>

Differential Revision: https://reviews.llvm.org/D93855
2020-12-31 11:48:09 +08:00
ShihPo Hung 096b02ebbf [RISCV] Add intrinsics for vcompress instruction
This patch defines vcompress intrinsics and lower to V instructions.

We work with @rogfer01 from BSC to come out this patch.

Authored-by: Roger Ferrer Ibanez <rofirrim@gmail.com>
Co-Authored-by: ShihPo Hung <shihpo.hung@sifive.com>

Differential revision: https://reviews.llvm.org/D93809
2020-12-29 18:38:15 -08:00
Zakk Chen 6da0033624 [RISCV] Define vsext/vzext intrinsics.
Define vsext/vzext intrinsics.and lower to V instructions.
Define new fraction register class fields in LMULInfo and a
NoReg to present invalid LMUL register classes.

Authored-by: ShihPo Hung <shihpo.hung@sifive.com>
Co-Authored-by: Zakk Chen <zakk.chen@sifive.com>

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D93893
2020-12-29 16:50:53 -08:00
Craig Topper 79cbb003c5 [RISCV] Don't use tail agnostic policy on instructions where destination is tied to source
If the destination is tied, then user has some control of the
register used for input. They would have the ability to control
the value of any tail elements. By using tail agnostic we take
this option away from them.

Its not clear that the intrinsics are defined such that this isn't
supposed to work. And undisturbed is a valid implementation for agnostic
so code wouldn't even fail to work on all systems if we always used
agnostic.

The vcompress intrinsic is defined to require tail undisturbed so
at minimum we need this for that instruction or need to redefine
the intrinsic.

I've made an exception here for vmv.s.x/fmv.s.f and reduction
instructions which only write to element 0 regardless of the tail
policy. This allows us to keep the agnostic policy on those which
should allow better redundant vsetvli removal.

An enhancement would be to check for undef input and keep the
agnostic policy, but we don't have good test coverage for that yet.

Reviewed By: khchen

Differential Revision: https://reviews.llvm.org/D93878
2020-12-29 10:37:58 -08:00
Craig Topper 2ae760e27e [RISCV] Add earlyclobber of destination register to vmsbf.m/vmsif.m/vmsof.m instructions
The spec for these instructions include this note. "The destination register
cannot overlap either the source register or the mask register ('v0') if the
instruction is masked." So we need earlyclobber to enforce this constraint.

I've regenerated the tests with update_llc_test_checks.py to show the
effects of the earlyclobber.

Reviewed By: khchen, frasercrmck

Differential Revision: https://reviews.llvm.org/D93867
2020-12-29 10:00:04 -08:00
Zakk Chen f3f9ce3b79 [RISCV] Define vmclr.m/vmset.m intrinsics.
Define vmclr.m/vmset.m intrinsics and lower to vmxor.mm/vmxnor.mm.

Ideally all rvv pseudo instructions could be implemented in C header,
but those two instructions don't take an input, codegen can not guarantee
that the source register becomes the same as the destination.

We expand pseduo-v-inst into corresponding v-inst in
RISCVExpandPseudoInsts pass.

Reviewed By: craig.topper, frasercrmck

Differential Revision: https://reviews.llvm.org/D93849
2020-12-28 18:57:17 -08:00
Zakk Chen e673d40199 [RISCV] Define vmsbf.m/vmsif.m/vmsof.m/viota.m/vid.v intrinsics.
Define those intrinsics and lower to V instructions.

Use update_llc_test_checks.py for viota.m tests to check
earlyclobber is applied correctly.
mask viota.m tests uses the same argument as input and mask for
avoid dependency of D93364.

We work with @rogfer01 from BSC to come out this patch.

Reviewed By: HsiangKai

Differential Revision: https://reviews.llvm.org/D93823
2020-12-28 05:54:18 -08:00
Monk Chiang 622ea9cf74 [RISCV] Define vector widening reduction intrinsic.
Define vwredsumu/vwredsum/vfwredosum/vfwredsum

We work with @rogfer01 from BSC to come out this patch.

Authored-by: Roger Ferrer Ibanez <rofirrim@gmail.com>
Co-Authored-by: Zakk Chen <zakk.chen@sifive.com>

Differential Revision: https://reviews.llvm.org/D93807
2020-12-26 21:42:30 +08:00
Zakk Chen da4a637e99 [RISCV] Define vpopc/vfirst intrinsics.
Define vpopc/vfirst intrinsics and lower to V instructions.

We work with @rogfer01 from BSC to come out this patch.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D93795
2020-12-24 19:44:34 -08:00
Zakk Chen 351c216f36 [RISCV] Define vector mask-register logical intrinsics.
Define vector mask-register logical intrinsics and lower them
to V instructions. Also define pseudo instructions vmmv.m
and vmnot.m.

We work with @rogfer01 from BSC to come out this patch.

Authored-by: Roger Ferrer Ibanez <rofirrim@gmail.com>
Co-Authored-by: Zakk Chen <zakk.chen@sifive.com>

Differential Revision: https://reviews.llvm.org/D93705
2020-12-24 18:59:05 -08:00
ShihPo Hung 912740a864 [RISCV] Add intrinsics for vrgather instruction
This patch defines vrgather intrinsics and lower to V instructions.

We work with @rogfer01 from BSC to come out this patch.

Authored-by: Roger Ferrer Ibanez <rofirrim@gmail.com>
Co-Authored-by: ShihPo Hung <shihpo.hung@sifive.com>

Differential revision: https://reviews.llvm.org/D93797
2020-12-24 18:16:02 -08:00
Monk Chiang afd03cd335 [RISCV] Define vector single-width reduction intrinsic.
integer group:
vredsum/vredmaxu/vredmax/vredminu/vredmin/vredand/vredor/vredxor
float group:
vfredosum/vfredsum/vfredmax/vfredmin

We work with @rogfer01 from BSC to come out this patch.

Authored-by: Roger Ferrer Ibanez <rofirrim@gmail.com>
Co-Authored-by: Zakk Chen <zakk.chen@sifive.com>

Differential Revision: https://reviews.llvm.org/D93746
2020-12-25 09:56:01 +08:00
Fraser Cormack 1a7ac29a89 [RISCV] Add ISel support for RVV vector/scalar forms
This patch extends the SDNode ISel support for RVV from only the
vector/vector instructions to include the vector/scalar and
vector/immediate forms.

It uses splat_vector to carry the scalar in each case, except when
XLEN<SEW (RV32 SEW=64) when a custom node `SPLAT_VECTOR_I64` is used for
type-legalization and to encode the fact that the value is sign-extended
to SEW. When the scalar is a full 64-bit value we use a sequence to
materialize the constant into the vector register.

The non-intrinsic ISel patterns have also been split into their own
file.

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/D93312
2020-12-23 20:16:18 +00:00
Craig Topper e0110a4740 [RISCV] Add intrinsics for vfmv.v.f
Also include a special case pattern to use vmv.v.x vd, zero when
the argument is 0.0.

Reviewed By: khchen

Differential Revision: https://reviews.llvm.org/D93672
2020-12-23 10:50:48 -08:00
ShihPo Hung 6301871d06 [RISCV] Add intrinsics for vfwmacc, vfwnmacc, vfwmsac, vfwnmsac instructions
This patch defines vfwmacc, vfwnmacc, vfwmsc, vfwnmsac intrinsics
and lower to V instructions.
We work with @rogfer01 from BSC to come out this patch.

Authored-by: Roger Ferrer Ibanez <rofirrim@gmail.com>
Co-Authored-by: ShihPo Hung <shihpo.hung@sifive.com>

Differential Revision: https://reviews.llvm.org/D93693
2020-12-23 00:42:04 -08:00
Zakk Chen 032600b9ae [RISCV] Define vmerge/vfmerge intrinsics.
Define vmerge/vfmerge intrinsics and lower to V instructions.

Include support for vector-vector vfmerge by vmerge.vvm.

We work with @rogfer01 from BSC to come out this patch.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D93674
2020-12-23 00:07:09 -08:00
Evandro Menezes 4d47944393 [RISCV] Define the vfmin, vfmax RVV intrinsics
Define the vfmin, vfmax IR intrinsics for the respective V instructions.

Authored-by: Roger Ferrer Ibanez <rofirrim@gmail.com>
Co-Authored-by: Evandro Menezes <evandro.menezes@sifive.com>

Differential Revision: https://reviews.llvm.org/D93673
2020-12-23 00:27:38 -06:00
ShihPo Hung ad0a7ad950 [RISCV] Add intrinsics for vf[n]macc/vf[n]msac/vf[n]madd/vf[n]msub instructions
This patch defines vfmadd/vfnmacc, vfmsac/vfnmsac, vfmadd/vfnmadd,
and vfmsub/vfnmsub lower to V instructions.

Authored-by: Roger Ferrer Ibanez <rofirrim@gmail.com>
Co-Authored-by: ShihPo Hung <shihpo.hung@sifive.com>

Differential Revision: https://reviews.llvm.org/D93691
2020-12-22 18:34:00 -08:00
ShihPo Hung 4268783998 [RISCV] Add intrinsics for vwmacc[u|su|us] instructions
This patch defines vwmacc[u|su|us] intrinsics and lower to V instructions.

We work with @rogfer01 from BSC to come out this patch.

Authored-by: Roger Ferrer Ibanez <rofirrim@gmail.com>
Co-Authored-by: ShihPo Hung <shihpo.hung@sifive.com>

Differential Revision: https://reviews.llvm.org/D93675
2020-12-22 18:17:39 -08:00
ShihPo Hung c8874464b5 [RISCV] Add intrinsics for vslide1up/down, vfslide1up/down instruction
This patch adds intrinsics for vslide1up, vslide1down, vfslide1up, vfslide1down.

Authored-by: Roger Ferrer Ibanez <rofirrim@gmail.com>
Co-Authored-by: ShihPo Hung <shihpo.hung@sifive.com>

Differential Revision: https://reviews.llvm.org/D93608
2020-12-22 18:14:22 -08:00
Craig Topper 53deef9e0b [RISCV] Remove unneeded !eq comparing a single bit value to 0/1 in RISCVInstrInfoVPseudos.td. NFC
Instead we can either use the bit directly. If it was checking for
0 we need to swap the operands or use !not.
2020-12-22 11:57:16 -08:00
Hsiangkai Wang 9a8ef927df [RISCV] Define vector compare intrinsics.
Define vector compare intrinsics and lower them to V instructions.

We work with @rogfer01 from BSC to come out this patch.

Authored-by: Roger Ferrer Ibanez <rofirrim@gmail.com>
Co-Authored-by: Hsiangkai Wang <kai.wang@sifive.com>

Differential Revision: https://reviews.llvm.org/D93368
2020-12-22 14:08:18 +08:00
Zakk Chen 7a2c8be641 [RISCV] Define vleff intrinsics.
Define vleff intrinsics and lower to V instructions.

We work with @rogfer01 from BSC to come out this patch.

Authored-by: Roger Ferrer Ibanez <rofirrim@gmail.com>
Co-Authored-by: Zakk Chen <zakk.chen@sifive.com>

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D93516
2020-12-21 22:05:38 -08:00
ShihPo Hung b15ba2cf6f [RISCV] Add intrinsics for vmacc/vnmsac/vmadd/vnmsub instructions
This defines vmadd, vmacc, vnmsub, and vnmsac intrinsics and
lower to V instructions.

Authored-by: Roger Ferrer Ibanez <rofirrim@gmail.com>
Co-Authored-by: ShihPo Hung <shihpo.hung@sifive.com>

Differential Revision: https://reviews.llvm.org/D93632
2020-12-21 17:37:20 -08:00
Evandro Menezes ed73a78924 [RISCV] Define the vand, vor and vxor RVV intrinsics
Define the `vand`, `vor` and `vxor` IR intrinsics for the respective V instructions.

Authored-by: Roger Ferrer Ibanez <rofirrim@gmail.com>
Co-Authored-by: Evandro Menezes <evandro.menezes@sifive.com>

Differential Revision: https://reviews.llvm.org/D93574
2020-12-21 16:20:26 -06:00
Monk Chiang 3183add534 [RISCV] Define the remaining vector fixed-point arithmetic intrinsics.
This patch base on D93366, and define vector fixed-point intrinsics.
    1. vaaddu/vaadd/vasubu/vasub
    2. vsmul
    3. vssrl/vssra
    4. vnclipu/vnclip

  We work with @rogfer01 from BSC to come out this patch.

  Authored-by: Roger Ferrer Ibanez <rofirrim@gmail.com>
  Co-Authored-by: ShihPo Hung <shihpo.hung@sifive.com>

  Differential Revision: https://reviews.llvm.org/D93508
2020-12-20 22:57:07 -08:00
ShihPo Hung d86a00d8fe [RISCV] Define vslideup/vslidedown intrinsics
Differential Revision: https://reviews.llvm.org/D93286
2020-12-20 05:08:15 -08:00
Hsiangkai Wang 41ab45d662 [RISCV] Define vector vfwmul intrinsics.
Define vector vfwmul intrinsics and lower them to V instructions.

We work with @rogfer01 from BSC to come out this patch.

Authored-by: Roger Ferrer Ibanez <rofirrim@gmail.com>
Co-Authored-by: Hsiangkai Wang <kai.wang@sifive.com>

Differential Revision: https://reviews.llvm.org/D93584
2020-12-20 17:39:20 +08:00
Hsiangkai Wang f86e61d886 [RISCV] Define vector vfwadd/vfwsub intrinsics.
Define vector vfwadd/vfwsub intrinsics and lower them to V
instructions.

We work with @rogfer01 from BSC to come out this patch.

Authored-by: Roger Ferrer Ibanez <rofirrim@gmail.com>
Co-Authored-by: Hsiangkai Wang <kai.wang@sifive.com>

Differential Revision: https://reviews.llvm.org/D93583
2020-12-20 17:39:13 +08:00
Hsiangkai Wang bd576ac8d4 [RISCV] Define vector vfsgnj/vfsgnjn/vfsgnjx intrinsics.
Define vector vfsgnj/vfsgnjn/vfsgnjx intrinsics and lower them to V
instructions.

We work with @rogfer01 from BSC to come out this patch.

Authored-by: Roger Ferrer Ibanez <rofirrim@gmail.com>
Co-Authored-by: Hsiangkai Wang <kai.wang@sifive.com>

Differential Revision: https://reviews.llvm.org/D93581
2020-12-20 17:39:04 +08:00
Hsiangkai Wang 62c94f0678 [RISCV] Define vector vfmul/vfdiv/vfrdiv intrinsics.
Define vector vfmul/vfdiv/vfrdiv intrinsics and lower them to V instructions.

We work with @rogfer01 from BSC to come out this patch.

Authored-by: Roger Ferrer Ibanez <rofirrim@gmail.com>
Co-Authored-by: Hsiangkai Wang <kai.wang@sifive.com>

Differential Revision: https://reviews.llvm.org/D93580
2020-12-20 17:38:57 +08:00
Zakk Chen 9cf3b1b666 [RISCV] Define vlxe/vsxe/vsuxe intrinsics.
Define vlxe/vsxe intrinsics and lower to vlxei<EEW>/vsxei<EEW>
instructions.

We work with @rogfer01 from BSC to come out this patch.

Authored-by: Roger Ferrer Ibanez <rofirrim@gmail.com>
Co-Authored-by: Zakk Chen <zakk.chen@sifive.com>

Differential Revision: https://reviews.llvm.org/D93471
2020-12-19 06:50:20 -08:00
Craig Topper 1c3a6671c2 Recommit "[RISCV] Add intrinsics for vfmv.f.s and vfmv.s.f"
This time with tests.

Original message:
Similar to D93365, but for floating point. No need for special ISD opcodes
though. We can directly isel these from intrinsics. I had to use anyfloat_ty
instead of anyvector_ty in the intrinsics to make LLVMVectorElementType not
crash when imported into the -gen-dag-isel tablegen backend.

Differential Revision: https://reviews.llvm.org/D93426
2020-12-18 11:19:05 -08:00
Craig Topper cd3e811864 Revert "[RISCV] Add intrinsics for vfmv.f.s and vfmv.s.f"
This reverts commit 46a40c4bc1.

I forgot to git add the tests.
2020-12-18 11:16:36 -08:00
Craig Topper 46a40c4bc1 [RISCV] Add intrinsics for vfmv.f.s and vfmv.s.f
Similar to D93365, but for floating point. No need for special ISD opcodes
though. We can directly isel these from intrinsics. I had to use anyfloat_ty
instead of anyvector_ty in the intrinsics to make LLVMVectorElementType not
crash when imported into the -gen-dag-isel tablegen backend.

Differential Revision: https://reviews.llvm.org/D93426
2020-12-18 11:11:15 -08:00
Craig Topper 86d282baed [RISCV] Add intrinsics for vmv.x.s and vmv.s.x
This adds intrinsics for vmv.x.s and vmv.s.x.

I've used stricter type constraints on these intrinsics than what we've been doing on the arithmetic intrinsics so far. This will allow us to not need to pass the scalar type to the Intrinsic::getDeclaration call when creating these intrinsics.

A custom ISD is used for vmv.x.s in order to implement the change in computeNumSignBitsForTargetNode which can remove sign extends on the result.

I also modified the MC layer description of these instructions to show the tied source/dest operand. This is different than what we do for masked instructions where we drop the tied source operand when converting to MC. But it is a more accurate description of the instruction. We can't do this for masked instructions since we use the same MC instruction for masked and unmasked. Tools like llvm-mca operate in the MC layer and rely on ins/outs and Uses/Defs for analysis so I don't know if we'll be able to maintain the current behavior for masked instructions. So I went with the accurate description here since it was easy.

Reviewed By: frasercrmck

Differential Revision: https://reviews.llvm.org/D93365
2020-12-18 10:30:48 -08:00
Craig Topper fc7b7fc066 [RISCV] Add intrinsics for vmv.v.v, vmv.v.x, and vmv.x.i
We work with @rogfer01 from BSC to come out this patch.

Authored-by: Roger Ferrer Ibanez <rofirrim@gmail.com>
Co-Authored-by: Craig Topper <craig.topper@sifive.com>

Differential Revision: https://reviews.llvm.org/D93514
2020-12-18 09:49:07 -08:00
Hsiangkai Wang 7087ae7be9 [RISCV] Remove NoVReg to avoid compile warning messages. 2020-12-18 11:37:47 +08:00
Monk Chiang ee2cb90e3b [RISCV] Define vsadd/vsaddu/vssub/vssubu intrinsics.
We work with @rogfer01 from BSC to come out this patch.

Authored-by: Roger Ferrer Ibanez <rofirrim@gmail.com>
Co-Authored-by: ShihPo Hung <shihpo.hung@sifive.com>
Co-Authored-by: Monk Chiang <monk.chiang@sifive.com>

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D93366
2020-12-18 10:24:24 +08:00
Zakk Chen 4b07c515ef [RISCV] Define vlse/vsse intrinsics.
Define vlse/vsse intrinsics and lower to V instructions.

We work with @rogfer01 from BSC to come out this patch.

Authored-by: Roger Ferrer Ibanez <rofirrim@gmail.com>
Co-Authored-by: Zakk Chen <zakk.chen@sifive.com>

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D93445
2020-12-17 17:00:01 -08:00
Hsiangkai Wang a5e4a513b0 [RISCV] Define vector widening mul intrinsics.
Define vector widening mul intrinsics and lower them to V instructions.

We work with @rogfer01 from BSC to come out this patch.

Authored-by: Roger Ferrer Ibanez <rofirrim@gmail.com>
Co-Authored-by: Hsiangkai Wang <kai.wang@sifive.com>

Differential Revision: https://reviews.llvm.org/D93381
2020-12-17 11:50:33 +08:00