[llvm] [RISCV] Promote fixed-length bf16 arith vector ops with zvfbfmin (PR #112393)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `llvm-clang-x86_64-gcc-ubuntu` running on `sie-linux-worker3` while building `llvm` at step 6 "test-build-unified-tree-check-all".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/174/builds/6860

<details>
<summary>Here is the relevant piece of the build log for the reference</summary>

```
Step 6 (test-build-unified-tree-check-all) failure: test (failure)
******************** TEST 'LLVM :: Analysis/CostModel/RISCV/arith-fp.ll' FAILED ********************
Exit Code: 1

Command Output (stderr):
--
RUN: at line 2: /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/bin/opt -passes="print<cost-model>" 2>&1 -disable-output -mtriple=riscv64 -mattr=+v,+f,+d,+zfh,+zvfh,+zvfbfmin < /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/test/Analysis/CostModel/RISCV/arith-fp.ll | /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/bin/FileCheck /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/test/Analysis/CostModel/RISCV/arith-fp.ll --check-prefixes=CHECK,ZVFH
+ /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/bin/opt '-passes=print<cost-model>' -disable-output -mtriple=riscv64 -mattr=+v,+f,+d,+zfh,+zvfh,+zvfbfmin
+ /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/bin/FileCheck /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/test/Analysis/CostModel/RISCV/arith-fp.ll --check-prefixes=CHECK,ZVFH
/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/test/Analysis/CostModel/RISCV/arith-fp.ll:12:15: error: CHECK-NEXT: expected string not found in input
; CHECK-NEXT: Cost Model: Found an estimated cost of 2 for instruction: %V1BF16 = fadd <1 x bfloat> undef, undef
              ^
<stdin>:4:90: note: scanning from here
Cost Model: Found an estimated cost of 2 for instruction: %F64 = fadd double undef, undef
                                                                                         ^
<stdin>:5:1: note: possible intended match here
Cost Model: Found an estimated cost of 5 for instruction: %V1BF16 = fadd <1 x bfloat> undef, undef
^
/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/test/Analysis/CostModel/RISCV/arith-fp.ll:140:15: error: CHECK-NEXT: expected string not found in input
; CHECK-NEXT: Cost Model: Found an estimated cost of 2 for instruction: %V1BF16 = fsub <1 x bfloat> undef, undef
              ^
<stdin>:52:90: note: scanning from here
Cost Model: Found an estimated cost of 2 for instruction: %F64 = fsub double undef, undef
                                                                                         ^
<stdin>:53:1: note: possible intended match here
Cost Model: Found an estimated cost of 5 for instruction: %V1BF16 = fsub <1 x bfloat> undef, undef
^
/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/test/Analysis/CostModel/RISCV/arith-fp.ll:268:15: error: CHECK-NEXT: expected string not found in input
; CHECK-NEXT: Cost Model: Found an estimated cost of 2 for instruction: %V1BF16 = fmul <1 x bfloat> undef, undef
              ^
<stdin>:100:90: note: scanning from here
Cost Model: Found an estimated cost of 2 for instruction: %F64 = fmul double undef, undef
                                                                                         ^
<stdin>:101:1: note: possible intended match here
Cost Model: Found an estimated cost of 5 for instruction: %V1BF16 = fmul <1 x bfloat> undef, undef
^
/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/test/Analysis/CostModel/RISCV/arith-fp.ll:396:15: error: CHECK-NEXT: expected string not found in input
; CHECK-NEXT: Cost Model: Found an estimated cost of 2 for instruction: %V1BF16 = fdiv <1 x bfloat> undef, undef
              ^
<stdin>:148:90: note: scanning from here
Cost Model: Found an estimated cost of 2 for instruction: %F64 = fdiv double undef, undef
                                                                                         ^
<stdin>:149:1: note: possible intended match here
Cost Model: Found an estimated cost of 5 for instruction: %V1BF16 = fdiv <1 x bfloat> undef, undef
^
/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/test/Analysis/CostModel/RISCV/arith-fp.ll:892:15: error: CHECK-NEXT: expected string not found in input
; CHECK-NEXT: Cost Model: Found an estimated cost of 5 for instruction: %V1BF16 = call <1 x bfloat> @llvm.fma.v1bf16(<1 x bfloat> undef, <1 x bfloat> undef, <1 x bfloat> undef)
              ^
<stdin>:340:133: note: scanning from here
Cost Model: Found an estimated cost of 1 for instruction: %F64 = call double @llvm.fma.f64(double undef, double undef, double undef)
                                                                                                                                    ^
...

```

</details>

https://github.com/llvm/llvm-project/pull/112393