[llvm] [RISCV] Cost bf16/f16 vector non-unit memory accesses as legal without zvfhmin/zvfbfmin (PR #150882)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `lld-x86_64-ubuntu-fast` running on `as-builder-4` while building `llvm` at step 6 "test-build-unified-tree-check-all".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/33/builds/21089

<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 :: Transforms/LoopVectorize/RISCV/bf16.ll' FAILED ********************
Exit Code: 1

Command Output (stderr):
--
/home/buildbot/worker/as-builder-4/ramdisk/lld-x86_64/build/bin/opt < /home/buildbot/worker/as-builder-4/ramdisk/lld-x86_64/llvm-project/llvm/test/Transforms/LoopVectorize/RISCV/bf16.ll -passes=loop-vectorize -mtriple riscv64 -mattr=+v -S | /home/buildbot/worker/as-builder-4/ramdisk/lld-x86_64/build/bin/FileCheck /home/buildbot/worker/as-builder-4/ramdisk/lld-x86_64/llvm-project/llvm/test/Transforms/LoopVectorize/RISCV/bf16.ll -check-prefix=NO-ZVFBFMIN # RUN: at line 2
+ /home/buildbot/worker/as-builder-4/ramdisk/lld-x86_64/build/bin/opt -passes=loop-vectorize -mtriple riscv64 -mattr=+v -S
+ /home/buildbot/worker/as-builder-4/ramdisk/lld-x86_64/build/bin/FileCheck /home/buildbot/worker/as-builder-4/ramdisk/lld-x86_64/llvm-project/llvm/test/Transforms/LoopVectorize/RISCV/bf16.ll -check-prefix=NO-ZVFBFMIN
/home/buildbot/worker/as-builder-4/ramdisk/lld-x86_64/build/bin/opt < /home/buildbot/worker/as-builder-4/ramdisk/lld-x86_64/llvm-project/llvm/test/Transforms/LoopVectorize/RISCV/bf16.ll -passes=loop-vectorize -mtriple riscv64 -mattr=+v -S -prefer-predicate-over-epilogue=predicate-else-scalar-epilogue | /home/buildbot/worker/as-builder-4/ramdisk/lld-x86_64/build/bin/FileCheck /home/buildbot/worker/as-builder-4/ramdisk/lld-x86_64/llvm-project/llvm/test/Transforms/LoopVectorize/RISCV/bf16.ll -check-prefix=NO-ZVFBFMIN-PREDICATED # RUN: at line 3
+ /home/buildbot/worker/as-builder-4/ramdisk/lld-x86_64/build/bin/opt -passes=loop-vectorize -mtriple riscv64 -mattr=+v -S -prefer-predicate-over-epilogue=predicate-else-scalar-epilogue
+ /home/buildbot/worker/as-builder-4/ramdisk/lld-x86_64/build/bin/FileCheck /home/buildbot/worker/as-builder-4/ramdisk/lld-x86_64/llvm-project/llvm/test/Transforms/LoopVectorize/RISCV/bf16.ll -check-prefix=NO-ZVFBFMIN-PREDICATED
/home/buildbot/worker/as-builder-4/ramdisk/lld-x86_64/llvm-project/llvm/test/Transforms/LoopVectorize/RISCV/bf16.ll:28:32: error: NO-ZVFBFMIN-PREDICATED-NEXT: expected string not found in input
; NO-ZVFBFMIN-PREDICATED-NEXT: br i1 false, label %[[SCALAR_PH:.*]], label %[[VECTOR_PH:.*]]
                               ^
<stdin>:7:7: note: scanning from here
entry:
      ^
<stdin>:20:2: note: possible intended match here
 br i1 %done, label %exit, label %loop
 ^
/home/buildbot/worker/as-builder-4/ramdisk/lld-x86_64/llvm-project/llvm/test/Transforms/LoopVectorize/RISCV/bf16.ll:186:32: error: NO-ZVFBFMIN-PREDICATED-NEXT: expected string not found in input
; NO-ZVFBFMIN-PREDICATED-NEXT: br i1 false, label %[[SCALAR_PH:.*]], label %[[VECTOR_PH:.*]]
                               ^
<stdin>:27:7: note: scanning from here
entry:
      ^
<stdin>:74:2: note: possible intended match here
 br i1 %done, label %exit, label %loop, !llvm.loop !3
 ^

Input file: <stdin>
Check file: /home/buildbot/worker/as-builder-4/ramdisk/lld-x86_64/llvm-project/llvm/test/Transforms/LoopVectorize/RISCV/bf16.ll

-dump-input=help explains the following input dump.

Input was:
<<<<<<
            1: ; ModuleID = '<stdin>' 
            2: source_filename = "<stdin>" 
            3: target datalayout = "e-m:e-p:64:64-i64:64-i128:128-n32:64-S128" 
            4: target triple = "riscv64" 
            5:  
            6: define void @fadd(ptr noalias %a, ptr noalias %b, i64 %n) #0 { 
            7: entry: 
next:28'0            X error: no match found
            8:  br label %loop 
next:28'0      ~~~~~~~~~~~~~~~~
            9:  
next:28'0      ~
           10: loop: ; preds = %loop, %entry 
...

```

</details>

https://github.com/llvm/llvm-project/pull/150882