[llvm] [RISCV] Rework memcpy test (PR #120364)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `clang-ppc64le-linux-multistage` running on `ppc64le-clang-multistage-test` while building `llvm` at step 5 "ninja check 1".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/76/builds/6047

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

```
Step 5 (ninja check 1) failure: stage 1 checked (failure)
******************** TEST 'LLVM :: CodeGen/RISCV/memcpy.ll' FAILED ********************
Exit Code: 1

Command Output (stderr):
--
RUN: at line 2: /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/stage1/bin/llc < /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/llvm/llvm/test/CodeGen/RISCV/memcpy.ll -mtriple=riscv32    | /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/stage1/bin/FileCheck /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/llvm/llvm/test/CodeGen/RISCV/memcpy.ll --check-prefixes=RV32-BOTH,RV32
+ /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/stage1/bin/llc -mtriple=riscv32
+ /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/stage1/bin/FileCheck /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/llvm/llvm/test/CodeGen/RISCV/memcpy.ll --check-prefixes=RV32-BOTH,RV32
/home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/llvm/llvm/test/CodeGen/RISCV/memcpy.ll:278:14: error: RV32-NEXT: expected string not found in input
; RV32-NEXT: lbu a2, 14(a1)
             ^
<stdin>:122:18: note: scanning from here
# %bb.0: # %entry
                 ^
<stdin>:123:2: note: possible intended match here
 li a2, 15
 ^
/home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/llvm/llvm/test/CodeGen/RISCV/memcpy.ll:371:14: error: RV32-NEXT: expected string not found in input
; RV32-NEXT: lbu a2, 15(a1)
             ^
<stdin>:132:18: note: scanning from here
# %bb.0: # %entry
                 ^
<stdin>:133:2: note: possible intended match here
 li a2, 16
 ^
/home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/llvm/llvm/test/CodeGen/RISCV/memcpy.ll:468:14: error: RV32-NEXT: expected string not found in input
; RV32-NEXT: lbu a2, 30(a1)
             ^
<stdin>:142:18: note: scanning from here
# %bb.0: # %entry
                 ^
<stdin>:143:2: note: possible intended match here
 li a2, 31
 ^
/home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/llvm/llvm/test/CodeGen/RISCV/memcpy.ll:861:14: error: RV32-NEXT: expected string not found in input
; RV32-NEXT: lbu a2, 30(a1)
             ^
<stdin>:271:18: note: scanning from here
# %bb.0: # %entry
                 ^
<stdin>:272:2: note: possible intended match here
 li a2, 31
 ^

Input file: <stdin>
Check file: /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/llvm/llvm/test/CodeGen/RISCV/memcpy.ll

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

...
Step 11 (ninja check 2) failure: stage 2 checked (failure)
******************** TEST 'LLVM :: CodeGen/RISCV/memcpy.ll' FAILED ********************
Exit Code: 1

Command Output (stderr):
--
RUN: at line 2: /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/stage2/bin/llc < /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/llvm/llvm/test/CodeGen/RISCV/memcpy.ll -mtriple=riscv32    | /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/stage2/bin/FileCheck /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/llvm/llvm/test/CodeGen/RISCV/memcpy.ll --check-prefixes=RV32-BOTH,RV32
+ /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/stage2/bin/llc -mtriple=riscv32
+ /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/stage2/bin/FileCheck /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/llvm/llvm/test/CodeGen/RISCV/memcpy.ll --check-prefixes=RV32-BOTH,RV32
/home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/llvm/llvm/test/CodeGen/RISCV/memcpy.ll:278:14: error: RV32-NEXT: expected string not found in input
; RV32-NEXT: lbu a2, 14(a1)
             ^
<stdin>:122:18: note: scanning from here
# %bb.0: # %entry
                 ^
<stdin>:123:2: note: possible intended match here
 li a2, 15
 ^
/home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/llvm/llvm/test/CodeGen/RISCV/memcpy.ll:371:14: error: RV32-NEXT: expected string not found in input
; RV32-NEXT: lbu a2, 15(a1)
             ^
<stdin>:132:18: note: scanning from here
# %bb.0: # %entry
                 ^
<stdin>:133:2: note: possible intended match here
 li a2, 16
 ^
/home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/llvm/llvm/test/CodeGen/RISCV/memcpy.ll:468:14: error: RV32-NEXT: expected string not found in input
; RV32-NEXT: lbu a2, 30(a1)
             ^
<stdin>:142:18: note: scanning from here
# %bb.0: # %entry
                 ^
<stdin>:143:2: note: possible intended match here
 li a2, 31
 ^
/home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/llvm/llvm/test/CodeGen/RISCV/memcpy.ll:861:14: error: RV32-NEXT: expected string not found in input
; RV32-NEXT: lbu a2, 30(a1)
             ^
<stdin>:271:18: note: scanning from here
# %bb.0: # %entry
                 ^
<stdin>:272:2: note: possible intended match here
 li a2, 31
 ^

Input file: <stdin>
Check file: /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/llvm/llvm/test/CodeGen/RISCV/memcpy.ll

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

...

```

</details>

https://github.com/llvm/llvm-project/pull/120364