[llvm] [NFCI][Globals] In GlobalObjects::setSectionPrefix, do conditional update if existing prefix is not equivalent to the new one. Returns whether prefix changed. (PR #158460)

Tue Sep 16 19:04:49 PDT 2025

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `ppc64le-lld-multistage-test` running on `ppc64le-lld-multistage-test` while building `llvm` at step 7 "test-build-stage1-unified-tree-check-all".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/168/builds/16188

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

```
Step 7 (test-build-stage1-unified-tree-check-all) failure: test (failure)
******************** TEST 'LLVM :: CodeGen/X86/memcmp-pgso.ll' FAILED ********************
Exit Code: 1

Command Output (stdout):
--
# RUN: at line 2
/home/buildbots/llvm-external-buildbots/workers/ppc64le-lld-multistage-test/ppc64le-lld-multistage-test/build/stage1/bin/llc < /home/buildbots/llvm-external-buildbots/workers/ppc64le-lld-multistage-test/ppc64le-lld-multistage-test/llvm-project/llvm/test/CodeGen/X86/memcmp-pgso.ll -mtriple=x86_64-unknown-unknown | /home/buildbots/llvm-external-buildbots/workers/ppc64le-lld-multistage-test/ppc64le-lld-multistage-test/build/stage1/bin/FileCheck /home/buildbots/llvm-external-buildbots/workers/ppc64le-lld-multistage-test/ppc64le-lld-multistage-test/llvm-project/llvm/test/CodeGen/X86/memcmp-pgso.ll --check-prefixes=X64,X64-SSE2
# executed command: /home/buildbots/llvm-external-buildbots/workers/ppc64le-lld-multistage-test/ppc64le-lld-multistage-test/build/stage1/bin/llc -mtriple=x86_64-unknown-unknown
# executed command: /home/buildbots/llvm-external-buildbots/workers/ppc64le-lld-multistage-test/ppc64le-lld-multistage-test/build/stage1/bin/FileCheck /home/buildbots/llvm-external-buildbots/workers/ppc64le-lld-multistage-test/ppc64le-lld-multistage-test/llvm-project/llvm/test/CodeGen/X86/memcmp-pgso.ll --check-prefixes=X64,X64-SSE2
# .---command stderr------------
# | /home/buildbots/llvm-external-buildbots/workers/ppc64le-lld-multistage-test/ppc64le-lld-multistage-test/llvm-project/llvm/test/CodeGen/X86/memcmp-pgso.ll:75:13: error: X64-NEXT: expected string not found in input
# | ; X64-NEXT: jne .LBB4_3
# |             ^
# | <stdin>:66:15: note: scanning from here
# |  cmpw %cx, %ax
# |               ^
# | <stdin>:67:2: note: possible intended match here
# |  jne .LBB4_1
# |  ^
# | /home/buildbots/llvm-external-buildbots/workers/ppc64le-lld-multistage-test/ppc64le-lld-multistage-test/llvm-project/llvm/test/CodeGen/X86/memcmp-pgso.ll:153:13: error: X64-NEXT: expected string not found in input
# | ; X64-NEXT: jne .LBB9_3
# |             ^
# | <stdin>:146:17: note: scanning from here
# |  cmpl %ecx, %eax
# |                 ^
# | <stdin>:147:2: note: possible intended match here
# |  jne .LBB9_1
# |  ^
# | /home/buildbots/llvm-external-buildbots/workers/ppc64le-lld-multistage-test/ppc64le-lld-multistage-test/llvm-project/llvm/test/CodeGen/X86/memcmp-pgso.ll:247:13: error: X64-NEXT: expected string not found in input
# | ; X64-NEXT: jne .LBB15_2
# |             ^
# | <stdin>:242:17: note: scanning from here
# |  cmpq %rdx, %rcx
# |                 ^
# | <stdin>:243:2: note: possible intended match here
# |  jne .LBB15_1
# |  ^
# | /home/buildbots/llvm-external-buildbots/workers/ppc64le-lld-multistage-test/ppc64le-lld-multistage-test/llvm-project/llvm/test/CodeGen/X86/memcmp-pgso.ll:277:13: error: X64-NEXT: expected string not found in input
# | ; X64-NEXT: jne .LBB16_2
# |             ^
# | <stdin>:272:17: note: scanning from here
# |  cmpq %rdx, %rcx
# |                 ^
# | <stdin>:273:2: note: possible intended match here
# |  jne .LBB16_1
# |  ^
# | 
# | Input file: <stdin>
# | Check file: /home/buildbots/llvm-external-buildbots/workers/ppc64le-lld-multistage-test/ppc64le-lld-multistage-test/llvm-project/llvm/test/CodeGen/X86/memcmp-pgso.ll
# | 
...
Step 13 (test-build-stage2-unified-tree-check-all) failure: test (failure)
******************** TEST 'LLVM :: CodeGen/X86/memcmp-pgso-x32.ll' FAILED ********************
Exit Code: 1

Command Output (stdout):
--
# RUN: at line 2
/home/buildbots/llvm-external-buildbots/workers/ppc64le-lld-multistage-test/ppc64le-lld-multistage-test/build/stage2/bin/llc < /home/buildbots/llvm-external-buildbots/workers/ppc64le-lld-multistage-test/ppc64le-lld-multistage-test/llvm-project/llvm/test/CodeGen/X86/memcmp-pgso-x32.ll -mtriple=i686-unknown-unknown -mattr=cmov | /home/buildbots/llvm-external-buildbots/workers/ppc64le-lld-multistage-test/ppc64le-lld-multistage-test/build/stage2/bin/FileCheck /home/buildbots/llvm-external-buildbots/workers/ppc64le-lld-multistage-test/ppc64le-lld-multistage-test/llvm-project/llvm/test/CodeGen/X86/memcmp-pgso-x32.ll --check-prefixes=X86,X86-NOSSE
# executed command: /home/buildbots/llvm-external-buildbots/workers/ppc64le-lld-multistage-test/ppc64le-lld-multistage-test/build/stage2/bin/llc -mtriple=i686-unknown-unknown -mattr=cmov
# executed command: /home/buildbots/llvm-external-buildbots/workers/ppc64le-lld-multistage-test/ppc64le-lld-multistage-test/build/stage2/bin/FileCheck /home/buildbots/llvm-external-buildbots/workers/ppc64le-lld-multistage-test/ppc64le-lld-multistage-test/llvm-project/llvm/test/CodeGen/X86/memcmp-pgso-x32.ll --check-prefixes=X86,X86-NOSSE
# .---command stderr------------
# | /home/buildbots/llvm-external-buildbots/workers/ppc64le-lld-multistage-test/ppc64le-lld-multistage-test/llvm-project/llvm/test/CodeGen/X86/memcmp-pgso-x32.ll:83:13: error: X86-NEXT: expected string not found in input
# | ; X86-NEXT: jne .LBB4_3
# |             ^
# | <stdin>:75:15: note: scanning from here
# |  cmpw %si, %dx
# |               ^
# | <stdin>:76:2: note: possible intended match here
# |  jne .LBB4_1
# |  ^
# | /home/buildbots/llvm-external-buildbots/workers/ppc64le-lld-multistage-test/ppc64le-lld-multistage-test/llvm-project/llvm/test/CodeGen/X86/memcmp-pgso-x32.ll:173:13: error: X86-NEXT: expected string not found in input
# | ; X86-NEXT: jne .LBB9_3
# |             ^
# | <stdin>:167:17: note: scanning from here
# |  cmpl %esi, %edx
# |                 ^
# | <stdin>:168:2: note: possible intended match here
# |  jne .LBB9_1
# |  ^
# | /home/buildbots/llvm-external-buildbots/workers/ppc64le-lld-multistage-test/ppc64le-lld-multistage-test/llvm-project/llvm/test/CodeGen/X86/memcmp-pgso-x32.ll:219:13: error: X86-NEXT: expected string not found in input
# | ; X86-NEXT: jne .LBB11_2
# |             ^
# | <stdin>:214:17: note: scanning from here
# |  cmpl %edx, %ecx
# |                 ^
# | <stdin>:215:2: note: possible intended match here
# |  jne .LBB11_1
# |  ^
# | 
# | Input file: <stdin>
# | Check file: /home/buildbots/llvm-external-buildbots/workers/ppc64le-lld-multistage-test/ppc64le-lld-multistage-test/llvm-project/llvm/test/CodeGen/X86/memcmp-pgso-x32.ll
# | 
# | -dump-input=help explains the following input dump.
# | 
# | Input was:
# | <<<<<<
# |             .
# |             .
# |             .
# |            70:  movl 8(%esp), %eax 
# |            71:  movzwl (%eax), %edx 
...

```

</details>

https://github.com/llvm/llvm-project/pull/158460