[llvm] [AArch64] Improve lowering of scalar abs(sub(a, b)). (PR #151180)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `sanitizer-aarch64-linux-bootstrap-hwasan` running on `sanitizer-buildbot12` while building `llvm` at step 2 "annotate".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/55/builds/15280

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

```
Step 2 (annotate) failure: 'python ../sanitizer_buildbot/sanitizers/zorg/buildbot/builders/sanitizers/buildbot_selector.py' (failure)
...
llvm-lit: /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/llvm/utils/lit/lit/llvm/config.py:520: note: using lld-link: /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm_build_hwasan/bin/lld-link
llvm-lit: /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/llvm/utils/lit/lit/llvm/config.py:520: note: using ld64.lld: /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm_build_hwasan/bin/ld64.lld
llvm-lit: /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/llvm/utils/lit/lit/llvm/config.py:520: note: using wasm-ld: /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm_build_hwasan/bin/wasm-ld
llvm-lit: /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/llvm/utils/lit/lit/llvm/config.py:520: note: using ld.lld: /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm_build_hwasan/bin/ld.lld
llvm-lit: /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/llvm/utils/lit/lit/llvm/config.py:520: note: using lld-link: /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm_build_hwasan/bin/lld-link
llvm-lit: /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/llvm/utils/lit/lit/llvm/config.py:520: note: using ld64.lld: /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm_build_hwasan/bin/ld64.lld
llvm-lit: /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/llvm/utils/lit/lit/llvm/config.py:520: note: using wasm-ld: /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm_build_hwasan/bin/wasm-ld
llvm-lit: /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/llvm/utils/lit/lit/main.py:73: note: The test suite configuration requested an individual test timeout of 0 seconds but a timeout of 900 seconds was requested on the command line. Forcing timeout to be 900 seconds.
-- Testing: 89622 tests, 72 workers --
Testing:  0.. 10.. 20..
FAIL: LLVM :: CodeGen/AArch64/midpoint-int.ll (26642 of 89622)
******************** TEST 'LLVM :: CodeGen/AArch64/midpoint-int.ll' FAILED ********************
Exit Code: 1

Command Output (stderr):
--
/home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm_build_hwasan/bin/llc -mtriple=aarch64-unknown-linux-gnu < /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/llvm/test/CodeGen/AArch64/midpoint-int.ll | /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm_build_hwasan/bin/FileCheck /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/llvm/test/CodeGen/AArch64/midpoint-int.ll # RUN: at line 2
+ /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm_build_hwasan/bin/FileCheck /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/llvm/test/CodeGen/AArch64/midpoint-int.ll
+ /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm_build_hwasan/bin/llc -mtriple=aarch64-unknown-linux-gnu
/home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/llvm/test/CodeGen/AArch64/midpoint-int.ll:304:15: error: CHECK-NEXT: expected string not found in input
; CHECK-NEXT: sxth w9, w1
              ^
<stdin>:197:10: note: scanning from here
// %bb.0:
         ^
<stdin>:200:7: note: possible intended match here
 subs w10, w9, w1, sxth
      ^
/home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/llvm/test/CodeGen/AArch64/midpoint-int.ll:429:15: error: CHECK-NEXT: expected string not found in input
; CHECK-NEXT: sxtb w9, w1
              ^
<stdin>:279:10: note: scanning from here
// %bb.0:
         ^
<stdin>:282:7: note: possible intended match here
 subs w10, w9, w1, sxtb
      ^

Input file: <stdin>
Check file: /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/llvm/test/CodeGen/AArch64/midpoint-int.ll

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

Input was:
<<<<<<
            .
            .
            .
          192:  // -- End function 
Step 11 (stage2/hwasan check) failure: stage2/hwasan check (failure)
...
llvm-lit: /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/llvm/utils/lit/lit/llvm/config.py:520: note: using lld-link: /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm_build_hwasan/bin/lld-link
llvm-lit: /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/llvm/utils/lit/lit/llvm/config.py:520: note: using ld64.lld: /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm_build_hwasan/bin/ld64.lld
llvm-lit: /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/llvm/utils/lit/lit/llvm/config.py:520: note: using wasm-ld: /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm_build_hwasan/bin/wasm-ld
llvm-lit: /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/llvm/utils/lit/lit/llvm/config.py:520: note: using ld.lld: /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm_build_hwasan/bin/ld.lld
llvm-lit: /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/llvm/utils/lit/lit/llvm/config.py:520: note: using lld-link: /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm_build_hwasan/bin/lld-link
llvm-lit: /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/llvm/utils/lit/lit/llvm/config.py:520: note: using ld64.lld: /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm_build_hwasan/bin/ld64.lld
llvm-lit: /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/llvm/utils/lit/lit/llvm/config.py:520: note: using wasm-ld: /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm_build_hwasan/bin/wasm-ld
llvm-lit: /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/llvm/utils/lit/lit/main.py:73: note: The test suite configuration requested an individual test timeout of 0 seconds but a timeout of 900 seconds was requested on the command line. Forcing timeout to be 900 seconds.
-- Testing: 89622 tests, 72 workers --
Testing:  0.. 10.. 20..
FAIL: LLVM :: CodeGen/AArch64/midpoint-int.ll (26642 of 89622)
******************** TEST 'LLVM :: CodeGen/AArch64/midpoint-int.ll' FAILED ********************
Exit Code: 1

Command Output (stderr):
--
/home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm_build_hwasan/bin/llc -mtriple=aarch64-unknown-linux-gnu < /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/llvm/test/CodeGen/AArch64/midpoint-int.ll | /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm_build_hwasan/bin/FileCheck /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/llvm/test/CodeGen/AArch64/midpoint-int.ll # RUN: at line 2
+ /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm_build_hwasan/bin/FileCheck /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/llvm/test/CodeGen/AArch64/midpoint-int.ll
+ /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm_build_hwasan/bin/llc -mtriple=aarch64-unknown-linux-gnu
/home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/llvm/test/CodeGen/AArch64/midpoint-int.ll:304:15: error: CHECK-NEXT: expected string not found in input
; CHECK-NEXT: sxth w9, w1
              ^
<stdin>:197:10: note: scanning from here
// %bb.0:
         ^
<stdin>:200:7: note: possible intended match here
 subs w10, w9, w1, sxth
      ^
/home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/llvm/test/CodeGen/AArch64/midpoint-int.ll:429:15: error: CHECK-NEXT: expected string not found in input
; CHECK-NEXT: sxtb w9, w1
              ^
<stdin>:279:10: note: scanning from here
// %bb.0:
         ^
<stdin>:282:7: note: possible intended match here
 subs w10, w9, w1, sxtb
      ^

Input file: <stdin>
Check file: /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/llvm/test/CodeGen/AArch64/midpoint-int.ll

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

Input was:
<<<<<<
            .
            .
            .
          192:  // -- End function 
Step 14 (stage3/hwasan check) failure: stage3/hwasan check (failure)
...
llvm-lit: /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/llvm/utils/lit/lit/llvm/config.py:520: note: using lld-link: /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm_build2_hwasan/bin/lld-link
llvm-lit: /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/llvm/utils/lit/lit/llvm/config.py:520: note: using ld64.lld: /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm_build2_hwasan/bin/ld64.lld
llvm-lit: /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/llvm/utils/lit/lit/llvm/config.py:520: note: using wasm-ld: /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm_build2_hwasan/bin/wasm-ld
llvm-lit: /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/llvm/utils/lit/lit/llvm/config.py:520: note: using ld.lld: /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm_build2_hwasan/bin/ld.lld
llvm-lit: /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/llvm/utils/lit/lit/llvm/config.py:520: note: using lld-link: /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm_build2_hwasan/bin/lld-link
llvm-lit: /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/llvm/utils/lit/lit/llvm/config.py:520: note: using ld64.lld: /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm_build2_hwasan/bin/ld64.lld
llvm-lit: /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/llvm/utils/lit/lit/llvm/config.py:520: note: using wasm-ld: /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm_build2_hwasan/bin/wasm-ld
llvm-lit: /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/llvm/utils/lit/lit/main.py:73: note: The test suite configuration requested an individual test timeout of 0 seconds but a timeout of 900 seconds was requested on the command line. Forcing timeout to be 900 seconds.
-- Testing: 86409 tests, 72 workers --
Testing:  0.. 10.. 20.. 
FAIL: LLVM :: CodeGen/AArch64/midpoint-int.ll (26654 of 86409)
******************** TEST 'LLVM :: CodeGen/AArch64/midpoint-int.ll' FAILED ********************
Exit Code: 1

Command Output (stderr):
--
/home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm_build2_hwasan/bin/llc -mtriple=aarch64-unknown-linux-gnu < /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/llvm/test/CodeGen/AArch64/midpoint-int.ll | /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm_build2_hwasan/bin/FileCheck /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/llvm/test/CodeGen/AArch64/midpoint-int.ll # RUN: at line 2
+ /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm_build2_hwasan/bin/llc -mtriple=aarch64-unknown-linux-gnu
+ /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm_build2_hwasan/bin/FileCheck /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/llvm/test/CodeGen/AArch64/midpoint-int.ll
/home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/llvm/test/CodeGen/AArch64/midpoint-int.ll:304:15: error: CHECK-NEXT: expected string not found in input
; CHECK-NEXT: sxth w9, w1
              ^
<stdin>:197:10: note: scanning from here
// %bb.0:
         ^
<stdin>:200:7: note: possible intended match here
 subs w10, w9, w1, sxth
      ^
/home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/llvm/test/CodeGen/AArch64/midpoint-int.ll:429:15: error: CHECK-NEXT: expected string not found in input
; CHECK-NEXT: sxtb w9, w1
              ^
<stdin>:279:10: note: scanning from here
// %bb.0:
         ^
<stdin>:282:7: note: possible intended match here
 subs w10, w9, w1, sxtb
      ^

Input file: <stdin>
Check file: /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/llvm/test/CodeGen/AArch64/midpoint-int.ll

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

Input was:
<<<<<<
            .
            .
            .
          192:  // -- End function 

```

</details>

https://github.com/llvm/llvm-project/pull/151180