[llvm] [InstCombine] Drop NSW when converting `shl X, BW - 1` back into mul (PR #121633)

Sat Jan 4 09:32:12 PST 2025

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `ml-opt-devrel-x86-64` running on `ml-opt-devrel-x86-64-b1` while building `llvm` at step 6 "test-build-unified-tree-check-all".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/175/builds/10907

<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 :: ExecutionEngine/JITLink/RISCV/ELF_branch.s' FAILED ********************
Exit Code: 134

Command Output (stderr):
--
RUN: at line 1: rm -rf /b/ml-opt-devrel-x86-64-b1/build/test/ExecutionEngine/JITLink/RISCV/Output/ELF_branch.s.tmp && mkdir -p /b/ml-opt-devrel-x86-64-b1/build/test/ExecutionEngine/JITLink/RISCV/Output/ELF_branch.s.tmp
+ rm -rf /b/ml-opt-devrel-x86-64-b1/build/test/ExecutionEngine/JITLink/RISCV/Output/ELF_branch.s.tmp
+ mkdir -p /b/ml-opt-devrel-x86-64-b1/build/test/ExecutionEngine/JITLink/RISCV/Output/ELF_branch.s.tmp
RUN: at line 2: /b/ml-opt-devrel-x86-64-b1/build/bin/llvm-mc -triple=riscv64 -filetype=obj -riscv-asm-relax-branches=0      -o /b/ml-opt-devrel-x86-64-b1/build/test/ExecutionEngine/JITLink/RISCV/Output/ELF_branch.s.tmp/elf_riscv64_branch.o /b/ml-opt-devrel-x86-64-b1/llvm-project/llvm/test/ExecutionEngine/JITLink/RISCV/ELF_branch.s
+ /b/ml-opt-devrel-x86-64-b1/build/bin/llvm-mc -triple=riscv64 -filetype=obj -riscv-asm-relax-branches=0 -o /b/ml-opt-devrel-x86-64-b1/build/test/ExecutionEngine/JITLink/RISCV/Output/ELF_branch.s.tmp/elf_riscv64_branch.o /b/ml-opt-devrel-x86-64-b1/llvm-project/llvm/test/ExecutionEngine/JITLink/RISCV/ELF_branch.s
RUN: at line 4: /b/ml-opt-devrel-x86-64-b1/build/bin/llvm-mc -triple=riscv32 -filetype=obj -riscv-asm-relax-branches=0      -o /b/ml-opt-devrel-x86-64-b1/build/test/ExecutionEngine/JITLink/RISCV/Output/ELF_branch.s.tmp/elf_riscv32_branch.o /b/ml-opt-devrel-x86-64-b1/llvm-project/llvm/test/ExecutionEngine/JITLink/RISCV/ELF_branch.s
+ /b/ml-opt-devrel-x86-64-b1/build/bin/llvm-mc -triple=riscv32 -filetype=obj -riscv-asm-relax-branches=0 -o /b/ml-opt-devrel-x86-64-b1/build/test/ExecutionEngine/JITLink/RISCV/Output/ELF_branch.s.tmp/elf_riscv32_branch.o /b/ml-opt-devrel-x86-64-b1/llvm-project/llvm/test/ExecutionEngine/JITLink/RISCV/ELF_branch.s
RUN: at line 6: /b/ml-opt-devrel-x86-64-b1/build/bin/llvm-jitlink -noexec      -slab-allocate 100Kb -slab-address 0xfff00ff4 -slab-page-size 4096      -abs external_func_positive_offset=0xfff00ffc -abs external_func_negative_offset=0xfff00000     -check /b/ml-opt-devrel-x86-64-b1/llvm-project/llvm/test/ExecutionEngine/JITLink/RISCV/ELF_branch.s /b/ml-opt-devrel-x86-64-b1/build/test/ExecutionEngine/JITLink/RISCV/Output/ELF_branch.s.tmp/elf_riscv64_branch.o
+ /b/ml-opt-devrel-x86-64-b1/build/bin/llvm-jitlink -noexec -slab-allocate 100Kb -slab-address 0xfff00ff4 -slab-page-size 4096 -abs external_func_positive_offset=0xfff00ffc -abs external_func_negative_offset=0xfff00000 -check /b/ml-opt-devrel-x86-64-b1/llvm-project/llvm/test/ExecutionEngine/JITLink/RISCV/ELF_branch.s /b/ml-opt-devrel-x86-64-b1/build/test/ExecutionEngine/JITLink/RISCV/Output/ELF_branch.s.tmp/elf_riscv64_branch.o
RUN: at line 10: /b/ml-opt-devrel-x86-64-b1/build/bin/llvm-jitlink -noexec      -slab-allocate 100Kb -slab-address 0xfff00ff4 -slab-page-size 4096      -abs external_func_positive_offset=0xfff00ffc -abs external_func_negative_offset=0xfff00000      -check /b/ml-opt-devrel-x86-64-b1/llvm-project/llvm/test/ExecutionEngine/JITLink/RISCV/ELF_branch.s /b/ml-opt-devrel-x86-64-b1/build/test/ExecutionEngine/JITLink/RISCV/Output/ELF_branch.s.tmp/elf_riscv32_branch.o
+ /b/ml-opt-devrel-x86-64-b1/build/bin/llvm-jitlink -noexec -slab-allocate 100Kb -slab-address 0xfff00ff4 -slab-page-size 4096 -abs external_func_positive_offset=0xfff00ffc -abs external_func_negative_offset=0xfff00000 -check /b/ml-opt-devrel-x86-64-b1/llvm-project/llvm/test/ExecutionEngine/JITLink/RISCV/ELF_branch.s /b/ml-opt-devrel-x86-64-b1/build/test/ExecutionEngine/JITLink/RISCV/Output/ELF_branch.s.tmp/elf_riscv32_branch.o
llvm-jitlink: /b/ml-opt-devrel-x86-64-b1/llvm-project/llvm/include/llvm/ExecutionEngine/Orc/SymbolStringPool.h:285: llvm::orc::SymbolStringPool::~SymbolStringPool(): Assertion `Pool.empty() && "Dangling references at pool destruction time"' failed.
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace.
Stack dump:
0.	Program arguments: /b/ml-opt-devrel-x86-64-b1/build/bin/llvm-jitlink -noexec -slab-allocate 100Kb -slab-address 0xfff00ff4 -slab-page-size 4096 -abs external_func_positive_offset=0xfff00ffc -abs external_func_negative_offset=0xfff00000 -check /b/ml-opt-devrel-x86-64-b1/llvm-project/llvm/test/ExecutionEngine/JITLink/RISCV/ELF_branch.s /b/ml-opt-devrel-x86-64-b1/build/test/ExecutionEngine/JITLink/RISCV/Output/ELF_branch.s.tmp/elf_riscv32_branch.o
 #0 0x000056492d2bd458 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/b/ml-opt-devrel-x86-64-b1/build/bin/llvm-jitlink+0x1143458)
 #1 0x000056492d2ba83c SignalHandler(int) Signals.cpp:0:0
 #2 0x00007f9fc2916140 __restore_rt (/lib/x86_64-linux-gnu/libpthread.so.0+0x13140)
 #3 0x00007f9fc240dd51 raise (/lib/x86_64-linux-gnu/libc.so.6+0x38d51)
 #4 0x00007f9fc23f7537 abort (/lib/x86_64-linux-gnu/libc.so.6+0x22537)
 #5 0x00007f9fc23f740f (/lib/x86_64-linux-gnu/libc.so.6+0x2240f)
 #6 0x00007f9fc24066d2 (/lib/x86_64-linux-gnu/libc.so.6+0x316d2)
 #7 0x000056492c8bcd7f (/b/ml-opt-devrel-x86-64-b1/build/bin/llvm-jitlink+0x742d7f)
 #8 0x000056492d1695ba llvm::orc::ExecutorProcessControl::~ExecutorProcessControl() (/b/ml-opt-devrel-x86-64-b1/build/bin/llvm-jitlink+0xfef5ba)
 #9 0x000056492d1697e3 llvm::orc::SelfExecutorProcessControl::~SelfExecutorProcessControl() crtstuff.c:0:0
#10 0x000056492d087ee6 llvm::orc::ExecutionSession::~ExecutionSession() (/b/ml-opt-devrel-x86-64-b1/build/bin/llvm-jitlink+0xf0dee6)
#11 0x000056492c86e2ce main (/b/ml-opt-devrel-x86-64-b1/build/bin/llvm-jitlink+0x6f42ce)
#12 0x00007f9fc23f8d7a __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x23d7a)
#13 0x000056492c8ac3fa _start (/b/ml-opt-devrel-x86-64-b1/build/bin/llvm-jitlink+0x7323fa)
/b/ml-opt-devrel-x86-64-b1/build/test/ExecutionEngine/JITLink/RISCV/Output/ELF_branch.s.script: line 5: 1263349 Aborted                 /b/ml-opt-devrel-x86-64-b1/build/bin/llvm-jitlink -noexec -slab-allocate 100Kb -slab-address 0xfff00ff4 -slab-page-size 4096 -abs external_func_positive_offset=0xfff00ffc -abs external_func_negative_offset=0xfff00000 -check /b/ml-opt-devrel-x86-64-b1/llvm-project/llvm/test/ExecutionEngine/JITLink/RISCV/ELF_branch.s /b/ml-opt-devrel-x86-64-b1/build/test/ExecutionEngine/JITLink/RISCV/Output/ELF_branch.s.tmp/elf_riscv32_branch.o

--

********************

```

</details>

https://github.com/llvm/llvm-project/pull/121633