[llvm-exegesis] tools/llvm-exegesis/RISCV/rvv/filter.test appears flaky #158735
Description
Saw the following output from a buildbot:
******************** TEST 'LLVM :: tools/llvm-exegesis/RISCV/rvv/filter.test' FAILED ********************
Exit Code: 2
Command Output (stdout):
--
# RUN: at line 1
/b/ml-opt-dev-x86-64-b1/build/bin/llvm-exegesis -mtriple=riscv64 -mcpu=sifive-x280 -benchmark-phase=assemble-measured-code --mode=inverse_throughput --opcode-name=PseudoVNCLIPU_WX_M1_MASK --riscv-filter-config='vtype = {VXRM: rod, AVL: VLMAX, SEW: e(8|16), Policy: ta/mu}' --max-configs-per-opcode=1000 --min-instructions=10 | /b/ml-opt-dev-x86-64-b1/build/bin/FileCheck /b/ml-opt-dev-x86-64-b1/llvm-project/llvm/test/tools/llvm-exegesis/RISCV/rvv/filter.test
# executed command: /b/ml-opt-dev-x86-64-b1/build/bin/llvm-exegesis -mtriple=riscv64 -mcpu=sifive-x280 -benchmark-phase=assemble-measured-code --mode=inverse_throughput --opcode-name=PseudoVNCLIPU_WX_M1_MASK '--riscv-filter-config=vtype = {VXRM: rod, AVL: VLMAX, SEW: e(8|16), Policy: ta/mu}' --max-configs-per-opcode=1000 --min-instructions=10
# .---command stderr------------
# | PseudoVNCLIPU_WX_M1_MASK: Failed to produce any snippet via: instruction has tied variables, avoiding Read-After-Write issue, picking random def and use registers not aliasing each other, for uses, one unique register for each position
# `-----------------------------
# executed command: /b/ml-opt-dev-x86-64-b1/build/bin/FileCheck /b/ml-opt-dev-x86-64-b1/llvm-project/llvm/test/tools/llvm-exegesis/RISCV/rvv/filter.test
# .---command stderr------------
# | FileCheck error: '<stdin>' is empty.
# | FileCheck command line: /b/ml-opt-dev-x86-64-b1/build/bin/FileCheck /b/ml-opt-dev-x86-64-b1/llvm-project/llvm/test/tools/llvm-exegesis/RISCV/rvv/filter.test
# `-----------------------------
# error: command failed with exit status: 2
--
********************
https://lab.llvm.org/buildbot/#/builders/137/builds/25541
It seems like there might be some seed that causes issues.