update_llc_test_checks.py doesn't report when a common prefix has been lost #48533
Description
| Bugzilla Link | 49189 |
| Version | trunk |
| OS | Windows NT |
| CC | @topperc,@gregbedwell,@MaskRay,@LebedevRI,@mtrofin |
Extended Description
https://reviews.llvm.org/rGf32dc6bb42fd24517289fd1e3418994daa4fec20
; RUN: llc < %s -mtriple=x86_64-- -mattr=+avx2 | FileCheck %s --check-prefixes=AVX,AVX2
; RUN: llc < %s -mtriple=x86_64-- -mattr=+avx2,+fast-variable-shuffle | FileCheck %s --check-prefixes=AVX,AVX2
update_llc_test_checks.py didn't report that two AVX2 runs had conflicting checks for all their common prefixes, which meant we lost ALL test coverage.