[Mlir-commits] [mlir] [mlir] Avoid rewriting unreachable blocks in the greedy driver (PR #225814)

[Krzysztof Parzyszek]

kparzysz wrote:

Git bisect pointed to this commit for the failure in
https://github.com/llvm/llvm-project/actions/runs/39983301913/job/120515986725?pr=229527

```
  FAIL: Clang :: CIR/Transforms/canonicalize.cir (3220 of 26796)
  ******************** TEST 'Clang :: CIR/Transforms/canonicalize.cir' FAILED ********************
  Exit Code: 1
  
  Command Output (stdout):
  --
  # RUN: at line 1
  /home/gha/actions-runner/_work/llvm-project/llvm-project/build/bin/cir-opt /home/gha/actions-runner/_work/llvm-project/llvm-project/clang/test/CIR/Transforms/canonicalize.cir -cir-canonicalize -o - | /home/gha/actions-runner/_work/llvm-project/llvm-project/build/bin/FileCheck /home/gha/actions-runner/_work/llvm-project/llvm-project/clang/test/CIR/Transforms/canonicalize.cir
  # executed command: /home/gha/actions-runner/_work/llvm-project/llvm-project/build/bin/cir-opt /home/gha/actions-runner/_work/llvm-project/llvm-project/clang/test/CIR/Transforms/canonicalize.cir -cir-canonicalize -o -
  # note: command had no output on stdout or stderr
  # executed command: /home/gha/actions-runner/_work/llvm-project/llvm-project/build/bin/FileCheck /home/gha/actions-runner/_work/llvm-project/llvm-project/clang/test/CIR/Transforms/canonicalize.cir
  # .---command stderr------------
  # | /home/gha/actions-runner/_work/llvm-project/llvm-project/clang/test/CIR/Transforms/canonicalize.cir:62:17: error: CHECK-NEXT: is not on the line after the previous match
  # |  // CHECK-NEXT: cir.br ^[[HEADER]](%[[KEEP]] : !s32i)
  # |                 ^
  # | <stdin>:26:2: note: 'next' match was here
  # |  cir.br ^bb1(%0 : !s32i)
  # |  ^
  # | <stdin>:23:35: note: previous match ended here
  # |  cir.call @use(%0) : (!s32i) -> ()
  # |                                   ^
  # | <stdin>:24:1: note: non-matching line after previous match is here
  # |  cir.br ^bb2
  # | ^
  # | 
  # | Input file: <stdin>
  # | Check file: /home/gha/actions-runner/_work/llvm-project/llvm-project/clang/test/CIR/Transforms/canonicalize.cir
  # | 
  # | -dump-input=help explains the following input dump.
  # | 
  # | Input was:
  # | <<<<<<
  # |            .
  # |            .
  # |            .
  # |           18:  } 
  # |           19:  cir.func private @use(!s32i) 
  # |           20:  cir.func @no_merge_self_arg_loop(%arg0: !s32i) -> !s32i { 
  # |           21:  cir.return %arg0 : !s32i 
  # |           22:  ^bb1(%0: !s32i): // pred: ^bb2 
  # |           23:  cir.call @use(%0) : (!s32i) -> () 
  # | next:62'0                                      {   search range start (exclusive)
  # |           24:  cir.br ^bb2 
  # |           25:  ^bb2: // pred: ^bb1 
  # |           26:  cir.br ^bb1(%0 : !s32i) 
  # | next:62'1      !~~~~~~~~~~~~~~~~~~~~~~   error: match on wrong line
  # |           27:  } 
  # |           28:  cir.func @scope_yield_value_fold() -> !u32i { 
  # |           29:  %0 = cir.const #cir.int<7> : !u32i 
  # |           30:  cir.return %0 : !u32i 
  # |           31:  } 
  # |            .
  # |            .
  # |            .
  # |          142:  cir.func @cast_zext_u8_s32() -> !s32i { 
  # |          143:  %0 = cir.const #cir.int<255> : !s32i 
  # |          144:  cir.return %0 : !s32i 
  # |          145:  } 
  # |          146: } 
  # |          147:  
  # | next:62'2      } search range end (exclusive)
  # | >>>>>>
  # `-----------------------------
  # error: command failed with exit status: 1
  
  --
  
  ********************
```

https://github.com/llvm/llvm-project/pull/225814