LU-JOHN 9abbec66bf
[AMDGPU] Reland "Remove redundant s_cmp_lg_* sX, 0" (#164201)
Reland PR https://github.com/llvm/llvm-project/pull/162352. Fix by
excluding SI_PC_ADD_REL_OFFSET from instructions that set SCC = DST!=0.
Passes check-libc-amdgcn-amd-amdhsa now.

Distribution of instructions that allowed a redundant S_CMP to be
deleted in check-libc-amdgcn-amd-amdhsa test:

```
S_AND_B32      485
S_AND_B64      47
S_ANDN2_B32    42
S_ANDN2_B64    277492
S_CSELECT_B64  17631
S_LSHL_B32     6
S_OR_B64       11
```

---------

Signed-off-by: John Lu <John.Lu@amd.com>
Co-authored-by: Matt Arsenault <arsenm2@gmail.com>
2025-10-22 08:42:29 -05:00
..

+==============================================================================+
| How to organize the lit tests                                                |
+==============================================================================+

- If you write a test for matching a single DAG opcode or intrinsic, it should
  go in a file called {opcode_name,intrinsic_name}.ll (e.g. fadd.ll)

- If you write a test that matches several DAG opcodes and checks for a single
  ISA instruction, then that test should go in a file called {ISA_name}.ll (e.g.
  bfi_int.ll

- For all other tests, use your best judgement for organizing tests and naming
  the files.

+==============================================================================+
| Naming conventions                                                           |
+==============================================================================+

- Use dash '-' and not underscore '_' to separate words in file names, unless
  the file is named after a DAG opcode or ISA instruction that has an
  underscore '_' in its name.