[AIROCMLIR-1077] Fix intermittent f32 attention tuning verification false-fail in Tune rocMLIR

mlir/utils/performance/tests/test_tuningRunner.py

@@ -32,7 +32,7 @@
     ConfigState, TuningState, TuningStateFile, TunedConfigsCache, Options, get_state_filepath,
     verify_mode_flags, format_error, get_config_class, get_git_commit_hash, NumaTopology, Operation,
     NumaNodeLock, resolve_verify_mode, canonicalize_test_vector, DebugFileWriter, TuningResult,
-    tune_config)
+    attention_cpu_verify_flags, ATTENTION_F32_ABSDIFF_THRESHOLD, tune_config)
 from perfRunner import (  # noqa: E402
     GemmConfiguration, ConvConfiguration, AttentionConfiguration, ConvGemmConfiguration,
     GemmGemmConfiguration, PerfConfiguration, canonicalize_config)
@@ -94,6 +94,33 @@ def test_invalid_raises(self):
             verify_mode_flags("invalid")
 
 
+class TestAttentionCpuVerifyFlags:
+    """Tests for attention_cpu_verify_flags (f32 attention allclose-style relDiff gate)."""
+
+    @staticmethod
+    def _cfg(cls, dtype):
+        # Bypass the heavy __init__ (arch-db lookups); the helper only needs the type + datatype.
+        cfg = object.__new__(cls)
+        cfg.datatype = dtype
+        return cfg
+
+    def test_f32_attention_cpu_gets_absdiff_gate(self):
+        flags = attention_cpu_verify_flags(self._cfg(AttentionConfiguration, "f32"), "cpu")
+        assert flags == ["-absDiff_threshold", ATTENTION_F32_ABSDIFF_THRESHOLD]
+
+    def test_non_f32_attention_no_gate(self):
+        # f16/bf16 disable relDiff in rocmlir-gen and i8 uses integer verification.
+        for dt in ("f16", "bf16", "i8"):
+            assert attention_cpu_verify_flags(self._cfg(AttentionConfiguration, dt), "cpu") == []
+
+    def test_non_attention_op_no_gate(self):
+        assert attention_cpu_verify_flags(self._cfg(GemmConfiguration, "f32"), "cpu") == []
+
+    def test_non_cpu_mode_no_gate(self):
+        for mode in ("gpu", "none"):
+            assert attention_cpu_verify_flags(self._cfg(AttentionConfiguration, "f32"), mode) == []
+
+
 class TestFormatError:
     """Tests for format_error."""
 

mlir/utils/performance/tuningRunner.py

@@ -1212,6 +1212,28 @@ def verify_mode_flags(verify_mode: str) -> str:
     raise ValueError(f"Unknown verification mode: {verify_mode}")
 
 
+# f32 attention CPU-verification tolerance.
+#
+# The GPU attention kernel runs a flash / online-softmax reduction whose accumulation order
+# differs from the sequential CPU reference. In f32 this diverges by up to ~1e-2 on a small
+# fraction of output elements while RMS and average stay ~1e-3 or better, so the result is
+# numerically sound but trips the strict relDiff_threshold. Gate relDiff on an absolute
+# tolerance (numpy/torch allclose style, via -absDiff_threshold) so this benign accumulation
+# noise does not false-fail tuning; RMS and absDiff still catch real regressions. rocmlir-gen
+# already disables relDiff for f16/bf16 and i8 uses integer verification, so only f32 needs
+# this. Same mechanism used by parameterSweeps.py and mlir/test/e2e/PrAttentionF32.toml.
+ATTENTION_F32_ABSDIFF_THRESHOLD = "5e-2"
+
+
+def attention_cpu_verify_flags(config: PerfConfiguration, verify_mode: str) -> List[str]:
+    """Extra rocmlir-gen flags for f32 attention CPU verification (allclose-style relDiff gate)."""
+    if verify_mode != "cpu":
+        return []
+    if isinstance(config, AttentionConfiguration) and getattr(config, "datatype", "") == "f32":
+        return ["-absDiff_threshold", ATTENTION_F32_ABSDIFF_THRESHOLD]
+    return []
+
+
 def kill_process(proc: Optional[subprocess.Popen]) -> None:
     """Terminate a subprocess and wait for cleanup."""
     if proc is None:
@@ -1292,8 +1314,14 @@ def verify_perfconfig(perfconfig: str, config: PerfConfiguration, paths: Paths,
 
     command_line_options = config.generate_mlir_driver_commandline(options.rocmlir_gen_flags,
                                                                    kernel_repeats=MLIR_N_REPEATS)
-    rocmlir_gen_command = [paths.mlir_paths.rocmlir_gen_path, '-print-verify-results=summary'
-                          ] + verify_mode_flags(verify_mode).split() + command_line_options.split()
+    # Append op/dtype-specific verification tolerances unless the user already set them explicitly
+    # (user --rocmlir-gen-flags live in command_line_options and must win).
+    extra_verify_flags = attention_cpu_verify_flags(config, verify_mode)
+    if extra_verify_flags and '-absDiff_threshold' in command_line_options:
+        extra_verify_flags = []
+    rocmlir_gen_command = ([paths.mlir_paths.rocmlir_gen_path, '-print-verify-results=summary'] +
+                           verify_mode_flags(verify_mode).split() + extra_verify_flags +
+                           command_line_options.split())
 
     rocmlir_driver_command = [paths.mlir_paths.rocmlir_driver_path, '-c']