[Mlir-commits] [mlir] [mlir][ArmSME] Enable native ArmSME integration testing on Darwin (PR #215296)

[Andrzej Warzyński]

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@@ -4,6 +4,20 @@ if not config.mlir_include_integration_tests:
     config.unsupported = True
 
 
+def configure_arm_sme_mattr():
+    # `+sve` is not required: FeatureSME does not imply FeatureSVE (see
+    # AArch64Features.td), and none of the tests using this substitution
+    # need base (non-streaming) SVE codegen. On Apple Silicon, which does
+    # not expose base SVE at EL0, requesting `+sve` makes LLVM select plain
+    # SVE instructions (e.g., `cntd`) that are illegal outside streaming
+    # mode and trap -- see #204853. Omitting it avoids that trap and is
+    # sufficient on every platform.
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banach-space wrote:

This comment belongs in the summary ;-)

Essentially, it documents why `+sve` is removed from the list of flags, i.e. it documents a change introduced in this PR. That's something that you would include in a summary.

Also, this code is merely defining a list of attributes and it suffices to justify what is **added** rather then documenting what is **not added.** While `+sve` is a bit special in this context, why not cover e.g. `+neon` or some other attributes?

https://github.com/llvm/llvm-project/pull/215296