[PATCH] D136361: [AArch64][SME] Disable GlobalISel/FastISel for SME functions.

[Sander de Smalen via Phabricator via llvm-commits]

sdesmalen added inline comments.


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Comment at: llvm/lib/Target/AArch64/AArch64FastISel.cpp:5121
+  SMEAttrs CallerAttrs(*FuncInfo.Fn);
+  if (!CallerAttrs.hasStreamingInterface() && CallerAttrs.hasStreamingBody())
+    return nullptr;
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david-arm wrote:
> Should we also check for arm_new_za here too?
I don't believe so, because the work for arm_new_za functions is done by the SMEABI pass at the LLVM IR level.


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Comment at: llvm/lib/Target/AArch64/AArch64ISelLowering.cpp:21892
+                                     /*BodyOverridesInterface=*/false) ||
+        CallerAttrs.requiresLazySave(CalleeAttrs))
+      return true;
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david-arm wrote:
> I guess this covers most cases, except I'm not sure what happens at -O0 if the caller is in a shared-ZA function and contains something like a 128-bit FP IR that ends up getting lowered to a library call to a private-ZA function. Maybe this just works and we just a need a test for it?
I've added two tests for this scenario, which seem to exhibit the desired behaviour.


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  https://reviews.llvm.org/D136361/new/

https://reviews.llvm.org/D136361