[llvm] [AArch64] Lower masked.expandload intrinsic using SVE2p2/SME2p2 EXPAND (PR #190999)

[Kerry McLaughlin via llvm-commits]

================
@@ -0,0 +1,281 @@
+; NOTE: Assertions have been autogenerated by utils/update_analyze_test_checks.py
+; RUN: opt < %s -passes="print<cost-model>" -cost-kind=all 2>&1 -disable-output -mtriple=aarch64-linux-gnu -mattr=sve -mattr=+sve2p2 | FileCheck %s --check-prefix=SVE2p2-SME2p2-NON-STREAMING
+; RUN: opt < %s -passes="print<cost-model>" -cost-kind=all 2>&1 -disable-output -mtriple=aarch64-linux-gnu -mattr=sve -mattr=+sme2p2 | FileCheck %s --check-prefix=SVE2p2-SME2p2-NON-STREAMING
+; RUN: opt < %s -passes="print<cost-model>" -cost-kind=all 2>&1 -disable-output -mtriple=aarch64-linux-gnu -mattr=sve -mattr=+sme2p2 -force-streaming | FileCheck %s --check-prefix=SVE2p2-SME2p2-STREAMING
+; RUN: opt < %s -passes="print<cost-model>" -cost-kind=all 2>&1 -disable-output -mtriple=aarch64-linux-gnu -mattr=sve -mattr=+sve2p2 -mattr=+sme-fa64 -force-streaming | FileCheck %s --check-prefix=SVE2p2-SME2p2
+; RUN: opt < %s -passes="print<cost-model>" -cost-kind=all 2>&1 -disable-output -mtriple=aarch64-linux-gnu -mattr=sve -mattr=sme -mattr=+sve2p2 -force-streaming | FileCheck %s --check-prefix=SVE-ONLY
+; RUN: opt < %s -passes="print<cost-model>" -cost-kind=all 2>&1 -disable-output -mtriple=aarch64-linux-gnu -mattr=sve -mattr=+sve2p2 -aarch64-sve-vector-bits-min=256 | FileCheck %s --check-prefix=SVE2p2-SME2p2-SVE256
----------------
kmclaughlin-arm wrote:

This is testing the cost when SVE is preferred for fixed-length vectors (Neon is preferred when the minimum SVE vector size is < 256 bits, see `useSVEForFixedLengthVectors()`).

https://github.com/llvm/llvm-project/pull/190999