[llvm] [AArch64][SDAG] Enable +sme2p2/+sve2p2 lowering for compressstore (PR #218624)

[Benjamin Maxwell via llvm-commits]

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@@ -95,21 +95,21 @@ define void @fixed() {
 ; SVE2p2-SME2p2-SVE256-NEXT:  Cost Model: Found costs of Invalid for: call void @llvm.masked.compressstore.v2i8.p0(<2 x i8> poison, ptr poison, <2 x i1> poison)
 ; SVE2p2-SME2p2-SVE256-NEXT:  Cost Model: Found costs of Invalid for: call void @llvm.masked.compressstore.v4i8.p0(<4 x i8> poison, ptr poison, <4 x i1> poison)
 ; SVE2p2-SME2p2-SVE256-NEXT:  Cost Model: Found costs of Invalid for: call void @llvm.masked.compressstore.v8i8.p0(<8 x i8> poison, ptr poison, <8 x i1> poison)
-; SVE2p2-SME2p2-SVE256-NEXT:  Cost Model: Found costs of Invalid for: call void @llvm.masked.compressstore.v16i8.p0(<16 x i8> poison, ptr poison, <16 x i1> poison)
+; SVE2p2-SME2p2-SVE256-NEXT:  Cost Model: Found costs of 2 for: call void @llvm.masked.compressstore.v16i8.p0(<16 x i8> poison, ptr poison, <16 x i1> poison)
 ; SVE2p2-SME2p2-SVE256-NEXT:  Cost Model: Found costs of Invalid for: call void @llvm.masked.compressstore.v2i16.p0(<2 x i16> poison, ptr poison, <2 x i1> poison)
 ; SVE2p2-SME2p2-SVE256-NEXT:  Cost Model: Found costs of Invalid for: call void @llvm.masked.compressstore.v4i16.p0(<4 x i16> poison, ptr poison, <4 x i1> poison)
-; SVE2p2-SME2p2-SVE256-NEXT:  Cost Model: Found costs of Invalid for: call void @llvm.masked.compressstore.v8i16.p0(<8 x i16> poison, ptr poison, <8 x i1> poison)
+; SVE2p2-SME2p2-SVE256-NEXT:  Cost Model: Found costs of 2 for: call void @llvm.masked.compressstore.v8i16.p0(<8 x i16> poison, ptr poison, <8 x i1> poison)
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MacDue wrote:

Can you check the codegen for some fixed-length cases now that they're legal too?

https://github.com/llvm/llvm-project/pull/218624