[llvm] [LoadStoreVectorizer] Postprocess and merge equivalence classes (PR #114501)

[Matt Arsenault via llvm-commits]

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+; RUN: opt %s -mtriple=x86_64-unknown-linux-gnu -passes=load-store-vectorizer -mcpu=skx -S -o %t.out.ll
+; RUN: FileCheck -input-file=%t.out.ll %s
+
+; This test verifies that the vectorizer can handle an extended sequence of
+; getelementptr instructions and generate longer vectors. With special handling,
+; some elements can still be vectorized even if they require looking up the
+; common underlying object deeper than 6 levels from the original pointer.
+
+; The test below is the simplified version of actual performance oriented
+; workload; the offsets in getelementptr instructions are similar or same for
+; the test simplicity.
+
+define void @v1_v2_v4_v1_to_v8_levels_6_7_8_8(i32 %arg0, ptr align 16 %arg1) {
+; CHECK-LABEL: @v1_v2_v4_v1_to_v8_levels_6_7_8_8
+; CHECK: store <8 x half>
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arsenm wrote:

Use update_test_checks so we can see full context 

https://github.com/llvm/llvm-project/pull/114501