[llvm] [Matrix] Add tests identifying GVN and DSE opportunities for matrix store / load intrinsics (PR #163573)

[Florian Hahn via llvm-commits]

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@@ -0,0 +1,198 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 6
+; RUN: opt -passes=dse -S %s | FileCheck %s
+
+define void @live_non_matrix_store(ptr noalias %src, ptr noalias %dst) {
+; CHECK-LABEL: define void @live_non_matrix_store(
+; CHECK-SAME: ptr noalias [[SRC:%.*]], ptr noalias [[DST:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    [[DST_OFFSET:%.*]] = getelementptr inbounds double, ptr [[SRC]], i32 12
+; CHECK-NEXT:    store double 4.200000e+01, ptr [[DST]], align 8
+; CHECK-NEXT:    [[L:%.*]] = call <8 x double> @llvm.matrix.column.major.load.v8f64.i32(ptr [[SRC]], i32 4, i1 false, i32 4, i32 2)
+; CHECK-NEXT:    call void @llvm.matrix.column.major.store.v8f64.i32(<8 x double> [[L]], ptr [[DST]], i32 4, i1 false, i32 4, i32 2)
+; CHECK-NEXT:    ret void
+;
+entry:
+  %dst.offset = getelementptr inbounds double, ptr %src, i32 12
+  store double 42.0, ptr %dst
+  %l = call <8 x double> @llvm.matrix.column.major.load.v8f64.i32(ptr %src, i32 4, i1 false, i32 4, i32 2)
+  call void @llvm.matrix.column.major.store(<8 x double> %l, ptr %dst, i32 4, i1 false, i32 4, i32 2)
+  ret void
+}
+
+define void @dead_unstrided_store_non_matrix_load(ptr noalias %src, ptr noalias %dst) {
+; CHECK-LABEL: define void @dead_unstrided_store_non_matrix_load(
+; CHECK-SAME: ptr noalias [[SRC:%.*]], ptr noalias [[DST:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    call void @llvm.matrix.column.major.store.v8f64.i32(<8 x double> zeroinitializer, ptr [[DST]], i32 4, i1 false, i32 4, i32 2)
+; CHECK-NEXT:    [[L:%.*]] = load double, ptr [[SRC]], align 8
+; CHECK-NEXT:    ret void
+;
+entry:
+  call void @llvm.matrix.column.major.store(<8 x double> zeroinitializer, ptr %dst, i32 4, i1 false, i32 4, i32 2)
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fhahn wrote:

would be good to store different values  here and below, to make sure we eliminate due to the later store overwriting the earlier one, not due to both storing the same value

https://github.com/llvm/llvm-project/pull/163573