[llvm] [MemoryLocation] Teach MemoryLocation about llvm.experimental.memset.pattern (PR #120421)

[Philip Reames via llvm-commits]

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@@ -66,6 +66,71 @@ define void @memset_and_store_2(ptr %ptr, i64 %len) {
   ret void
 }
 
+define void @memset_pattern_equal_size_values(ptr %ptr, i64 %len) {
+; CHECK-LABEL: @memset_pattern_equal_size_values(
+; CHECK-NEXT:    call void @llvm.experimental.memset.pattern.p0.i8.i64(ptr align 1 [[PTR:%.*]], i8 0, i64 [[LEN:%.*]], i1 false)
+; CHECK-NEXT:    ret void
+;
+  call void @llvm.experimental.memset.pattern.p0.i8.i64(ptr align 1 %ptr, i8 0, i64 %len, i1 false)
+  call void @llvm.experimental.memset.pattern.p0.i8.i64(ptr align 1 %ptr, i8 0, i64 %len, i1 false)
+  ret void
+}
+
+define void @memset_pattern_different_size_values_1(ptr %ptr, i64 %len.1, i64 %len.2) {
+; CHECK-LABEL: @memset_pattern_different_size_values_1(
+; CHECK-NEXT:    call void @llvm.experimental.memset.pattern.p0.i8.i64(ptr align 1 [[PTR:%.*]], i8 0, i64 [[LEN_1:%.*]], i1 false)
+; CHECK-NEXT:    call void @llvm.experimental.memset.pattern.p0.i8.i64(ptr align 1 [[PTR]], i8 0, i64 [[LEN_2:%.*]], i1 false)
+; CHECK-NEXT:    ret void
+;
+  call void @llvm.experimental.memset.pattern.p0.i8.i64(ptr align 1 %ptr, i8 0, i64 %len.1, i1 false)
+  call void @llvm.experimental.memset.pattern.p0.i8.i64(ptr align 1 %ptr, i8 0, i64 %len.2, i1 false)
+  ret void
+}
+
+define void @memset_pattern_different_size_values_2(ptr %ptr, i64 %len) {
+; CHECK-LABEL: @memset_pattern_different_size_values_2(
+; CHECK-NEXT:    call void @llvm.experimental.memset.pattern.p0.i8.i64(ptr align 1 [[PTR:%.*]], i8 0, i64 [[LEN:%.*]], i1 false)
+; CHECK-NEXT:    call void @llvm.experimental.memset.pattern.p0.i8.i64(ptr align 1 [[PTR]], i8 0, i64 100, i1 false)
+; CHECK-NEXT:    ret void
+;
+  call void @llvm.experimental.memset.pattern.p0.i8.i64(ptr align 1 %ptr, i8 0, i64 %len, i1 false)
+  call void @llvm.experimental.memset.pattern.p0.i8.i64(ptr align 1 %ptr, i8 0, i64 100, i1 false)
+  ret void
+}
+
+define void @memset_pattern_different_size_values_3(ptr %ptr, i64 %len) {
+; CHECK-LABEL: @memset_pattern_different_size_values_3(
+; CHECK-NEXT:    call void @llvm.experimental.memset.pattern.p0.i8.i64(ptr align 1 [[PTR:%.*]], i8 0, i64 100, i1 false)
+; CHECK-NEXT:    call void @llvm.experimental.memset.pattern.p0.i8.i64(ptr align 1 [[PTR]], i8 0, i64 [[LEN:%.*]], i1 false)
+; CHECK-NEXT:    ret void
+;
+  call void @llvm.experimental.memset.pattern.p0.i8.i64(ptr align 1 %ptr, i8 0, i64 100, i1 false)
+  call void @llvm.experimental.memset.pattern.p0.i8.i64(ptr align 1 %ptr, i8 0, i64 %len, i1 false)
+  ret void
+}
+
+define void @memset_pattern_and_store_1(ptr %ptr, i64 %len) {
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preames wrote:

Can you add a positive test?  One which shows we *can* eliminate the store if the length is a constant?

https://github.com/llvm/llvm-project/pull/120421