[llvm] [GlobalOpt] Precommit tests for PR84694 (PR #87443)

[Anshil Gandhi via llvm-commits]

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@@ -0,0 +1,42 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 4
+; RUN: opt -passes=globalopt < %s -S | FileCheck %s
+
+ at gv = internal unnamed_addr global [3 x ptr] zeroinitializer, align 16
+ at gv2 = internal unnamed_addr global i32 0, align 4
+
+;; This test includes a load from @gv. No stores
+;; or memintrinsics with destination @gv should be removed.
+define i32 @main_with_load_from_b() local_unnamed_addr {
+; CHECK-LABEL: define i32 @main_with_load_from_b() local_unnamed_addr {
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[E:%.*]] = alloca i32, align 4
+; CHECK-NEXT:    store ptr [[E]], ptr getelementptr inbounds ([3 x ptr], ptr @gv, i64 0, i64 2), align 16
+; CHECK-NEXT:    [[LOAD_B:%.*]] = load ptr, ptr getelementptr inbounds ([3 x ptr], ptr @gv, i64 0, i64 2), align 16
+; CHECK-NEXT:    call void @llvm.memcpy.p0.p0.i64(ptr @gv, ptr null, i64 8, i1 false)
+; CHECK-NEXT:    ret i32 0
+;
+entry:
+  %e = alloca i32, align 4
+  store ptr %e, ptr getelementptr inbounds ([3 x ptr], ptr @gv, i64 0, i64 2), align 16
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gandhi56 wrote:

It is actually, it is one of the fallbacks I fix in the algorithm in my patch.

https://github.com/llvm/llvm-project/pull/87443