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

[Florian Hahn via llvm-commits]

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@@ -0,0 +1,71 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 4
+; RUN: opt -passes=globalopt < %s -S | FileCheck %s
+
+ at a = internal unnamed_addr global i32 0, align 4
+ at b = internal unnamed_addr global [3 x ptr] zeroinitializer, align 16
+
+;; This test is extracted from the issue reported in #64680, with an
+;; additional memcpy and a memset. Ensure all stores and memintrinsics with
+;; destination @b are removed as @b is dead.
+define i32 @main() local_unnamed_addr {
+; CHECK-LABEL: define i32 @main() local_unnamed_addr {
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[E:%.*]] = alloca i32, align 4
+; CHECK-NEXT:    [[DOTPR:%.*]] = load i32, ptr @a, align 4
+; CHECK-NEXT:    [[CMP1:%.*]] = icmp slt i32 [[DOTPR]], 3
+; CHECK-NEXT:    br i1 [[CMP1]], label [[FOR_BODY:%.*]], label [[FOR_END:%.*]]
+; CHECK:       for.body:
+; CHECK-NEXT:    store i32 8, ptr [[E]], align 4
+; CHECK-NEXT:    call void @bar20_()
+; CHECK-NEXT:    [[TMP0:%.*]] = load i32, ptr [[E]], align 4
+; CHECK-NEXT:    [[TOBOOL_NOT:%.*]] = icmp eq i32 [[TMP0]], 0
+; CHECK-NEXT:    br i1 [[TOBOOL_NOT]], label [[IF_THEN:%.*]], label [[IF_END:%.*]]
+; CHECK:       if.then:
+; CHECK-NEXT:    call void @foo()
+; CHECK-NEXT:    br label [[IF_END]]
+; CHECK:       if.end:
+; CHECK-NEXT:    store ptr [[E]], ptr getelementptr inbounds ([3 x ptr], ptr @b, i64 0, i64 2), align 16
+; CHECK-NEXT:    [[TMP1:%.*]] = load i32, ptr @a, align 4
+; CHECK-NEXT:    [[INC:%.*]] = add nsw i32 [[TMP1]], 1
+; CHECK-NEXT:    store i32 [[INC]], ptr @a, align 4
+; CHECK-NEXT:    [[CMP:%.*]] = icmp slt i32 [[TMP1]], 2
+; CHECK-NEXT:    br i1 [[CMP]], label [[FOR_BODY]], label [[FOR_END]]
+; CHECK:       for.end:
+; CHECK-NEXT:    call void @llvm.memcpy.p0.p0.i64(ptr @b, ptr null, i64 8, i1 false)
+; CHECK-NEXT:    ret i32 0
+;
+entry:
+  %e = alloca i32, align 4
+  %.pr = load i32, ptr @a, align 4
+  %cmp1 = icmp slt i32 %.pr, 3
+  br i1 %cmp1, label %for.body, label %for.end
+
+for.body:                                         ; preds = %entry, %if.end
+  store i32 8, ptr %e, align 4
+  call void @bar20_()
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fhahn wrote:

nit: just `@bar`?

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