[DA] add testcase

Make sure the testcase for this bug continues to work:
#31196

Author: sebpop

llvm/test/Analysis/DependenceAnalysis/PR31848.ll

@@ -0,0 +1,74 @@
+; NOTE: Assertions have been autogenerated by utils/update_analyze_test_checks.py UTC_ARGS: --version 5
+; RUN: opt < %s -disable-output "-passes=print<da>" -aa-pipeline=basic-aa 2>&1 \
+; RUN: | FileCheck %s
+
+; DependenceAnalysis used to run into a heap buffer overflow on this testcase.
+; See https://github.com/llvm/llvm-project/issues/31196 for details.
+
+define void @barney(ptr nocapture %arg, i32 %arg1) {
+; CHECK-LABEL: 'barney'
+; CHECK-NEXT:  Src: store i32 7, ptr %getelementptr, align 4 --> Dst: store i32 7, ptr %getelementptr, align 4
+; CHECK-NEXT:    da analyze - output [* * * *]!
+;
+bb:
+  %icmp = icmp sgt i32 %arg1, 0
+  br i1 %icmp, label %bb2, label %bb31
+
+bb2:                                              ; preds = %bb28, %bb
+  %phi = phi i32 [ %add29, %bb28 ], [ 0, %bb ]
+  br label %bb3
+
+bb3:                                              ; preds = %bb25, %bb2
+  %phi4 = phi i32 [ %add26, %bb25 ], [ 0, %bb2 ]
+  br label %bb5
+
+bb5:                                              ; preds = %bb22, %bb3
+  %phi6 = phi i32 [ -1, %bb3 ], [ %add23, %bb22 ]
+  %add7 = add nsw i32 %phi6, %phi4
+  br label %bb8
+
+bb8:                                              ; preds = %bb19, %bb5
+  %phi9 = phi i32 [ -1, %bb5 ], [ %add20, %bb19 ]
+  %add10 = add nsw i32 %phi9, %phi
+  br label %bb11
+
+bb11:                                             ; preds = %bb11, %bb8
+  %phi12 = phi i32 [ %add7, %bb8 ], [ %add14, %bb11 ]
+  %icmp13 = icmp slt i32 %phi12, 0
+  %add14 = add nsw i32 %phi12, %arg1
+  br i1 %icmp13, label %bb11, label %bb15
+
+bb15:                                             ; preds = %bb15, %bb11
+  %phi16 = phi i32 [ %add18, %bb15 ], [ %add10, %bb11 ]
+  %icmp17 = icmp slt i32 %phi16, 0
+  %add18 = add nsw i32 %phi16, %arg1
+  br i1 %icmp17, label %bb15, label %bb19
+
+bb19:                                             ; preds = %bb15
+  %mul = mul nsw i32 %phi16, %arg1
+  %add = add nsw i32 %mul, %phi12
+  %sext = sext i32 %add to i64
+  %getelementptr = getelementptr inbounds i32, ptr %arg, i64 %sext
+  store i32 7, ptr %getelementptr, align 4
+  %add20 = add nsw i32 %phi9, 1
+  %icmp21 = icmp eq i32 %add20, 2
+  br i1 %icmp21, label %bb22, label %bb8
+
+bb22:                                             ; preds = %bb19
+  %add23 = add nsw i32 %phi6, 1
+  %icmp24 = icmp eq i32 %add23, 2
+  br i1 %icmp24, label %bb25, label %bb5
+
+bb25:                                             ; preds = %bb22
+  %add26 = add nuw nsw i32 %phi4, 1
+  %icmp27 = icmp eq i32 %add26, %arg1
+  br i1 %icmp27, label %bb28, label %bb3
+
+bb28:                                             ; preds = %bb25
+  %add29 = add nuw nsw i32 %phi, 1
+  %icmp30 = icmp eq i32 %add29, %arg1
+  br i1 %icmp30, label %bb31, label %bb2
+
+bb31:                                             ; preds = %bb28, %bb
+  ret void
+}