[llvm] [DA] Add test for the Weak Crossing SIV test misses dependency (NFC) (PR #186355)

[Ryotaro Kasuga via llvm-commits]

https://github.com/kasuga-fj created https://github.com/llvm/llvm-project/pull/186355

Add a test case where the value of `Delta` in the Weak Crossing SIV test becomes the signed minimum, causing the test to miss the dependency.

>From 68469f120140ddbb4e07f12d0028ef8df47bd0d5 Mon Sep 17 00:00:00 2001
From: Ryotaro Kasuga <kasuga.ryotaro at fujitsu.com>
Date: Fri, 13 Mar 2026 09:54:31 +0000
Subject: [PATCH] [DA] Add test for the Weak Crossing SIV test misses
 dependency (NFC)

---
 .../weak-crossing-siv-delta-signed-min.ll     | 64 +++++++++++++++++++
 1 file changed, 64 insertions(+)
 create mode 100644 llvm/test/Analysis/DependenceAnalysis/weak-crossing-siv-delta-signed-min.ll

diff --git a/llvm/test/Analysis/DependenceAnalysis/weak-crossing-siv-delta-signed-min.ll b/llvm/test/Analysis/DependenceAnalysis/weak-crossing-siv-delta-signed-min.ll
new file mode 100644
index 0000000000000..d089b8fd5dd6b
--- /dev/null
+++ b/llvm/test/Analysis/DependenceAnalysis/weak-crossing-siv-delta-signed-min.ll
@@ -0,0 +1,64 @@
+; NOTE: Assertions have been autogenerated by utils/update_analyze_test_checks.py UTC_ARGS: --version 6
+; RUN: opt < %s -disable-output "-passes=print<da>" 2>&1 \
+; RUN:     | FileCheck %s --check-prefixes=CHECK,CHECK-ALL
+; RUN: opt < %s -disable-output "-passes=print<da>" -da-enable-dependence-test=weak-crossing-siv 2>&1 \
+; RUN:     | FileCheck %s --check-prefixes=CHECK,CHECK-WEAK-CROSSING-SIV
+
+; c = (1 << 62);
+; for (i = 0; i < c + 10; i++) {
+;   if (c - 1 <=u i && i <=u c + 1) {
+;     A[i - c] = 0;
+;     A[-i + c] = 1;
+;   }
+; }
+;
+; FIXME: There is a dependency between the two stores in all directions.
+;
+define void @weak_crossing_siv_delta_signed_min(ptr %A) {
+; CHECK-ALL-LABEL: 'weak_crossing_siv_delta_signed_min'
+; CHECK-ALL-NEXT:  Src: store i8 0, ptr %gep.0, align 1 --> Dst: store i8 0, ptr %gep.0, align 1
+; CHECK-ALL-NEXT:    da analyze - none!
+; CHECK-ALL-NEXT:  Src: store i8 0, ptr %gep.0, align 1 --> Dst: store i8 1, ptr %gep.1, align 1
+; CHECK-ALL-NEXT:    da analyze - none!
+; CHECK-ALL-NEXT:  Src: store i8 1, ptr %gep.1, align 1 --> Dst: store i8 1, ptr %gep.1, align 1
+; CHECK-ALL-NEXT:    da analyze - none!
+;
+; CHECK-WEAK-CROSSING-SIV-LABEL: 'weak_crossing_siv_delta_signed_min'
+; CHECK-WEAK-CROSSING-SIV-NEXT:  Src: store i8 0, ptr %gep.0, align 1 --> Dst: store i8 0, ptr %gep.0, align 1
+; CHECK-WEAK-CROSSING-SIV-NEXT:    da analyze - output [*]!
+; CHECK-WEAK-CROSSING-SIV-NEXT:  Src: store i8 0, ptr %gep.0, align 1 --> Dst: store i8 1, ptr %gep.1, align 1
+; CHECK-WEAK-CROSSING-SIV-NEXT:    da analyze - none!
+; CHECK-WEAK-CROSSING-SIV-NEXT:  Src: store i8 1, ptr %gep.1, align 1 --> Dst: store i8 1, ptr %gep.1, align 1
+; CHECK-WEAK-CROSSING-SIV-NEXT:    da analyze - output [*]!
+;
+entry:
+  br label %loop.header
+
+loop.header:
+  %i = phi i64 [ 0, %entry ], [ %i.inc, %loop.latch ]
+  %offset.0 = phi i64 [ -4611686018427387904, %entry ], [ %offset.0.next, %loop.latch ]
+  %offset.1 = phi i64 [ 4611686018427387904, %entry ], [ %offset.1.next, %loop.latch ]
+  %cond.0 = icmp ule i64 4611686018427387903, %i
+  %cond.1 = icmp ule i64 %i, 4611686018427387905
+  %cond = and i1 %cond.0, %cond.1
+  br i1 %cond, label %if.then, label %loop.latch
+
+if.then:
+  %gep.0 = getelementptr i8, ptr %A, i64 %offset.0
+  store i8 0, ptr %gep.0
+  %gep.1 = getelementptr i8, ptr %A, i64 %offset.1
+  store i8 1, ptr %gep.1
+  br label %loop.latch
+
+loop.latch:
+  %i.inc = add i64 %i, 1
+  %offset.0.next = add i64 %offset.0, 1
+  %offset.1.next = add i64 %offset.1, -1
+  %ec = icmp eq i64 %i.inc, 4611686018427387914
+  br i1 %ec, label %exit, label %loop.header
+
+exit:
+  ret void
+}
+;; NOTE: These prefixes are unused and the list is autogenerated. Do not add tests below this line:
+; CHECK: {{.*}}