[BasicAA] Add tests for #76789 (NFC)

Author: nikic

llvm/test/Analysis/BasicAA/inttoptr_constexpr.ll

@@ -0,0 +1,49 @@
+; RUN: opt -passes=aa-eval -print-all-alias-modref-info -disable-output < %s 2>&1 | FileCheck %s
+
+; CHECK: NoAlias: i8* %a, i8* %gep
+define void @inttoptr_alloca() {
+  %a = alloca i8
+  %a.int = ptrtoint ptr %a to i64
+  %a.int.1 = add i64 %a.int, 1
+  %gep = getelementptr i8, ptr inttoptr (i64 -1 to ptr), i64 %a.int.1
+  %load = load i8, ptr %gep
+  store i8 1, ptr %a
+  ret void
+}
+
+; CHECK: NoAlias: i8* %a, i8* %gep
+define void @inttoptr_alloca_unknown_relation(i64 %offset) {
+  %a = alloca i8
+  %a.int = ptrtoint ptr %a to i64
+  %gep = getelementptr i8, ptr inttoptr (i64 -1 to ptr), i64 %offset
+  %load = load i8, ptr %gep
+  store i8 1, ptr %a
+  ret void
+}
+
+; CHECK: NoAlias: i8* %a, i8* %gep
+define void @inttoptr_alloca_noescape(i64 %offset) {
+  %a = alloca i8
+  %gep = getelementptr i8, ptr inttoptr (i64 -1 to ptr), i64 %offset
+  %load = load i8, ptr %gep
+  store i8 1, ptr %a
+  ret void
+}
+
+; CHECK: NoAlias: i8* %a, i8* %gep
+define void @inttoptr_noalias(ptr noalias %a) {
+  %a.int = ptrtoint ptr %a to i64
+  %a.int.1 = add i64 %a.int, 1
+  %gep = getelementptr i8, ptr inttoptr (i64 -1 to ptr), i64 %a.int.1
+  %load = load i8, ptr %gep
+  store i8 1, ptr %a
+  ret void
+}
+
+; CHECK: NoAlias: i8* %a, i8* %gep
+define void @inttoptr_noalias_noescape(ptr noalias %a, i64 %offset) {
+  %gep = getelementptr i8, ptr inttoptr (i64 -1 to ptr), i64 %offset
+  %load = load i8, ptr %gep
+  store i8 1, ptr %a
+  ret void
+}