From aa89f08afad7ee0581c39638abd8ee0df9ba1c65 Mon Sep 17 00:00:00 2001
From: Nikita Popov <npopov@redhat.com>
Date: Mon, 17 Oct 2022 12:31:02 +0200
Subject: [PATCH] [BasicAA] Add tests for constant memory with loop phi (NFC)

---
 llvm/test/Analysis/BasicAA/constant-memory.ll   | 33 +++++++++++++++++++++++
 llvm/test/Transforms/FunctionAttrs/readattrs.ll | 35 +++++++++++++++++++++++++
 2 files changed, 68 insertions(+)
 create mode 100644 llvm/test/Analysis/BasicAA/constant-memory.ll

diff --git a/llvm/test/Analysis/BasicAA/constant-memory.ll b/llvm/test/Analysis/BasicAA/constant-memory.ll
new file mode 100644
index 0000000..a14a1ea
--- /dev/null
+++ b/llvm/test/Analysis/BasicAA/constant-memory.ll
@@ -0,0 +1,33 @@
+; RUN: opt < %s -passes=aa-eval -print-all-alias-modref-info 2>&1 | FileCheck %s
+
+@c = constant [8 x i32] zeroinitializer
+
+declare void @dummy()
+
+; FIXME: This could be NoModRef
+; CHECK-LABEL: Function: basic
+; CHECK: Just Ref: Ptr: i32* @c	<->  call void @dummy()
+define void @basic(ptr %p) {
+  call void @dummy()
+  load i32, ptr @c
+  ret void
+}
+
+; FIXME: This should be at least only Ref.
+; CHECK-LABEL: Function: recphi
+; Both ModRef: Ptr: i32* %p	<->  call void @dummy()
+define void @recphi() {
+entry:
+  br label %loop
+
+loop:
+  %p = phi ptr [ @c, %entry ], [ %p.next, %loop ]
+  call void @dummy()
+  load i32, ptr %p
+  %p.next = getelementptr i32, ptr %p, i64 1
+  %c = icmp ne ptr %p.next, getelementptr (i32, ptr @c, i64 8)
+  br i1 %c, label %loop, label %exit
+
+exit:
+  ret void
+}
diff --git a/llvm/test/Transforms/FunctionAttrs/readattrs.ll b/llvm/test/Transforms/FunctionAttrs/readattrs.ll
index f1f1c4c..ba968ec 100644
--- a/llvm/test/Transforms/FunctionAttrs/readattrs.ll
+++ b/llvm/test/Transforms/FunctionAttrs/readattrs.ll
@@ -287,3 +287,38 @@ define void @fptr_test2c(ptr %p, ptr %f) {
   call void %f(ptr readonly %p) readonly
   ret void
 }
+
+define void @alloca_recphi() {
+; CHECK: Function Attrs: nofree norecurse nosync nounwind
+; CHECK-LABEL: define {{[^@]+}}@alloca_recphi
+; CHECK-SAME: () #[[ATTR14:[0-9]+]] {
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[A:%.*]] = alloca [8 x i32], align 4
+; CHECK-NEXT:    [[A_END:%.*]] = getelementptr i32, ptr [[A]], i64 8
+; CHECK-NEXT:    br label [[LOOP:%.*]]
+; CHECK:       loop:
+; CHECK-NEXT:    [[P:%.*]] = phi ptr [ [[A]], [[ENTRY:%.*]] ], [ [[P_NEXT:%.*]], [[LOOP]] ]
+; CHECK-NEXT:    store i32 0, ptr [[P]], align 4
+; CHECK-NEXT:    [[TMP0:%.*]] = load i32, ptr [[P]], align 4
+; CHECK-NEXT:    [[P_NEXT]] = getelementptr i32, ptr [[P]], i64 1
+; CHECK-NEXT:    [[C:%.*]] = icmp ne ptr [[P_NEXT]], [[A_END]]
+; CHECK-NEXT:    br i1 [[C]], label [[LOOP]], label [[EXIT:%.*]]
+; CHECK:       exit:
+; CHECK-NEXT:    ret void
+;
+entry:
+  %a = alloca [8 x i32]
+  %a.end = getelementptr i32, ptr %a, i64 8
+  br label %loop
+
+loop:
+  %p = phi ptr [ %a, %entry ], [ %p.next, %loop ]
+  store i32 0, ptr %p
+  load i32, ptr %p
+  %p.next = getelementptr i32, ptr %p, i64 1
+  %c = icmp ne ptr %p.next, %a.end
+  br i1 %c, label %loop, label %exit
+
+exit:
+  ret void
+}
-- 
2.7.4