[memoryssa] Exclude llvm.allow.{runtime,ubsan}.check()

[vitalybuka]

RFC: https://discourse.llvm.org/t/rfc-add-llvm-experimental-hot-intrinsic-or-llvm-hot/77641

[llvmbot]

@llvm/pr-subscribers-llvm-analysis

Author: Vitaly Buka (vitalybuka)

Changes

RFC: https://discourse.llvm.org/t/rfc-add-llvm-experimental-hot-intrinsic-or-llvm-hot/77641

---

Full diff: https://github.com/llvm/llvm-project/pull/86066.diff

2 Files Affected:

• (modified) llvm/lib/Analysis/MemorySSA.cpp (+4)
• (added) llvm/test/Analysis/MemorySSA/allow-check.ll (+29)

diff --git a/llvm/lib/Analysis/MemorySSA.cpp b/llvm/lib/Analysis/MemorySSA.cpp
index 82a6c470650cc9..49450d85d74225 100644
--- a/llvm/lib/Analysis/MemorySSA.cpp
+++ b/llvm/lib/Analysis/MemorySSA.cpp
@@ -292,6 +292,8 @@ instructionClobbersQuery(const MemoryDef *MD, const MemoryLocation &UseLoc,
     // clobbers where they don't really exist at all. Please see D43269 for
     // context.
     switch (II->getIntrinsicID()) {
+    case Intrinsic::allow_runtime_check:
+    case Intrinsic::allow_ubsan_check:
     case Intrinsic::invariant_start:
     case Intrinsic::invariant_end:
     case Intrinsic::assume:
@@ -1725,6 +1727,8 @@ MemoryUseOrDef *MemorySSA::createNewAccess(Instruction *I,
     switch (II->getIntrinsicID()) {
     default:
       break;
+    case Intrinsic::allow_runtime_check:
+    case Intrinsic::allow_ubsan_check:
     case Intrinsic::assume:
     case Intrinsic::experimental_noalias_scope_decl:
     case Intrinsic::pseudoprobe:
diff --git a/llvm/test/Analysis/MemorySSA/allow-check.ll b/llvm/test/Analysis/MemorySSA/allow-check.ll
new file mode 100644
index 00000000000000..dcdad001ca6f5b
--- /dev/null
+++ b/llvm/test/Analysis/MemorySSA/allow-check.ll
@@ -0,0 +1,29 @@
+; RUN: opt -aa-pipeline=basic-aa -passes='print<memoryssa>,verify<memoryssa>' -disable-output < %s 2>&1 | FileCheck %s --implicit-check-not=MemoryDef
+;
+; Ensures that allow.*.check are treated as not reading or writing memory.
+
+target triple = "aarch64-linux"
+
+define i1 @test_runtime(ptr %a) local_unnamed_addr {
+entry:
+; CHECK: 1 = MemoryDef(liveOnEntry)
+  store i32 4, ptr %a, align 4
+  %allow = call i1 @llvm.allow.runtime.check(metadata !"test_check")
+  %0 = load i32, ptr %a, align 4
+; CHECK: MemoryUse(1)
+  ret i1 %allow
+}
+
+declare i1 @llvm.allow.runtime.check(metadata)
+
+define i1 @test_ubsan(ptr %a) local_unnamed_addr {
+entry:
+; CHECK: 1 = MemoryDef(liveOnEntry)
+  store i32 4, ptr %a, align 4
+  %allow = call i1 @llvm.allow.ubsan.check(i8 7)
+  %0 = load i32, ptr %a, align 4
+; CHECK: MemoryUse(1)
+  ret i1 %allow
+}
+
+declare i1 @llvm.allow.ubsan.check(i8)

[alinas]

lgtm