[Verifier] Only allow invariant.group metadata on stores and loads

As specified by https://llvm.org/docs/LangRef.html#invariant-group-metadata.

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D109182

Author: aeubanks

llvm/lib/IR/Verifier.cpp

@@ -4470,6 +4470,11 @@ void Verifier::visitInstruction(Instruction &I) {
     visitRangeMetadata(I, Range, I.getType());
   }
 
+  if (I.hasMetadata(LLVMContext::MD_invariant_group)) {
+    Assert(isa<LoadInst>(I) || isa<StoreInst>(I),
+           "invariant.group metadata is only for loads and stores", &I);
+  }
+
   if (I.getMetadata(LLVMContext::MD_nonnull)) {
     Assert(I.getType()->isPointerTy(), "nonnull applies only to pointer types",
            &I);

llvm/test/Verifier/invariant.group.ll

@@ -0,0 +1,14 @@
+; RUN: not opt -passes=verify -disable-output < %s 2>&1 | FileCheck %s
+
+; CHECK: invariant.group metadata is only for loads and stores
+; CHECK-NEXT: alloca
+; CHECK-NEXT: invariant.group metadata is only for loads and stores
+; CHECK-NEXT: ret void
+define void @f() {
+  %a = alloca i32, !invariant.group !0
+  %b = load i32, i32* %a, !invariant.group !0
+  store i32 43, i32* %a, !invariant.group !0
+  ret void, !invariant.group !0
+}
+
+!0 = !{}