[llvm] r289872 - [Verifier] Allow TBAA metadata on atomicrmw and atomiccmpxchg

[Sanjoy Das via llvm-commits]

Author: sanjoy
Date: Thu Dec 15 15:23:44 2016
New Revision: 289872

URL: http://llvm.org/viewvc/llvm-project?rev=289872&view=rev
Log:
[Verifier] Allow TBAA metadata on atomicrmw and atomiccmpxchg

This used to be allowed before r289402 by default (before r289402 you
could have TBAA metadata on any instruction), and while I'm not sure
that it helps, it does sound reasonable enough to not fail the verifier
and we have out-of-tree users who use this.

Added:
    llvm/trunk/test/Verifier/tbaa-allowed.ll
Modified:
    llvm/trunk/lib/IR/Verifier.cpp

Modified: llvm/trunk/lib/IR/Verifier.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/IR/Verifier.cpp?rev=289872&r1=289871&r2=289872&view=diff
==============================================================================
--- llvm/trunk/lib/IR/Verifier.cpp (original)
+++ llvm/trunk/lib/IR/Verifier.cpp Thu Dec 15 15:23:44 2016
@@ -4062,7 +4062,8 @@ void Verifier::visitInstruction(Instruct
 
   if (MDNode *TBAA = I.getMetadata(LLVMContext::MD_tbaa)) {
     Assert(isa<LoadInst>(I) || isa<StoreInst>(I) || isa<CallInst>(I) ||
-               isa<VAArgInst>(I),
+               isa<VAArgInst>(I) || isa<AtomicRMWInst>(I) ||
+               isa<AtomicCmpXchgInst>(I),
            "TBAA is only for loads, stores and calls!", &I);
     visitTBAAMetadata(I, TBAA);
   }

Added: llvm/trunk/test/Verifier/tbaa-allowed.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Verifier/tbaa-allowed.ll?rev=289872&view=auto
==============================================================================
--- llvm/trunk/test/Verifier/tbaa-allowed.ll (added)
+++ llvm/trunk/test/Verifier/tbaa-allowed.ll Thu Dec 15 15:23:44 2016
@@ -0,0 +1,22 @@
+; RUN: opt -S < %s
+
+; This file contains TBAA metadata that is okay and should pass the verifier.
+
+declare void @callee()
+declare void @llvm.va_start(i8*) nounwind
+
+define void @f_0(i8* %ptr, ...) {
+  %args = alloca i8, align 8
+  call void @llvm.va_start(i8* %args)
+
+  %old = atomicrmw add i8* %ptr, i8 0 seq_cst,          !tbaa !{!1, !1, i64 0}
+  %pair = cmpxchg i8* %ptr, i8 0, i8 1 acquire acquire, !tbaa !{!1, !1, i64 0}
+  %ld = load i8, i8* %ptr,                              !tbaa !{!1, !1, i64 0}
+  store i8 1, i8* %ptr,                                 !tbaa !{!1, !1, i64 0}
+  call void @callee(),                                  !tbaa !{!1, !1, i64 0}
+  %argval = va_arg i8* %args, i8,                       !tbaa !{!1, !1, i64 0}
+  ret void
+}
+
+!0 = !{!"root"}
+!1 = !{!"scalar-a", !0}