[llvm] f00cd27 - [Verifier] Verify llvm.access.group metadata

[Nikita Popov via llvm-commits]

Author: Nikita Popov
Date: 2022-03-14T16:16:36+01:00
New Revision: f00cd27646c08ee2ab68a561c3db34dd8f259951

URL: https://github.com/llvm/llvm-project/commit/f00cd27646c08ee2ab68a561c3db34dd8f259951
DIFF: https://github.com/llvm/llvm-project/commit/f00cd27646c08ee2ab68a561c3db34dd8f259951.diff

LOG: [Verifier] Verify llvm.access.group metadata

According to LangRef, an access scope must have zero operands and
be distinct. The access group may either be a single access scope
or a list of access scopes.

LoopInfo may assert if this is not the case.

Added: 
    llvm/test/Verifier/access_group.ll

Modified: 
    llvm/lib/IR/Verifier.cpp
    llvm/test/Transforms/SimplifyCFG/X86/combine-parallel-mem-md.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/IR/Verifier.cpp b/llvm/lib/IR/Verifier.cpp
index 66218ba6d1453..bc6f6757311f1 100644
--- a/llvm/lib/IR/Verifier.cpp
+++ b/llvm/lib/IR/Verifier.cpp
@@ -464,6 +464,7 @@ class Verifier : public InstVisitor<Verifier>, VerifierSupport {
   void visitAnnotationMetadata(MDNode *Annotation);
   void visitAliasScopeMetadata(const MDNode *MD);
   void visitAliasScopeListMetadata(const MDNode *MD);
+  void visitAccessGroupMetadata(const MDNode *MD);
 
   template <class Ty> bool isValidMetadataArray(const MDTuple &N);
 #define HANDLE_SPECIALIZED_MDNODE_LEAF(CLASS) void visit##CLASS(const CLASS &N);
@@ -4477,6 +4478,24 @@ void Verifier::visitAliasScopeListMetadata(const MDNode *MD) {
   }
 }
 
+void Verifier::visitAccessGroupMetadata(const MDNode *MD) {
+  auto IsValidAccessScope = [](const MDNode *MD) {
+    return MD->getNumOperands() == 0 && MD->isDistinct();
+  };
+
+  // It must be either an access scope itself...
+  if (IsValidAccessScope(MD))
+    return;
+
+  // ...or a list of access scopes.
+  for (const MDOperand &Op : MD->operands()) {
+    const MDNode *OpMD = dyn_cast<MDNode>(Op);
+    Assert(OpMD != nullptr, "Access scope list must consist of MDNodes", MD);
+    Assert(IsValidAccessScope(OpMD),
+           "Access scope list contains invalid access scope", MD);
+  }
+}
+
 /// verifyInstruction - Verify that an instruction is well formed.
 ///
 void Verifier::visitInstruction(Instruction &I) {
@@ -4641,6 +4660,9 @@ void Verifier::visitInstruction(Instruction &I) {
   if (MDNode *MD = I.getMetadata(LLVMContext::MD_alias_scope))
     visitAliasScopeListMetadata(MD);
 
+  if (MDNode *MD = I.getMetadata(LLVMContext::MD_access_group))
+    visitAccessGroupMetadata(MD);
+
   if (MDNode *AlignMD = I.getMetadata(LLVMContext::MD_align)) {
     Assert(I.getType()->isPointerTy(), "align applies only to pointer types",
            &I);

diff  --git a/llvm/test/Transforms/SimplifyCFG/X86/combine-parallel-mem-md.ll b/llvm/test/Transforms/SimplifyCFG/X86/combine-parallel-mem-md.ll
index 019e757ab2225..d6462d5566d0f 100644
--- a/llvm/test/Transforms/SimplifyCFG/X86/combine-parallel-mem-md.ll
+++ b/llvm/test/Transforms/SimplifyCFG/X86/combine-parallel-mem-md.ll
@@ -17,30 +17,30 @@ entry:
 for.body:                                         ; preds = %cond.end, %entry
   %indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %cond.end ]
   %arrayidx = getelementptr inbounds i32, i32* %p, i64 %indvars.iv
-  %0 = load i32, i32* %arrayidx, align 4, !llvm.access.group !0
+  %0 = load i32, i32* %arrayidx, align 4, !llvm.access.group !10
   %cmp1 = icmp eq i32 %0, 0
   br i1 %cmp1, label %cond.true, label %cond.false
 
 cond.false:                                       ; preds = %for.body
   %arrayidx3 = getelementptr inbounds i32, i32* %res, i64 %indvars.iv
-  %v = load i32, i32* %arrayidx3, align 4, !llvm.access.group !0
+  %v = load i32, i32* %arrayidx3, align 4, !llvm.access.group !10
   %arrayidx7 = getelementptr inbounds i32, i32* %d, i64 %indvars.iv
-  %1 = load i32, i32* %arrayidx7, align 4, !llvm.access.group !0
+  %1 = load i32, i32* %arrayidx7, align 4, !llvm.access.group !10
   %add = add nsw i32 %1, %v
   br label %cond.end
 
 cond.true:                                       ; preds = %for.body
   %arrayidx4 = getelementptr inbounds i32, i32* %res, i64 %indvars.iv
-  %w = load i32, i32* %arrayidx4, align 4, !llvm.access.group !0
+  %w = load i32, i32* %arrayidx4, align 4, !llvm.access.group !10
   %arrayidx8 = getelementptr inbounds i32, i32* %d, i64 %indvars.iv
-  %2 = load i32, i32* %arrayidx8, align 4, !llvm.access.group !0
+  %2 = load i32, i32* %arrayidx8, align 4, !llvm.access.group !10
   %add2 = add nsw i32 %2, %w
   br label %cond.end
 
 cond.end:                                         ; preds = %for.body, %cond.false
   %cond = phi i32 [ %add, %cond.false ], [ %add2, %cond.true ]
   %arrayidx9 = getelementptr inbounds i32, i32* %res, i64 %indvars.iv
-  store i32 %cond, i32* %arrayidx9, align 4, !llvm.access.group !0
+  store i32 %cond, i32* %arrayidx9, align 4, !llvm.access.group !10
   %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
   %exitcond = icmp eq i64 %indvars.iv.next, 16
   br i1 %exitcond, label %for.end, label %for.body, !llvm.loop !0

diff  --git a/llvm/test/Verifier/access_group.ll b/llvm/test/Verifier/access_group.ll
new file mode 100644
index 0000000000000..b1fdb4eea364d
--- /dev/null
+++ b/llvm/test/Verifier/access_group.ll
@@ -0,0 +1,18 @@
+; RUN: not llvm-as < %s -o /dev/null 2>&1 | FileCheck %s
+
+define void @test(i8* %p) {
+; CHECK: Access scope list contains invalid access scope
+  load i8, i8* %p, !llvm.access.group !1
+; CHECK: Access scope list must consist of MDNodes
+  load i8, i8* %p, !llvm.access.group !2
+; CHECK-NOT: Access scope
+  load i8, i8* %p, !llvm.access.group !3
+  load i8, i8* %p, !llvm.access.group !4
+  ret void
+}
+
+!0 = !{}
+!1 = !{!0}
+!2 = !{!"foo"}
+!3 = distinct !{}
+!4 = !{!3}