[GVN] Handle empty attrs in Expression ==

Change-Id: I75e876452af701191d36331703654581c6eb46f2

Author: macurtis-amd

llvm/lib/Transforms/Scalar/GVN.cpp

@@ -156,7 +156,7 @@ struct llvm::GVNPass::Expression {
       return false;
     if (varargs != other.varargs)
       return false;
-    if (!attrs.isEmpty() && !other.attrs.isEmpty() &&
+    if ((!attrs.isEmpty() || !other.attrs.isEmpty()) &&
         !attrs.intersectWith(type->getContext(), other.attrs).has_value())
       return false;
     return true;

llvm/test/Transforms/GVN/intersect-empty-attr.ll

@@ -0,0 +1,21 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
+; RUN: opt -S -passes=gvn < %s | FileCheck %s
+
+declare i32 @bar() #0
+
+define i32 @foo() {
+; CHECK-LABEL: define i32 @foo() {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    [[TMP0:%.*]] = tail call i32 @bar() #[[ATTR1:[0-9]+]]
+; CHECK-NEXT:    [[TMP1:%.*]] = tail call i32 @bar()
+; CHECK-NEXT:    ret i32 1
+;
+entry:
+  %0 = tail call i32 @bar() #1
+  %1 = tail call i32 @bar()
+  ret i32 1
+}
+
+
+attributes #0 = { memory(none) }
+attributes #1 = { "llvm.assume"="ompx_no_call_asm" }