[Analysis] Attribute deref/deref_or_null should not prevent tail call optimization
diff --git a/llvm/lib/CodeGen/Analysis.cpp b/llvm/lib/CodeGen/Analysis.cpp
index 023c236..4b738ca 100644
--- a/llvm/lib/CodeGen/Analysis.cpp
+++ b/llvm/lib/CodeGen/Analysis.cpp
@@ -567,12 +567,16 @@
AttrBuilder CalleeAttrs(cast<CallInst>(I)->getAttributes(),
AttributeList::ReturnIndex);
- // NoAlias and NonNull are completely benign as far as calling convention
+ // Following attributes are completely benign as far as calling convention
// goes, they shouldn't affect whether the call is a tail call.
CallerAttrs.removeAttribute(Attribute::NoAlias);
CalleeAttrs.removeAttribute(Attribute::NoAlias);
CallerAttrs.removeAttribute(Attribute::NonNull);
CalleeAttrs.removeAttribute(Attribute::NonNull);
+ CallerAttrs.removeAttribute(Attribute::Dereferenceable);
+ CalleeAttrs.removeAttribute(Attribute::Dereferenceable);
+ CallerAttrs.removeAttribute(Attribute::DereferenceableOrNull);
+ CalleeAttrs.removeAttribute(Attribute::DereferenceableOrNull);
if (CallerAttrs.contains(Attribute::ZExt)) {
if (!CalleeAttrs.contains(Attribute::ZExt))
diff --git a/llvm/test/CodeGen/X86/tail-call-deref.ll b/llvm/test/CodeGen/X86/tail-call-deref.ll
new file mode 100644
index 0000000..5df7cf4
--- /dev/null
+++ b/llvm/test/CodeGen/X86/tail-call-deref.ll
@@ -0,0 +1,36 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc -mtriple=x86_64-linux < %s | FileCheck %s
+
+declare i8* @foo()
+
+define dereferenceable(8) i8* @test1() nounwind {
+; CHECK-LABEL: test1:
+; CHECK: # %bb.0:
+; CHECK-NEXT: jmp foo # TAILCALL
+ %ret = tail call i8* @foo()
+ ret i8* %ret
+}
+
+define i8* @test2() nounwind {
+; CHECK-LABEL: test2:
+; CHECK: # %bb.0:
+; CHECK-NEXT: jmp foo # TAILCALL
+ %ret = tail call dereferenceable(8) i8* @foo()
+ ret i8* %ret
+}
+
+define dereferenceable_or_null(8) i8* @test3() nounwind {
+; CHECK-LABEL: test3:
+; CHECK: # %bb.0:
+; CHECK-NEXT: jmp foo # TAILCALL
+ %ret = tail call i8* @foo()
+ ret i8* %ret
+}
+
+define i8* @test4() nounwind {
+; CHECK-LABEL: test4:
+; CHECK: # %bb.0:
+; CHECK-NEXT: jmp foo # TAILCALL
+ %ret = tail call dereferenceable_or_null(8) i8* @foo()
+ ret i8* %ret
+}