I wonder if 'notailcall' be better, since it contains a verb (like 'noinline'). I don't have a strong opinion; just putting the alternative out there.
> On 2015-Sep-16, at 19:21, Akira Hatanaka via cfe-commits > <cfe-commits@lists.llvm.org> wrote: > > ahatanak created this revision. > ahatanak added a reviewer: aaron.ballman. > ahatanak added a subscriber: cfe-commits. > > This patch adds support for a new function attribute "notail". The attribute > is used to disable tail call optimization on calls to functions marked with > the attribute. > > This is different from the attribute proposed in D12547, which disables tail > call optimizations on call sites within the marked function. > > http://reviews.llvm.org/D12547 > > http://reviews.llvm.org/D12922 > > Files: > include/clang/Basic/Attr.td > include/clang/Basic/AttrDocs.td > lib/CodeGen/CGCall.cpp > lib/Sema/SemaDeclAttr.cpp > test/CodeGen/attr-no-tail.c > > Index: test/CodeGen/attr-no-tail.c > =================================================================== > --- /dev/null > +++ test/CodeGen/attr-no-tail.c > @@ -0,0 +1,25 @@ > +// RUN: %clang_cc1 -triple x86_64-apple-macosx10.7.0 %s -emit-llvm -o - | > FileCheck %s > + > +// CHECK: define i32 @callee0(i32 %a) [[ATTRNOTAIL0:#[0-9]+]] { > +// CHECK: declare i32 @callee1(i32) [[ATTRNOTAIL1:#[0-9]+]] > +// CHECK: declare i32 @callee2(i32) [[ATTRTAIL0:#[0-9]+]] > + > +int callee0(int a) __attribute__((notail)) { > + return a + 1; > +} > + > +int callee1(int) __attribute__((notail)); > + > +int callee2(int); > + > +int caller0(int a) { > + if (a > 0) > + return callee0(a); > + if (a < 0) > + return callee1(a); > + return callee2(a); > +} > + > +// CHECK: attributes [[ATTRNOTAIL0]] = { {{.*}}notail{{.*}} } > +// CHECK: attributes [[ATTRNOTAIL1]] = { {{.*}}notail{{.*}} } > +// CHECK-NOT: attributes [[ATTRTAIL0]] = { {{.*}}notail{{.*}} } > Index: lib/Sema/SemaDeclAttr.cpp > =================================================================== > --- lib/Sema/SemaDeclAttr.cpp > +++ lib/Sema/SemaDeclAttr.cpp > @@ -4878,6 +4878,9 @@ > case AttributeList::AT_ReturnsTwice: > handleSimpleAttribute<ReturnsTwiceAttr>(S, D, Attr); > break; > + case AttributeList::AT_NoTail: > + handleSimpleAttribute<NoTailAttr>(S, D, Attr); > + break; > case AttributeList::AT_Used: > handleUsedAttr(S, D, Attr); > break; > Index: lib/CodeGen/CGCall.cpp > =================================================================== > --- lib/CodeGen/CGCall.cpp > +++ lib/CodeGen/CGCall.cpp > @@ -1414,6 +1414,8 @@ > FuncAttrs.addAttribute(llvm::Attribute::NoReturn); > if (TargetDecl->hasAttr<NoDuplicateAttr>()) > FuncAttrs.addAttribute(llvm::Attribute::NoDuplicate); > + if (TargetDecl->hasAttr<NoTailAttr>()) > + FuncAttrs.addAttribute(llvm::Attribute::NoTail); > > if (const FunctionDecl *Fn = dyn_cast<FunctionDecl>(TargetDecl)) { > const FunctionProtoType *FPT = > Fn->getType()->getAs<FunctionProtoType>(); > Index: include/clang/Basic/AttrDocs.td > =================================================================== > --- include/clang/Basic/AttrDocs.td > +++ include/clang/Basic/AttrDocs.td > @@ -1612,3 +1612,10 @@ > arguments, with arbitrary offsets. > }]; > } > + > +def NoTailDocs : Documentation { > + let Category = DocCatFunction; > + let Content = [{ > +Tail call optimization is not performed on calls to a function marked > ``notail``. > + }]; > +} > Index: include/clang/Basic/Attr.td > =================================================================== > --- include/clang/Basic/Attr.td > +++ include/clang/Basic/Attr.td > @@ -1020,6 +1020,12 @@ > let Documentation = [Undocumented]; > } > > +def NoTail : InheritableAttr { > + let Spellings = [GNU<"notail">, CXX11<"clang", "notail">]; > + let Subjects = SubjectList<[Function, ObjCMethod]>; > + let Documentation = [NoTailDocs]; > +} > + > def NoThrow : InheritableAttr { > let Spellings = [GCC<"nothrow">, Declspec<"nothrow">]; > let Documentation = [Undocumented]; > > > <D12922.34960.patch>_______________________________________________ > cfe-commits mailing list > cfe-commits@lists.llvm.org > http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
