r208927 - MS ABI: Use musttail for thunk IR generation
Reid Kleckner
reid at kleckner.net
Thu May 15 16:01:47 PDT 2014
Author: rnk
Date: Thu May 15 18:01:46 2014
New Revision: 208927
URL: http://llvm.org/viewvc/llvm-project?rev=208927&view=rev
Log:
MS ABI: Use musttail for thunk IR generation
This allows us to perfectly forward non-trivial arguments that use
inalloca.
We still can't forward non-trivial arguments through thunks when we have
a covariant return type with a non-trivial adjustment. This would
require emitting an extra copy, which is non-conforming anyway.
Added:
cfe/trunk/test/CodeGenCXX/microsoft-abi-nontrivial-covariant-thunk.cpp
Removed:
cfe/trunk/test/CodeGenCXX/microsoft-abi-nontrivial-memptr-thunks.cpp
Modified:
cfe/trunk/lib/CodeGen/CGCall.cpp
cfe/trunk/lib/CodeGen/MicrosoftCXXABI.cpp
cfe/trunk/test/CodeGenCXX/microsoft-abi-virtual-member-pointers.cpp
Modified: cfe/trunk/lib/CodeGen/CGCall.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGCall.cpp?rev=208927&r1=208926&r2=208927&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGCall.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGCall.cpp Thu May 15 18:01:46 2014
@@ -2616,7 +2616,7 @@ RValue CodeGenFunction::EmitCall(const C
IP = IP->getNextNode();
AI = new llvm::AllocaInst(ArgStruct, "argmem", IP);
} else {
- AI = Builder.CreateAlloca(ArgStruct, nullptr, "argmem");
+ AI = CreateTempAlloca(ArgStruct, "argmem");
}
AI->setUsedWithInAlloca(true);
assert(AI->isUsedWithInAlloca() && !AI->isStaticAlloca());
Modified: cfe/trunk/lib/CodeGen/MicrosoftCXXABI.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/MicrosoftCXXABI.cpp?rev=208927&r1=208926&r2=208927&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/MicrosoftCXXABI.cpp (original)
+++ cfe/trunk/lib/CodeGen/MicrosoftCXXABI.cpp Thu May 15 18:01:46 2014
@@ -1111,8 +1111,31 @@ llvm::Function *MicrosoftCXXABI::EmitVir
CGF.Builder.CreateConstInBoundsGEP1_64(VTable, ML.Index, "vfn");
llvm::Value *Callee = CGF.Builder.CreateLoad(VFuncPtr);
- // Make the call and return the result.
- CGF.EmitCallAndReturnForThunk(MD, Callee, 0);
+ unsigned CallingConv;
+ CodeGen::AttributeListType AttributeList;
+ CGM.ConstructAttributeList(FnInfo, MD, AttributeList, CallingConv, true);
+ llvm::AttributeSet Attrs =
+ llvm::AttributeSet::get(CGF.getLLVMContext(), AttributeList);
+
+ // Do a musttail call with perfect argument forwarding. Any inalloca argument
+ // will be forwarded in place without any copy.
+ SmallVector<llvm::Value *, 8> Args;
+ for (llvm::Argument &A : ThunkFn->args())
+ Args.push_back(&A);
+ llvm::CallInst *Call = CGF.Builder.CreateCall(Callee, Args);
+ Call->setTailCallKind(llvm::CallInst::TCK_MustTail);
+ Call->setAttributes(Attrs);
+ Call->setCallingConv(static_cast<llvm::CallingConv::ID>(CallingConv));
+
+ if (Call->getType()->isVoidTy())
+ CGF.Builder.CreateRetVoid();
+ else
+ CGF.Builder.CreateRet(Call);
+
+ // Finish the function to maintain CodeGenFunction invariants.
+ // FIXME: Don't emit unreachable code.
+ CGF.EmitBlock(CGF.createBasicBlock());
+ CGF.FinishFunction();
return ThunkFn;
}
Added: cfe/trunk/test/CodeGenCXX/microsoft-abi-nontrivial-covariant-thunk.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/microsoft-abi-nontrivial-covariant-thunk.cpp?rev=208927&view=auto
==============================================================================
--- cfe/trunk/test/CodeGenCXX/microsoft-abi-nontrivial-covariant-thunk.cpp (added)
+++ cfe/trunk/test/CodeGenCXX/microsoft-abi-nontrivial-covariant-thunk.cpp Thu May 15 18:01:46 2014
@@ -0,0 +1,24 @@
+// RUN: %clang_cc1 %s -fno-rtti -emit-llvm-only -o - -triple=i386-pc-win32 -verify
+
+// A is not trivially copyable and must be passed indirectly or with inalloca.
+struct A {
+ A();
+ A(const A &o);
+ virtual ~A();
+ int a;
+};
+
+struct B {
+ B();
+ int b;
+ virtual B *clone(A);
+};
+
+// Converting from C* to B* requires a this adjustment.
+struct C : A, B {
+ C();
+ int c;
+ virtual C *clone(A); // expected-error {{cannot compile this non-trivial argument copy for thunk yet}}
+};
+B::B() {} // force emission
+C::C() {} // force emission
Removed: cfe/trunk/test/CodeGenCXX/microsoft-abi-nontrivial-memptr-thunks.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/microsoft-abi-nontrivial-memptr-thunks.cpp?rev=208926&view=auto
==============================================================================
--- cfe/trunk/test/CodeGenCXX/microsoft-abi-nontrivial-memptr-thunks.cpp (original)
+++ cfe/trunk/test/CodeGenCXX/microsoft-abi-nontrivial-memptr-thunks.cpp (removed)
@@ -1,11 +0,0 @@
-// RUN: %clang_cc1 -fno-rtti -emit-llvm-only -triple=i386-pc-win32 %s -verify
-
-struct A {
- A();
- ~A();
- int a;
-};
-struct B {
- virtual void f(A); // expected-error {{cannot compile this non-trivial argument copy for thunk yet}}
-};
-void (B::*mp)(A) = &B::f;
Modified: cfe/trunk/test/CodeGenCXX/microsoft-abi-virtual-member-pointers.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/microsoft-abi-virtual-member-pointers.cpp?rev=208927&r1=208926&r2=208927&view=diff
==============================================================================
--- cfe/trunk/test/CodeGenCXX/microsoft-abi-virtual-member-pointers.cpp (original)
+++ cfe/trunk/test/CodeGenCXX/microsoft-abi-virtual-member-pointers.cpp Thu May 15 18:01:46 2014
@@ -5,10 +5,19 @@ struct S {
int x, y, z;
};
+// U is not trivially copyable, and requires inalloca to pass by value.
+struct U {
+ int u;
+ U();
+ ~U();
+ U(const U &);
+};
+
struct C {
virtual void foo();
virtual int bar(int, double);
virtual S baz(int);
+ virtual S qux(U);
};
namespace {
@@ -31,6 +40,10 @@ void f() {
void (D::*ptr4)();
ptr4 = &D::foo;
+ S (C::*ptr5)(U);
+ ptr5 = &C::qux;
+
+
// CHECK32-LABEL: define void @"\01?f@@YAXXZ"()
// CHECK32: store i8* bitcast (void (%struct.C*)* @"\01??_9C@@$BA at AE" to i8*), i8** %ptr
// CHECK32: store i8* bitcast (i32 (%struct.C*, i32, double)* @"\01??_9C@@$B3AE" to i8*), i8** %ptr2
@@ -51,14 +64,14 @@ void f() {
// CHECK32-LABEL: define linkonce_odr x86_thiscallcc void @"\01??_9C@@$BA at AE"(%struct.C* %this) unnamed_addr
// CHECK32: [[VPTR:%.*]] = getelementptr inbounds void (%struct.C*)** %{{.*}}, i64 0
// CHECK32: [[CALLEE:%.*]] = load void (%struct.C*)** [[VPTR]]
-// CHECK32: call x86_thiscallcc void [[CALLEE]](%struct.C* %{{.*}})
+// CHECK32: musttail call x86_thiscallcc void [[CALLEE]](%struct.C* %{{.*}})
// CHECK32: ret void
// CHECK32: }
//
// CHECK64-LABEL: define linkonce_odr void @"\01??_9C@@$BA at AA"(%struct.C* %this) unnamed_addr
// CHECK64: [[VPTR:%.*]] = getelementptr inbounds void (%struct.C*)** %{{.*}}, i64 0
// CHECK64: [[CALLEE:%.*]] = load void (%struct.C*)** [[VPTR]]
-// CHECK64: call void [[CALLEE]](%struct.C* %{{.*}})
+// CHECK64: musttail call void [[CALLEE]](%struct.C* %{{.*}})
// CHECK64: ret void
// CHECK64: }
@@ -66,14 +79,14 @@ void f() {
// CHECK32-LABEL: define linkonce_odr x86_thiscallcc i32 @"\01??_9C@@$B3AE"(%struct.C* %this, i32, double) unnamed_addr
// CHECK32: [[VPTR:%.*]] = getelementptr inbounds i32 (%struct.C*, i32, double)** %{{.*}}, i64 1
// CHECK32: [[CALLEE:%.*]] = load i32 (%struct.C*, i32, double)** [[VPTR]]
-// CHECK32: [[CALL:%.*]] = call x86_thiscallcc i32 [[CALLEE]](%struct.C* %{{.*}}, i32 %{{.*}}, double %{{.*}})
+// CHECK32: [[CALL:%.*]] = musttail call x86_thiscallcc i32 [[CALLEE]](%struct.C* %{{.*}}, i32 %{{.*}}, double %{{.*}})
// CHECK32: ret i32 [[CALL]]
// CHECK32: }
//
// CHECK64-LABEL: define linkonce_odr i32 @"\01??_9C@@$B7AA"(%struct.C* %this, i32, double) unnamed_addr
// CHECK64: [[VPTR:%.*]] = getelementptr inbounds i32 (%struct.C*, i32, double)** %{{.*}}, i64 1
// CHECK64: [[CALLEE:%.*]] = load i32 (%struct.C*, i32, double)** [[VPTR]]
-// CHECK64: [[CALL:%.*]] = call i32 [[CALLEE]](%struct.C* %{{.*}}, i32 %{{.*}}, double %{{.*}})
+// CHECK64: [[CALL:%.*]] = musttail call i32 [[CALLEE]](%struct.C* %{{.*}}, i32 %{{.*}}, double %{{.*}})
// CHECK64: ret i32 [[CALL]]
// CHECK64: }
@@ -81,14 +94,14 @@ void f() {
// CHECK32-LABEL: define linkonce_odr x86_thiscallcc void @"\01??_9C@@$B7AE"(%struct.C* %this, %struct.S* noalias sret %agg.result, i32) unnamed_addr
// CHECK32: [[VPTR:%.*]] = getelementptr inbounds void (%struct.C*, %struct.S*, i32)** %{{.*}}, i64 2
// CHECK32: [[CALLEE:%.*]] = load void (%struct.C*, %struct.S*, i32)** [[VPTR]]
-// CHECK32: call x86_thiscallcc void [[CALLEE]](%struct.C* %{{.*}}, %struct.S* sret %agg.result, i32 %{{.*}})
+// CHECK32: musttail call x86_thiscallcc void [[CALLEE]](%struct.C* %{{.*}}, %struct.S* sret %agg.result, i32 %{{.*}})
// CHECK32: ret void
// CHECK32: }
//
// CHECK64-LABEL: define linkonce_odr void @"\01??_9C@@$BBA at AA"(%struct.C* %this, %struct.S* noalias sret %agg.result, i32) unnamed_addr
// CHECK64: [[VPTR:%.*]] = getelementptr inbounds void (%struct.C*, %struct.S*, i32)** %{{.*}}, i64 2
// CHECK64: [[CALLEE:%.*]] = load void (%struct.C*, %struct.S*, i32)** [[VPTR]]
-// CHECK64: call void [[CALLEE]](%struct.C* %{{.*}}, %struct.S* sret %agg.result, i32 %{{.*}})
+// CHECK64: musttail call void [[CALLEE]](%struct.C* %{{.*}}, %struct.S* sret %agg.result, i32 %{{.*}})
// CHECK64: ret void
// CHECK64: }
@@ -96,13 +109,28 @@ void f() {
// CHECK32-LABEL: define internal x86_thiscallcc void @"\01??_9D@?A@@$BA at AE"(%"struct.(anonymous namespace)::D"* %this) unnamed_addr
// CHECK32: [[VPTR:%.*]] = getelementptr inbounds void (%"struct.(anonymous namespace)::D"*)** %{{.*}}, i64 0
// CHECK32: [[CALLEE:%.*]] = load void (%"struct.(anonymous namespace)::D"*)** [[VPTR]]
-// CHECK32: call x86_thiscallcc void [[CALLEE]](%"struct.(anonymous namespace)::D"* %{{.*}})
+// CHECK32: musttail call x86_thiscallcc void [[CALLEE]](%"struct.(anonymous namespace)::D"* %{{.*}})
// CHECK32: ret void
// CHECK32: }
//
// CHECK64-LABEL: define internal void @"\01??_9D@?A@@$BA at AA"(%"struct.(anonymous namespace)::D"* %this) unnamed_addr
// CHECK64: [[VPTR:%.*]] = getelementptr inbounds void (%"struct.(anonymous namespace)::D"*)** %{{.*}}, i64 0
// CHECK64: [[CALLEE:%.*]] = load void (%"struct.(anonymous namespace)::D"*)** [[VPTR]]
-// CHECK64: call void [[CALLEE]](%"struct.(anonymous namespace)::D"* %{{.*}})
+// CHECK64: musttail call void [[CALLEE]](%"struct.(anonymous namespace)::D"* %{{.*}})
+// CHECK64: ret void
+// CHECK64: }
+
+// Thunk for calling the fourth virtual function in C, taking a struct parameter and returning a struct.
+// CHECK32-LABEL: define linkonce_odr x86_thiscallcc %struct.S* @"\01??_9C@@$BM at AE"(%struct.C* %this, <{ %struct.S*, %struct.U }>* inalloca) unnamed_addr
+// CHECK32: [[VPTR:%.*]] = getelementptr inbounds %struct.S* (%struct.C*, <{ %struct.S*, %struct.U }>*)** %{{.*}}, i64 3
+// CHECK32: [[CALLEE:%.*]] = load %struct.S* (%struct.C*, <{ %struct.S*, %struct.U }>*)** [[VPTR]]
+// CHECK32: [[CALL:%.*]] = musttail call x86_thiscallcc %struct.S* [[CALLEE]](%struct.C* %this, <{ %struct.S*, %struct.U }>* inalloca %{{.*}})
+// CHECK32: ret %struct.S* [[CALL]]
+// CHECK32: }
+//
+// CHECK64-LABEL: define linkonce_odr void @"\01??_9C@@$BBI at AA"(%struct.C* %this, %struct.S* noalias sret %agg.result, %struct.U*) unnamed_addr
+// CHECK64: [[VPTR:%.*]] = getelementptr inbounds void (%struct.C*, %struct.S*, %struct.U*)** %{{.*}}, i64 3
+// CHECK64: [[CALLEE:%.*]] = load void (%struct.C*, %struct.S*, %struct.U*)** [[VPTR]]
+// CHECK64: musttail call void [[CALLEE]](%struct.C* %this, %struct.S* sret %agg.result, %struct.U* %{{.*}})
// CHECK64: ret void
// CHECK64: }
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