[cfe-commits] r151122 - in /cfe/trunk: lib/CodeGen/TargetInfo.cpp test/CodeGenCXX/thiscall-struct-return.cpp

[Nico Weber]

On Tue, Feb 21, 2012 at 7:04 PM, Aaron Ballman <aaron at aaronballman.com> wrote:
> Author: aaronballman
> Date: Tue Feb 21 21:04:13 2012
> New Revision: 151122
>
> URL: http://llvm.org/viewvc/llvm-project?rev=151122&view=rev
> Log:
> Adding support for Microsoft's thiscall calling convention.  Clang side of the patch.
>
> Added:
>    cfe/trunk/test/CodeGenCXX/thiscall-struct-return.cpp   (with props)
> Modified:
>    cfe/trunk/lib/CodeGen/TargetInfo.cpp
>
> Modified: cfe/trunk/lib/CodeGen/TargetInfo.cpp
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/TargetInfo.cpp?rev=151122&r1=151121&r2=151122&view=diff
> ==============================================================================
> --- cfe/trunk/lib/CodeGen/TargetInfo.cpp (original)
> +++ cfe/trunk/lib/CodeGen/TargetInfo.cpp Tue Feb 21 21:04:13 2012
> @@ -424,7 +424,8 @@
>     return (Size == 8 || Size == 16 || Size == 32 || Size == 64);
>   }
>
> -  static bool shouldReturnTypeInRegister(QualType Ty, ASTContext &Context);
> +  static bool shouldReturnTypeInRegister(QualType Ty, ASTContext &Context,
> +                                          unsigned callingConvention);
>
>   /// getIndirectResult - Give a source type \arg Ty, return a suitable result
>   /// such that the argument will be passed in memory.
> @@ -435,11 +436,13 @@
>
>  public:
>
> -  ABIArgInfo classifyReturnType(QualType RetTy) const;
> +  ABIArgInfo classifyReturnType(QualType RetTy,
> +                                unsigned callingConvention) const;
>   ABIArgInfo classifyArgumentType(QualType RetTy) const;
>
>   virtual void computeInfo(CGFunctionInfo &FI) const {
> -    FI.getReturnInfo() = classifyReturnType(FI.getReturnType());
> +    FI.getReturnInfo() = classifyReturnType(FI.getReturnType(),
> +                                            FI.getCallingConvention());
>     for (CGFunctionInfo::arg_iterator it = FI.arg_begin(), ie = FI.arg_end();
>          it != ie; ++it)
>       it->info = classifyArgumentType(it->type);
> @@ -485,7 +488,8 @@
>  /// shouldReturnTypeInRegister - Determine if the given type should be
>  /// passed in a register (for the Darwin ABI).
>  bool X86_32ABIInfo::shouldReturnTypeInRegister(QualType Ty,
> -                                               ASTContext &Context) {
> +                                               ASTContext &Context,
> +                                               unsigned callingConvention) {
>   uint64_t Size = Context.getTypeSize(Ty);
>
>   // Type must be register sized.
> @@ -510,7 +514,8 @@
>
>   // Arrays are treated like records.
>   if (const ConstantArrayType *AT = Context.getAsConstantArrayType(Ty))
> -    return shouldReturnTypeInRegister(AT->getElementType(), Context);
> +    return shouldReturnTypeInRegister(AT->getElementType(), Context,
> +                                      callingConvention);
>
>   // Otherwise, it must be a record type.
>   const RecordType *RT = Ty->getAs<RecordType>();
> @@ -518,6 +523,13 @@
>
>   // FIXME: Traverse bases here too.
>
> +  // For thiscall conventions, structures will never be returned in
> +  // a register.  This is for compatibility with the MSVC ABI
> +  if (callingConvention == llvm::CallingConv::X86_ThisCall &&
> +      RT->isStructureType()) {
> +    return false;
> +  }
> +
>   // Structure types are passed in register if all fields would be
>   // passed in a register.
>   for (RecordDecl::field_iterator i = RT->getDecl()->field_begin(),
> @@ -529,14 +541,15 @@
>       continue;
>
>     // Check fields recursively.
> -    if (!shouldReturnTypeInRegister(FD->getType(), Context))
> +    if (!shouldReturnTypeInRegister(FD->getType(), Context,
> +                                    callingConvention))
>       return false;
>   }
> -
>   return true;
>  }
>
> -ABIArgInfo X86_32ABIInfo::classifyReturnType(QualType RetTy) const {
> +ABIArgInfo X86_32ABIInfo::classifyReturnType(QualType RetTy,
> +                                            unsigned callingConvention) const {
>   if (RetTy->isVoidType())
>     return ABIArgInfo::getIgnore();
>
> @@ -583,7 +596,8 @@
>
>     // Small structures which are register sized are generally returned
>     // in a register.
> -    if (X86_32ABIInfo::shouldReturnTypeInRegister(RetTy, getContext())) {
> +    if (X86_32ABIInfo::shouldReturnTypeInRegister(RetTy, getContext(),
> +                                                  callingConvention)) {
>       uint64_t Size = getContext().getTypeSize(RetTy);
>
>       // As a special-case, if the struct is a "single-element" struct, and
>
> Added: cfe/trunk/test/CodeGenCXX/thiscall-struct-return.cpp
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/thiscall-struct-return.cpp?rev=151122&view=auto
> ==============================================================================
> --- cfe/trunk/test/CodeGenCXX/thiscall-struct-return.cpp (added)
> +++ cfe/trunk/test/CodeGenCXX/thiscall-struct-return.cpp Tue Feb 21 21:04:13 2012
> @@ -0,0 +1,41 @@
> +// For MSVC ABI compatibility, all structures returned by value using the
> +// thiscall calling convention must use the hidden parameter.
> +//
> +// RUN: %clang_cc1 -triple i386-PC-Win32 %s -fms-compatibility -O0 -emit-llvm -o - | FileCheck %s
> +
> +// This structure would normally be returned via EAX
> +struct S {
> +  int i;
> +};
> +
> +// This structure would normally be returned via EAX/EDX
> +struct M {
> +  int i;
> +  int j;
> +};
> +
> +class C {
> +public:
> +  C() {}
> +
> +  struct S __attribute__((thiscall)) Small() const {
> +    struct S s = { 0 };
> +    return s;
> +  }
> +
> +  struct M __attribute__((thiscall)) Medium() const {
> +    struct M m = { 0 };
> +    return m;
> +  }
> +};
> +
> +// CHECK: define void @_Z4testv()
> +void test( void ) {
> +// CHECK: call void @_ZN1CC1Ev(%class.C* %c)
> +  C c;
> +
> +// CHECK: call x86_thiscallcc void @_ZNK1C5SmallEv(%struct.S* sret %tmp, %class.C* %c)
> +  (void)c.Small();
> +// CHECK: call x86_thiscallcc void @_ZNK1C6MediumEv(%struct.M* sret %tmp1, %class.C* %c)
> +  (void)c.Medium();
> +}
>
> Propchange: cfe/trunk/test/CodeGenCXX/thiscall-struct-return.cpp
> ------------------------------------------------------------------------------
>    svn:eol-style = native

I think I was told once that clang prefers no svn:eol-style property
on its files.

Nico