Index: include/clang/Frontend/CodeGenOptions.h =================================================================== --- include/clang/Frontend/CodeGenOptions.h (revision 183584) +++ include/clang/Frontend/CodeGenOptions.h (working copy) @@ -71,6 +71,12 @@ FPC_Fast // Aggressively fuse FP ops (E.g. FMA). }; + enum SmallStructsConventionKind { + SSC_Default, // No special option was passed. + SSC_OnStack, // Small structs on the stack (-fpcc-struct-return). + SSC_InRegs // Small structs in registers (-freg-struct-return). + }; + /// The code model to use (-mcmodel). std::string CodeModel; Index: include/clang/Frontend/CodeGenOptions.def =================================================================== --- include/clang/Frontend/CodeGenOptions.def (revision 183584) +++ include/clang/Frontend/CodeGenOptions.def (working copy) @@ -85,6 +85,10 @@ ///< enabled. VALUE_CODEGENOPT(OptimizationLevel, 3, 0) ///< The -O[0-4] option specified. VALUE_CODEGENOPT(OptimizeSize, 2, 0) ///< If -Os (==1) or -Oz (==2) is specified. + + /// If -fpcc-struct-return or -freg-struct-return is specified. +ENUM_CODEGENOPT(SmallStructsConvention, SmallStructsConventionKind, 2, SSC_Default) + CODEGENOPT(RelaxAll , 1, 0) ///< Relax all machine code instructions. CODEGENOPT(RelaxedAliasing , 1, 0) ///< Set when -fno-strict-aliasing is enabled. CODEGENOPT(StructPathTBAA , 1, 0) ///< Whether or not to use struct-path TBAA. @@ -143,4 +147,3 @@ #undef CODEGENOPT #undef ENUM_CODEGENOPT #undef VALUE_CODEGENOPT - Index: include/clang/Driver/Options.td =================================================================== --- include/clang/Driver/Options.td (revision 183584) +++ include/clang/Driver/Options.td (working copy) @@ -659,6 +659,8 @@ HelpText<"Specify the default maximum struct packing alignment">; def fpascal_strings : Flag<["-"], "fpascal-strings">, Group, Flags<[CC1Option]>, HelpText<"Recognize and construct Pascal-style string literals">; +def fpcc_struct_return : Flag<["-"], "fpcc-struct-return">, Group, Flags<[CC1Option]>, + HelpText<"Override the default ABI to return all structs on the stack">; def fpch_preprocess : Flag<["-"], "fpch-preprocess">, Group; def fpic : Flag<["-"], "fpic">, Group; def fno_pic : Flag<["-"], "fno-pic">, Group; @@ -668,6 +670,8 @@ def fprofile_generate : Flag<["-"], "fprofile-generate">, Group; def framework : Separate<["-"], "framework">, Flags<[LinkerInput]>; def frandom_seed_EQ : Joined<["-"], "frandom-seed=">, Group; +def freg_struct_return : Flag<["-"], "freg-struct-return">, Group, Flags<[CC1Option]>, + HelpText<"Override the default ABI to return small structs in registers">; def frtti : Flag<["-"], "frtti">, Group; def fsched_interblock : Flag<["-"], "fsched-interblock">, Group; def fshort_enums : Flag<["-"], "fshort-enums">, Group, Flags<[CC1Option]>, Index: lib/Frontend/CompilerInvocation.cpp =================================================================== --- lib/Frontend/CompilerInvocation.cpp (revision 183584) +++ lib/Frontend/CompilerInvocation.cpp (working copy) @@ -473,6 +473,15 @@ Diags.Report(diag::err_drv_invalid_value) << A->getAsString(Args) << Val; } + if (Arg *A = Args.getLastArg(OPT_fpcc_struct_return, OPT_freg_struct_return)) { + if (A->getOption().matches(OPT_fpcc_struct_return)) { + Opts.setSmallStructsConvention(CodeGenOptions::SSC_OnStack); + } else { + assert(A->getOption().matches(OPT_freg_struct_return)); + Opts.setSmallStructsConvention(CodeGenOptions::SSC_InRegs); + } + } + return Success; } Index: lib/Driver/Tools.cpp =================================================================== --- lib/Driver/Tools.cpp (revision 183584) +++ lib/Driver/Tools.cpp (working copy) @@ -2160,6 +2160,18 @@ CmdArgs.push_back(A->getValue()); } + if (Arg *A = Args.getLastArg(options::OPT_fpcc_struct_return, options::OPT_freg_struct_return)) { + if (getToolChain().getTriple().getArch() != llvm::Triple::x86) { + D.Diag(diag::err_drv_unsupported_opt_for_target) + << A->getSpelling() << getToolChain().getTriple().str(); + } else if (A->getOption().matches(options::OPT_fpcc_struct_return)) { + CmdArgs.push_back("-fpcc-struct-return"); + } else { + assert(A->getOption().matches(options::OPT_freg_struct_return)); + CmdArgs.push_back("-freg-struct-return"); + } + } + if (Args.hasFlag(options::OPT_mrtd, options::OPT_mno_rtd, false)) CmdArgs.push_back("-mrtd"); Index: lib/CodeGen/TargetInfo.cpp =================================================================== --- lib/CodeGen/TargetInfo.cpp (revision 183584) +++ lib/CodeGen/TargetInfo.cpp (working copy) @@ -575,6 +575,9 @@ bool d, bool p, bool w, unsigned r) :TargetCodeGenInfo(new X86_32ABIInfo(CGT, d, p, w, r)) {} + static bool isStructReturnInRegABI( + const llvm::Triple &Triple, const CodeGenOptions &Opts); + void SetTargetAttributes(const Decl *D, llvm::GlobalValue *GV, CodeGen::CodeGenModule &CGM) const; @@ -4410,7 +4413,36 @@ return ResAddr; } +bool X86_32TargetCodeGenInfo::isStructReturnInRegABI( + const llvm::Triple &Triple, const CodeGenOptions &Opts) { + assert(Triple.getArch() == llvm::Triple::x86); + switch (Opts.getSmallStructsConvention()) { + case CodeGenOptions::SSC_Default: + break; + case CodeGenOptions::SSC_OnStack: // -fpcc-struct-return + return false; + case CodeGenOptions::SSC_InRegs: // -freg-struct-return + return true; + } + + if (Triple.isOSDarwin()) + return true; + + switch (Triple.getOS()) { + case llvm::Triple::Cygwin: + case llvm::Triple::MinGW32: + case llvm::Triple::AuroraUX: + case llvm::Triple::DragonFly: + case llvm::Triple::FreeBSD: + case llvm::Triple::OpenBSD: + case llvm::Triple::Bitrig: + return true; + default: + return false; + } +} + ABIArgInfo SystemZABIInfo::classifyReturnType(QualType RetTy) const { if (RetTy->isVoidType()) return ABIArgInfo::getIgnore(); @@ -5472,31 +5504,20 @@ return *(TheTargetCodeGenInfo = new TCETargetCodeGenInfo(Types)); case llvm::Triple::x86: { - if (Triple.isOSDarwin()) - return *(TheTargetCodeGenInfo = - new X86_32TargetCodeGenInfo(Types, true, true, false, - CodeGenOpts.NumRegisterParameters)); + bool IsDarwinVectorABI = Triple.isOSDarwin(); + bool IsSmallStructInRegABI = + X86_32TargetCodeGenInfo::isStructReturnInRegABI(Triple, CodeGenOpts); + bool IsWin32FloatStructABI = (Triple.getOS() == llvm::Triple::Win32); - switch (Triple.getOS()) { - case llvm::Triple::Cygwin: - case llvm::Triple::MinGW32: - case llvm::Triple::AuroraUX: - case llvm::Triple::DragonFly: - case llvm::Triple::FreeBSD: - case llvm::Triple::OpenBSD: - case llvm::Triple::Bitrig: + if (Triple.getOS() == llvm::Triple::Win32) { return *(TheTargetCodeGenInfo = - new X86_32TargetCodeGenInfo(Types, false, true, false, - CodeGenOpts.NumRegisterParameters)); - - case llvm::Triple::Win32: - return *(TheTargetCodeGenInfo = new WinX86_32TargetCodeGenInfo(Types, CodeGenOpts.NumRegisterParameters)); - - default: + } else { return *(TheTargetCodeGenInfo = - new X86_32TargetCodeGenInfo(Types, false, false, false, + new X86_32TargetCodeGenInfo(Types, + IsDarwinVectorABI, IsSmallStructInRegABI, + IsWin32FloatStructABI, CodeGenOpts.NumRegisterParameters)); } }