Add support for -fpcc-struct-return. Patch by Arthur O'Dwyer!
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@184166 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/CodeGen/x86_32-fpcc-struct-return.c b/CodeGen/x86_32-fpcc-struct-return.c
new file mode 100644
index 0000000..6851102
--- /dev/null
+++ b/CodeGen/x86_32-fpcc-struct-return.c
@@ -0,0 +1,34 @@
+// RUN: %clang_cc1 -triple i386-apple-darwin9 -emit-llvm -o - %s | FileCheck %s --check-prefix=REG
+// RUN: %clang_cc1 -triple i386-apple-darwin9 -fpcc-struct-return -emit-llvm -o - %s | FileCheck %s --check-prefix=PCC
+// RUN: %clang_cc1 -triple i386-apple-darwin9 -freg-struct-return -emit-llvm -o - %s | FileCheck %s --check-prefix=REG
+// RUN: %clang_cc1 -triple i386-pc-linux-gnu -emit-llvm -o - %s | FileCheck %s --check-prefix=PCC
+// RUN: %clang_cc1 -triple i386-pc-linux-gnu -fpcc-struct-return -emit-llvm -o - %s | FileCheck %s --check-prefix=PCC
+// RUN: %clang_cc1 -triple i386-pc-linux-gnu -freg-struct-return -emit-llvm -o - %s | FileCheck %s --check-prefix=REG
+// RUN: %clang_cc1 -triple i386-pc-win32 -emit-llvm -o - %s | FileCheck %s --check-prefix=REG
+// RUN: %clang_cc1 -triple i386-pc-win32 -fpcc-struct-return -emit-llvm -o - %s | FileCheck %s --check-prefix=PCC
+// RUN: %clang_cc1 -triple i386-pc-win32 -freg-struct-return -emit-llvm -o - %s | FileCheck %s --check-prefix=REG
+
+typedef struct { int a,b,c,d; } Big;
+typedef struct { int i; } Small;
+typedef struct { short s; } Short;
+typedef struct { } ZeroSized;
+
+// CHECK: define void @returnBig
+// CHECK: ret void
+Big returnBig(Big x) { return x; }
+
+// CHECK-PCC: define void @returnSmall
+// CHECK-PCC: ret void
+// CHECK-REG: define i32 @returnSmall
+// CHECK-REG: ret i32
+Small returnSmall(Small x) { return x; }
+
+// CHECK-PCC: define void @returnShort
+// CHECK-PCC: ret void
+// CHECK-REG: define i16 @returnShort
+// CHECK-REG: ret i16
+Short returnShort(Short x) { return x; }
+
+// CHECK: define void @returnZero()
+// CHECK: ret void
+ZeroSized returnZero(ZeroSized x) { return x; }
diff --git a/include/clang/Driver/Options.td b/include/clang/Driver/Options.td
index c0e4c49..5eb4286 100644
--- a/include/clang/Driver/Options.td
+++ b/include/clang/Driver/Options.td
@@ -687,6 +687,8 @@
HelpText<"Specify the default maximum struct packing alignment">;
def fpascal_strings : Flag<["-"], "fpascal-strings">, Group<f_Group>, Flags<[CC1Option]>,
HelpText<"Recognize and construct Pascal-style string literals">;
+def fpcc_struct_return : Flag<["-"], "fpcc-struct-return">, Group<f_Group>, Flags<[CC1Option]>,
+ HelpText<"Override the default ABI to return all structs on the stack">;
def fpch_preprocess : Flag<["-"], "fpch-preprocess">, Group<f_Group>;
def fpic : Flag<["-"], "fpic">, Group<f_Group>;
def fno_pic : Flag<["-"], "fno-pic">, Group<f_Group>;
@@ -696,6 +698,8 @@
def fprofile_generate : Flag<["-"], "fprofile-generate">, Group<f_Group>;
def framework : Separate<["-"], "framework">, Flags<[LinkerInput]>;
def frandom_seed_EQ : Joined<["-"], "frandom-seed=">, Group<clang_ignored_f_Group>;
+def freg_struct_return : Flag<["-"], "freg-struct-return">, Group<f_Group>, Flags<[CC1Option]>,
+ HelpText<"Override the default ABI to return small structs in registers">;
def frtti : Flag<["-"], "frtti">, Group<f_Group>;
def fsched_interblock : Flag<["-"], "fsched-interblock">, Group<clang_ignored_f_Group>;
def fshort_enums : Flag<["-"], "fshort-enums">, Group<f_Group>, Flags<[CC1Option]>,
diff --git a/include/clang/Frontend/CodeGenOptions.def b/include/clang/Frontend/CodeGenOptions.def
index f6e2472..b414d75 100644
--- a/include/clang/Frontend/CodeGenOptions.def
+++ b/include/clang/Frontend/CodeGenOptions.def
@@ -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(StructReturnConvention, StructReturnConventionKind, 2, SRCK_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.
diff --git a/include/clang/Frontend/CodeGenOptions.h b/include/clang/Frontend/CodeGenOptions.h
index db6b418..6717791 100644
--- a/include/clang/Frontend/CodeGenOptions.h
+++ b/include/clang/Frontend/CodeGenOptions.h
@@ -71,6 +71,12 @@
FPC_Fast // Aggressively fuse FP ops (E.g. FMA).
};
+ enum StructReturnConventionKind {
+ SRCK_Default, // No special option was passed.
+ SRCK_OnStack, // Small structs on the stack (-fpcc-struct-return).
+ SRCK_InRegs // Small structs in registers (-freg-struct-return).
+ };
+
/// The code model to use (-mcmodel).
std::string CodeModel;
diff --git a/lib/CodeGen/TargetInfo.cpp b/lib/CodeGen/TargetInfo.cpp
index 09f7779..01fd8e7 100644
--- a/lib/CodeGen/TargetInfo.cpp
+++ b/lib/CodeGen/TargetInfo.cpp
@@ -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;
@@ -1293,8 +1296,9 @@
class WinX86_32TargetCodeGenInfo : public X86_32TargetCodeGenInfo {
public:
- WinX86_32TargetCodeGenInfo(CodeGen::CodeGenTypes &CGT, unsigned RegParms)
- : X86_32TargetCodeGenInfo(CGT, false, true, true, RegParms) {}
+ WinX86_32TargetCodeGenInfo(CodeGen::CodeGenTypes &CGT,
+ bool d, bool p, bool w, unsigned RegParms)
+ : X86_32TargetCodeGenInfo(CGT, d, p, w, RegParms) {}
void getDependentLibraryOption(llvm::StringRef Lib,
llvm::SmallString<24> &Opt) const {
@@ -4444,6 +4448,36 @@
return ResAddr;
}
+bool X86_32TargetCodeGenInfo::isStructReturnInRegABI(
+ const llvm::Triple &Triple, const CodeGenOptions &Opts) {
+ assert(Triple.getArch() == llvm::Triple::x86);
+
+ switch (Opts.getStructReturnConvention()) {
+ case CodeGenOptions::SRCK_Default:
+ break;
+ case CodeGenOptions::SRCK_OnStack: // -fpcc-struct-return
+ return false;
+ case CodeGenOptions::SRCK_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:
+ case llvm::Triple::Win32:
+ return true;
+ default:
+ return false;
+ }
+}
ABIArgInfo SystemZABIInfo::classifyReturnType(QualType RetTy) const {
if (RetTy->isVoidType())
@@ -5506,31 +5540,22 @@
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:
- return *(TheTargetCodeGenInfo =
- new X86_32TargetCodeGenInfo(Types, false, true, false,
- CodeGenOpts.NumRegisterParameters));
-
- case llvm::Triple::Win32:
+ if (Triple.getOS() == llvm::Triple::Win32) {
return *(TheTargetCodeGenInfo =
new WinX86_32TargetCodeGenInfo(Types,
+ IsDarwinVectorABI, IsSmallStructInRegABI,
+ IsWin32FloatStructABI,
CodeGenOpts.NumRegisterParameters));
-
- default:
+ } else {
return *(TheTargetCodeGenInfo =
- new X86_32TargetCodeGenInfo(Types, false, false, false,
+ new X86_32TargetCodeGenInfo(Types,
+ IsDarwinVectorABI, IsSmallStructInRegABI,
+ IsWin32FloatStructABI,
CodeGenOpts.NumRegisterParameters));
}
}
diff --git a/lib/Driver/Tools.cpp b/lib/Driver/Tools.cpp
index add0c62..373939c 100644
--- a/lib/Driver/Tools.cpp
+++ b/lib/Driver/Tools.cpp
@@ -2165,6 +2165,18 @@
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");
diff --git a/lib/Frontend/CompilerInvocation.cpp b/lib/Frontend/CompilerInvocation.cpp
index 4e62fda..1407e10 100644
--- a/lib/Frontend/CompilerInvocation.cpp
+++ b/lib/Frontend/CompilerInvocation.cpp
@@ -478,6 +478,15 @@
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.setStructReturnConvention(CodeGenOptions::SRCK_OnStack);
+ } else {
+ assert(A->getOption().matches(OPT_freg_struct_return));
+ Opts.setStructReturnConvention(CodeGenOptions::SRCK_InRegs);
+ }
+ }
+
return Success;
}
diff --git a/test/CodeGen/x86_32-fpcc-struct-return.c b/test/CodeGen/x86_32-fpcc-struct-return.c
new file mode 100644
index 0000000..6851102
--- /dev/null
+++ b/test/CodeGen/x86_32-fpcc-struct-return.c
@@ -0,0 +1,34 @@
+// RUN: %clang_cc1 -triple i386-apple-darwin9 -emit-llvm -o - %s | FileCheck %s --check-prefix=REG
+// RUN: %clang_cc1 -triple i386-apple-darwin9 -fpcc-struct-return -emit-llvm -o - %s | FileCheck %s --check-prefix=PCC
+// RUN: %clang_cc1 -triple i386-apple-darwin9 -freg-struct-return -emit-llvm -o - %s | FileCheck %s --check-prefix=REG
+// RUN: %clang_cc1 -triple i386-pc-linux-gnu -emit-llvm -o - %s | FileCheck %s --check-prefix=PCC
+// RUN: %clang_cc1 -triple i386-pc-linux-gnu -fpcc-struct-return -emit-llvm -o - %s | FileCheck %s --check-prefix=PCC
+// RUN: %clang_cc1 -triple i386-pc-linux-gnu -freg-struct-return -emit-llvm -o - %s | FileCheck %s --check-prefix=REG
+// RUN: %clang_cc1 -triple i386-pc-win32 -emit-llvm -o - %s | FileCheck %s --check-prefix=REG
+// RUN: %clang_cc1 -triple i386-pc-win32 -fpcc-struct-return -emit-llvm -o - %s | FileCheck %s --check-prefix=PCC
+// RUN: %clang_cc1 -triple i386-pc-win32 -freg-struct-return -emit-llvm -o - %s | FileCheck %s --check-prefix=REG
+
+typedef struct { int a,b,c,d; } Big;
+typedef struct { int i; } Small;
+typedef struct { short s; } Short;
+typedef struct { } ZeroSized;
+
+// CHECK: define void @returnBig
+// CHECK: ret void
+Big returnBig(Big x) { return x; }
+
+// CHECK-PCC: define void @returnSmall
+// CHECK-PCC: ret void
+// CHECK-REG: define i32 @returnSmall
+// CHECK-REG: ret i32
+Small returnSmall(Small x) { return x; }
+
+// CHECK-PCC: define void @returnShort
+// CHECK-PCC: ret void
+// CHECK-REG: define i16 @returnShort
+// CHECK-REG: ret i16
+Short returnShort(Short x) { return x; }
+
+// CHECK: define void @returnZero()
+// CHECK: ret void
+ZeroSized returnZero(ZeroSized x) { return x; }
