On Tue, 4 Feb 2020 22:23:09 +0900
rgc <
[hidden email]> wrote:
> a) applied a base-clang patch from George Koehler
> [Subject: [ports] [macppc] devel/llvm: add clang -msvr4-struct-return]
>
> ls -la `which clang`
> -r-xr-xr-x 3 root bin 52656676 Feb 4 18:47 /usr/bin/clang*
Here is a copy of the base-clang patch for ppc@.
(I will send it to tech@ in a moment.)
The patch changes the ABI for functions returning small structs, so
the ABI becomes compatible with gcc. I have not seen any such functions
in the kernel, so the patch might not help with kernel builds.
Apply the patch to /usr/src/gnu/llvm, then build clang like
# cd /usr/src/gnu/usr.bin/clang
# make obj
# make
# make install
If you have less than 1024M RAM, then the build might be too slow.
My iMac G3 with 512M RAM got stuck (using over 800M swap) trying to
build the ports-clang patch that I sent to ports@,
https://marc.info/?l=openbsd-ports&m=158026852003182&w=2--George
Index: tools/clang/include/clang/Driver/Options.td
===================================================================
RCS file: /cvs/src/gnu/llvm/tools/clang/include/clang/Driver/Options.td,v
retrieving revision 1.11
diff -u -p -r1.11 Options.td
--- tools/clang/include/clang/Driver/Options.td 23 Jun 2019 22:05:15 -0000 1.11
+++ tools/clang/include/clang/Driver/Options.td 30 Jan 2020 01:13:29 -0000
@@ -2238,6 +2238,12 @@ def mlongcall: Flag<["-"], "mlongcall">,
Group<m_ppc_Features_Group>;
def mno_longcall : Flag<["-"], "mno-longcall">,
Group<m_ppc_Features_Group>;
+def maix_struct_return : Flag<["-"], "maix-struct-return">,
+ Group<m_Group>, Flags<[CC1Option]>,
+ HelpText<"Return all structs in memory (PPC32 only)">;
+def msvr4_struct_return : Flag<["-"], "msvr4-struct-return">,
+ Group<m_Group>, Flags<[CC1Option]>,
+ HelpText<"Return small structs in registers (PPC32 only)">;
def mvx : Flag<["-"], "mvx">, Group<m_Group>;
def mno_vx : Flag<["-"], "mno-vx">, Group<m_Group>;
Index: tools/clang/lib/CodeGen/TargetInfo.cpp
===================================================================
RCS file: /cvs/src/gnu/llvm/tools/clang/lib/CodeGen/TargetInfo.cpp,v
retrieving revision 1.1.1.7
diff -u -p -r1.1.1.7 TargetInfo.cpp
--- tools/clang/lib/CodeGen/TargetInfo.cpp 23 Jun 2019 21:37:39 -0000 1.1.1.7
+++ tools/clang/lib/CodeGen/TargetInfo.cpp 30 Jan 2020 01:13:30 -0000
@@ -4092,12 +4092,24 @@ namespace {
/// PPC32_SVR4_ABIInfo - The 32-bit PowerPC ELF (SVR4) ABI information.
class PPC32_SVR4_ABIInfo : public DefaultABIInfo {
bool IsSoftFloatABI;
+ bool IsRetSmallStructInRegABI;
CharUnits getParamTypeAlignment(QualType Ty) const;
public:
- PPC32_SVR4_ABIInfo(CodeGen::CodeGenTypes &CGT, bool SoftFloatABI)
- : DefaultABIInfo(CGT), IsSoftFloatABI(SoftFloatABI) {}
+ PPC32_SVR4_ABIInfo(CodeGen::CodeGenTypes &CGT, bool SoftFloatABI,
+ bool RetSmallStructInRegABI)
+ : DefaultABIInfo(CGT), IsSoftFloatABI(SoftFloatABI),
+ IsRetSmallStructInRegABI(RetSmallStructInRegABI) {}
+
+ ABIArgInfo classifyReturnType(QualType RetTy) const;
+
+ void computeInfo(CGFunctionInfo &FI) const override {
+ if (!getCXXABI().classifyReturnType(FI))
+ FI.getReturnInfo() = classifyReturnType(FI.getReturnType());
+ for (auto &I : FI.arguments())
+ I.info = classifyArgumentType(I.type);
+ }
Address EmitVAArg(CodeGenFunction &CGF, Address VAListAddr,
QualType Ty) const override;
@@ -4105,8 +4117,13 @@ public:
class PPC32TargetCodeGenInfo : public TargetCodeGenInfo {
public:
- PPC32TargetCodeGenInfo(CodeGenTypes &CGT, bool SoftFloatABI)
- : TargetCodeGenInfo(new PPC32_SVR4_ABIInfo(CGT, SoftFloatABI)) {}
+ PPC32TargetCodeGenInfo(CodeGenTypes &CGT, bool SoftFloatABI,
+ bool RetSmallStructInRegABI)
+ : TargetCodeGenInfo(new PPC32_SVR4_ABIInfo(CGT, SoftFloatABI,
+ RetSmallStructInRegABI)) {}
+
+ static bool isStructReturnInRegABI(const llvm::Triple &Triple,
+ const CodeGenOptions &Opts);
int getDwarfEHStackPointer(CodeGen::CodeGenModule &M) const override {
// This is recovered from gcc output.
@@ -4142,6 +4159,34 @@ CharUnits PPC32_SVR4_ABIInfo::getParamTy
return CharUnits::fromQuantity(4);
}
+ABIArgInfo PPC32_SVR4_ABIInfo::classifyReturnType(QualType RetTy) const {
+ uint64_t Size;
+
+ // -msvr4-struct-return puts small aggregates in GPR3 and GPR4.
+ if (isAggregateTypeForABI(RetTy) && IsRetSmallStructInRegABI &&
+ (Size = getContext().getTypeSize(RetTy)) <= 64) {
+ // System V ABI (1995), page 3-22, specified:
+ // > A structure or union whose size is less than or equal to 8 bytes
+ // > shall be returned in r3 and r4, as if it were first stored in the
+ // > 8-byte aligned memory area and then the low addressed word were
+ // > loaded into r3 and the high-addressed word into r4. Bits beyond
+ // > the last member of the structure or union are not defined.
+ //
+ // GCC for big-endian PPC32 inserts the pad before the first member,
+ // not "beyond the last member" of the struct. To stay compatible
+ // with GCC, we coerce the struct to an integer of the same size.
+ // LLVM will extend it and return i32 in r3, or i64 in r3:r4.
+ if (Size == 0)
+ return ABIArgInfo::getIgnore();
+ else {
+ llvm::Type *CoerceTy = llvm::Type::getIntNTy(getVMContext(), Size);
+ return ABIArgInfo::getDirect(CoerceTy);
+ }
+ }
+
+ return DefaultABIInfo::classifyReturnType(RetTy);
+}
+
// TODO: this implementation is now likely redundant with
// DefaultABIInfo::EmitVAArg.
Address PPC32_SVR4_ABIInfo::EmitVAArg(CodeGenFunction &CGF, Address VAList,
@@ -4299,6 +4344,25 @@ Address PPC32_SVR4_ABIInfo::EmitVAArg(Co
return Result;
}
+bool PPC32TargetCodeGenInfo::isStructReturnInRegABI(
+ const llvm::Triple &Triple, const CodeGenOptions &Opts) {
+ assert(Triple.getArch() == llvm::Triple::ppc);
+
+ switch (Opts.getStructReturnConvention()) {
+ case CodeGenOptions::SRCK_Default:
+ break;
+ case CodeGenOptions::SRCK_OnStack: // -maix-struct-return
+ return false;
+ case CodeGenOptions::SRCK_InRegs: // -msvr4-struct-return
+ return true;
+ }
+
+ if (Triple.isOSBinFormatELF() && !Triple.isOSLinux())
+ return true;
+
+ return false;
+}
+
bool
PPC32TargetCodeGenInfo::initDwarfEHRegSizeTable(CodeGen::CodeGenFunction &CGF,
llvm::Value *Address) const {
@@ -9330,9 +9394,13 @@ const TargetCodeGenInfo &CodeGenModule::
return SetCGInfo(new ARMTargetCodeGenInfo(Types, Kind));
}
- case llvm::Triple::ppc:
+ case llvm::Triple::ppc: {
+ bool RetSmallStructInRegABI =
+ PPC32TargetCodeGenInfo::isStructReturnInRegABI(Triple, CodeGenOpts);
return SetCGInfo(
- new PPC32TargetCodeGenInfo(Types, CodeGenOpts.FloatABI == "soft"));
+ new PPC32TargetCodeGenInfo(Types, CodeGenOpts.FloatABI == "soft",
+ RetSmallStructInRegABI));
+ }
case llvm::Triple::ppc64:
if (Triple.isOSBinFormatELF()) {
PPC64_SVR4_ABIInfo::ABIKind Kind = PPC64_SVR4_ABIInfo::ELFv1;
Index: tools/clang/lib/Driver/ToolChains/Clang.cpp
===================================================================
RCS file: /cvs/src/gnu/llvm/tools/clang/lib/Driver/ToolChains/Clang.cpp,v
retrieving revision 1.20
diff -u -p -r1.20 Clang.cpp
--- tools/clang/lib/Driver/ToolChains/Clang.cpp 25 Oct 2019 00:40:56 -0000 1.20
+++ tools/clang/lib/Driver/ToolChains/Clang.cpp 30 Jan 2020 01:13:30 -0000
@@ -3870,6 +3870,19 @@ void Clang::ConstructJob(Compilation &C,
CmdArgs.push_back(A->getValue());
}
+ if (Arg *A = Args.getLastArg(options::OPT_maix_struct_return,
+ options::OPT_msvr4_struct_return)) {
+ if (TC.getArch() != llvm::Triple::ppc) {
+ D.Diag(diag::err_drv_unsupported_opt_for_target)
+ << A->getSpelling() << RawTriple.str();
+ } else if (A->getOption().matches(options::OPT_maix_struct_return)) {
+ CmdArgs.push_back("-maix-struct-return");
+ } else {
+ assert(A->getOption().matches(options::OPT_msvr4_struct_return));
+ CmdArgs.push_back("-msvr4-struct-return");
+ }
+ }
+
if (Arg *A = Args.getLastArg(options::OPT_fpcc_struct_return,
options::OPT_freg_struct_return)) {
if (TC.getArch() != llvm::Triple::x86) {
Index: tools/clang/lib/Frontend/CompilerInvocation.cpp
===================================================================
RCS file: /cvs/src/gnu/llvm/tools/clang/lib/Frontend/CompilerInvocation.cpp,v
retrieving revision 1.4
diff -u -p -r1.4 CompilerInvocation.cpp
--- tools/clang/lib/Frontend/CompilerInvocation.cpp 23 Jun 2019 22:05:15 -0000 1.4
+++ tools/clang/lib/Frontend/CompilerInvocation.cpp 30 Jan 2020 01:13:30 -0000
@@ -1199,11 +1199,18 @@ static bool ParseCodeGenArgs(CodeGenOpti
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)) {
+ // X86_32 has -fppc-struct-return and -freg-struct-return.
+ // PPC32 has -maix-struct-return and -msvr4-struct-return.
+ if (Arg *A =
+ Args.getLastArg(OPT_fpcc_struct_return, OPT_freg_struct_return,
+ OPT_maix_struct_return, OPT_msvr4_struct_return)) {
+ const Option &O = A->getOption();
+ if (O.matches(OPT_fpcc_struct_return) ||
+ O.matches(OPT_maix_struct_return)) {
Opts.setStructReturnConvention(CodeGenOptions::SRCK_OnStack);
} else {
- assert(A->getOption().matches(OPT_freg_struct_return));
+ assert(O.matches(OPT_freg_struct_return) ||
+ O.matches(OPT_msvr4_struct_return));
Opts.setStructReturnConvention(CodeGenOptions::SRCK_InRegs);
}
}
Locked
