[PowerPC] FreeBSD >= 13 default ABI is ELFv2

[adalava]

Summary

FreeBSD for PowerPC* transitioned[1][2] from gcc4.2 to LLVM9 on Dec 26, 2019 (starting from r356111). The PowerPC64 target also transitioned to ELFv2 ABI at same time, so this makes it default for FreeBSD releases >= 13

*Also would like to have this back ported to LLVM 9 on upstream if possible

[1] https://wiki.freebsd.org/powerpc/llvm-elfv2
[2] https://lists.freebsd.org/pipermail/freebsd-ppc/2019-December/011042.html

[MaskRay]

Are you still using -target powerpc64-unknown-freebsd12.0-elfv2 or -target powerpc64-unknown-freebsd12.0-elfv1 added in https://reviews.llvm.org/rL361355 ?

[MaskRay]

clang/lib/Basic/Targets/PPC.h

389

Which ABI does powerpc64le-linux-gnu use after this change?

[adalava]

In D72306#1807097, @MaskRay wrote:

Are you still using -target powerpc64-unknown-freebsd12.0-elfv2 or -target powerpc64-unknown-freebsd12.0-elfv1 added in https://reviews.llvm.org/rL361355 ?

No, we are not using this triplet anymore after decision to OS version to change ABI, nobody is relying on it.
Are you willing to remove it? User can add "-mabi=[elfv1|elfv2]" to override the default ABI for that OS version, anyway.

clang/lib/Basic/Targets/PPC.h

389

It should be using ELFv2:

[alfredo.junior@FreeBSD_x86 ~/src/llvm-project/build-release-master]$ ./bin/clang -target powerpc64le-linux-gnu -dM -E - < /dev/null | grep CALL_ELF
#define _CALL_ELF 2

Is it ok?

[MaskRay]

Obsoleted by D72352 ?

[adalava]

In D72306#1808613, @MaskRay wrote:

Obsoleted by D72352 ?

Sure, abandoning in favor of D72352. Thank you!

clang/lib/Basic/Targets/PPC.h

 class LLVM_LIBRARY_VISIBILITY PPC64TargetInfo : public PPCTargetInfo {
 public:
   PPC64TargetInfo(const llvm::Triple &Triple, const TargetOptions &Opts)
       : PPCTargetInfo(Triple, Opts) {
     LongWidth = LongAlign = PointerWidth = PointerAlign = 64;
     IntMaxType = SignedLong;
     Int64Type = SignedLong;
 
+    if (Triple.getEnvironment() != llvm::Triple::UnknownEnvironment) {
+      switch (Triple.getEnvironment()){
+        case llvm::Triple::ELFv1:
+          ABI = "elfv1";
+          break;
+        default:
+          ABI = "elfv2";
+          break;
+      }
+    } else {
+      if ((Triple.getOS() == llvm::Triple::FreeBSD) &&
+           (Triple.getOSMajorVersion() < 13)) {
+        ABI = "elfv1";
+      } else {
+        ABI = "elfv2";
+      }
+    }
+
+
     if ((Triple.getArch() == llvm::Triple::ppc64le)) {
       resetDataLayout("e-m:e-i64:64-n32:64");
-      ABI = "elfv2";
     } else {
       resetDataLayout("E-m:e-i64:64-n32:64");
-      ABI = Triple.getEnvironment() == llvm::Triple::ELFv2 ? "elfv2" : "elfv1";
     }
 
     if (Triple.getOS() == llvm::Triple::AIX)
       SuitableAlign = 64;
 
     if (Triple.isOSFreeBSD() || Triple.getOS() == llvm::Triple::AIX ||
         Triple.isMusl()) {
       LongDoubleWidth = LongDoubleAlign = 64;

llvm/lib/Target/PowerPC/PPCTargetMachine.cpp

static std::unique_ptr<TargetLoweringObjectFile> createTLOF(const Triple &TT) {
 
   return std::make_unique<PPC64LinuxTargetObjectFile>();
 }
 
 static PPCTargetMachine::PPCABI computeTargetABI(const Triple &TT,
                                                  const TargetOptions &Options) {
   if (TT.isOSDarwin())
     report_fatal_error("Darwin is no longer supported for PowerPC");
-  
   if (Options.MCOptions.getABIName().startswith("elfv1"))
     return PPCTargetMachine::PPC_ABI_ELFv1;
   else if (Options.MCOptions.getABIName().startswith("elfv2"))
     return PPCTargetMachine::PPC_ABI_ELFv2;
 
   assert(Options.MCOptions.getABIName().empty() &&
          "Unknown target-abi option!");
 
+  if (TT.getEnvironment() == llvm::Triple::ELFv1)
+    return PPCTargetMachine::PPC_ABI_ELFv1;
+  else if (TT.getEnvironment() == llvm::Triple::ELFv2)
+    return PPCTargetMachine::PPC_ABI_ELFv2;
+
   if (TT.isMacOSX())
     return PPCTargetMachine::PPC_ABI_UNKNOWN;
 
+  if (TT.isOSFreeBSD()) {
+    switch (TT.getArch()) {
+    case Triple::ppc64le:
+    case Triple::ppc64:
+      if (TT.getOSMajorVersion() >= 13)
+        return PPCTargetMachine::PPC_ABI_ELFv2;
+      else
+        return PPCTargetMachine::PPC_ABI_ELFv1;
+    case Triple::ppc:
+    default:
+      return PPCTargetMachine::PPC_ABI_UNKNOWN;
+    }
+  }
+
   switch (TT.getArch()) {
   case Triple::ppc64le:
     return PPCTargetMachine::PPC_ABI_ELFv2;
   case Triple::ppc64:
     if (TT.getEnvironment() == llvm::Triple::ELFv2)
       return PPCTargetMachine::PPC_ABI_ELFv2;
     return PPCTargetMachine::PPC_ABI_ELFv1;
   default:

llvm/test/CodeGen/PowerPC/ppc64-elf-abi.ll

 ; RUN: llc -verify-machineinstrs -mtriple=powerpc64-unknown-linux-gnu < %s | FileCheck %s -check-prefix=CHECK-ELFv1
 ; RUN: llc -verify-machineinstrs -mtriple=powerpc64-unknown-linux-gnu -target-abi elfv1 < %s | FileCheck %s -check-prefix=CHECK-ELFv1
 ; RUN: llc -verify-machineinstrs -mtriple=powerpc64-unknown-linux-gnu -target-abi elfv2 < %s | FileCheck %s -check-prefix=CHECK-ELFv2
 ; RUN: llc -verify-machineinstrs -mtriple=powerpc64le-unknown-linux-gnu < %s | FileCheck %s -check-prefix=CHECK-ELFv2
 ; RUN: llc -verify-machineinstrs -mtriple=powerpc64le-unknown-linux-gnu -target-abi elfv1 < %s | FileCheck %s -check-prefix=CHECK-ELFv1
 ; RUN: llc -verify-machineinstrs -mtriple=powerpc64le-unknown-linux-gnu -target-abi elfv2 < %s | FileCheck %s -check-prefix=CHECK-ELFv2
 
+; RUN: llc -verify-machineinstrs -mtriple=powerpc64-unknown-freebsd11 < %s | FileCheck %s -check-prefix=CHECK-ELFv1
+; RUN: llc -verify-machineinstrs -mtriple=powerpc64-unknown-freebsd12 < %s | FileCheck %s -check-prefix=CHECK-ELFv1
+; RUN: llc -verify-machineinstrs -mtriple=powerpc64-unknown-freebsd13 < %s | FileCheck %s -check-prefix=CHECK-ELFv2
+; RUN: llc -verify-machineinstrs -mtriple=powerpc64-unknown-freebsd14 < %s | FileCheck %s -check-prefix=CHECK-ELFv2
+; RUN: llc -verify-machineinstrs -mtriple=powerpc64-unknown-freebsd11 -target-abi elfv1 < %s | FileCheck %s -check-prefix=CHECK-ELFv1
+; RUN: llc -verify-machineinstrs -mtriple=powerpc64-unknown-freebsd11 -target-abi elfv2 < %s | FileCheck %s -check-prefix=CHECK-ELFv2
+; RUN: llc -verify-machineinstrs -mtriple=powerpc64-unknown-freebsd12 -target-abi elfv1 < %s | FileCheck %s -check-prefix=CHECK-ELFv1
+; RUN: llc -verify-machineinstrs -mtriple=powerpc64-unknown-freebsd12 -target-abi elfv2 < %s | FileCheck %s -check-prefix=CHECK-ELFv2
+; RUN: llc -verify-machineinstrs -mtriple=powerpc64-unknown-freebsd13 -target-abi elfv1 < %s | FileCheck %s -check-prefix=CHECK-ELFv1
+; RUN: llc -verify-machineinstrs -mtriple=powerpc64-unknown-freebsd13 -target-abi elfv2 < %s | FileCheck %s -check-prefix=CHECK-ELFv2
+; RUN: llc -verify-machineinstrs -mtriple=powerpc64-unknown-freebsd14 -target-abi elfv1 < %s | FileCheck %s -check-prefix=CHECK-ELFv1
+; RUN: llc -verify-machineinstrs -mtriple=powerpc64-unknown-freebsd14 -target-abi elfv2 < %s | FileCheck %s -check-prefix=CHECK-ELFv2
+
+; RUN: llc -verify-machineinstrs -mtriple=powerpc64-unknown-freebsd11-elfv1 < %s | FileCheck %s -check-prefix=CHECK-ELFv1
+; RUN: llc -verify-machineinstrs -mtriple=powerpc64-unknown-freebsd11-elfv2 < %s | FileCheck %s -check-prefix=CHECK-ELFv2
+; RUN: llc -verify-machineinstrs -mtriple=powerpc64-unknown-freebsd12-elfv1 < %s | FileCheck %s -check-prefix=CHECK-ELFv1
+; RUN: llc -verify-machineinstrs -mtriple=powerpc64-unknown-freebsd12-elfv2 < %s | FileCheck %s -check-prefix=CHECK-ELFv2
+; RUN: llc -verify-machineinstrs -mtriple=powerpc64-unknown-freebsd13-elfv1 < %s | FileCheck %s -check-prefix=CHECK-ELFv1
+; RUN: llc -verify-machineinstrs -mtriple=powerpc64-unknown-freebsd13-elfv2 < %s | FileCheck %s -check-prefix=CHECK-ELFv2
+; RUN: llc -verify-machineinstrs -mtriple=powerpc64-unknown-freebsd14-elfv1 < %s | FileCheck %s -check-prefix=CHECK-ELFv1
+; RUN: llc -verify-machineinstrs -mtriple=powerpc64-unknown-freebsd14-elfv2 < %s | FileCheck %s -check-prefix=CHECK-ELFv2
+
+; FreeBSD target triple without OS version number is incorrect, but checking for regressions anyway
+; RUN: llc -verify-machineinstrs -mtriple=powerpc64-unknown-freebsd < %s | FileCheck %s -check-prefix=CHECK-ELFv1
 ; RUN: llc -verify-machineinstrs -mtriple=powerpc64-unknown-freebsd < %s | FileCheck %s -check-prefix=CHECK-ELFv1
 ; RUN: llc -verify-machineinstrs -mtriple=powerpc64-unknown-freebsd -target-abi elfv1 < %s | FileCheck %s -check-prefix=CHECK-ELFv1
 ; RUN: llc -verify-machineinstrs -mtriple=powerpc64-unknown-freebsd -target-abi elfv2 < %s | FileCheck %s -check-prefix=CHECK-ELFv2
 ; RUN: llc -verify-machineinstrs -mtriple=powerpc64-unknown-freebsd-elfv1  < %s | FileCheck %s -check-prefix=CHECK-ELFv1
 ; RUN: llc -verify-machineinstrs -mtriple=powerpc64-unknown-freebsd-elfv2  < %s | FileCheck %s -check-prefix=CHECK-ELFv2
 
 ; CHECK-ELFv2: .abiversion 2
 ; CHECK-ELFv1-NOT: .abiversion 2