[PowerPC] Correctly use ELFv2 ABI on all OS's that use the ELFv2 ABI

Add a member function isPPC64ELFv2ABI() to determine what ABI is used on the
64-bit PowerPC big endian operating environment.

Reviewed By: nemanjai, dim, pkubaj

Differential Revision: https://reviews.llvm.org/D144321

Author: brad0

clang/lib/Basic/Targets/PPC.h

@@ -427,7 +427,10 @@ class LLVM_LIBRARY_VISIBILITY PPC64TargetInfo : public PPCTargetInfo {
       ABI = "elfv2";
     } else {
       DataLayout = "E-m:e-i64:64-n32:64";
-      ABI = "elfv1";
+      if (Triple.isPPC64ELFv2ABI())
+        ABI = "elfv2";
+      else
+        ABI = "elfv1";
     }
 
     if (Triple.isOSFreeBSD() || Triple.isOSOpenBSD() || Triple.isMusl()) {

clang/lib/Driver/ToolChains/Clang.cpp

@@ -2006,8 +2006,7 @@ void Clang::AddPPCTargetArgs(const ArgList &Args,
   if (T.isOSBinFormatELF()) {
     switch (getToolChain().getArch()) {
     case llvm::Triple::ppc64: {
-      if ((T.isOSFreeBSD() && T.getOSMajorVersion() >= 13) ||
-          T.isOSOpenBSD() || T.isMusl())
+      if (T.isPPC64ELFv2ABI())
         ABIName = "elfv2";
       else
         ABIName = "elfv1";

clang/test/Driver/ppc-abi.c

@@ -20,6 +20,7 @@
 // RUN: %clang -target powerpc64-unknown-freebsd12 %s -### 2>&1 | FileCheck --check-prefix=CHECK-ELFv1 %s
 // RUN: %clang -target powerpc64-unknown-freebsd13 %s -### 2>&1 | FileCheck --check-prefix=CHECK-ELFv2-BE %s
 // RUN: %clang -target powerpc64-unknown-freebsd14 %s -### 2>&1 | FileCheck --check-prefix=CHECK-ELFv2-BE %s
+// RUN: %clang -target powerpc64-unknown-freebsd %s -### 2>&1 | FileCheck --check-prefix=CHECK-ELFv2-BE %s
 // RUN: %clang -target powerpc64le-unknown-freebsd13 %s -### 2>&1 | FileCheck --check-prefix=CHECK-ELFv2 %s
 // RUN: %clang -target powerpc64-unknown-openbsd %s -### 2>&1 | FileCheck --check-prefix=CHECK-ELFv2-BE-PIE %s
 // RUN: %clang -target powerpc64-linux-musl %s -### 2>&1 | FileCheck --check-prefix=CHECK-ELFv2-BE-PIE %s

llvm/include/llvm/TargetParser/Triple.h

@@ -882,6 +882,14 @@ class Triple {
     return getArch() == Triple::ppc64 || getArch() == Triple::ppc64le;
   }
 
+  /// Tests whether the target 64-bit PowerPC big endian ABI is ELFv2.
+  bool isPPC64ELFv2ABI() const {
+    return (getArch() == Triple::ppc64 &&
+            ((getOS() == Triple::FreeBSD &&
+            (getOSMajorVersion() >= 13 || getOSVersion().empty())) ||
+            getOS() == Triple::OpenBSD || isMusl()));
+  }
+
   /// Tests whether the target is 32-bit RISC-V.
   bool isRISCV32() const { return getArch() == Triple::riscv32; }
 

llvm/lib/Target/PowerPC/PPCTargetMachine.cpp

@@ -237,7 +237,10 @@ static PPCTargetMachine::PPCABI computeTargetABI(const Triple &TT,
   case Triple::ppc64le:
     return PPCTargetMachine::PPC_ABI_ELFv2;
   case Triple::ppc64:
-    return PPCTargetMachine::PPC_ABI_ELFv1;
+    if (TT.isPPC64ELFv2ABI())
+      return PPCTargetMachine::PPC_ABI_ELFv2;
+    else
+      return PPCTargetMachine::PPC_ABI_ELFv1;
   default:
     return PPCTargetMachine::PPC_ABI_UNKNOWN;
   }

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

@@ -5,9 +5,14 @@
 ; 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-freebsd < %s | FileCheck %s -check-prefix=CHECK-ELFv1
+; RUN: llc -verify-machineinstrs -mtriple=powerpc64-linux-musl < %s | FileCheck %s -check-prefix=CHECK-ELFv2
+
+; RUN: llc -verify-machineinstrs -mtriple=powerpc64-unknown-freebsd12 < %s | FileCheck %s -check-prefix=CHECK-ELFv1
+; RUN: llc -verify-machineinstrs -mtriple=powerpc64-unknown-freebsd < %s | FileCheck %s -check-prefix=CHECK-ELFv2
 ; 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-openbsd < %s | FileCheck %s -check-prefix=CHECK-ELFv2
+
 ; CHECK-ELFv2: .abiversion 2
 ; CHECK-ELFv1-NOT: .abiversion 2

llvm/test/CodeGen/PowerPC/pr47373.ll

@@ -1,5 +1,5 @@
 ; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
-; RUN: llc -mtriple=powerpc64-unknown-freebsd13.0 -verify-machineinstrs \
+; RUN: llc -mtriple=powerpc64-unknown-freebsd12.0 -verify-machineinstrs \
 ; RUN:   -mcpu=ppc64 -ppc-asm-full-reg-names < %s | FileCheck %s
 @a = local_unnamed_addr global ptr null, align 8