Add ABI infrastructure for PPC64.

The generic ABI works well with PPC64 except for LLVM PR 14779.
(http://llvm.org/bugs/show_bug.cgi?id=14779)
The new ABI infrastucture is based on the UnknownTargetABI. The
PPC64 specific parts coming soon.

gen/abi-ppc64.cpp

@@ -0,0 +1,59 @@
+//===-- abi-x86-64.cpp ----------------------------------------------------===//
+//
+//                         LDC – the LLVM D compiler
+//
+// This file is distributed under the BSD-style LDC license. See the LICENSE
+// file for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// The PowerOpen 64bit ABI can be found here:
+// http://refspecs.linuxfoundation.org/ELF/ppc64/PPC-elf64abi-1.9.html
+//
+//===----------------------------------------------------------------------===//
+
+#include "gen/abi.h"
+#include "gen/irstate.h"
+#include "gen/tollvm.h"
+#include "gen/llvmhelpers.h"
+#include "gen/dvalue.h"
+
+struct PPC64TargetABI : TargetABI {
+
+    void newFunctionType(TypeFunction* tf)
+    {
+    }
+
+    bool returnInArg(TypeFunction* tf)
+    {
+#if DMDV2
+        if (tf->isref)
+            return false;
+#endif
+        // Return structs and static arrays on the stack. The latter is needed
+        // because otherwise LLVM tries to actually return the array in a number
+        // of physical registers, which leads, depending on the target, to
+        // either horrendous codegen or backend crashes.
+        Type* rt = tf->next->toBasetype();
+        return (rt->ty == Tstruct || rt->ty == Tsarray);
+    }
+
+    bool passByVal(Type* t)
+    {
+        return t->toBasetype()->ty == Tstruct;
+    }
+
+    void doneWithFunctionType()
+    {
+    }
+
+    void rewriteFunctionType(TypeFunction* tf)
+    {
+    }
+};
+
+// The public getter for abi.cpp
+TargetABI* getPPC64TargetABI()
+{
+    return new PPC64TargetABI();
+}

gen/abi-ppc64.h

@@ -0,0 +1,23 @@
+//===-- gen/abi-x86-64.h - x86_64 ABI description ---------------*- C++ -*-===//
+//
+//                         LDC – the LLVM D compiler
+//
+// This file is distributed under the BSD-style LDC license. See the LICENSE
+// file for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// The ABI implementation used for 64 bit PowerPC targets.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef __LDC_GEN_ABI_PPC64_H__
+#define __LDC_GEN_ABI_PPC64_H__
+
+#include "gen/abi.h"
+
+
+TargetABI* getPPC64TargetABI();
+
+
+#endif

gen/abi.cpp

@@ -20,6 +20,7 @@
 #include "gen/logger.h"
 #include "gen/dvalue.h"
 #include "gen/abi-generic.h"
+#include "gen/abi-ppc64.h"
 #include "gen/abi-x86.h"
 #include "gen/abi-x86-64.h"
 #include "ir/irfunction.h"
@@ -74,6 +75,8 @@ TargetABI * TargetABI::getTarget()
         return getX86TargetABI();
     case ARCHx86_64:
         return getX86_64TargetABI();
+    case ARCHppc_64:
+        return getPPC64TargetABI();
     default:
         Logger::cout() << "WARNING: Unknown ABI, guessing...\n";
         return new UnknownTargetABI;