[PowerPC] Support powerpc64le as a syntax-checking target.

This patch provides basic support for powerpc64le as an LLVM target.
However, use of this target will not actually generate little-endian
code.  Instead, use of the target will cause the correct little-endian
built-in defines to be generated, so that code that tests for
__LITTLE_ENDIAN__, for example, will be correctly parsed for
syntax-only testing.  Code generation will otherwise be the same as
powerpc64 (big-endian), for now.

The patch leaves open the possibility of creating a little-endian
PowerPC64 back end, but there is no immediate intent to create such a
thing.

The LLVM portions of this patch simply add ppc64le coverage everywhere
that ppc64 coverage currently exists.  There is nothing of any import
worth testing until such time as little-endian code generation is
implemented.  In the corresponding Clang patch, there is a new test
case variant to ensure that correct built-in defines for little-endian
code are generated.

llvm-svn: 187179

1 files changed, 3 insertions, 0 deletions

diff --git a/llvm/lib/Target/PowerPC/PPCSubtarget.cpp b/llvm/lib/Target/PowerPC/PPCSubtarget.cpp
index 51fbfdaef8c..12d0326855c 100644
--- a/llvm/lib/Target/PowerPC/PPCSubtarget.cpp
+++ b/llvm/lib/Target/PowerPC/PPCSubtarget.cpp
@@ -137,6 +137,9 @@ void PPCSubtarget::resetSubtargetFeatures(StringRef CPU, StringRef FS) {
   // is enabled because external functions will assume this alignment.
   if (hasQPX() || isBGQ())
     StackAlignment = 32;
+
+  // Determine endianness.
+  IsLittleEndian = (TargetTriple.getArch() == Triple::ppc64le);
 }
 
 /// hasLazyResolverStub - Return true if accesses to the specified global have