This patch adds alignment information for long double to the 64-bit PowerPC
ELF subtarget.

The existing logic is used as a fallback to avoid any changes to the Darwin
ABI.  PPC64 ELF now has two possible data layout strings: one for FreeBSD,
which requires 8-byte alignment, and a default string that requires
16-byte alignment.

I've added a test for PPC64 Linux to verify the 16-byte alignment.  If
somebody wants to add a separate test for FreeBSD, that would be great.

Note that there is a companion patch to update the alignment information
in Clang, which I am committing now as well.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166928 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/PowerPC/PPCSubtarget.h b/lib/Target/PowerPC/PPCSubtarget.h
index c20995a..77784e0 100644
--- a/lib/Target/PowerPC/PPCSubtarget.h
+++ b/lib/Target/PowerPC/PPCSubtarget.h
@@ -113,6 +113,12 @@
   const char *getDataLayoutString() const {
     // Note, the alignment values for f64 and i64 on ppc64 in Darwin
     // documentation are wrong; these are correct (i.e. "what gcc does").
+    if (isPPC64() && isSVR4ABI())
+      if (TargetTriple.getOS() == llvm::Triple::FreeBSD)
+        return "E-p:64:64-f64:64:64-i64:64:64-f128:64:64-v128:128:128-n32:64";
+      else
+        return "E-p:64:64-f64:64:64-i64:64:64-f128:128:128-v128:128:128-n32:64";
+
     return isPPC64() ? "E-p:64:64-f64:64:64-i64:64:64-f128:64:128-n32:64"
                      : "E-p:32:32-f64:64:64-i64:64:64-f128:64:128-n32";
   }