Index: lib/Target/PowerPC/PPCSubtarget.cpp
===================================================================
--- lib/Target/PowerPC/PPCSubtarget.cpp
+++ lib/Target/PowerPC/PPCSubtarget.cpp
@@ -129,8 +129,13 @@
 void PPCSubtarget::initSubtargetFeatures(StringRef CPU, StringRef FS) {
   // Determine default and user specified characteristics
   std::string CPUName = CPU;
-  if (CPUName.empty())
-    CPUName = "generic";
+  if (CPUName.empty()) {
+    // If cross-compiling with -march=ppc64le without -mcpu
+    if (TargetTriple.getArch() == Triple::ppc64le)
+      CPUName = "ppc64le";
+    else
+      CPUName = "generic";
+  }
 #if (defined(__APPLE__) || defined(__linux__)) && \
     (defined(__ppc__) || defined(__powerpc__))
   if (CPUName == "generic")
Index: test/CodeGen/PowerPC/ppc64le-aggregates.ll
===================================================================
--- test/CodeGen/PowerPC/ppc64le-aggregates.ll
+++ test/CodeGen/PowerPC/ppc64le-aggregates.ll
@@ -1,8 +1,11 @@
 ; RUN: llc < %s -march=ppc64le -mcpu=pwr8 -mattr=+altivec -mattr=-vsx | FileCheck %s
+; RUN: llc < %s -march=ppc64le -mattr=+altivec -mattr=-vsx | FileCheck %s
 
 ; Currently VSX support is disabled for this test because we generate lxsdx
 ; instead of lfd, and stxsdx instead of stfd.  That is a poor choice when we
 ; have reg+imm addressing, and is on the list of things to be fixed.
+; The second run step is to ensure that -march=ppc64le is adequate to select
+; the same feature set as with -mcpu=pwr8 since that is the baseline for ppc64le.
 
 target datalayout = "e-m:e-i64:64-n32:64"
 target triple = "powerpc64le-unknown-linux-gnu"