This is one of the first steps at moving to replace target-dependent

intrinsics with target-indepdent intrinsics.  The first instruction(s) to be 
handled are the vector versions of count leading zeros (ctlz).

The changes here are to clang so that it generates a target independent 
vector ctlz when it sees an ARM dependent vector ctlz.  The changes in llvm 
are to match the target independent vector ctlz and in VMCore/AutoUpgrade.cpp 
to update any existing bc files containing ARM dependent vector ctlzs with 
target-independent ctlzs.  There are also changes to an existing test case in 
llvm for ARM vector count instructions and a new test for the bitcode upgrade.

<rdar://problem/11831778>

There is deliberately no test for the change to clang, as so far as I know, no
consensus has been reached regarding how to test neon instructions in clang;
q.v. <rdar://problem/8762292>

llvm-svn: 160201

1 files changed, 4 insertions, 1 deletions

diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
index 575fa5d1acd..d8fdad64537 100644
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -1629,7 +1629,10 @@ Value *CodeGenFunction::EmitARMBuiltinExpr(unsigned BuiltinID,
   }
   case ARM::BI__builtin_neon_vclz_v:
   case ARM::BI__builtin_neon_vclzq_v: {
-    Function *F = CGM.getIntrinsic(Intrinsic::arm_neon_vclz, Ty);
+    // generate target-independent intrinsic; also need to add second argument
+    // for whether or not clz of zero is undefined; on ARM it isn't.
+    Function *F = CGM.getIntrinsic(Intrinsic::ctlz, Ty);
+    Ops.push_back(Builder.getInt1(Target.isCLZForZeroUndef()));
     return EmitNeonCall(F, Ops, "vclz");
   }
   case ARM::BI__builtin_neon_vcnt_v: