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: 160200

2 files changed, 26 insertions, 1 deletions

diff --git a/llvm/lib/Target/ARM/ARMInstrNEON.td b/llvm/lib/Target/ARM/ARMInstrNEON.td
index 404b3ad176e..c540d0ddd70 100644
--- a/llvm/lib/Target/ARM/ARMInstrNEON.td
+++ b/llvm/lib/Target/ARM/ARMInstrNEON.td
@@ -4825,7 +4825,7 @@ defm VCLS     : N2VInt_QHS<0b11, 0b11, 0b00, 0b01000, 0,
 //   VCLZ     : Vector Count Leading Zeros
 defm VCLZ     : N2VInt_QHS<0b11, 0b11, 0b00, 0b01001, 0,
                            IIC_VCNTiD, IIC_VCNTiQ, "vclz", "i",
-                           int_arm_neon_vclz>;
+                           ctlz>;
 //   VCNT     : Vector Count One Bits
 def  VCNTd    : N2VDInt<0b11, 0b11, 0b00, 0b00, 0b01010, 0,
                         IIC_VCNTiD, "vcnt", "8",
diff --git a/llvm/lib/VMCore/AutoUpgrade.cpp b/llvm/lib/VMCore/AutoUpgrade.cpp
index 1defd20728f..8febce18c03 100644
--- a/llvm/lib/VMCore/AutoUpgrade.cpp
+++ b/llvm/lib/VMCore/AutoUpgrade.cpp
@@ -52,6 +52,22 @@ static bool UpgradeIntrinsicFunction1(Function *F, Function *&NewFn) {
 
   switch (Name[0]) {
   default: break;
+  case 'a': {
+    if (Name.startswith("arm.neon.vclz")) {
+      Type* args[2] = {
+        F->arg_begin()->getType(), 
+        Type::getInt1Ty(F->getContext())
+      };
+      // Can't use Intrinsic::getDeclaration here as it adds a ".i1" to
+      // the end of the name. Change name from llvm.arm.neon.vclz.* to
+      //  llvm.ctlz.*
+      FunctionType* fType = FunctionType::get(F->getReturnType(), args, false);
+      NewFn = Function::Create(fType, F->getLinkage(), 
+                               "llvm.ctlz." + Name.substr(14), F->getParent());
+      return true;
+    }
+    break;
+  }
   case 'c': {
     if (Name.startswith("ctlz.") && F->arg_size() == 1) {
       F->setName(Name + ".old");
@@ -295,6 +311,15 @@ void llvm::UpgradeIntrinsicCall(CallInst *CI, Function *NewFn) {
     CI->eraseFromParent();
     return;
 
+  case Intrinsic::arm_neon_vclz: {
+    // Change name from llvm.arm.neon.vclz.* to llvm.ctlz.*
+    CI->replaceAllUsesWith(Builder.CreateCall2(NewFn, CI->getArgOperand(0),
+                                               Builder.getFalse(), 
+                                               "llvm.ctlz." + Name.substr(14)));
+    CI->eraseFromParent();
+    return;
+  }
+
   case Intrinsic::x86_xop_vfrcz_ss:
   case Intrinsic::x86_xop_vfrcz_sd:
     CI->replaceAllUsesWith(Builder.CreateCall(NewFn, CI->getArgOperand(1),