Teach the verifier to reject all non-constant arguments to the second

argument of the cttz and ctlz intrinsics.

llvm-svn: 146360

2 files changed, 22 insertions, 0 deletions

diff --git a/llvm/lib/VMCore/Verifier.cpp b/llvm/lib/VMCore/Verifier.cpp
index f74d762be94..003de442d61 100644
--- a/llvm/lib/VMCore/Verifier.cpp
+++ b/llvm/lib/VMCore/Verifier.cpp
@@ -1688,6 +1688,12 @@ void Verifier::visitIntrinsicFunctionCall(Intrinsic::ID ID, CallInst &CI) {
   switch (ID) {
   default:
     break;
+  case Intrinsic::ctlz:  // llvm.ctlz
+  case Intrinsic::cttz:  // llvm.cttz
+    Assert1(isa<ConstantInt>(CI.getArgOperand(1)),
+            "is_zero_undef argument of bit counting intrinsics must be a "
+            "constant int", &CI);
+    break;
   case Intrinsic::dbg_declare: {  // llvm.dbg.declare
     Assert1(CI.getArgOperand(0) && isa<MDNode>(CI.getArgOperand(0)),
                 "invalid llvm.dbg.declare intrinsic call 1", &CI);
diff --git a/llvm/test/Verifier/cttz-undef-arg.ll b/llvm/test/Verifier/cttz-undef-arg.ll
new file mode 100644
index 00000000000..48cd061d322
--- /dev/null
+++ b/llvm/test/Verifier/cttz-undef-arg.ll
@@ -0,0 +1,16 @@
+; RUN: not llvm-as < %s -o /dev/null |& FileCheck %s
+
+declare i32 @llvm.ctlz.i32(i32, i1)
+declare i32 @llvm.cttz.i32(i32, i1)
+
+define void @f(i32 %x, i1 %is_not_zero) {
+entry:
+; CHECK: is_zero_undef argument of bit counting intrinsics must be a constant int
+; CHECK-NEXT: @llvm.ctlz.i32
+  call i32 @llvm.ctlz.i32(i32 %x, i1 %is_not_zero)
+
+; CHECK: is_zero_undef argument of bit counting intrinsics must be a constant int
+; CHECK-NEXT: @llvm.cttz.i32
+  call i32 @llvm.cttz.i32(i32 %x, i1 %is_not_zero)
+  ret void
+}