[AbstractCallSite][FIX] Correct faulty assertion

When the Attributor run on the IPConstantProp test case for multiple
callbacks it triggered a faulty assertion in the AbstractCallSite
implementation. The callee can well be at argument position 0.

2 files changed, 2 insertions, 1 deletions

diff --git a/llvm/include/llvm/IR/CallSite.h b/llvm/include/llvm/IR/CallSite.h
index 13b1ae8d0e3..60f656e7a27 100644
--- a/llvm/include/llvm/IR/CallSite.h
+++ b/llvm/include/llvm/IR/CallSite.h
@@ -850,7 +850,7 @@ public:
   /// callee of this ACS. Only valid for callback calls!
   int getCallArgOperandNoForCallee() const {
     assert(isCallbackCall());
-    assert(CI.ParameterEncoding.size() && CI.ParameterEncoding[0] > 0);
+    assert(CI.ParameterEncoding.size() && CI.ParameterEncoding[0] >= 0);
     return CI.ParameterEncoding[0];
   }
 
diff --git a/llvm/test/Transforms/IPConstantProp/multiple_callbacks.ll b/llvm/test/Transforms/IPConstantProp/multiple_callbacks.ll
index 3288b5b94de..0d1df8dff52 100644
--- a/llvm/test/Transforms/IPConstantProp/multiple_callbacks.ll
+++ b/llvm/test/Transforms/IPConstantProp/multiple_callbacks.ll
@@ -1,4 +1,5 @@
 ; RUN: opt -ipconstprop -S < %s | FileCheck %s
+; RUN: opt -S -passes=attributor -aa-pipeline='basic-aa' -attributor-disable=false -attributor-max-iterations-verify -attributor-max-iterations=1 < %s | FileCheck %s
 ;
 ;
 ;                            /---------------------------------------|