[ThinLTO] Remove too aggressive assertion in building function call graph.

The assertion was introduced in r317853 but there are cases when a call
isn't handled either as direct or indirect. In this case we add a
reference graph edge but not a call graph edge.

Reviewers: tejohnson

Reviewed By: tejohnson

Subscribers: mehdi_amini, inglorion, eraman, hiraditya, efriedma, llvm-commits

Differential Revision: https://reviews.llvm.org/D40056



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@318540 91177308-0d34-0410-b5e6-96231b3b80d8

Author: vsapsai

lib/Analysis/ModuleSummaryAnalysis.cpp

@@ -280,8 +280,9 @@ computeFunctionSummary(ModuleSummaryIndex &Index, const Module &M,
         // Skip inline assembly calls.
         if (CI && CI->isInlineAsm())
           continue;
-        assert(CalledValue && !isa<Constant>(CalledValue) &&
-               "Expected indirect call");
+        // Skip direct calls.
+        if (!CalledValue || isa<Constant>(CalledValue))
+          continue;
 
         uint32_t NumVals, NumCandidates;
         uint64_t TotalCount;

test/Bitcode/thinlto-function-summary-callgraph-cast.ll

@@ -5,8 +5,10 @@
 
 ; CHECK:       <GLOBALVAL_SUMMARY_BLOCK
 ; CHECK-NEXT:    <VERSION
-; "op7=1" is a call to "callee" function.
-; CHECK-NEXT:    <PERMODULE {{.*}} op7=1 op8=[[ALIASID:[0-9]+]]/>
+; "op7" is a call to "callee" function.
+; CHECK-NEXT:    <PERMODULE {{.*}} op7=3 op8=[[ALIASID:[0-9]+]]/>
+; "another_caller" has only references but no calls.
+; CHECK-NEXT:    <PERMODULE {{.*}} op4=3 {{.*}} op7={{[0-9]+}}/>
 ; CHECK-NEXT:    <PERMODULE {{.*}} op0=[[ALIASEEID:[0-9]+]]
 ; CHECK-NEXT:    <ALIAS {{.*}} op0=[[ALIASID]] {{.*}} op2=[[ALIASEEID]]/>
 ; CHECK-NEXT:  </GLOBALVAL_SUMMARY_BLOCK>
@@ -21,6 +23,12 @@ define void @caller() {
     ret void
 }
 
+define void @another_caller() {
+    ; Test calls that aren't handled either as direct or indirect.
+    call void select (i1 icmp eq (i32* @global, i32* null), void ()* @f, void ()* @g)()
+    ret void
+}
+
 declare void @callee(...)
 
 @analias = alias void (...), bitcast (void ()* @aliasee to void (...)*)
@@ -29,3 +37,7 @@ define void @aliasee() {
 entry:
     ret void
 }
+
+declare void @f()
+declare void @g()
+@global = extern_weak global i32