[CGProfile] don't emit cgprofile entry if called function is dllimport

Differential Revision: https://reviews.llvm.org/D88127

Author: ZequanWu

llvm/lib/Transforms/Instrumentation/CGProfile.cpp

@@ -53,7 +53,8 @@ static bool runCGProfilePass(
   InstrProfSymtab Symtab;
   auto UpdateCounts = [&](TargetTransformInfo &TTI, Function *F,
                           Function *CalledF, uint64_t NewCount) {
-    if (!CalledF || !TTI.isLoweredToCall(CalledF))
+    if (!CalledF || !TTI.isLoweredToCall(CalledF) ||
+        CalledF->hasDLLImportStorageClass())
       return;
     uint64_t &Count = Counts[std::make_pair(F, CalledF)];
     Count = SaturatingAdd(Count, NewCount);

llvm/test/Instrumentation/cgprofile.ll

@@ -13,6 +13,7 @@ declare i32 @func1()
 declare i32 @func2()
 declare i32 @func3()
 declare i32 @func4()
+declare dllimport i32 @func5()
 
 define void @freq(i1 %cond) !prof !1 {
   %tmp = load i32 ()*, i32 ()** @foo, align 8
@@ -28,7 +29,7 @@ B:
 
 !1 = !{!"function_entry_count", i64 32}
 !2 = !{!"branch_weights", i32 5, i32 10}
-!3 = !{!"VP", i32 0, i64 1600, i64 7651369219802541373, i64 1030, i64 -4377547752858689819, i64 410, i64 -6929281286627296573, i64 150, i64 -2545542355363006406, i64 10}
+!3 = !{!"VP", i32 0, i64 1600, i64 7651369219802541373, i64 1030, i64 -4377547752858689819, i64 410, i64 -6929281286627296573, i64 150, i64 -2545542355363006406, i64 10, i64 3667884930908592509, i64 0}
 
 ; CHECK: !llvm.module.flags = !{![[cgprof:[0-9]+]]}
 ; CHECK: ![[cgprof]] = !{i32 5, !"CG Profile", ![[prof:[0-9]+]]}
@@ -40,3 +41,4 @@ B:
 ; CHECK: ![[e4]] = !{void (i1)* @freq, i32 ()* @func1, i64 10}
 ; CHECK: ![[e5]] = !{void (i1)* @freq, void ()* @a, i64 11}
 ; CHECK: ![[e6]] = !{void (i1)* @freq, void ()* @b, i64 21}
+; CHECK-NOT: !{void (i1)* @freq, void ()* @func5, i64 0}