[clang] [compiler-rt] [llvm] [TypeProf][InstrFDO]Implement more efficient comparison sequence for indirect-call-promotion with vtable profiles. (PR #81442)

[Mingming Liu via cfe-commits]

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@@ -89,41 +93,50 @@
 // ICTEXT: # NumValueSites:
 // ICTEXT: 2
 // ICTEXT: 2
-// ICTEXT: {{.*}}instrprof-vtable-value-prof.cpp;_ZN12_GLOBAL__N_18Derived25func1Eii:750
-// ICTEXT: _ZN8Derived15func1Eii:250
+// ICTEXT: {{.*}}instrprof-vtable-value-prof.cpp;_ZN12_GLOBAL__N_18Derived24funcEii:150
+// ICTEXT: _ZN8Derived14funcEii:50
 // ICTEXT: 2
-// ICTEXT: {{.*}}instrprof-vtable-value-prof.cpp;_ZN12_GLOBAL__N_18Derived25func2Eii:750
-// ICTEXT: _ZN8Derived15func2Eii:250
+// ICTEXT: {{.*}}instrprof-vtable-value-prof.cpp;_ZN12_GLOBAL__N_18Derived2D0Ev:750
+// ICTEXT: _ZN8Derived1D0Ev:250
 // ICTEXT: # ValueKind = IPVK_VTableTarget:
 // ICTEXT: 2
 // ICTEXT: # NumValueSites:
 // ICTEXT: 2
 // ICTEXT: 2
-// ICTEXT: {{.*}}instrprof-vtable-value-prof.cpp;_ZTVN12_GLOBAL__N_18Derived2E:750
-// ICTEXT: _ZTV8Derived1:250
+// ICTEXT: {{.*}}instrprof-vtable-value-prof.cpp;_ZTVN12_GLOBAL__N_18Derived2E:150
+// ICTEXT: _ZTV8Derived1:50
 // ICTEXT: 2
 // ICTEXT: {{.*}}instrprof-vtable-value-prof.cpp;_ZTVN12_GLOBAL__N_18Derived2E:750
 // ICTEXT: _ZTV8Derived1:250
 
+// Test indirect call promotion transformation using vtable profiles.
+// RUN: %clangxx -fprofile-use=test.profdata -fuse-ld=lld -flto=thin -fwhole-program-vtables -O2 -mllvm -enable-vtable-value-profiling -mllvm -icp-enable-vtable-cmp -Rpass=pgo-icall-prom %s 2>&1 | FileCheck %s --check-prefix=REMARK --implicit-check-not="!VP"
+
+// REMARK: Promote indirect call to _ZN12_GLOBAL__N_18Derived24funcEii with count 150 out of 200, compare 1 vtables and sink 1 instructions
+// REMARK: Promote indirect call to _ZN8Derived14funcEii with count 50 out of 50, compare 1 vtables and sink 1 instructions
+// REMARK: Promote indirect call to _ZN12_GLOBAL__N_18Derived2D0Ev with count 750 out of 1000, compare 1 vtables and sink 2 instructions
+// REMARK: Promote indirect call to _ZN8Derived1D0Ev with count 250 out of 250, compare 1 vtables and sink 2 instructions
----------------
minglotus-6 wrote:

As explained above, only the first candidate of an indirect call site sees the original function count.

This is consistent with existing remarks, as shown in this regression test (https://github.com/llvm/llvm-project/blob/cc2fafa1788908f69366821a04407083f770483e/llvm/test/Transforms/PGOProfile/indirect_call_promotion.ll#L5-L8)

https://github.com/llvm/llvm-project/pull/81442